Environmental Factors of Asthma in Abu Dhabi City Thesis

Introduction

Asthma is a persistent and incurable lung disease whereby the ways of respiratory air passage slender due to thickening of the walls. This disease has not only aroused speculation and alertness from researchers, but also caused significant control mechanisms worldwide. In this regard, it is pertinent to evaluate various current incidents related to asthma and identify the outcomes or strategies initiated to fight this woeful demise facing the globe. In a bid to perform this evaluation, the issues relating to Abu Dhabi and its surrounding will be considered. Furthermore, the information will be compared to other capital cities from various countries apart from the United Arab Emirates (UAE).

Background

In 2010, the Health Authority of Abu Dhabi reported that 155,379 people demanded attention from asthma specialist [1]. Surprisingly, apart from 57% of the affected persons being male, 46% involved children below the age of fifteen. In this regard, training programs were initiated to ensure provision of qualified healthcare services for asthmatic individuals including the adults and kids. Furthermore, this authority indicated that 449,967 incidents of service requirements were apparent, where health checkups comprised of 63% as compared to the 9% tragedy occurrences [1]. The manager of this authority, Dr. Jaberi, provided insight about the necessity of asthma training program by pointing out that it would raise the number of practitioners, identify new cases, improve asthma management at individual level, and lower the tally of admissions basing on proper management.

A countrywide evaluation of the demises related to environmental pollution that takes a significant role in the rising cases of asthma shows UAE as the most affected nations since the discovery of oil in 1958 [2]. Essentially, UAE was one of the poor Arab countries before this discovery. However, the oil has included it among the best income earners worldwide. The life expectancy has improved by about 30 units for 60 years since the 1950 where it has led to such adequate resources as modernized health facilities. These improvements and achievements have risen with various health risks attributed to air pollution. In this regard, an environmental commission was set to anticipate the Environmental Burden of Disease (EBD) targeting to avail the causative agents associated with these outcomes. The agents causing asthma were related significantly to combustion of fuel where the end products were subject to cause harmful effects or react in presence of light to produce toxic substances.

The World Health Organization (WHO) has it that the adequate resources are not solely a solution for the asthmatic conditions in Abu Dhabi [3]. This organization indicated that the diagnosis and treatment of asthmatic case within UAE, including the capital city, are below the standards levels. In this light, 50% of the overall affected population cannot manage the condition without frequent interventions from the practitioners. In comparison to the overall population of UAE, 13% are asthmatic where children complement the largest population that is outstanding within the globe [4]. According to the American Hospital Dubai [4], the prevalent cases of asthma are attributed to infections of airways, nose and/or esophagus, pollution, weather, allergies, irritants, pollen, animals, and dust among others. Table I presents the placement of UAE in terms of asthma percentage prevalence with other nations around the globe [5].

Objective

The present research study has a target to evaluate among the aspects of related the causes, infections, prevalence, effect and resolution on asthma. Therefore, it has the objectives to;

• Identify the environmental variables determining the cases of asthma in Abu Dhabi
• Determine the weather variations influencing asthma in Abu Dhabi
• Evaluate the environmental pollutants participating in increments of asthma
• Investigate the role of vegetation in asthma
• Explain the asthmatic effects of dust for people residing in Abu Dhabi
• Describe and analyze the sources and complements of dust in UAE
• Describe how asthma clinically relates to various environmental attributes
• Identify the pertinent activities that raise the dust levels in UAE

Table 1. PREVALENCE OF ASTHMA IN THE WORLD [5].

Literature Review

Climate and Weather Overview

Climate and weather pattern heavily rely on the position of UAE within the globe. Essentially, it has been located on the northern hemisphere between 22.83o to 26o implying that there are adequate sessions of sunlight energy. Figure 1 shows the actual location of the country and its surroundings.

Temperature

It harbors the subtropical climate characterized with high temperatures reaching 45oC due to light energy and sandiness on the ground [8]. In fact, the temperatures are extremely uncomfortable towards the water bodies due the heated humid air. Therefore, this aspect is a challenge to the residents staying in such towns as Abu Dhabi that are close to the shores. This implies that the residents of Abu Dhabi relies on adequate air conditioning for fresh and cooled air especially in working conditions such as companies and other organizations. The extreme levels are evident during the month of September and June when the sun is on the northern hemisphere and rays closely perpendicular to UAE [8]. On the other hand, the temperature lowers to their minimum as the sun heads toward the Tropic of Capricorn. Essentially, the temperature of the environment has imperative role in influencing the breathing rates of asthmatics. Consequently, the high temperatures raise the heart rate, pulse rate and breathing rate of an individual due to the increasing respiration of the body. The outcomes of these events are heavily influential to asthmatic through increasing their sensitivity and triggering the disease. Moreover, high temperatures are causes of most clinical attentions from asthmatics.

Buckley and Richardson [7] performed a crossover research to establish whether seasons were a complement in the factors leading to deviations of adult patients admitted to hospitals. The researchers managed to collect data through the surveillance of emergency admission throughout the state. The data was analyzed through conditional logistic regression of the calculated monthly measurements of temperature and the admissions made. The relationship between temperature and asthma were established to be positive on seasonal basis. They concluded that the temperature increased the rates of asthma admittance if other factors were held at their constants.

The relationship between childhood asthma and diurnal temperatures was investigated by Xu et al. [6]. The researchers applied the lag and Poisson linear models to verify the admittance of asthmatic children in relation to the diurnal temperature range (DTR) [6]. After considering data collected for six years, the analysis of the outcomes dictated that the associations between the variables were transparent. They, therefore, concluded that DTR raised the cases of asthma in children.

Basis on the fact that the data used was adequate, comprehensive and applying accepted methods, the two studies have proved that temperature is a variables affecting the cases of asthmatics in Abu Dhabi as it does elsewhere in the globe.

Humidity

This is another attribute that affects the cases of asthma in Abu Dhabi. This city has a humid content of 51% since the sea evaporations and precipitation are prevalent in the area. Essentially, researchers have investigated the effect of humid air to the asthma variations. It is argued that when the vapor content in water is higher, the overall density raise making it tougher to breathe when compared to dry air. Furthermore, most fungi grow and produce spores that act as initiators of asthma. This works in conjunction with other complements of the humid air incorporating dust mites and moulds. However, other arguments are raised that both cold and dry air are negatively influential to the asthmatic conditions in UAE. When the sun is in the southern hemisphere towards the furthest possible latitude (23.5oS), the water cools down leading to a lowered level of humidity since vapor is rarely formed or converts to ice and falls. Practically, the vapor content of humid air is far much lower for cold air than warm air. Technically, some attributes like exercising dry the level of inspired air causing an eventual inflammation of the airways. The dust mites also survive well in areas of humid air. All these work in the principle of dry and cold air as well as their humidity.

A research study conducted by Singh, Bara, and Gibson [9] noted that dehumidification of air was vital to prevent trigger and extension of asthma. This research involved the collection of data from registers and application of a predesigned data extraction form [9]. However, the sample size was far low and less reliable even though it provides a progress for future researches. In fact, it has been suggested through this literature that the necessity of dehumidification should be studied to show its effects.

In light of investigating the impacts of hot humid air to asthmatics, Haye et al. [10] involved six individuals affected mildly by asthma and 6 healthy individuals as the population sample for the assessment. The affected population comprised of patients at the age of 21-26 years while the healthy ones were at the ages of 19-46. The methods applied in their research incorporated breathing into an instrument made to provide specified humid and temperature levels for four hours. The participants were then asked to pant where the resistance of air passage ways was recorded as well as other parameters such as oxygen levels, pulse rate, blood pressure and body temperature [10]. The findings indicated that hot and humid air activates the rise in the resistance of air passageways for the affected individuals.

However, there were no relevant effects for the individuals without mild asthma. In facts, the asthmatics experienced habitual coughs which were not apparent when they used an ipratropium aerosol prior to the test. Moreover, the resistances were not records if the aerosol was used before the tests commenced [82]. After failing to provide a comprehensive explanation these results, Hayes et al. [10] performed another study hypothesizing that various pulmonary defenses reflex responses could exist if the C-fiber nerves were triggered by temperature of 102oF. Stimulation of the C-fibers increased the constrictions within the bronchus and raised the rate of coughing. In this regard, Hayes et al. indicated that ambient vapor content and temperature are vital for asthmatics and the study of how it can be treated. Consequently, they recommended further research to verify and provide an explicit evaluation on this issue.

A random purposive study conducted by Strachan and Sanders [11] through questionnaires evaluated the effect of relative humidity on indoor basis in relationship to asthma. The study was conducted in a population of 1000 kids at an age of 7 years where they were influenced through difficulty in breathing, coughs and colds [11]. The kids were from 3 primary schools where the study was conducted initially and later extended through seeking information from the parents by using mailed questionnaires. The analysis of the questionnaires indicated that 91% of the households attributed asthmatic cases to moulds and dampness.

This research went further to investigate various households where the students had come from, where they noted that the mean temperature was 22.9 and the relative humidity ranged widely from 28%-77%. Consistent and approximated measurements of temperature and humidity were performed on 778 kids for one week, which did not depict any concise correlations because the symptoms were similar throughout. However, the data collections were heavily affected during the snowy situations where moisture content varies between 9% and 20%. The researchers concluded that humidity was a determinant of asthma not only because of it mechanical effects, but also for facilitating the growth of other triggers of asthma such as moulds and house dust mites.

Finally, the level of humidity rises with increase in precipitations. Therefore, this makes it apparent that since precipitation affects this core trigger of asthma, it then follows that the rainfall is a key players in increasing of reducing the cases of asthma. Essentially, high precipitations are expected to raise the cases of asthma. However, an explicit evaluation of the attributes of rainfall either connected to humidity or other factors in order to influence the asthmatic cases in Abu Dhabi have been addressed in the following topic.

Precipitation

Precipitation is a factor that is core to most agents triggering asthma. It has been recorded that the cases of asthma raises when there are thunderstorms since spores of fungi and pollen increase in the atmosphere [84]. A study conducted by Anderson et al. [12] was aimed at identifying whether thunderstorms influence asthma admissions and how various factors such as pollen took part in it. In this light, a study was conducted for thirty two separate days where data on spore count, amount of rainfall, and temperature was collected. The data was also retrieved from records of hospitals that record information of individuals admitted on at the emergency section. The most suited days for data collection were when there was lightening covering the area around the hospital subject to data collection. The asthmatic cases related to more than 100 pollens and spores were insignificant.

However, admissions associated to lightening between 1-16 strikes led to a record of 0-12 admissions [12]. The analyses were performed using Poisson regression model in order to retrieve the relationships lying between each factor chosen and patients admitted. Unsurprisingly, the results showed that thunderstorms had a potent role in the number of asthmatic cases, which were not attributed to the spores. In fact, when the researchers isolated the study of pollen and the admissions, it was noted that the number of admissions was not reliant to the spores. In this regard, the data collected on admissions was varied without correlation to the level of spores recorded within the selected dates. Fig 2, fig 3, and fig 4 illustrate the trends of thunder in association to the admissions, pollen, and spores experienced respectively [12].

In Abu Dhabi, the rainy seasons commences towards the end of the years in November and December and heightens in March as shown by fig 5.

Various aspects of weather are much related since each has parameters that influence the other. For instance, it is true that temperatures are usually high during summer and the rainfall during this period is low. Fig 6 indicates that the amount of rainfall is much reduced during summer between July and September. At this time, increments of temperature lead to evaporation of high contents of water. Therefore, the humidity of cities around or close to the shores between these months is high. In fact, the moisture content of Abu Dhabi move up to 78% during the month of august which correlation with the temperatures. In another study performed by Celenza et al. [13] initiated to evaluate how environmental variables affect the cases of asthma, a retrospective research set to assess the admissions of patients’ records through the use of multivariate and bivariate analysis was conducted for 2 months.

Records of asthmatics beyond the age of 15 were taken and included in an analysis with adequate information from measurements of temperature, rainfall, humidity and pressure. The emergency department indicated that there was a correlation between the lowering of temperatures and overall epidemics of asthma. Furthermore, the research indicated that there was relationship between the thunderstorms, high humidity, atmospheric pressure, and high rainfall to the non-epidemic asthma recorded. It was concluded that epidemics were correlated to the low temperatures and the level of pollen suspended in the atmosphere. On the other hand, the lightening was the major attribute connected to the regular incidences of asthma termed as non-epidemic.

Wind

Wind is an important aspect in the distribution of humidity, rainfall, temperature, and other factors triggering the prevalence of asthma in UAE such as pollen and spores [88]. For instance, rainfall in Abu Dhabi is reliant on wind from the shores while the winds from the lands are dry. The table 2 correlates temperature and wind speed for a period of 12 months in Abu Dhabi.

Table 2: correlation of wind speed and temperature as factors affecting cases of asthma [15].

Air Quality in Abu Dhabi

The air quality in Abu Dhabi is highly polluted with pollutants that mainly come from the main sectors of the economy in the industrious city within UAE. These sectors include industries, mainly the quarrying industry, transport sector, oil sector and lastly the gas sector.

Sources of Air Pollution

Scientific research and recent studies show that the poor air quality in Abu Dhabi that is attributed to the main sectors of the economy pose serious and dangerous health risks to the ever- growing population of the city [89]. The five major pollutants that can be attributed to the deteriorating quality of air in Abu Dhabi include nitrogen dioxide, carbon monoxide, sulphur dioxide, ground level ozone and lastly particle pollution or particulate matter [90]. Most important to note is that Ground level ozone and particulate matter are secondary pollutants, whereas nitrogen dioxide, carbon monoxide and sulphur dioxide are primary pollutants. The difference comes out in the mode that each pollutant comes about to the atmosphere [17]. Primary pollutants come naturally to the atmosphere when the several industries expose the pollutants onto the atmosphere. Secondary pollutants are substances that form in the atmosphere when reactions with the primary pollutants occur. All these pollutants play a role in contaminating the air around the city of Abu Dhabi to toxic levels that diminishes the air quality. Ground-level ozone, or smog, is formed when compounds released by machines react with other substances in the atmosphere in the presence of sunlight [96].

Particulate matter refers to the tiny particles of sand, dust or chemicals that are able to penetrate deep into people’s lungs. Scientists have been researching on particles not bigger than the human hair, that are approximately 10 micrometers in size and they are known as PM10. Surprisingly, smaller particles known as P22.5 are also being researched as types of particulate matter. They are the most harmful ones due to their ability to easily penetrate the human lungs, which is a hazardous trait [93]. Nitrogen oxide is formed when there is combustion of fuels, basically from motor vehicles and airplanes in the traffic industry which is the leading sector in the air pollution. Carbon monoxide, a pollutant, is also a form of incomplete burning or combustion of fuels by vehicles in the Abu Dhabi city. Sulphur dioxide is a pollutant from the quarrying industry that has had its levels in the atmosphere around Abu Dhabi shoot to more toxic levels [94]. There are also other pollutants in the atmosphere around Abu Dhabi that have led to the air quality being poor. Methane and Hydrogen sulphide that are emitted from petroleum refineries, paper mills and tanneries also contribute to the poor air quality in the city of Abu Dhabi. Noise pollution, also a form of pollution, is rampant in Abu Dhabi, due to the huge traffic congestions and many industries [27].

Effects of Poor Air Quality

Most importantly to look at would be the health effects from the poor air quality in the city of Abu Dhabi, which poses a serious danger to the habitants and tourists to the ever crowded city. Poor air quality in Abu Dhabi poses serious consequences to both the habitants of the town and the tourists. Firstly, it poses a serious health risk due to the numerous diseases and complications brought about by the five pollutants discussed. Then secondly the cost of living in the City of Abu Dhabi will shoot to uneconomical levels and last but not least would be the reduction in the number of foreign investors and tourists[29].

Health Effects

High Ground ozone levels may lead to complaints of respiratory diseases such as asthma and bronchitis. These respiratory diseases are really dangerous to the ever-growing population of Abu Dhabi, and if not treated in time and correctly, they may lead to rising numbers of deaths from the population. It is important to note also that the high levels of high ground ozone levels at times leads to the greenhouse effect which is a major concern to most environmental scientists. The greenhouse effect traps all the pollution from the industries and transport sectors around the atmosphere. This effect will tend to show that the air quality in the city of Abu Dhabi will never be improved, due to the clouding action of the greenhouse effects.

The end result of the greenhouse effect in Abu Dhabi will be an increase in respiratory diseases. Increased exposure to Sulphur dioxide to the human lungs leads to lung diseases as a result of breathing complications. Nitrous dioxide, when inhaled by human beings, leads to heart and breathing difficulties that may be fatal when not attended to medically[29]. High levels of the organic volatile compounds from methane and hydrogen sulphide have harmful effects on the human central nervous system. This is dangerous since a change in the operation of the central nervous system may lead to someone being insane or medically unfit to be termed as a normal human being. The particulate matter on the atmosphere of the city of Abu Dhabi, due to the pollution, may also affect the central nervous system and the brain. Insanity will be the medical report of the affected individuals. At a spur, the poor air quality in Abu Dhabi due to the atmospheric pollution has massive health effects to the occupants of the city[28].

Cost of Living

With the increasing levels of respiratory diseases in the city of Abu Dhabi, a lot of resources and capital is directed to the health sector and the other sectors of the economy risk being ignored. Individuals in the private sector use a lot of resources to treat themselves from the respiratory diseases. The government in Abu Dhabi converts the economy concentration and input to the health sector. A lot of resources are used to treat the affected members of the city of Abu Dhabi, and less input is put to other sectors of the economy like the industrial sector or transport sector. The cost of living rises as the money that the government uses in the health sector has to be recovered by increasing the tax rates on almost all the commodities[27].

Low Tourist and Investors’ Turn-up

Environmental research about Abu Dhabi poor air quality is recorded in reports that are freely accessed by everyone in the city or tourists who want to visit. This has a negative influence to the tourists or foreign investors who are keen on their health. Many tourists and investors will stop visits to the city of Abu Dhabi with the fear of the increasing respiratory diseases, which are expensive to cure. Most investors in the economy will turn to the neighboring cities that are also good investments areas. So the poor quality of air in the city of Abu Dhabi slowly decreases the level of tourist turn up, yet tourism has a big impact in the economy of the city. With the increase in the levels of pollution of the atmosphere in the city of Abu Dhabi, the government may be forced to take drastic measures that may include the close down of major industries. The economy of Abu Dhabi will suffer a set-back with certain industries like the quarrying and mining industries being closed down. A lot of resources and revenue sources will have been cut, and again the cost of living will be expensive for both the natives and tourists.

Ways of Reducing It

The only best way to ensure that the air quality in the city of Abu Dhabi is maintained at a healthy state is by setting rules and regulations to control all the sectors of the economy that have a great impact in the pollution of the atmosphere. This can be done by Legislation, where laws are set to regulate the quarrying industry and transport industry. The industries in Abu Dhabi are to be fitted with smoke regulators and transmitters to ensure that smoke released to the atmosphere is safe to human breathing[29]. Also the transport sector should be asked to fit the vehicles with regulators that transform the exhaust to a safer and less harmful one. The oil and gas sectors in Abu Dhabi also should be mandated to conform to an improved mode of production. The air quality in the city, though at an alarming poor rate, can be improved with only the proper legislations to save all sectors of the economy.

Effect of Vegetation on the Quality of the Air in Abu Dhabi (Pollen Activity)

The vegetation has a major effect on the quality of air which can negatively influence the air quality of a place [95]. The plants produce greenhouse gases that pollute the atmosphere and compromise the quality of air. Burning of forests and some plants also produce toxic gases and compounds. When these toxic gases and compounds are released to the air they react with the water in the atmosphere to form heavy metals, acids and ozone, thus affecting the quality of air drastically. When these pollutants combine with the water vapor in the atmosphere they cause acidic rains making most natural water resources like rivers, lakes, streams and oceans to suffer from high acidity[29]. The vegetation also releases volatile organic compounds to the air through evaporation. These volatile organic compounds are very toxic to the environment because they destroy the ozone layer. The ozone layer is very important due to its ability to act as a shield against UV rays. When the ozone layer is destroyed the temperatures become extremely high hence causing air pollution. The ozone layer can also act as a pollutant when it is deposited in the stratosphere.

Abu Dhabi is a semi-arid region that experiences high temperatures, dry winds and minimum rainfall, this harsh natural environment poses a challenge to plants. Abu Dhabi is therefore covered with salt flats, dwarf shrubs and sandy deserts. The sandy deserts in Abu Dhabi cause a lot of dust in the air [97]. When the dust levels are too concentrated in the atmosphere the quality of air is negatively affected. The dust is further worsened with the lack of sufficient rains in the region. When the ground is dry it has a tendency of breaking loss thus what follows is dust particles that are blown to the air by the strong winds experienced in Abu Dhabi. A large area in Abu Dhabi is also covered with shrubs; the shrubs are desert plants that barely have leaves. Plants mainly avoid soil erosion that is the main cause of dust in the air[16]. The shrubs in Abu Dhabi are very scarce and hence cannot effectively control soil erosion, this leads to more dust in the air. All these factors has made the air quality in Abu Dhabi to be very poor, the excess dust particles in the air leads to increase respiratory diseases such as asthma. This is common in the southern and eastern Abu Dhabi that is characterized by sand dunes and sand sheets[19].

The strong winds in Abu Dhabi also increase the pollen activity in the atmosphere. The strong winds help to carry and distribute moulds spores and pollen in the atmosphere. These pollens cause allergic reactions in the air thus triggering nasal allergies among the people. The pollen in the air therefore worsens the quality of air in Abu Dhabi and increases the respiratory diseases among the residents of Abu Dhabi. The rains further facilitate the growth of mould spores thus increases air pollution further. The high levels of mould pollen lead to poor air quality[16].

The high temperatures in Abu Dhabi have also made it very favorable for bee keeping. Bees do very well in areas of high temperatures. Bees are responsible for most vegetation and fruit production through pollen pollination. The bees carry pollen from one plant to the other and in the process scatter these pollens in the air. When the plant pollens are in the air they cause a lot of nasal irritations to the people. The nasal irritations cause allergic reactions that mostly lead to asthma. This has caused the number of asthma causes in Abu Dhabi to increase especially among the vulnerable groups like the young children and the old.

Despite the harsh weather conditions in Abu Dhabi is still the home of over 400 species of vascular plants. These plants also play a big role in affecting the quality of air in Abu Dhabi. Some of these vascular plants produce allergenic pollen grains that can cause respiratory diseases such as asthma. Some parts of Abu Dhabi experience humid and warm climate that facilitate the growth of house dust mites. The house dust mites are associated with severe and persistent asthma. Indigenous pollen found in indigenous plants that are found in some regions of Abu Dhabi also causes indigenous allergic reactions that can lead to asthma. Fungal plants found in terrestrial regions like Abu Dhabi also form major cause pollen pollution. Fungal plants produce fungal spores that are a major threat to the respiratory health. Fungal spores cause respiratory disease and fungal infections mostly in children[23].

Abu Dhabi is also faced by massive population growth and over grazing. This leads to a lot of forests vegetation been cleared to be used for human settlement. Forests help in reducing dust in the air by breaking strong winds and soil erosion [48]. So when the forests are cleared the level of dust in the air increases causing the air quality in Abu Dhabi to worsen. Over grazing also reduces the grass exposing the land to harsh environmental conditions such as extreme temperatures and strong winds. The land is exposed to sun and wind thus the soil is likely to be blown in the air causing dust particles to increase in the air[19].

Dust Emission Models

The areas of Sahara desert and parts of the east Mediterranean are mostly affected by sand storms and dust events [47]. Abu Dhabi also falls under these areas and it is adversely affected by the dust occasions that have seen increased asthma cases in this capital. This has forced more research on dust emission models. The models are majorly divided into sub sections; the remote sensing models and the land surface models of dust emissions [17].

Remote Sensing Models of Dust Detection

These models major on getting the regions of dust source and then monitoring how the dust plume are transported from their primary outflow until it reaches the final point of deposition [49]. The remote sensing models of dust detection include MODIS, OMI, CALIPSO and DREAM. In February 2009, two major dust occasions were experienced in the eastern Mediterranean where the effects were also felt in Abu Dhabi. The MODIS and OMI observations were used to get clear definition of the spatial distribution of these dust plumes [18]. The CALIPSO model on the other hand was used to get a clear view of the vertical structure of these dust layers. At the end, the observations showed that the dust occasions started over in the Sahara desert regions and finally the dust plumes got deposited in the eastern Mediterranean where we have Abu Dhabi. This tells us that the remote sensing models are used connectively to get clear dust detection. These models are briefly discussed in the following paragraphs.

MODIS Retrievals

This model is reliable in monitoring dust at both global and regional levels but it is not the most preferred when defining the sources because of the problems related to large albedo in arid surfaces. This model has been getting its global data on a daily basis from 36 spectral bands. These spectral bands run through from the visible infrared to those that are thermal. Of these thirty six spectral bands, 29 of them have one kilometer resolution, 5 of them have 500 meters resolution while the remaining 2 have a resolution of 250 meters. This combination helps the MODIS retrievals in retrieving aerosol properties on the ocean and also the land in a clear way. In relation to the case in Abu Dhabi, the MODIS retrievals were used during the dust event experienced in the Eastern Mediterranean in February 2009. During this period, a 10 by 10 kilometer spatial resolution was used in the retrievals.

CALIPSO Retrievals

This module in full is the Cloud AerosalLidar and Infrared Pathfinder Satellite Observation. This module comes in with a new idea in the monitoring of atmospheric dust since it entails checking the profiles of the clouds and aerosols vertically. This remote sensing model of dust detection engages a variety of satellites [53] [54] [57]. These satellites are Aura, CloudSat, PARASOL and Aqua satellites. The CALIPSO is at an altitude of 705 kilometer where it flies at an orbit inclination of 98 degrees. At this point the remote sensing model is able to detect the aerosols and dust in the atmosphere [24]. One great advantage of the CALIPSO retrievals is that it can make observations even in surfaces that are brighter and also beneath clouds that are thin. In the eastern Mediterranean this retrieval module has been in place since the year 2006 and Abu Dhabi has been relying on it to in detecting the aerosols in the atmosphere. With the increasing asthma cases in Abu Dhabi this dust detection module has been of importance since it helps the people in the area to know periods to expect more aerosols and dust. This enables the people of Abu Dhabi to find a way to reduce asthma cases by being extra cautious during this periods that there are a lot of aerosols in the atmosphere [24].

OMI Retrievals

This is another remote sensing model that majors on identifying the regions where we have the dust sources. For instance, during this period of dust events in the Mediterranean and Sahara deserts in February 2009 the OMI retrieval methods were put in place to establish the dust sources. Abu Dhabi that also falls in the eastern Mediterranean was part of this study that saw an aerosol index (AI) with a spatial resolution of 0.25 degrees by 0.25 degrees observed through the aura-OMI. One great challenge facing this remote sensing model is the fact that the sensitivity of the AI to these dust aerosol highly depends on the height of the aerosol layer [21]. This becomes a challenge because some dust depositions do not result to high layers and this would mean no detection and thus no connectivity to the aerosol index (AI).

Studies and research have indicated that aerosol below one thousand meters cannot be detected in this type of remote sensing model. With relation to the topic involving the asthma cases in Abu Dhabi, the OMI retrievals are integral when trying to solve the problem [22]. This model seeks to identify the dust sources and after this it becomes easier to get these regions and try to find ways to reduce the volume of dust coming from the points. This in one way will help tackle the increasing asthma cases in Abu Dhabi. Though it is quite important, this model has been experiencing rejection of late. This is because some of the instruments used in the OMI retrievals have been recording row anomalies forcing some current studies to avoid the model where a lot of quantitative data might be of importance very much [23].

DREAM Model Simulations

The Dust Regional Atmospheric Modeling (DREAM) is an integrated remote sensing model used in detecting dust. This model caters for the main processes involved in dust cycle through the 3D simulation. It retrieves the aerosol in the atmosphere from the points of uplift straight to their areas of dry deposition. The properties of the soil, the wind close to the surface and thermal conditions are some of the factors used for the soil production simulation. This model makes use of spatial resolutions that have high databases. The DREAM model simulations include elevation, properties of soil and the vegetation cover in the areas of study. Due to the higher spatial resolutions used in this model, it can be used to detect most of the dust events to be experienced in the Mediterranean and Sahara desert areas. In relation to the case in Abu Dhabi where we have the environmental condition resulting to more asthma cases, this model is relatively of good use. Since research has proven that this model can be used to make nearly all the possible predictions about dust events, relevant bodies in Abu Dhabi area can rely on this to help their people keep safe and cautious [26].

Land Surface Models of Dust Emissions

Dust emission from the surface of the earth is caused by many factors. Abu Dhabi being a semi-arid area is prone to dust. This is because Abu Dhabi is a dry land hence when the land is cultivated using the strong farming equipments the land surface is broken and the soil and rocks broken into fine particles. When the soil particles are fine they because lighter and hence makes it easy for dust to be emitted to the air.

Abu Dhabi is also developing and roads are been constructed, even though construction some these roads has a lot of advantages to the economy and development of Abu Dhabi they also come with a share of disadvantages to the environment. During construction of roads very heavy machinery are used to shape and level the ground. These strong machines weaken the land surface thus making it volatile soil erosion by strong winds. When then the land surface is weak and loose the soil particles can be carried away by the wind thus increasing dust emission to the air [25].

Abu Dhabi also has large deserts areas that are mostly used by the army to train. The military activities have a great impact on the earth surface. The militants use strong equipments and very trucks that fragment the land surface further hence making the soil on the land surface vulnerable to soil erosion agents. This increases dust emissions in the atmosphere of Abu Dhabi [30].

Overgrazing and deforestation in Abu Dhabi causes dust emission in the air. Plants help in clamping the soil particles together and protecting it from the harsh rays of the sun. Over grazing loosens the soil particles making it possible for the wind to blow it away. When animals stamp the ground continuously they cause some soil particles to be scattered to the air in the form of dust. Forests also clamp the soil particles together using their deep roots. When the forest is cleared through deforestation dust emission to the air is increased. Trees also help in controlling the winds this has a great effect in reducing dust emissions to the air. Deforestation therefore increases dust emission by loosens the soil particles and exposing the earth surface to strong winds [26]. Deforestation also makes the soil to loss moisture; moisture is very important to the soil as it clogs the soil particles together thus preventing it from being carried away by the wind.

Controls of Dust Emission in Abu Dhabi

Availability of soil crusts; one important soil crust is the lichen that is biological and resistant to wind erosion therefore, this soil crust help reduce the effects of erosion due to wind in the areas with desert conditions. This model of dust emission control is currently been employed in Abu Dhabi [29].

The presence of vegetation; ensuring good vegetation in the areas where emissions levels are high is very important [50]. Vegetation cover will work as a protective cover and checks wind erosion since it reduces the direct contact of wind with the soil.

Soil moisture has an impact of bringing together the soil particles. This helps in making the ground surface more resistant to forces of erosion that usually leads to dust emissions.

Sources of Atmospheric Dust

According to Gornitz [36], dust refers to minute particles that are slowly suspended by slight currents, and are present in fluctuating level, in all air. The levels of atmospheric dust vary with the altitude, that is, least dust is present in high level grounds while most dust levels occur at low level grounds and cities. Therefore, dust that occurs in different places must have some of its sources. The major sources of atmospheric dust are blowing winds; products of combustion; particles that arise from meteors; materials from plans and pollen; volcanic eruptions; and salt spray that comes from oceans [34].

Blowing wind normally carry dust particles. The major dust sources that are spread by wind include the Saharan region, the Arabian Peninsula, Australian Desert, Taklimakan and Gobi Deserts in Asia [36]. Emission of dust takes place when the surface wind stress exceeds a specific threshold value [36]. Fine soil particles, which are transported over long distances, usually come about, as a result of larger wind blowing the sand impacts on the soil thereby, mobilizing smaller particles [32]. In Abu Dhabi, wind blowing over cultivated lands results in the accumulation of the dust particles in the air which eventually result in the suspension of the dust in the air. The hot desert climate in Abu Dhabi implies that the soil surface is exposed [37]. During the season where it is scorching in Abu Dhabi, sandstorms usually occur intermittently (stuut.tv). This expedites the accumulation of dust in the environment.

The other source of atmospheric dust in Abu Dhabi is combustion products. Some of plants found in Abu Dhabi promote the accumulation of dust in the environment. The industries that are usually involved in the production of oil and cement emit much dust into the environment [35]. This in turn results into the accumulation of the dust in the atmosphere that is further spread by the wind blowing over the city. Human activities which involve burning of fossil fuels in the vehicles, power plants in Abu Dhabi are able to generate significant levels of particles that can remain suspended in the environment.

Volcanic eruptions are also one of the sources of atmospheric dust. In Abu Dhabi, the recent Iceland volcano eruption resulted in mass disruption to the skies over Europe [44]. This resulted in the suspension of dust particles, in the environment that is capable of being suspended in the environment for several years. It is undoubtedly that this eruption is one of the sources of dust that affects the health of the population found in Abu Dhabi. The dusts from very large storms that occur in Africa, often travels very far distances together with wind [44]. This dust affects the quality of air in vast regions. These dust storms, therefore, have negative impacts in the health of individuals [56].

Abu Dhabi, the city located on the northeastern side of the Persian Gulf. Some parts of the Abu Dhabi city are located on the island while most of the suburbs are on the mainland. This means that Abu Dhabi is affected by atmospheric dust that originates from the salt spray in the Arctic Ocean, Mediterranean Sea, Arabian Sea, and the Red Sea. The sea sprays usually forms when the ocean waves crash or in some cases, when high winds are blowing [37]. The salt sprays usually contain a very high concentration of Chloride ions. These salts do not dissolve in the air directly, therefore; remain suspended as fine particles [43]. Hence, the particles can be found as atmospheric dust in the atmosphere.

The other source of atmospheric dust in Abu Dhabi effects from plant materials and pollen grains [58]. There are agricultural activities that take place in Abu Dhabi. Crops that are grown in Abu Dhabi produce pollen that results in a significant increase, in the amount of dust, in the environment. Pollen is usually found in seed-bearing plants which are eventually transported by wind and insects [45]. These particles usually accumulate in the environment as dust particles.

Lastly, Meteoritic particles are also one of the atmospheric dust sources that are found in Abu Dhabi. Over the years, there have been reports that Abu Dhabi is usually affected by tiny particles that result from the effects of meteorites [35]. The National, one of the local dailies in Abu Dhabi, reported a significant increase in the levels of these particles. These particles can also be found suspended in the air over a period. The rise in these particles was attributed to an increase in respiratory illness in Abu Dhabi.

Conclusively, most of the atmospheric dusts which usually accumulate in the air are usually invisible in the free air while others are visible [60]. Some of the dust particles are hygroscopic, that is, they are the particles that water adheres to. The particles can also be organic or inorganic dust. The dust storms discussed above can also carry potentially harmful mineral particles together with pathogenic organisms like viruses, fungal pathogens and bacteria. The dust particles are usually associated with respiratory health risks such as asthma. Hence, the dust sources are associated with the risk factors of asthma in the entire Abu Dhabi [35].

Dust in UAE

There has been a significant increase in the levels of dust in UAE, the National reports. The dust storms that have been in the increase have been believed to occur naturally [41]. The dust particles pose high health risks to the current population as well the future generations [43].

Sources of Dust in UAE

Dust that has been evident in UAE has been associated with sources such like dust that is usually lifted by wind, dust from the soil, volcanic eruptions as well as air pollution due to anthropogenic activities [59]. In many homes and offices found in UAE, dust accumulation is associated with the plant materials such as pollen, hairs from animals and humans, fibers from paper material, burnt meteorite particles and combustion of fuels.

Construction sites like that of roads and buildings have also resulted in an increase, in the level of dust in UAE. On January 07, 2014, the Today’s Paper reported that weather forecasters warned that UAE was to experience dust storms in its most parts (c/Todays-News). According to Haggett [37], the landscape of UAE is generally sandy and low-lying apart from the coastal salt flats. Together with its hot and dry climate, strong seasonal winds usually bring fierce dust storms [37].

Dust Storms Hitting UAE

Recently, there have many reports indicated that UAE experiences dust, rain and high winds (uaeinteract.com). This has been observed in streets by both motorists and pedestrians. Layers of fine dust were also reported to cover the Abu Dhabi city and the doctors in many stations advised the residents with breathing problems to restrain from outdoor activities (uaeinteract.com). Therefore, it is clearly evident that UAE is prone to dust storms.

Level of Dust and Health Risks in UAE

Recently, some residents have been reportedly complaining of asthma attack [41]. This resulted from large dust storms on 31 times in the year 2012 compared to 25 days that were experienced in 2011 [41]. The levels of dust in the air were found to be higher than that which is considered to be safe. This inculcates that the people that suffered from respiratory illness were in great danger. Other people who just had other lung or heart problems were at high risk. This indicated how dust poses a high risk to the people who are asthmatic. Dust therefore, is one of the environmental risks to persons with asthmatic conditions [31].

Asthma and Its Clinical Features and Its Causes

The Meaning of Asthma

World Health Organization (WHO) has defined asthma as a chronic disease which is characterized by recurrent attacks of breathlessness and wheezing, which vary in severity and frequency from person to person. During the attack, the lining of the bronchial tubes swells, which eventually cause the airways to narrow and reduce the movement of air through the nose into the lungs and out [31]. The disease causes airways of human lungs to swell and close as shown in the pictures below:

This disease is a respiratory disease that attack all ages. Because of its varied manifestation and causative agents, the definition of asthma (bronchial asthma) has been changing over years. A consensus has been reached that asthma is a chronic inflammatory disease of the airways in whereby, many cells, including mast cells, lymphocytes, and eosinophils, play a role [31]. According to Busse and Holgate [31], in susceptible individuals, the inflammation is reversible either spontaneously or upon with treatment.

Tracing the history of asthma, the ancient people also suffered from this disease [46]. The first ever recorded case of asthma was in China over more than 4,000 years ago [46]. Therefore, asthma is not a recent disease.

There are different types of asthma:

• Childhood asthma-this is where the onset of asthma is from birth.
• Adult-onset asthma-the symptoms do not appear in an individual until at least the age of 20.
• Allergic or extrinsic asthma-this is usually triggered by allergens like food preservatives, pollen, mold and pet dander. This type of asthma appears to be seasonal since the allergens are also seasonal.
• Non-allergic or Intrinsic asthma-this is where irritants in the air triggers asthma. The irritants are not allergens and they include substances such as cigarette or wood smoke, room deodorants, household cleaning products, some perfumes, and air pollution [31].
• Cough –variant asthma-this does not have the classic symptoms of asthma except one symptom, a persistent cough [31]
• Exercise-induced asthma-a disease which affects people during or even after physical activity [46].
• Nocturnal asthma-this is characterized by asthma symptoms that worsen at night [46].
• Occupational asthma-this is caused by triggers that exist in an individual’s workplace.

Clinical Manifestations of Asthma

Various types of asthma present rather similar clinical symptoms. In most asthma patients, the attack is usually separated by symptom-free periods [40]. Some patients usually have long-term shortness of breath with episodes of increased shortness of breath [40]. The major symptom that is usually manifested by the patients is wheezing or coughs [46].

Other clinical symptoms of asthma include the following:

• Intercostal retractions-this refers to the pulling in of the skin between the ribs when breathing. This condition occurs when the muscles between the ribs pull inwards [40].
• Cough with or without production of sputum-this is where there is too much cough. The coughs can either be dry or productive.
• Shortness of breath that gets worse when one does some exercise or activity
• Wheezing-the sound that is normally produced as a result of the constriction of the airways.
• Abnormal breathing pattern -breathing out takes more than twice as long as breathing in
• Breathing temporarily stops
• Chest pain-this is felt anywhere along the front of an individual’s body between the neck and the upper abdomen.
• Tightness in the chest-the patients usually feels as if the chest is constricted and even has difficulty in sitting in upright position.

In some cases, asthma may present the following emergency cases that may also necessitate medical attention:

• Bluish color to the lips and face-this is apparent in the mucus membranes that occur as a result of insufficient oxygen in the body. such condition is known as cyanosis.
• There is reduced level of alertness, like the severe drowsiness or confusion, during an asthma attack
• Extreme difficulty breathing-this entails difficult breathing; uncomfortable breathing; and the feel of the lack of enough air.
• Rapid pulse-this is strong and forceful pulse which occur due to abnormal and rapid heart rhythms.
• Severe anxiety due to shortness of breath-this is the condition that from someone’s feels of fear, unease, and worries [40].
• Sweating-excessive sweats are usually characterized by abnormalities in the body. Most asthma victims sweat excessively as a result of the body’s response to situations that make them nervous, angry and embarrassed assed.

In the case of intrinsic asthma, features is seen where the patients with allergic asthma were predisposed to viral infections, sinus surgery and recurrent bronchitis. The symptoms usually attributed to this disease are persistent cough which is followed by progressive obstruction of airflow and wheezing. This will then persist if no remedy is administered.

Causes of Asthma

Asthma has been characterized by different causative agents. The body of the person responds to these antigens through inflammation in the airways. The lining of the air passages will swell, and the muscles that surround the airways finally become tight. The final effect will be reduced amount of air that is able to pass through the airway [46].

Being a respiratory disease, agents that usually trigger asthma when inspired or felt include the following: animal and human hairs; certain medicines like aspirin; changes in weather conditions, mostly cold weather; dust mites; chemicals present in the air or sometimes in the food; physical activity or exercise; presence of pollen in the air; mold; respiratory infections such as common cold; strong emotions; and wood or cigarette smoke [46].

In most cases, individuals with allergenic asthma have exhibit genetic predisposition. This is common among the intrinsic asthma patients where there is a positive family history for the inflammatory response to a specific allergen [31]. In Abu Dhabi therefore, there are various allergens that can trigger the inflammatory response. These substances that are regarded as nonself by the body include dust particles like the pollen grains, the aerosols, as well as weather changes [51]. The most common causes of asthma in most countries is dust and cold weather. In Abu Dhabi, dust is more common hence; it is usually related to the risks factors of asthma.

Epidemiological Factors of Asthma

Asthma has been one of the most common chronic conditions that affect both children and adults [42]. The burden of asthma has been felt in both children and adults with Abu Dhabi exhibiting high prevalence. The environmental risk factors here are the exposures to allergens and also lifestyle factors [42]. These risk factors are present throughout a person’s life.

In children, the maternal smoke can cause a high inflammation to the child. Environmental aspects that are widely attributed to the spread of asthma include dust particles [33]. In Abu Dhabi, the causative agent of asthma is dust particles. Sometimes genetic predisposition is apparent, together with gene-by-environment interaction. Some prenatal risk factors include the maternal smoking, diet of the mother, stress, the use of antibiotics, and mode of delivery. Asthma has also been linked with the size and structure of the family of a given person.

Asthma in Abu Dhabi and Its Clinical Related to Various Substances

In Abu Dhabi, there have been some cases of asthma problems. The most common type of asthma that is evident here is the extrinsic asthma. This illness affects both children and adults in Abu Dhabi. Asthma in Abu Dhabi has got strong relation with the following substances:

Dust Storm

This refers to a meteorological phenomenon commonly found in the arid and semi-arid areas where gust front loose sand and dirt from a dry surface [37]. The most important component of dust storms is that that they can be transported over a long distance from their source areas [37].

There is a great relationship between dust storms and asthma in Abu Dhabi. Following the rise of dust levels in Abu Dhabi as a result of dust storms, there has been a significant rise in the asthma cases in most parts of the UAE, the National reports. This indicates that there is a strong link between asthma and the suspension of the dust in atmosphere. One possible reason why asthma cases may be on the rise is that, the intrinsic asthma patients faces a major risk in such conditions [33].

Since most cases of asthma are intrinsic, the patients become more exposed to the dust particles thereby eliciting an immune response. The body will defend itself from the antigens (dust) by mounting an inflammatory response. This will eventually result into the condition referred as asthma [42]. This phenomenon explains how the level of asthma rises with an increase in dust storms. Asthmatic conditions therefore worsened whenever is high levels of dust periods [38].

Pollen Activity

Pollen grains are normally produced from the plants. In Abu Dhabi, the level of pollen grains is dependent on the population of trees as well as the level of agriculture in most parts of the region. In as much as the region appears to be dry, there is pollen as a component of dust in the atmosphere. Pollen has been characterized as one of the triggers of asthma [42].

Different individuals respond differently to the pollen grains. Pollen causes an inflammatory response that result in the clinical manifestations of asthma. Some research shows that the level of asthma worsens when the level of pollen grains rises in the atmosphere. This is further complicated by the accumulation of dust particles in the air [38]. As the level of Cedar pollens increased, there was a significant rise in the number of reported cases on asthma [46].

This gives a clear indication that pollen activity increases the incidences of asthma in the population. This relationship applies to all asthmatic people who normally present some allergic response to the pollen grains [38].

PM10 and PM 2.5, SO4, O3, CO, and NO2

These substances have always been categorized as air pollutants [39]. Particulate Matter 10 (PM 10), PM 2.5 are normally found in the air and are one of the international air pollutants. The substances have got adverse effects on the health of the public as well as the sensitive ecosystems.

This pollution results from transport of natural materials like sand. Dust from the construction sites has also been associated with the emission of these particulates [50]. These particles penetrate deep into the human respiratory tract and therefore the result asthma [46]. The health risk of the particulate is normally higher in the presence of SO2. This is due to the fact that the two pollutants work synergistically [46]. There is therefore, a very close relationship between the SO2 and asthma and this is normally experienced in Abu Dhabi.

NO2 is a pollutant that arises from all combustions. This gas is usually associated with adverse a respiratory effect which is normally produced during the combustion of the hydrocarbons fuels [44]. The major sources of this pollutant in Abu Dhabi are the power stations, industries and road traffic. The effect of this gas in the respiratory tract of a human being is that there is normally inflammation of the airways. The effects of this substance can be felt by all patients of asthma even if they substance is at its low concentrations in the atmosphere [46].

O3 is also one of the pollutants that are found internationally. This pollutant is normally formed in the atmosphere whenever there is a chemical reaction involving VOCs, sunlight and nitrogen oxides [44]. One interesting thing with ozone is that, ozone that is measured in at a particular area can be formed from the precursor compounds several kilometers away. The concentrations of ozone over the city of Abu Dhabi are normally reduced as a result of the continuous reaction between ozone and nitric oxide with the end product being nitrogen dioxide.

Exposure to these substances normally results in the damage of the airways lining. This will eventually lead to an inflammation with the result being asthmatic condition in the patient who inhaled the gas. This therefore, presents a very strong relationship between asthma and ozone [46]. The action of ozone is considered to be lethal as its inhalation leads to the irritation of the eyes as well as the nose. The inflation of the airways normally occurs upon exposure to the ozone of the order 1000 to 2000 μg/m3 [44].

CO is normally produced by the incomplete combustion of the hydrocarbon fuels. The effect of the CO in the body is very fatal since the gas leads to the formation of the carboxyhaemoglobin in the blood [44]. This substance will lead to the reduction of the oxygen uptake. These will eventual lead to difficulty in breathing and eventual the clinical manifestations of asthma will appear [42]. The patient will be no doubt suffering from this condition. The hydrocarbons that are continually burnt in the roads by the motorists in Abu Dhabi leads to the accumulation of CO which eventually poses a great risk among asthmatic populations.

SO4 sulfate is normally produced from burning of fuels that contains sulfur contaminants. SO4 is highly soluble in water and therefore can easily dissolve in water vapor to form sulphuric acid. Inhalation of the sulphates causes constriction of the airways that eventually results in breathing difficulties [42]. This effect is very common in asthmatic individuals.

These substances therefore, present a very close relationship with asthma. The amount of increase in their level in the atmosphere will result in the rise of asthma cases [42]. The hydrocarbons that are incompletely burnt in the roads or any other construction sites in Abu Dhabi have resulted in the accumulation of these substances in the atmosphere. These substances form part of the dust which increases the risk factors of asthma.

Relation Between Wind Speed/Direction and Dust Concentration in the Atmosphere

Experiments have shown that a linear correlation that occurs between dust particles and the speed of wind yields a poor relationship. The correlation coefficient is relatively low, r-value ranging between 0.063 and -0.510 and statistically is not significant at 0.05 (lodz.pl). On high level emission of dusts, the effect of speed of wind operates far more effectively compared to the lower level emission of dust [32]. According to Chow and Lim [32], the wind that blows an altitude of 1 Km over the urban centers is mostly light and variable [69]. This implies that the dispersion of horizontal pollutants by wind is suspected to be relatively limited (lodz.pl). There is also very poor correlation between the inhalable dust particulate and the speed of wind or even the direction of wind [32].

From the relationship described above, it is evident that the there is negative correlation between the dust particles and the speed of wind [32]. This implies that, there is always low concentration of dust particulates whenever there is high speed of wind.

Occasions that increases the dust in the atmosphere (how it relates to precipitation, temperature, and humidity)

There has been a constant increase in the levels of atmospheric dust and Abu Dhabi is no exception. The major occasions that results in the return of dust into the atmosphere are mostly anthropogenic. Constructions in most parts of UAE have promoted this phenomenon. In the construction site, there is normally dust emission which normally finds their way onto the atmosphere. There is usually less air pollution during rains (lodz.pl). This is due to the negative correlation between rainfall and the dust particles. This poor relation between the dust particles and the amount of precipitation usually results from the generally more stable atmospheric condition [32]. Therefore, there is less dispersion of the pollutants whenever there is rainfall. Precipitation is therefore more important in scavenging of pollutants [34]. This therefore shows that increase in the level of dust in the atmosphere occur during the periods when there is no or little rain.

Relative humidity has got influence in the rise of dust particles in the atmosphere. However, the correlation between the relative humidity and the dust particles is negative (lodz.pl). This relationship between the relative humidity and the dust particles is otherwise very insignificant [32]. It is therefore evident that, the occasions that return the dust particles into the atmosphere cannot be determined by the relative humidity. Combustion of the hydrocarbons as well as the dust storms cannot be altered by the change in relative humidity [32]. Therefore, higher relative humidity leads to greater settling of the dust from the atmosphere.

The emission of dust from the soil into the atmosphere can also be related to the atmospheric temperature. The relationship between the dust particles and the temperature appears to be a moderate positive relationship (lodz.pl). This therefore shows that the return of dust particles is very high whenever there are high temperatures. The high temperatures, hence, facilitate the increase in the amount of dust particles in the atmosphere [32]. It is evident that whenever there is increase in the atmospheric temperature, the impact will be an increase in the level of dust in the atmosphere.

The Effect of Dust Concentration on the Number of Asthma Admissions by the Data MODIS, SEVERI, and AERONET

MODIS

According to MODIS website [61], the region that comprises the Persian Gulf incurred a dust storm on March 12, 2014. Using the NASA satellites, they obtained an aerial view of dust concentration within this are as shown in the figure below.

In this pictorial representation, it was evident that the dust swept across various countries, including Bahrain, UAE, Saudi Arabia, Qatar, and Iran among other Arabian regions [62]. Whereas the Nothern Part of Saudi Arabia experienced thick storms, UAE incurred thin plumes that swept across the country. The dust caused weather instability for five days causing the trough of the surface to enter into the Red Sea. Weather specialists hypothesized that the instable weather condition could result to gusty winds which lead to increased dust. The United Arabs Emirates’ meteorological center observed another windstorm that blew over the country on March 15, 2014 [64]. The wind was picking and blowing dust over the country owing to high velocity. Having experienced these strong storms, Abu Dhabi meteorological center set out to predict future condition in regard to prevalence of dust storms. They found out that there could be storms similar storms on March 16, 2014 moving at an average speed of 26mph which is approximately 44 kilometers per hour. In additional, the meteorologists predicted that those storms will be capable of carrying dust particles and blowing them in the air [65].

In a different research conducted in Abu Dhabi to determine prevalence of dust storms and dust, ADIA discovered that haze, which is mostly caused by dust, occurs on 242 days per annum. On the other hand, they suggest that dust storms envisage less prevalence than the haze since they occur at a frequency of 3-8 per annum. In fact, the research study revealed that from 1994 to 2003, 141 dust hazes were experience while 32 dust storms occurred during that period of about 10 years. The table below shows the prevalence of dust events and events in those ten years according to this research.

Table 3: Prevalence of dust events [38].

From this research, it is evident that the dust storms are not as prevalent as most people could think. The country experiences few events of dust storms as compared to haze. This has been portrayed throughout the ten-year period where the number of storms hardly exceeds 8 per year. Actually, in 2001, the country did not experience any occasion of sand storms. However, it is very clear that UAE is used to incurring haze which is mainly caused by dust sand particles found in the country.

SEVIRI

On March 2, 2012, SEVIRI satellites shown that the country had experienced dust storms. It predicted that the storms could be experienced again on the following Saturday where they could make the sea very rough. The meteorologists warned the citizens of continuous blowing dust for four days after March 6, 2012. Hazy conditions were also experienced on the seventh day of that month due to excessive concentration of dust in air. Since it reduced visibility to 3 kilometers, it was concluded that the dust concentration was not severe. The table below shows the prevalence of dust storms across UAE alongside concentration level in 2012 as recorded by MSG SEVIRI satellites.

The meteorologists the focused on the coverage of dust in the country where they divided dust particles in accordance to the size. The table below shows the prevalence of dust particles alongside the size of land that it covered.

Table 4: Prevalence of dust particles [40].

According to Hamza et al. (2011) the coastal region experienced different quantities of dust deposition in wet and dry seasons. During the dry seasons, the average rate of deposition was 9.34g/ m2 daily with a rage of 19 g/m2 per day. This rate reduced profoundly during the rainy seasons where the coastal deposition of dust was 7.61g/m2 daily. They authors also discovered that this part of the country experienced dust storms at an average rate of 33 days per annum. The mineral components of the dust particles differed according to the time that dust storms occurred. In essence, the components of dust particles are thought to have an effect of prevalence of asthma. Some minerals are capable of triggering asthma conditions more than others. Additionally, the research established that wind direction impacted the magnitude of dust concentration where the months of February and March have the highest concentration. On the other hand, May and June experience negligible amounts of dust concentration give that the windstorms that carry the dust particles originate from different areas.

AERONET

AERONET Satellite shows that eighty percent of UAE is covered by deserts whereas 20 percent is mountainous [85]. The images show that dust that affect UAE is transported from the surrounding areas. This makes implies that the concentration of dust in UAE is essentially less than other countries such as Saudi Arabia and Tehran. This factor becomes very important when determining the asthmatic effect of dust from a comparative perspective.

Asthma and Dust Concentration

Dust is one of the most significant agents that cause asthma prevalence in human beings. When the dust particles come into contact with the sensitive parts of the tracheal system they irritate it and trigger those components to react. This could cause a possible clogging of the respiratory system leading to asthmatic condition. Considering that dust is such an important factor that causes asthma, the prevalence of dust particles in UAE has a profound impact on the asthmatic conditions in the country. First, it has been established that the month of March is affected by relatively strong sand storms which blow dust. This implies that many cases of asthma are recorded during this month due to the temporal rise of dust concentration in the air. This is based is based on the premises that dust particles concentrate leading to inhalation and subsequent contraction of asthma.

Comparatively, UAE could experience less cases of asthma occasioned by dust particles than its neighbors, including Saudi Arabia, Bahrain and Iran. This is because it has been established that the storms carrying dust are thicker in those countries than UAE. In addition, it is clear that dust particles destabilize the weather and lead to increased severity of storms. This situation could lead to propagation and continuous rise of asthmatic cases. In accordance to the analysis carried out in this chapter, it has been discovered that UAE is prone to more hazy conditions than windstorms. However, the hazy conditions are mainly caused by the concentration of dust in the air due to gentle wind currents. These hazy conditions are experienced for about 144 days per year. As a result, the country’s population is prone to frequent increment in cases of asthma.

In fact, 144 days is equivalent of 39 percent of the whole year with 365 days annually. In addition, the hazy conditions result due to combination of various particles besides dust. These particles, which include industrial gases and humidity, increase the effectiveness of causing asthma when released in the air along with dust. In fact, some dust storms are also reported to contain Sulphur IV Oxide and Nitrogen IV Oxide particles. The two components intensify the effect of dust storms on asthmatic patients. Although the impact is not caused by dust particles specifically, the two gases are strongly associated with the dust storms. This implies that their effect is taken into consideration when analyzing the impact of these storms to the patients with asthma. Evidently, hazy conditions and those ones evoked by dust storms are essentially different since the concentration of dust in the air differs. In this regard, the haze contains minimal dust concentration as compared to dust storms. As a result, it is expected that more patients could be admitted during the dust storms as compared to when the country is affected by haze.

Another crucial aspect of the correlation between asthma and dust is the geographical characteristics of the country. According to previous analysis, it was discovered that the largest part of the land is covered by the desert. This implies that the largest part of the country is covered by sand that contains dust. As a result, slight wind that blows across the surface could definitely cause dust concentration to increase. This could lead to increased cases of asthmatic responses on the patients. The coastal region also comprise of a crucial part of the country as far as asthma in concerned. In this regard, it was noted that the coastal region incurs profound dust deposition which varies according to seasons.

During the wet periods the dust deposition rate is measured at 9.34g/ m2 while the one recorded for dry seasons is 7.61g/m2. This means that the effect of dust concentration is higher during the rainy season than the dry one. Further, it means that the asthmatic prevalence among people living along the coast could vary in accordance to these statistics. Particularly, the number of people affected by dust could increase during the dry season. On the other hand, the number could reduce during the rainy seasons owing to reduced dust concentration. In this case, it is assumed that the rate of dust deposition reflects its concentration in the air. Although this conclusion is made has been made, it is essentially important to state that the analysis relates to dust concentration alone. Otherwise, when we consider all factors, the finding might not make sense since there are other aspects that must be considered. For example, rainy conditions increase the atmospheric humidity which could also cause asthmatic responses among patients.

Lastly, the direction of windstorms is another important aspect of asthmatic admissions experienced within the country. In this regard, the direction of windstorms affects the components of dust, speed and concentration. If the storms come from a desert, then the concentration of dust could be more as compared to when they come from a semi-arid place. Besides affecting concentration, direction of windstorms determines the components of dust. When the sandstorms come from industrialized areas, there is high probability of carrying other particles, such as SO2 and NO2. These particles intensify the capability of dust storms to cause asthmatic responses among patients and subsequent admissions. Additionally, it the direction from which the wind originates could determine its velocity. If the velocity is very high, then the wind is capable of carrying large volumes of dust. In UAE, it is evident that dust storms come from the surrounding areas rather than the jurisdiction of the country. This means that the velocity determines the amount of dust that lands in the country’s borders. The storms must have a velocity that enables them to carry the dust through various countries up to the United Arabs Emirate. This could thus impact on the prevalence of asthmatic admissions recorded in the country bearing in mind that the level of dust concentration in the atmosphere affects prevalence of asthma.

Summary of Dust and Asthma

It is evident that UAE experiences periods of hazy weather conditions as well as string dust storms. According to statistics, it is clear that haze is more prevalent than sand and dust storms. While hazy weather conditions appear for about 140 times on average, dust storms hardly exceed eight of them per year. Previous literature shows that there is insignificant correlation between dust concentration and inflammatory responses among patients with respiratory problem. Although it is termed as a weak correlation, it causes increased admissions of asthmatic patients following inflammation of respiratory surfaces.

In UAE, statistics show that dust storms are mostly prevalent within the months of March and May. Since this trend has been established by analyzing data from weather stations for ten consecutive years, it could be predicted that the tendency will continue in future. As a result, health professionals and authorities should conceive strategies to ensure that the expected rise of asthmatic admissions could be attended satisfactorily. In addition, patients with asthma should also take precautions during this period to avoid excessive exposure to sand storms that could cause inflammation and admission in hospital.

Analytical Correlation of Asthma Admissions and Average Wind Speed/Direction, PM 10, PM 2.5, SO4, NO2, O23, and Carbon Monoxide Concentration

Wind Speed and Asthma

A research conducted in 2013 to give a monthly overview of the climate shown the average wind speed along the maximum recorded ones. The monthly measure of speed was obtained by calculating the average daily measure in knots. This was tabulated to give the results as reflected in the table below.

Table 5: monthly wind speed tabulated in average daily measures [30].

From a critical point of view, it is evident that UAE expects wind whose speed does not vary profoundly. This is drawn from the fact that the speed ranges from 11 to 14 so as the range is 3 knots. Whereas this holds, it is clear that the months of May, June, July, and August recorded the highest wind speed. The months of October and November records the least measure of wind speed. The yearly wind speed has been shown from 2011 to 2013 in the fig. 18, fig. 19, and fig 20. Arguing form these analyses, asthma admissions rises as the wind speed increases. High wind speed from the semi-arid regions of UAE poses adequate challenges to asthmatics. This is attributed to the drying of the mucosa membrane, inhaling dust collected from the lands, and raising the overall atmospheric temperatures. The cases, therefore, prevail from May to August which has the highest speed.

For instance, the fig. 20 has the maximum records on Jun 9th and July 30th. On the other hand, the maximum recorded wind speed was in May 24th, and July 19th 2012. It, therefore, implies that the effects of wind speed are prevalent during this period. However, other parameters do not remain at their constant as wind speed affects the cases of asthma admissions. For instance, wind direction deviates and causes consequent repercussions from the normal trends. Fast flowing winds from the sea towards the city between May and August carry with them a lot of moisture and often lead to precipitation in the highlands. Technically, it was argued initially that from various researches that high humidity has brutal effects to asthmatics leading to more admissions in the emergency departments of hospitals. Moreover, the admissions from Abu Dhabi hospitals provide a view relating to the overall country’s records on asthma since it is a centre/city. Therefore, most people tend to seek medical attention from them because they are properly and highly facilitated with treatment equipments.

The relationship between parameters dry and moist highly moving winds have significant effects on asthma. In a bid to elaborate this significance, it is vital to understand the features of the air quality in them. Inland winds usually flowing towards the sea or the land are the major causes of sand hovering that reduce the air quality and support the prevalence of dust mites in the atmosphere. Most dust storms arise from them which not only cause deaths associated with asthma, but also lead to high economic losses when buildings are destroyed and tourism is reduced. The moisture content of the winds is obsolete except in cases where the wind passes over an inland lakes or water body. In comparison, oversea breezes provide cool and moist air from May to August. Unlike the inland winds, they vary heavily from January to December due to the shifting seasons where the water is either warm or cold. During winter, the sea water is not adsorbed or vaporized into the wind. Therefore, the winds from the shores are dry than those from the inlands. This dry and cold air gives the asthmatics a hard time to breath as well as drying their airways and constricting them. Finally, there are incidences where the inland and overseas’ winds collide leading to modification of the weather depending of the present season. For instance, summer wind collisions have leads to better conditions for the survival and prevalence of dust mites. The moist air from the overseas combines with the dry and dusty air from the deserts of Arabian nation.

PM

Particulate matter was associated to the desert conditions of Abu Dhabi. High speed inland winds take most dust towards the city of Abu Dhabi. Other sources include emissions from the transport industry, which has elevated greatly since the discovery and commercialization of oil. For instance, leaded petroleum products released lead particles to the air causing health effects to the people of Abu Dhabi. Some of the metals contained in the atmosphere cause allergies to people that have asthmatic effects. Consequently, a rising level of PM causes significant effects to the cases of asthma recorded. In Utah, particulate PM is correlated to the increased asthmatic conditions [47]. Considering that the Abu Dhabi also has high levels of particulate matter, it applies that the same effects exist in Abu Dhabi. According to Perden [43], determining specific causative agents causing asthma in the environment is hard. However, substances such as silica and metal ions of copper nickel and iron as well as aerosols have detrimental effects on people [47]. Controlling these PM requires that the particles released by diesel and endotoxin be avoided as they cause harmful effects to asthmatics.

The use of tobacco has direct effects and high concentration of particulate matter that usually lead to asthmatic conditions. Asthmatic cannot afford to use cigarettes because their airways require to be supplied with sufficient air without any disturbances. In fact, patients diagnosed with asthma are under strict prohibition to the use of cigarettes and such related substances as bhang. These can lead to immediate death of an individual due to continued insufficient inhalation. Practitioners take caution and guide patients on such occasions where they direct them on how to live under. For instance, they recommend patients to avoid damp houses, keep the inhalers close at all time, and avoid identifiable allergens at all time.

SO2

The increments in the emergency attendances of asthmatic patients exposed to SO4 require medical and guidance interventions [47]. A prolonged exposure to the sulphur dioxide has attributed a significant appreciation in the number of patients admitted with chronic asthma. This gas mixes with water to for acid aerosols that irritate the air cavities when sulphuric acid is formed [53]. Reports indicate that the acid concentrations of above 100nmol/m3 have been recorded from some asthma patients. The airway constrictions are known to appear even when the concentrations are too low at about 0.25ppm. Areas with volcanic activities are known to release sulphur dioxide to the atmosphere. The residents of these areas and tourists visiting the areas are at a risk of inhaling the gas and creating a base for asthma development. The gas is usually adsorbed in the mucosa membrane to form acids within the lungs. In addition, this occurs in the acid producing industries where the SO4 is not properly regulated. The emergencies record high cases of asthma which are attributed to the gas emissions. This implies that occupation of people, such as those working in geothermal electric production, are at high risks of developing asthmatic conditions.

NO2

Urban and industrial regions appear to contain high contents of NO2. Apart from the industries, nitrogen gas reacts in the presence of light energy and lightening to form NO2. Other sources include the burning of fossil fuel and exhaust releases which are pertinent in Abu Dhabi. However, it has been argued that indoor cooking is the most viable cause of the NO2 leading to asthma [66]. This gas is retrieved from kerosene and gas cookers. In this regard, admissions related to this gas are evenly distributed, although most cases are from hospitals involve people residing in towns. This can be explained by the fact the town residents are much exposed to the gases because they use them often, while the fossil fuels are not used a lot in the local place. Furthermore, the population of Abu Dhabi is high and dense reducing the concentration of the gas produced per individuals. On the other hand, local places are much open and scattered allowing the distribution of the harmful gas over a large area. Peden argues that very low concentrations of NO2 at about 0.4ppm have asthmatic consequences to people [43]. The gas acts through facilitating the effects of allergens and causing bronchospasm as well as asthmatic responses.

Ozone

Ozone has been noted as a cause of increased asthma cases in hospitals. When asthmatic individuals are exposed, the symptoms appear after 48 hours. It causes discomfort and reduced oxygen intake in to the bold stream. The reactions of asthma are through the inflammation of the neutrophils and lower rate bronchial responses to air demands. This implies that the airways do are not elastic and resist the urge to contract and expend in order to push air into or out of the lungs. The ozone caused asthma admissions effectively when in conjunction with the other time of exposure and the period of performing exercises [52]. Evaluations of the effects of ozone to the individuals with mild asthma show that they were less affected by low levels of ozone unlike the non-asthmatics. However, the ozone facilitates the actions of allergens inhaled by the asthmatics.

CO

The prevalence of CO related admission is no doubt influential in the admissions of the hospitals. CO is common from industries, vehicle exhausts, coal and charcoal burning, cooking gas burning, active geothermal locales, and kerosene among others. The discovery is oil came with significant and unexceptional effects to the air pollutions in terms of CO. Research have indicated that the CO emissions from the transport industry are too much. The cost of fuel reduced and people tuned into the use of vehicles which release CO. Admissions related to CO and asthma are many since many people work in factories that use these fuel, inhale them from the roads and vehicles release them, and breath the gas when cooking. It is, therefore, a constant factor that causes emergent asthma evenly through area and time.

Analytical Evaluation of Precipitation, Wind Speed, Humidity, and Air Quality in Abu Dhabi Between Jan 2011 and Dec 2013

Precipitation

Summer precipitations are vital in the study of prevalence of asthmatic cases. The analysis presented in figure 10 shows how rain was distributed in August 2013. Essentially, there are clear comparison made between heavy, light, and drizzle rain.

Fig. 8 shows August 2013 precipitation on “the fraction of days in which various types of precipitation are observed. If more than one type of precipitation is reported in a given day, the more severe precipitation is counted. For example, if light rain is observed in the same day as a thunderstorm, that day counts towards the thunderstorm totals. The order of severity is from the top down in this graph, with the most severe at the bottom [70].

Analysis of the data from weather spark indicates that the highest precipitation was recorded on 21st November. The recorded amount of precipitation was 25.6mm. The period with obsolete precipitation was from the beginning of May to the middle November. From the year 2012, there are distinguishable characteristics of precipitation patterns. For instance, it is clear that the maximum amount of rainfall recorded in 2012 was at 132.1 mm in December as compared to a maximum of 25.6mm in November 2013. This deviation is also practical in March 26th with a second tally of 106.1mm as compared to the year 2012 where the precipitation records indicated 13.0mm in April. In this respect, the month with maximum rain changes as well as the total amount of rainfall between the two years.

Fig. 9 shows 2013 precipitation quantity on “the daily measured quantity of liquid (or liquid equivalent in the case of solid precipitation) precipitation over the course of 2013, with the median non-zero quantity (thick gray line) and 10th, 25th, 75th, and 90th non-zero percentiles (shaded areas). The bar at the top of the graph is green if any precipitation was measured that day and white otherwise [73].

Although the amount of rain in 2013 is low, the reports presented hereby indicate that the rainfall experienced within the year 2013 followed the climatic patterns of Abu Dhabi. In fact, the hours of precipitation were higher in 2013 than in 2012. For instance, the highest time of recorded in 2012 was about 5 hours while a maximum of 10 hours was seen in 2013. Also, there is a shift of months of precipitation. For instance, the highest hours of daily precipitation were evident on January while this moved to February the following year. In addition, the highest precipitations recorded in December 2012 were pulled to November in the following year. The precipitations observed in April were not much affected except for the fact that higher hours of thunderstorms were recorded in 2012 than 2013

Fig. 10 shows 2013 precipitation reports according to weatherspark “the daily number of hourly observed precipitation reports during 2013, color coded according to precipitation type, and stacked in order of severity. From the bottom up, the categories are thunderstorms (orange); heavy, moderate, and light snow (dark to light blue); heavy, moderate, and light rain (dark to light green); and drizzle (lightest green). Not all categories are necessarily present in this particular graph. The faint shaded areas indicate climate normal. The bar at the top of the graph is green if any precipitation was observed that day and white otherwise” [73].

The record for 2012 on hourly distribution of precipitations was not availed by the data station. However, it is apparent that the month of June recorded the highest shading for freezing rain and sleet in 2013. The year 2011 depicts a rather uniform distribution of the freezing rain and sleet between June and August.

Fig. 11 shows 2013 reports on “the full year of hourly present weather reports with the days of the year on the horizontal and the hours of the day on the vertical. The color-coded categories are thunderstorms (orange); heavy, moderate, and light snow (dark to light blue); heavy, moderate, and light rain (dark to light green); drizzle (lightest green); freezing rain and sleet (light and dark cyan); snow grains (lightest blue); hail (red); fog (gray); and haze (brownish gray)” [73].

Fig. 12 Year 2012 precipitation report for “the daily number of hourly observed precipitation reports during 2012, color coded according to precipitation type, and stacked in order of severity. From the bottom up, the categories are thunderstorms (orange); heavy, moderate, and light snow (dark to light blue); heavy, moderate, and light rain (dark to light green); and drizzle (lightest green). Not all categories are necessarily present in this particular graph. The faint shaded areas indicate climate normals. The bar at the top of the graph is green if any precipitation was observed that day and white otherwise” [71].

Fig. 13 shows precipitation quantity for “The daily measured quantity of liquid (or liquid equivalent in the case of solid precipitation) precipitation over the course of 2012, with the median non-zero quantity (thick gray line) and 10th, 25th, 75th, and 90th non-zero percentiles (shaded areas). The bar at the top of the graph is green if any precipitation was measured that day and white otherwise” [71].

January is the preceding month with the highest recorded precipitation according to the information from weatherspark station in Abu Dhabi. The highest recorded time for the precipitation was about twenty one hours. This record was taken in close proximity from the station where 49 hours were recorded in January. This does not imply that precipitation was absent during the rest of the year. The green band at the top of the graph shows that precipitation was present in February and November at very low amounts. April has a significant record on precipitation since the graph shows a strong band with the highest hourly precipitation being 7 hours. It is also evident that the remaining months possessed hardly any precipitation.

In such a presentation of precipitation, the year 2011 has low record of precipitation basing on this information retrieved from the graph. Consequently, the cases of asthma admissions were affected during this period. However, the variation might be rather constant from June to October were there is no record of precipitation.

Fig. 14 shows “The daily number of hourly observed precipitation reports during 2011, colour coded according to precipitation type, and stacked in order of severity. From the bottom up, the categories are thunderstorms (orange); heavy, moderate, and light snow (dark to light blue); heavy, moderate, and light rain (dark to light green); and drizzle (lightest green). Not all categories are necessarily present in this particular graph. The faint shaded areas indicate climate normalcy. The bar at the top of the graph is green if any precipitation was observed that day and white otherwise” [72].

A record of hourly reports on precipitation comparing various aspects such as thunderstorms and rain of distinct attributes. The shading observed from the graph indicates that most precipitation happens between 6am to 12pm. During this period, it appears that there is freezing rain and sleets.

Fig. 15 shows “The full year of hourly present weather reports with the days of the year on the horizontal and the hours of the day on the vertical. The color-coded categories are thunderstorms (orange); heavy, moderate, and light snow (dark to light blue); heavy, moderate, and light rain (dark to light green); drizzle (lightest green); freezing rain and sleet (light and dark cyan); snow grains (lightest blue); hail (red); fog (gray); and haze (brownish gray)” [72].

Wind Speed

It is now clear that wind is an unexceptional parameter in determining the cases of asthma in Abu Dhabi. In this regard, it is vital to evaluate its speed that determines the kind of pollen, spores, rain, temperatures of this city. In order to perform this task, the graphs below show the distribution of hourly speed of wind for the year 2011. Technically, it is clear that the common hourly speed of wind lies between 2m/s to 6m/s. In fact, the mean speed of the wind at the highest level was March at 5 m/s According to the data source [72], it is implied that a wind speed of 14m/s was recorded in first of February. It has also been evaluated and indicated that the annual daily mean of speed was 8m/s. Furthermore, it was recorded that the wind speed was at its lowest tally in November. The other highest records of wind speed are seen in April 15, July 6 and October 21 at 13m/s, 10m/s and 10m/s respectively.

Consequently, wind is practical in Abu Dhabi and the content it carries heavily lies on the direction it takes. Although it might be hard to tabulate the yearly wind direction at hourly levels, it is worth noting that wind moving from the seas during summer carry moisture while the wind from the lands are usually dry and dusty. At times, these winds corrodes and increase the cases of asthma basing of the warm, moist, and dust air that is favorable for dust mites and spores’ hovering. The cases of asthma prevalence in March 2011 can be attributed to this aspect.

The wind speed data imply that the records made have more similarities than differences. For instance, the maximum wind speeds were 11 m/s or 12m/s in most cases except for one case in 2011 where it was 13m/s. The speed rarely went to zero in 2011 while many zero records were taken in the following 2 consecutive years (2012 and 2013). July had a high record between the 3 years but did not appear to be holding the highest monthly mean speed. The windiest months with the highest mean were March, February, and June for the years 2011, 2012, and 2013 respectively.

Fig. 16 “The daily low and high wind speed (light gray area) and the maximum daily wind gust speed (tiny blue dashes)” [72].

Fig. 17 shows “the daily low and high wind speed (light gray area) and the maximum daily wind gust speed (tiny blue dashes)” [71].

Fig. 18 “The daily low and high wind speed (light gray area) and the maximum daily wind gust speed (tiny blue dashes)” [73].

Humidity

Asthma can be investigated in relation to humidity. Therefore, the graphs of fig. 21 to fig. 23 show yearly variances of relative humidity for the 3 years. It is not apparent that high humidity is a cause or a trigger for asthma. It is, therefore, expected that the increase in humidity for one day has significant effects on the asthmatic cases in Abu Dhabi. Similarly, low humidity dries the airways causing an irritating feeling which eventually prompts asthma. Consequently, it can be argued that high and low humidity does not suit asthmatics since it raises the levels of asthma. An optimum humidity must be attained for the asthmatics if they are not to attend the health institutions for treatment. Furthermore, humidity is a potent cause of lowered temperature since high humidity cools the area.

The relative humidity of Abu Dhabi for three years has been analyzed and presented in the 3 graphs. April and may are the months with the least recorded amount of humidity for these years while highest records are associated with January and December. Generally, the humidity records in 2011 show an elevated level of vapor in the atmosphere as compared to the year 2012 and 2013. In this regard, it is apparent from the graphs that both the low and high relative humidity is high in the year 2011. The similarities between the year 2012 and 2013 are adequate following the fact that the trends of the graphs are almost similar. An incident of low clavicle is observed in May. In addition, towards the end of the year, there is a highest point that indicates the highest relative humidity which then drops slowly for both curves from 2012 and 2013.

Fig. 19 “The daily low (brown) and high (blue) relative humidity during 2013 with the area between them shaded gray and superimposed over the corresponding averages (thick lines), and with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile)” [73].

Fig. 20 “The daily low (brown) and high (blue) relative humidity during 2012 with the area between them shaded gray and superimposed over the corresponding averages (thick lines), and with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile)” [71].

Fig. 21 “the daily low (brown) and high (blue) relative humidity during 2011 with the area between them shaded gray and superimposed over the corresponding averages (thick lines), and with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile)” [72].

Effect of Vegetation (Pollen Activity) and the Number of Asthma Admission

Abu Dhabi is one city situated in the Arab states that have desert conditions in most of its area coverage. This city also has vegetation that is more of that in the desert. Dry vegetation is seen in most parts of Abu Dhabi. These are areas where we find a lot of short shrubs and desert plants due to the little amount of rainfall in the areas. The vegetation of Abu Dhabi has impacted on the number of asthma cases in this capital in various ways. First the fact that the vegetation in many parts of Abu Dhabi is scarce has seen dust and other tiny soil particles getting carried easily into the atmosphere. The dust in the atmosphere does affect the health of the residents of Abu Dhabi by causing a lot of harm to their respiratory systems. This in the long run leads to respiratory difficulties and hence diseases such as asthma come in to attack the people [75]. Therefore, this is one way in which the vegetation impacts on the number of asthma cases in the city of Abu Dhabi. Lack of a good vegetation cover leads to dust being blown easily into the atmosphere.

Another way in which vegetation of Abu Dhabi has affected the number of people being admitted with asthma is through the pollen activity. This case takes place when the strong winds experienced in most parts of Abu Dhabi carry around the pollen materials from the plants into the atmosphere. Once the atmosphere is polluted with these pollen materials, the residents of the city are likely to experience nasal irritations and allergies that may result to the asthma cases [74]. Now to discuss how the vegetation of Abu Dhabi through the pollen activity has affected the number of asthma cases reported in this city, it is important to relook into the vegetation of Abu Dhabi briefly. After that, it will also be of use to discuss asthma as respiratory disease touching on its causes, symptoms and transmission with regard to pollen activity. Then finally the different case studies in relation to asthma admissions in Abu Dhabi to be highlighted in connection to the pollen activity.

Vegetation of Abu Dhabi

The region where Abu Dhabi is found is a semi-arid region and therefore the vegetation of most of the parts is expected to be that of arid and semi-arid lands (ASAL). However, this does not mean that we do not expect to find well growing plants and flowers in some parts of the city of Abu Dhabi. This explains why pollen activity is still a major experience in this city though many people associate the vegetation of the area with desert conditions [76]. It is true that the region where Abu Dhabi is has a desert climate and thus we expect little rainfall in the region with high temperatures accompanied with dry winds. This conditions that come along with the desert climate are what bring out the vegetation we see in Abu Dhabi.

The vegetation of this place is characterized by short shrubs in the areas where rainfall is very scarce, and moulds, fungi and some other plants with pores in those areas that receive some reasonable amount of rainfall. In these areas with desert conditions like Abu Dhabi we usually experience strong winds. It is these strong winds that facilitate the processes of pollen activity [78]. The strong winds help in carrying the pollen grains and mould spores into the atmosphere. Research has found that the atmosphere of the city of Abu Dhabi is polluted with a lot of dust and pollen materials that get lifted through the pollen activity. This is not good for the people since it exposes them to high risks of conducting asthma.

The vegetation of Abu Dhabi is also related to small flying insects such as the bee that are attracted to the flowers of the plants and other vegetation in the area. The high temperature recorded in many parts of Abu Dhabi is responsible for the existence of many bees in the area. This is because such insects like hot temperatures. Their presence in this vegetation of mould spores and plants carrying pollen is useful for pollination purposes [77]. Therefore this is another way in which pollen activity takes action in this vegetation. As these flying insects transport the pollen grains from one plant to another, some pollen materials are dropped in the atmosphere. This shows how this pollen activity exposes the people of Abu Dhabi to asthma by polluting the atmosphere with the pollen materials.

Now this is the typical vegetation of Abu Dhabi; few upper plants, dwarf shrubs, moulds and fungi. To crown all that, flying insects such as bees are common in the area to enhance pollen activity with its processes.

Relation of Asthma to Pollen Activity

Asthma is a disease that comes about when the air tracts found in human bodies go through inflammation due to chemical changes in the body, physical factors and allergens. In the city of Abu Dhabi the main cause of this respiratory disease is exposure to allergens. The atmosphere of this area is polluted with a lot of dust particles and pollen materials. Inhalation of cold air is another cause of asthma apart from the allergens. Once a person is already diagnosed as asthmatic, there exist a collection of things that he or she is expected to avoid depending on the type of allergy one has. These things that they ought to stay away from are what are termed as triggers. Some of asthma triggers that are common include the following; infections, pollens, molds and mildew, irritants, stress and dust mites. Exposure to these triggers may cause an asthmatic person to start showing symptoms of being infected with the respiratory disease such as breathing heavily and wheezing [78]. In the case of Abu Dhabi, the pollen grains and dust particles are the main asthma triggers. This is because the areas of Abu Dhabi are usually having vegetation containing moulds with spores and also the dusts are caused by strong winds.

Some of the symptoms of asthma attacks include chest congestion, cold going for more than 10 days, coughs going through long periods and wheezing in some cases. These symptoms of asthma are also the ones used to detect the disease in the Middle East Arabian countries [79].When a person is seen to have a cough that takes time to cool down for example taking weeks or months, this person is highly expected to read positive when tasted for asthma. This is because these regions found in the eastern of the Mediterranean are usually prone to respiratory disease such as asthma. For instance, in Abu Dhabi the health personnel usually rely mostly on reading symptoms from the people than making all the residents of the city to go through the asthma tests. This is usually the case because the vegetation of Abu Dhabi makes the area one point where for one to conduct the disease is so easy. This vegetation that is highly characterized by pollen activities adversely affects the proportion of the city’s population that is attacked by asthma. The pollen activity is responsible for carrying around the spores and pollen materials that are triggers and causes of the respiratory disease.

Relating the Number of Asthma Admission in Abu Dhabi to Its Vegetation (Pollen Activity)

Studies and research carried out in the UAE have recorded that the number of asthma admissions in Abu Dhabi has been on the rise over the years. This placed serious concerns on the people living in the city and also the business persons of this commercial city because it hinders investors from coming in this city. Therefore, the much attention that the people of Abu Dhabi showed to the increasing cases of asthma in their city forced further studies to conducted to establish some of the reasons why this has been the situation. The vegetation of Abu Dhabi was studied in relation to how it affects the asthma cases in the area. When looking at the vegetation of this city in relation to the asthma cases, the pollen activity is put into much consideration [29].

First over the years the climatic conditions of Abu Dhabi has been changing to the worse as the desert conditions become more worsened due to factors like the global warming that affects every part of the world. This climatic changes has seen the vegetation of some of the areas in Abu Dhabi also change. The effect of global warming has seen increased rainfall in most parts of the globe and Abu Dhabi is not left out in this. When the rainfall amounts increase in parts of this Arabian city, the vegetation also moves to another level in stages [80]. For example, the rainfall favors the growth of fungal plants and mosses. This therefore means that the vegetation of Abu Dhabi with time has been introducing more spores and pollen materials. The effect of this is that pollen activity in the area has been boosted and more pollen materials are expected to be suspended in the atmosphere. Over the years there has also been more strong winds experienced in the city of Abu Dhabi and this enhances further the processes of pollen activity. This is because the more the winds we have in this region, the more the pollen materials will be carried into the atmosphere [81]. When the atmosphere of this city gets more polluted by these asthma triggers, the city records more asthma admissions. This is clear evidence that more avenues for the people of Abu Dhabi to contact asthma have always been created by the area’s vegetation through the pollen activity.

To prove the rising number of asthma admission in Abu Dhabi is one study conducted in the city where government hospitals were used as the reference points and source of data. The method used for data acquisition and calculation was simple. The number of patients who were admitted in the government hospitals having asthma diagnosis was taken. Also retrieved was the number of total admissions in the government hospitals over the same period. It is important to note that this was done per age brackets. The data taken from the government medical records is believed to be reliable and it was taken from the period of April 2009 to April 2011. The result of the study analyzed in percentages showed an increasing trend of the value of percentage of the number of patients with asthma diagnosis [29].

Over from February 2009 to the year 2011 there have been more cases of dust events being recorded increasingly over the years in Abu Dhabi. This tells us that the strong winds being experienced in the area have been becoming more over the years. During the same period the city of Abu Dhabi recorded more contamination on its atmosphere by the mould spores and pollen materials. This was due to changes in the amount of rainfall received that has been on slight increase. Thus the vegetation of Abu Dhabi has also been going through some modifications making it more ready for pollen activity to take place.

The period in which the cases of asthma admission have been on the rise happen to be the same period when the vegetation of Abu Dhabi was transforming to allow more pollen activities. With this a conclusion can be drawn that the vegetation of Abu Dhabi played a role in the increased number of asthma admission in this city.

Remedy to Asthma Cases

Looking into the asthma case in Abu Dhabi, it is one type of asthma that is mostly caused by the vegetation of the area and the environment generally. Trying to find a solution to the problem so that the asthma admissions will stop being on the increase always is important to this business hub in the Arabian state. Some things are almost impossible to change like for example the climate of an area that determines the vegetation of the same area. Therefore, to tackle the issue of asthma in Abu Dhabi entail making the people learn how to live in that environment without being attacked by asthma.

For instance the people in this city will have to be precautious and adopt some activities to keep them safe. During the morning hours till midday is when the pollen counts are registered as being highest. It will be advisable for people to reduce outdoor activities during this period. The residents of the area can also be extra keen and notice the pollen seasons [80]. During these seasons they can keep their windows closed to reduce their encounter with pollen materials. It is also advisable for the people living in areas of Abu Dhabi where pollen activity is common to maintain showering every time they get back into their houses. This is important for these people to remove the pollen materials that might have settled on their clothes and hair while they were undertaking their outdoor activities.

Generally, it is clear that the vegetation of Abu Dhabi in relation to the pollen activity has been one of the factors behind the rising number of asthma cases in this city. It is this vegetation that avails the mould spores and pollen materials which act as some of the main triggers of asthma.

Conclusion

The attributes of the environment play tactical roles in the determination of asthmatic cases. The prevalent environmental aspects participating in these influences are the weather patterns that not only determine the trends in asthma admissions, but also depend on each other to do it. This implies that an evaluation of one weather condition is heavily affected by the other. This has been evident in the relationships between temperature and humidity, wind speed and direction, wind and dust, and their contributions in asthma. Dust was noted to rise when there is sufficient wind speed to blow the dust and sand particles from the desert to the city. The respiratory system then harbors challenges when trying to regulate pollutions and these weather factors. The factors may act in conjunction or as sole triggers of asthmatic conditions. It is unfortunate that most of these factors cannot be controlled properly. For instance, it is not possible to controlled temperature in order to suit the asthmatics. However, optimal conditions can be raise to suit the asthmatics during indoor periods to reduce the chances of trigger. This can be the control of parameter such as temperature, humidity, and air circulation in the houses. For the outdoor variances of weather conditions, there are no salient features to control without the involvement of masses. For example, the control of humidity in the environment is beyond human control especially due to the seasons. However, an inhaler can be used to treat the triggered asthma and reduce its effects.

However, there is one issue that can be addressed nationwide in order to reduce the cases of asthma. This factor is environmental pollution that causes allergic reaction in light of harmful particles in air [68]. The control strategies include monitoring gas emissions at the industrial level where products such as oil are investigated properly before they are released for use. Industries that release gases such as carbon monoxide, sulphur dioxide, nitrogen dioxide, and acid aerosols among others must also take precautionary measure against air pollution. It has been identified that the air quality of Abu Dhabi is under peculiar survey and repercussions due to the use of fuel. Probably, the government should invest heavily on mass transport through the use of trains and buses to reduce the release of pollutants. In fact, researchers have identified that trains are the most suited strategies to reduce air pollution and increase the quality of air.

Spores and pollen allergens can be controlled through farming regulations and use of suited chemical. The advantage present in the control of these factors is that the two are season and basis on known plants and fungi. This will allow the cultivation of some plants to avoid vegetations that release allergic spores and pollen. Some spores and pollens act as inducers of airway’ diseases. Some occupations might, therefore, cause risks to asthma conditions such as the farming of the spore produces fungi and pollinating plants.

For the affected population, it is critical to avoid allergens and follow pharmacological interventions to solve the problems. In case these two principles do not work effectively, it is pertinent that the individuals attend an immunitherapist for further guidance and assistances. As this research ends, there are still so many question and gaps in this disease that needs to be addressed. It is, therefore, recommended that further research on the epidemiologic aspects and controlled exposure be studied to provide solutions for issues related to asthma.

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