Introduction
Air pollution occurs when air has substances that cause harmful effects on humans, animals, plants, and the environment. As nations become industrialized and their population increase, more and more pollutants are being added into the environment. In the United Arab Emirates (UAE), atmospheric pollution has a great impact on humans, animals, and plants. The main air pollutants in the UAE include sandstorms, dust storms, emissions from industrial plants and vehicles as well as air pollutants emanating from the built environment. In the UAE and the Middle East, air pollution is more severe due to the extreme heat, rainfall shortage, and harsh geographic conditions (McGranahan & Murray, 2003). One of the most poisonous and harmful gases causing air pollution is sulfur dioxide (SO2). In this study, an environmental risk assessment of sulfur dioxide in the UAE was carried out.
Case Profile
Rationale
Air pollution in the UAE and other Middle East countries is becoming an important issue. The country is experiencing increased growth due to oil, trade, and tourism. The number of constructions (built environment), vehicles, industries, and people has increased considerably. It is projected that all these recent developments will increase the level of air pollutants such as sulfur dioxide. Data from the UAE National Bureau of Statistics indicate that the level of sulfur dioxide, nitrogen dioxide, and ozone has continued to increase from 2007 to 2011 (UAE National Bureau of Statistics, 2013). According to the statistics bureau, the level of air pollutants has continued to increase in areas such as Abu Dhabi, Dubai, Fujairah, Ras Al- Khaimah, and Ajman for the last six years. These chemicals are harmful to human health, causing environmental pollution, and global warming. Due to the rapid development and urbanization, the natural habitats and ecosystems have been disturbed. It is therefore important to carry out an environmental risk assessment on sulfur dioxide in the UAE.
Risks Assessment criteria
Risk can be defined as systematic identification and characterization of potential negative impacts that certain chemicals and materials have on human health. During the risk assessment process, the hazardous substance is analyzed to determine, its quantity, safe levels, adverse effects, and its residual impacts. The risk assessment process has the following main processes;
Hazard identification
The chemical under assessment is sulfur dioxide SO2. It is one of the main air pollutants. Sulfur dioxide is one of the most reactive agents of sulfur. Even though the other oxides of sulfur are toxic, SO2 is the most harmful oxide if exposed to humans and animals. Fossil fuel combustion is the main source of SO2 gas. These fuels are widely used in vehicles, industries, and energy generation plants. Sulfur dioxide is one of the five main air pollutants. The other primary air pollutants are nitrogen oxides, lead, carbon oxides, and particulates. According to EPA (2013), short and long term exposure to SO2 has adverse respiratory effects.
Exposure to this gas results in respiratory illnesses such as asthma and bronchoconstriction. Studies have shown that individuals exposed to SO2 have increased breathing problems and are normally hospitalized frequently. Children and old people are highly affected by SO2 even in low concentration. When SO2 is emitted in large quantities, other oxides of sulfur are formed (SOx). These SOx react with other gases in the atmosphere forming small particles that penetrate deep into the lungs where they cause many respiratory diseases. Patients with respiratory diseases are also greatly affected by exposure to these chemicals. Other diseases caused by SO2 include emphysema and bronchitis. SO2 causes serious irritation to the skin and eyes and a large dosage can cause blindness. Most of the SO2 that is inhaled is absorbed in the upper respiratory system and causes severe illness in the long run.
Sulfur dioxide contributes to the formation of acidic rain. When SO2 mixes with water droplets or vapor, it reacts to produce sulphuric or sulfurous acid. These two chemicals are then released as acidic rain. An increase in the concentration of SO2 results in an increase in the pH of acidic rain and the damages caused by it. Acidic rain causes severe damage to trees and degrades buildings. The acid reacts with an iron sheet destroying building roofs. Acidic rain is very common in highly industrialized cities that rely on fossil fuels to power their industries. When acid rain accumulates in the soil, it increases the acidity in the soil killing most microorganisms and plants. Percolation of acidic water in rivers and lakes increases the pH of the water and this destroys aquatic life in the long run. Normally, most of the precipitation from surface runoffs which enter water bodies.
Dose-response assessment
Sulfur oxide is dangerous at low and high doses. Inhaling a small amount of this gas causes asthma and other respiratory diseases. Sulfur dioxide is poisonous to asthmatic people and the problem manifests itself immediately the gas is inhaled. Exposure to large doses of sulfur dioxide causes death. Current occupational safety and health standards recommend that individuals should not be exposed to more than 5 PPM (parts per million) of SO2 for 8 hours. Other agencies dictate that people should not be exposed to more than 2 PPM of sulfur dioxide. The main route of exposure is through inhalation. Sulfur oxide is also known to be harmful if it comes into contact with the eyes and skin.
Exposure assessment
Several tests have designed to determine the levels of SO2 in the air. These toxicological tests vary with the different standardizing agencies. It must be noted that most of the pollutants exist naturally in the air and are considered pollutants if they exceed the normal level. For example, though the air has sulfur oxides in it, they become pollutants if they exceed a certain level (Robson & Toscano, 2007). SO2 pollution in the UAE can be assessed using several methods. One of the assessment methods in toxicological testing. In this test, samples of air should be taken from different areas in the UAE. An appropriate sampling method must be used during the collection of these samples to ensure the whole region is studied (Harrop, 2002). The samples should then be subjected to chemical tests or a gas analyzer to determine the percentages of sulfur oxide. The level of impurities should then be compared with safe levels (Hanrahan, 2011). The SO2 gas levels are shown in Tables 1 and 2 below.
Table 1: the amount of sulfur dioxide in Dubai city (Source UAE National Bureau of statistics, 2013).
Table 2: showing the SO2 levels in Fujairah(source: (Source UAE National Bureau of statistics, 2013)).
Risk characterization
SO2 is one of the most dangerous air pollutants. Exposure to this gas causes serious respiratory diseases. In the UAE, most towns in the UAE have lower SO2 gas levels. However, exposing residents to this gas for a long time means could result in respiratory problems. The gas would also lead to acidic rain causing damage to plants and animals.
Causes of the Problem
In the UAE, the main sources of SO2 pollution are;
Emissions from vehicles
One of the causes of SO2 pollution in the UAE is emissions from vehicles, especially in large cities. According to Rasheed (2011), car emissions contribute to over 82% of all the total air pollution in Dubai. For example, the municipal council of Dubai noted that in 2009, 1,021,880 cars emitted about 2,334,762 Kg of carbon dioxide every day. As aforementioned, the principal source of SO2 is the combustion of fossil fuels. Since most vehicles combust fossil fuels, sulfur dioxide is emitted alongside other pollutants such as carbon monoxide CO, carbon dioxide CO2, methane CH4, volatile organic compounds, and nitrogen oxides.
Industrial emissions
Industries are another principal source of SO2. Most industries combust fossil fuel or coal and emit sulfur oxides as one of the exhaust gases. Due to the rapid industrialization in UAE, industries are a principal source of SO2 pollution. EPA states that industries account for 20% of all the SO2 emissions.
Power plants
Power generation plants combusting fuels to generate electrical power emit large amounts of sulfur dioxide. This is the largest source of SO2 and it accounts for half of the gas in the environment.
Natural processes
Sulfur dioxide is emitted in small quantities through natural processes such as lightning, volcanic eruptions, and geothermal wells and processes. These sources emit minute amounts of sulfur which is not detrimental to the environment.
Lack of proper legal and regulatory mechanisms
Lack of proper policies, laws, and regulations on pollution control exacerbates the pollution problem in the UAE. Currently, the government is concentrating on real estate development, industrialization, urbanization, trade, and tourism. Though such develops are profitable, policymakers should also examine the impact they have on the environment and develop appropriate legislation to reduce pollution.
SWOT Analysis of the Possible Solution
Some solutions can be adapted to reduce air pollution levels in the UAE. Some of these are analyzed below.
Adapting strict policies and legislation
One of the main interventions, in this case, is to develop strict policies and legislation that control SO2 emissions. Such legislation should focus on controlling emissions from the main sources Cooper & Alley, 2010). Such legislation should:
- Reduce the number of vehicles in the city: – residents would have to use electric trains which are powered by electricity and don’t cause much pollution.
- Reduce the average SO2 pollution from industries: – Laws banning emissions from industries would prompt them to adopt energy-efficient methods and also use equipment that doesn’t emit pollutants. The legislation would also force industries to purchase exhaust gas cleaning equipment such as precipitators, scrubber units, air filters, and air cleaners. Industries can also use renewable energy sources such as solar energy.
- Reduce emissions from power plants:-Nearly half of the SO2 comes from power plants burning fossil fuels. The legislation should ensure that such plants have a scrubber unit or other gas cleaning methods. This will reduce the SO2 from the exhaust gases.
The SWOT matrix for this intervention is tabulated below.
Figure 1 SWOT analysis for the first intervention.
Carry out air pollution awareness campaigns
In this strategy, organizations and individuals would be trained on the need to adopt safer practices to reduce air pollution. It is expected that such training and campaigns would reduce air pollution and subsequently SO2 gases. The campaigns would also prompt individuals to plant trees near their homes or organizations. This strategy is quite effective as the initiative will be from citizens themselves. A SWOT analysis of this intervention is shown in figure 2.
Figure 2 SWOT analyses for the first intervention.
Recommendations
Sulfur dioxide is one of the main air pollutants and is a primary concern in UAE. Exposure to a small amount of sulfur dioxide causes serious respiratory problems. The gas also causes acidic rain which destroys plant, aquatic life and increases the soil pH. The gas is mainly emitted by vehicles, industries, and power generation plants. The levels of SOÂ2 can be determined using a gas analyzer. One of the main control strategies is the formulation of legislation and policies restricting the amount of sulfur dioxide emitted by vehicles, industries, and power plants. Other control strategies include: creating awareness on the impacts of air pollution, educating citizens and company workers on strategies to reduce pollution, adopting energy-efficient methods, use of solar energy, tree planting, and the use of air cleaning equipment.
References
Cooper, D., & Alley, F. (2010). Air Pollution Control: A Design Approach. Long Grove, Illinois: Waveland Press Inc.
EPA (United States Environmental Protection Agency). (2013). Sulphur dioxide: basic information and health. Web.
Hanrahan, G. (2011). Key Concepts in Environmental Chemistry. Waltham, Massachusetts: Academic Press.
Harrop, O. (2002). Air Quality Assessment and Management: A Practical Guide. New York: CRC Press.
McGranahan, G., & Murray, F. (2003). Air Pollution and Health in Rapidly Developing Countries. London: Routledge publishers.
Robson, M., & Toscano,W. (2007). Risk Assessment for Environmental Health. New York: Jossey-Bass.
UAE National bureau of statistics. (2013). Air quality: average concentration of sulphur dioxide in UAE cities. Web.