Abstract
Access to safe water for a healthy life is a major requirement for people in the world today. Water faces contamination from various sources of both microbial and chemical origin. Chemical contaminants include both metallic and non-metallic sources as well as organic and inorganic. Water is also contaminated by oil spills, sewage as well as wastes for industries and factories.
Such contamination affects human life by causing various diseases that include nervous systems infections and cancers. Reducing impact of chemical contaminants can be done using methods that are either chemical or mechanical. It is recommended that some methods of water disinfection should be used carefully. Treatment of water is imperative before consumption to ensure that the water is safe for drinking.
Introduction
Water safety for health is a key concern for all people in the world. One of the major requirements for a healthy life is an adequate supply of safe water for human consumption. Nonetheless, waterborne diseases remain a major cause of death globally and the most affected are children.
There are chemicals as well as biological sources of contamination in water. Microbial organisms including bacteria and fungi are the main biological causes of contamination in water while chemical contaminants include both metallic and non-metallic compounds that may be radioactive or not. This report pays particular attention to the chemical contaminants, their sources, effects on health and the potential remedy that can improve the safety of water thus improving health for both humans and animals.
Background
Definitions
World Health Organization (2012), defines health as ‘a state of complete mental, physical, and social wellbeing and not merely the absence of disease or infirmity’. Thus, a healthy being is expected to be of sound mind, physically fit and socially approvable. Although chemicals may contaminate water to unhealthy levels, the same chemicals if available in the right quantity are essential in human bodies.
Thus for water to be said to be of good quality ecologically, the Maximum Concentration Level must not be surpassed (US Environmental Protection Agency, 2012). The article indicates that Maximum Concentration Level (MCL) are concentrations of contaminants in water such that if the concentrations go beyond that limit, then the adverse effects that may result pose a risk that cannot be accepted.
Thus for water to be termed as safe, the MCL should be within the acceptable range. Such a range is not universal for all contaminants but each chemical has its own MCL. Nonetheless, research has revealed that although an individual contaminant may not reach its MCL, a combined effect of many contaminants may compromise the quality of water (US Environmental Protection Agency, 2012).
Water pollution
Water pollution can occur both on surface and underground water sources. In addition, bottled water may also be contaminated. However, the presence of contaminants in water does not always imply that the water is likely to cause any health concern issues (Portland Water Bureau, 2011).
In America, between 2004 and 2009, 316 water contaminants were found in the water supplied to the public. Of the contaminants, 97 were agriculture based, 204 were industrial, and factory discharges, 86 are from wastewater treatment and 42 are by products of disinfectants (Environmental Working Group, 2012).
Table 1: Selected chemical contaminants and their ranks in the order of significance found in the US Nationally with the number of states they affect.
Table Adapted from Drinking Water Database (2012).
Metal and non metals
Radionuclides
These contaminants are of a radioactive nature and originate from nuclides that emit alpha or better particles. The main source of these compounds in drinking water is erosions from natural deposits. The contaminants in this case are alpha particles, beta particles and photon emitter, Radium 226 and Radium 228 and uranium (US Environmental Protection Agency, 2012).
Nitrates measured as Nitrogen
Nitrates have the potential to promote microbial growth in water both algae and bacteria (Portland Water Bureau, 2011) such as cyan bacteria which is a toxin producing bacteria.
Chemical contaminants
By products of water treatment
Although the treatment of drinking water is aimed at removing microorganisms and in many case chemical contaminants, the process may in itself be a source of water contaminants (US Environmental Protection Agency, 2012). For instance, there may be formation of trihalomethanes and halo acetic acids because of reaction between chemical oxidants and naturally occurring substances. Trihalomethanes appear to be the only one of these by products that is routinely monitored. A 2010 consumer confidence report revealed that chlorination is a typical source of these contaminants in drinking water (Consumer confidence report, 2011).
Disinfectants
Chloramines, chlorine, and chlorine dioxide are chemicals that are usually used for disinfecting water to control microbes (US Environmental Protection Agency, 2012). However, they may also have effects on health.
Inorganic substances
Inorganic chemicals that may originate from erosion of natural deposits, agricultural wastes, corrosion of household plumbing systems, or industrial discharge are also potential contaminants in water. They include asbestos, arsenic, barium, beryllium, cadmium, copper, fluoride, lead, mercury, selenium, nitrates, and nitrites (US Environmental Protection Agency, 2012).
Industrial wastes
Another major source of contaminants in water is industrial wastes. These chemicals originate from various sources including chemical and agricultural factories discharge, runoff from herbicides, petroleum refineries discharge, and PVC pipes. These chemicals include benzene, endrin, xylene, glyphosphate, lindane, styrene, toluene, vinyl chloride among others (US Environmental Protection Agency, 2012).
Oil wastes
Oil waste products that end up in the ocean or in rivers have a variety of sources. Some of them are accidental while others are not. They are occasioned by continued and lackadaisical use of oil and its products. Wastes from factories and industries that enter the ocean untreated coupled with boating for recreation that is not regulated are the major sources of most oil wastes that enter the oceans (Water Encyclopaedia, 2012). The US Environmental Protection Agency (2012) has noted that “over four hundred thousand releases of petroleum-based fuels” have been confirmed from leakages of underground storage tanks.
Sewage
Before being disposed to either underground or surface waters, community wastewaters are treated. Wastewater may be from domestic or industrial sources. These water, irrespective of their sources; be it institutions, industries, households, factories and so on, they have various chemical character. Even after treatment, such wastewaters may still contain chemicals both of organic and inorganic nature including metal, nutrients, and non-metals (US Geological Survey, 2012).
Reducing impact of chemical contaminants
Mechanical methods
Physical methods of containing underground water contamination include using clay, cement, or steel.
Absorbent materials
To deal with chemical contamination due to radioactive material, the North Carolina University State has come up with a material to this effect. Products acquired from crustacean shells make the absorbent material. The absorbent material cannot only soak up the contaminants, but can also remove salt from seas water by absorption (Dickinson, 2011).
Activated Carbon filter
Activated carbons are particles of carbon, which are treated to improve their surface area to enable them to absorb more waste products (contaminants). It is usually effective in adsorbing organic compounds (Drinking Water Resources, 2012).
Granular activated carbon
In this case, water is passed through loose granules of activated carbon. These granules trap particulate matter, organic contaminants, unattractive tastes, and smell and remove chlorine water (Drinking Water Resources, 2012).
Solid Block Activated Carbon
Here, rather than granules, solid carbon block filters are used. The solid carbon reduces more contaminants that include pesticides, chlorine, and chlorine by products, parasitic cysts, and asbestos among others, compared to the above two. The solid carbon can also be modified to remove contaminants such as mercury, arsenic and lead among others. Some beneficial minerals such as calcium, potassium, and magnesium are not removed and thus the taste of the water is improved apart from gains in nutrient supply from the water (Drinking Water Resources, 2012).
Chemical methods
KDF filter
This entails use of a matrix of zinc /copper alloy in a process of electrochemical oxidation-reduction. It has a potential to remove chlorine, kill algae and fungi, remove hydrogen sulphide, iron. Lead, cadmium, mercury, arsenic and other inorganic compounds (Drinking Water Resources, 2012).
Activated alumina
Mainly, contaminated water is sanitized using granulated form of aluminum oxide (Consumer confidence report, 2011). By passing the contaminated water through a cartridge containing activated alumina, contaminants are removed completely (Consumer confidence report, 2011). Although it is an effective way to reduce levels of fluorine, arsenic and selenium, water from this kind of a treatment may have more bacteria counts than raw water (Drinking Water Resources, 2012).
Chlorination
Chlorination is a water treatment method that uses chlorine and its compound to remove disinfectants. It is the most widely used due to its cost effectiveness. It removes soluble iron, manganese, and hydrogen sulphide from water (US Environmental Protection Agency, 2012).
Types of diseases caused by water pollution
Disinfection by product (DBP) have been linked with cancers of the bladder, colon, rectum, colon as well as undesirable birth outcomes like spontaneous abortions, low birth weight, still births and congenital malformation (Consumer confidence report, 2011).
Disinfectants may cause eye and nose irritation, stomach discomfort, anemia and unprecedented nervous system effects (US Environmental Protection Agency, 2012). Inorganic substances such as barium causes blood pressure, beryllium causes lesions in the intestines, and cadmium may cause damage to the kidney. Others like Lead may lead to slowed intellectual as well as development with children having reduced concentration span (US Environmental Protection Agency, 2012).
Others like mercury have the potential of bio-accumulated in fish and later be consumed by humans where their effects are felt. The effects include damage to the nervous system and brains of human.
In cases where bioaccumulation is suspected to have reached unsafe levels of consumption by humans, governments issue fish consumption advisories to protect people from consuming contaminated fish (Pollution issues, 2012). The chemicals have various adverse effects on human and animal health that include risks of cancer, damage to the nervous system, liver and kidney problems, thyroid problems, and reproductive health issues.
Conclusion
Various chemicals including metal, non-metals, organic or inorganic substances contaminate water resource. The origin of these substances may be industries, factories, sewage and oil spills. The most mentioned source of water contamination is discharge from industrial wastes.
However, through treatment using various methods water can be made safe for human consumption. Chemical methods of reducing water contamination include chlorination and use of aluminum alloy. Mechanical methods include use of physical barriers and filters as discussed above.
Recommendations
Chlorination as a method of removing contaminant from water has revealed to have potentials of developing other by products, which may be harmful to human health. Thus, it should be sued as the process of last resort or else it should be combined with other methods to ensure no by products are formed.
As far as possible, wastewater should be treated thoroughly before being discharged into surface water. As such, there should be strict adherence by institutions, factories, and households to the policy relating to wastewater disposal.
Countries should be careful to keep testing fish to offer relevant measure when bioaccumulation of compounds such as mercury is noticed. Oils spills should also be kept to a minimum to avoid contaminating seas and oceans. This calls for more care while handling oil and oil products.
It is also necessary for consumers to keep testing their water for various chemicals often and comparing the levels with the recommended MCL. They should also ensure that their domestic water is treated to rid any contaminant that may be available.
There should be stricter guideline on chemicals whose effects take a long time to manifest. Such include radionuclide, lead, and mercury. Since they also have a bioaccumulation potential, they should be monitored regularly on both birds and other carriers.
Reference List
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Dickinson, B. (2011). New material strips radioactive contaminants from drinking water. Web.
Drinking Water Resources. (2012). Drinking Water Treatment Methods. Web.
Environmental Working Group. (2012). EWG Rated the Water Utilities. Web.
Pollution Issues. (2012). Water Pollution: Fresh water. Web.
Portland Water Bureau. (2011). 2011 Drinking water quality report. Web.
US Environmental Protection Agency. (2012). Drinking Water Contaminants. Web.
US Geological Survey. (2012). Toxic Subsatnces Hydrology Programe. Web.
Water Encyclopedia. (2012). Oil spills: impact on the Ocean. Web.
World Health Organization. (2012). Definition of Health. Web.