Water safety and quality are essential to the development and well-being of people, but they are a source of danger to health in the event of pollution. Besides the risks posed by water containing microbes, many chemical pollutants present in water resulting from human activities can be dangerous to humans. The United States Environmental Protection Agency ( U.S. EPA) defines a pollutant as any physical, chemical, biological, or radioactive substance in water.
1-Sources of chemical contamination
Chemicals may be present in the water through disinfection processes, the release of chemicals to water sources resulting from industrial and livestock activity, and the distribution of system components. Human exposure to these compounds may occur through ingestion, inhalation, or skin contact. Research has shown that pollutants in water can affect human growth, fertility, and reproductive function. For example, exposure to water disinfection byproducts in drinking water can lead to abnormalities in heart development. In addition, exposure to bisphenol A (BPA) and phthalates is known to reduce fertility by prematurely activating primal follicles and changing levels of sex steroid hormones.
Pesticides have been detected in drinking water sources, and some are known to be toxic to reproduction. Exposure to some pesticides is associated with decreased sperm numbers and negative pregnancy results. Fluorine may also be found in drinking water. Studies have indicated that PFOA and PFOS are responsible for deteriorating sperm viability and fertility in humans. Previous studies have also unanimously agreed that chemical pollutants in surface water and drinking water worldwide could adversely affect children’s fertility and reproductive ability.
2. By-products of water disinfection
Water treatment with disinfectants such as chlorine significantly reduced water-borne illnesses and contributed to an increase in life expectancy. However, the interaction between disinfecting agents and organic or inorganic materials in source water can form compounds called water disinfection by-products (DBPs). DBP in drinking water has become a concern for human health because epidemiological studies have shown associations between exposure to DBP and an increased risk for cancer and reproduction problems.
3- Sources of exposure to DBPs
Various factors may affect the formation of DBPs in drinking water. The presence of organic material in the water source plays a significant role in forming these compounds. Organic matter in water consists primarily of molecules like fulvic, humic, carboxylic, and free amino acids. The chemical composition of the source water is also an essential factor regarding the formation of DPBs. For example, in areas with a high bromide or iodide content in the soil and water source, the prevalence of brominated or iodine DBPs tends to be higher than in less brominated or iodine regions.
Other essential components of DPB composition include the type and concentration of the disinfectant used in water treatment. For example, chlorine is better able to form DPB, especially halophytic acids, than chloramine, chlorine dioxide, or ozone. Many individuals are exposed to DPBs due to the widespread use of disinfectants and water treatment agents. The most common route of exposure is an intake of treated water, but other potential sources include food and beverages prepared with treated water. Inhalation and dermal absorption may also occur using showers, tubs, swimming pools, or hammams.
Established human pollutants certainly have adverse health effects for humans as these toxic substances have to act directly or indirectly on the reproductive system, impairing growth and fertility.