ABSTRACT
Environmental pollution involves unfavorable alteration or addition of harmful substances to the environment. Pollutants include diverse inorganic and organic substances, sediments, radioactive substances, noise, and heat, which can contaminate our air, water, and soil. Major air pollutants include carbon monoxide, oxides of sulfur and nitrogen, hydrocarbons, tropospheric ozone, different heavy metals, and particulate matter of different size, some of which also react together to form photochemical smog. Exposure to these pollutants poses serious threat to public health. Aquatic ecosystems including rivers, lakes, and even the ocean face the threat of pollution from domestic or municipal wastewater, industrial, agricultural, radioactive, thermal, solid, and plastic wastes, and sediments. These wastes contain heavy metals, pesticides, various organic compounds including endocrine-disrupting chemicals, and other toxic substances, which also contaminate groundwater aquifers. Nitrate pollution of groundwater can cause methemoglobinemia to which infants are especially susceptible. However, groundwater in many parts of the world is also contaminated from natural sources of arsenic and fluoride, with widespread impact on public health. Oil and microplastic pollution of marine ecosystems, soil pollution, and problems of solid and medical waste are among the other contentious issues. Several case studies on pollution are presented in this chapter.
