An Overview Of Water Pollution
Water pollution refers to degradation of water quality as measured by biological, chemical, or physical criteria. This degradation is judged according to the intended use of the water, its departure from the norm, and public health or ecological impacts. From a public health or ecological point of view, a pollutant is any substance that, in excess, is known to be harmful to desirable living organisms. In fact, the primary water pollution problem facing billions of people today, especially in the third world, is the lack of clean drinking water that is free of disease-causing organisms or substances. The concentration at which a material becomes harmful to living things is the subject of toxicology.
The greatest water pollution problem in the world today is lack of disease-free drinking water for about 20 percent of the world’s population. Another 20 percent have poor sanitation conditions that favor waterborne diseases that kill about 2 million people a year. Most of the deaths are of children under the age of 5. Chemical pollution is also an emerging problem on a global scale that occurs almost everywhere where people live. Agricultural, industrial, and municipal processes release chemical pollutants whose long-term effects on the environment and human health are largely unknown.