Introduction
Water Pollution,
contamination of streams, lakes, underground water, bays, or
oceans by substances harmful to living things. Water is necessary
to life on earth. All organisms contain it; some live in it; some
drink it. Plants and animals require water that is moderately
pure, and they cannot survive if their water is loaded with toxic
chemicals or harmful microorganisms.
If severe, water pollution can kill large numbers of fish, birds, and
other animals, in some cases killing all members of a species in
an affected area. Pollution makes streams, lakes, and coastal
waters unpleasant to look at, to smell, and to swim in. Fish and
shellfish harvested from polluted waters may be unsafe to eat.
People who ingest polluted water can become ill, and, with
prolonged exposure, may develop cancers or bear children with
birth defects.