Water pollution is the contamination of streams, lakes, underground water, bays or oceans by substances harmful to any living thing. Water is a necessity to every living thing on Earth. Seventy-one percent of the Earth is covered by water, yet there is still not enough water to fulfill our needs. Only one percent of the water we have is fresh water, the other seventy percent is saltwater. The World Water Council claims that if we do not begin to conserve water now, we will not have any fresh water by the year 2025.
All organisms on earth contain water; some live in it; others need to drink it to survive. Plants and animals require water that is moderately pure, and they cannot survive if their water is loaded with toxic chemicals or harmful microorganisms. Some examples of toxic chemicals that pollute our waterways are: sodium, mercury, lead, dichlorodiphenyltrichloroethane (DDT), and polychlorinated biphenyls (PCB).
The affects in humans are: sodium is implicated in cardiovascular disease and nitrates in blood disorders, mercury and lead can cause nervous disorders, DDT is a toxic to humans and can alter chromosomes, PCB's cause liver and nerve damage, skin eruptions, vomiting, fever, diarrhea, and fetal abnormalities. Dysentery, salmonellas, cryptosporidium, and hepatitis are among the maladies transmitted by sewage in both drinking and bathing in water.
In the United States, beaches along the coasts, riverbanks and lakeshores have been ruined for bathers by industrial waste, municipal sewage and medical waste. Water pollution is an even greater problem in emerging countries. Millions of people are forced to obtain drinking water from contaminated streams and ponds. This type of contamination has been estimated to cause more than three million deaths annually. Most of the deaths are children. In severe cases water pollution can kill large numbers of fish, birds...