Water pollution is the contamination of water bodies, it affects plants and organisms living in these bodies of water; and, in almost all cases the effect is damaging either to individual species and populations, but also to the natural biological communities.
Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequatetreatment to remove harmful compounds.
Water pollution is a major problem in the global context. It has been suggested that it is the leading worldwide cause of deaths and diseases, and that it accounts for the deaths of more than 14,000 people daily. An estimated 700 million Indians have no access to a proper toilet, and 1,000 Indian children die of diarrhealsickness every day. Some 90% of China's cities suffer from some degree of water pollution, and nearly 500 million people lack access to safe drinking water. In addition to the acute problems of water pollution in developing countries, industrialized countries continue to struggle with pollution problems as well. In the most recent national report on water quality in the United States, 45 percentof assessed stream miles, 47 percent of assessed lake acres, and 32 percent of assessed bay and estuarine square miles were classified as polluted.
Water is typically referred to as polluted when it is impaired by anthropogenic contaminants and either does not support a human use, like serving as drinking water, and/or undergoes a marked shift in its ability to support its constituent bioticcommunities, such as fish. Natural phenomena such as volcanoes, algae blooms, storms, and earthquakes also cause major changes in water quality and the ecological status of water.
Water pollution can come from a number of different sources. If the pollution comes from a single source, such as an oil spill, it is called point-source pollution. If the pollution comes from many sources, it is callednonpoint-source pollution.
Most types of pollution affect the immediate area surrounding the source. Sometimes the pollution may affect the environment hundreds of miles away from the source, such as nuclear waste, this is called transboundary pollution.
Surface Water Pollution
These are the natural water resources of the Earth. These are found on the exterior of theEarth's crust, oceans, rivers and lakes.
Considerable amount of Earth's water is found in soil or under rock structures called aquifers. People use aquifers to obtain drinking water and build wells to access it. In case this water becomes polluted, it is called groundwater pollution. This is caused by pesticide contamination from the soil and this can infect the drinkingwater and lead to huge problems.
This is a natural form of water pollution caused by microorganisms. Most of these microorganims thrive in water and fish, land animals and humans to become ill. Microorganims like bacteria, viruses and protozoa cause serious diseases like cholera. In poor countries, there are no facilities to treat polluted water and hence the healthof people are affected.
Oxygen depletion Pollution
Microorganisms that thrive in water feed on biodegradable substances. When a lot of biodegradable material is mixed with water, the number of microorganims increase and utilize the available oxygen. This called oxygen depletion. As oxygen levels in water are depleted, harmless aerobic microorganisms die and anaerobic microorganims prosper.Some anaerobic microorganisms are harmful to people, environment and animals and they produce toxins like ammonia and sulfides.
These are necessary for plant growth and development. Most of these are found in wastewater and fertilizers. These can cause excess weed and algae growth if there are large concentrations in water. Drinking water and clog filters can be contaminated. The...