1. News worthy : water pollution occurs when a body of water is adversely affected due to the addition of large amounts of materials to the water. The sources of water pollution are categorized as being a point source or a non-source point of pollution. Point sources of pollution occur when the polluting substance is emitted directly into the waterway. A pipe spewing toxic chemicals directly into a river is an example. A non-point source occurs when there is runoff of pollutants into a waterway, for instance when fertilizer from a field is carried into a stream by surface runoff. And did you know how many types of water pollution? types of water pollution devided into 3 parts there are toxic substance, organic substence and thermal pollution.
Reference : Mbgnet, water pollution, available at: http://www.mbgnet.net/fresh/pollute.htm accessed on: 27th of october 2011
2. Background : Toxic Substance A toxic substance is a chemical pollutant that is not a naturally occurring substance in aquatic ecosystems. The greatest contributors to toxic pollution are herbicides, pesticides and industrial compounds.Reference : Mbgnet, water pollution, available at: http://www.mbgnet.net/fresh/pollute.htm accessed on: 27th of october 2011
Organic Substance Organic pollution occurs when an excess of organic matter, such as manure or sewage, enters the water. When organic matter increases in a pond, the number of decomposers will increase. These decomposers grow rapidly and use a great deal of oxygen during their growth. This leads to a depletion of oxygen as the decomposition process occurs. A lack of oxygen can kill aquatic organisms. As the aquatic organisms die, they are broken down by decomposers which leads to further depletion of the oxygen levels. A type of organic pollution can occur when inorganic pollutants such as nitrogen and phosphates accumulate in aquatic ecosystems. High levels of these nutrients cause an overgrowth of plants and algae. As the plants and algae die, they become organic material in the water. The enormous decay of this plant matter, in turn, lowers the oxygen level. The process of rapid plant growth followed by increased activity by decomposers and a depletion of the oxygen level is called eutrophication. Thermal Pollution -- Thermal pollution can occur when water is used as a coolant near a power or industrial plant and then is returned to the aquatic environment at a higher temperature than it was originally. Thermal pollution can lead to a decrease in the dissolved oxygen level in the water while also increasing the biological demand of aquatic organisms for oxygen. oil pollution. Oceans can be polluted by oil on a daily basis from oil spills, routine shipping, run-offs and dumping. These are the fact about oil pollution:
Pollutants from industrial sources include:
Reference : Mbgnet, water pollution, available at: http://www.mbgnet.net/fresh/pollute.htm accessed on: 27th of october 2011
2. Background : Toxic Substance A toxic substance is a chemical pollutant that is not a naturally occurring substance in aquatic ecosystems. The greatest contributors to toxic pollution are herbicides, pesticides and industrial compounds.Reference : Mbgnet, water pollution, available at: http://www.mbgnet.net/fresh/pollute.htm accessed on: 27th of october 2011
Organic Substance Organic pollution occurs when an excess of organic matter, such as manure or sewage, enters the water. When organic matter increases in a pond, the number of decomposers will increase. These decomposers grow rapidly and use a great deal of oxygen during their growth. This leads to a depletion of oxygen as the decomposition process occurs. A lack of oxygen can kill aquatic organisms. As the aquatic organisms die, they are broken down by decomposers which leads to further depletion of the oxygen levels. A type of organic pollution can occur when inorganic pollutants such as nitrogen and phosphates accumulate in aquatic ecosystems. High levels of these nutrients cause an overgrowth of plants and algae. As the plants and algae die, they become organic material in the water. The enormous decay of this plant matter, in turn, lowers the oxygen level. The process of rapid plant growth followed by increased activity by decomposers and a depletion of the oxygen level is called eutrophication. Thermal Pollution -- Thermal pollution can occur when water is used as a coolant near a power or industrial plant and then is returned to the aquatic environment at a higher temperature than it was originally. Thermal pollution can lead to a decrease in the dissolved oxygen level in the water while also increasing the biological demand of aquatic organisms for oxygen. oil pollution. Oceans can be polluted by oil on a daily basis from oil spills, routine shipping, run-offs and dumping. These are the fact about oil pollution:
- Oil spills make up about 12% of the oil that enters the ocean. The rest come from shipping travel, drains and dumping.
- Oil spills cause a very localised problem but can be catastrophic to local marine wildlife such as fish, birds and sea otters.
- Oil cannot dissolve in water and forms a thick sludge in the water. This suffocates fish, gets caught in the feathers of marine birds stopping them from flying and blocks light from photosynthetic aquatic plants
Pollutants from industrial sources include:
- Asbestos – This pollutant is a serious health hazard and carcinogenic. Asbestos fibres can be inhaled and cause illnesses such as asbestosis, mesothelioma, lung cancer, intestinal cancer and liver cancer.
- Lead – This is a metallic element and can cause health and environmental problems. It is a non-biodegradable substance so is hard to clean up once the environment is contaminated. Lead is harmful to the health of many animals, including humans, as it can inhibit the action of bodily enzymes.
- Mercury – This is a metallic element and can cause health and environmental problems. It is a non-biodegradable substance so is hard to clean up once the environment is contaminated. Mercury is also harmful to animal health as it can cause illness through mercury poisoning.
- Nitrates – The increased use of fertilisers means that nitrates are more often being washed from the soil and into rivers and lakes. This can cause eutrophication, which can be very problematic to marine environments.
- Phosphates - The increased use of fertilisers means that phosphates are more often being washed from the soil and into rivers and lakes. This can cause eutrophication, which can be very problematic to marine environments.
- Sulphur – This is a non-metallic substance that is harmful for marine life.
- Petrochemicals – This is formed from gas or petrol and can be toxic to marine life.
- In the atmosphere, water particles mix with carbon dioxide sulphur dioxide and nitrogen oxides, this forms a weak acid.
- Air pollution means that water vapour absorbs more of these gases and becomes even more acidic.
- When it rains the water is polluted with these gases, this is called acid rain.
- When acid rain pollutes marine habitats such as rivers and lakes, aquatic life is harmed.
Reference : Water-pollution, the causes of water pollution, 2011, available at: http://www.water-pollution.org.uk/causes.html accesed on: 30th of october 2011
3. sources : The Environmental Protection Agency (EPA) has identified 582 highly toxic chemicals, which are produced, manufactured, and stored in locations across the United States. Reference : The free dictionary, water pollution, available at:http://legal-dictionary.thefreedictionary.com/Water+polution accessed on: 27th of october 2011
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