Thermal pollution is the degradation of water by any process that changes water temperature. It is usually associated with increases in water temperature as a result of the discharge of heated water from industrial processes. Increases in water temperature also tend to occur in water bodies where shading vegetation along the banks is scarce or where sediments have made the water more turbid; both allow more energy from the sun to be absorbed by the water, therefore increasing its temperature.
Examples of thermal pollution come from both point and non-point sources. Point source examples of thermal heat are the burning of wood in a fire place or the conversion of heat energy to mechanical energy by use of a heat engine (steam engine, turbine, internal combustion engine).
Internal combustion engine.
A non-point example of thermal pollution is when the waste heat from electrical generating stations is transferred to cooling water obtained from local bodies of water, like at The San Onofre Nuclear Generating Station, where they use 2,400 million gallons per day of ocean water, and after the process a rise of approximately 2 degrees Fahrenheit is noted in the water.
To detect this category of pollution, thermometers are used to test the expected rise in temperature of the water. Also, thermal infrared imaging is utilized by means of satellite or overhead imaging systems.
The effects of thermal pollution are primarily thermal shock, changes in dissolved oxygen, and the redistribution of organisms in the local community. Since water can absorb thermal energy with only small changes in temperature, most organisms that live in the water have developed systems that only operate in a specific range of temperature (stenothermic organisms). These organisms can be killed with any sudden increase in temperature. Also, cold water carries more oxygen than warm water and therefore with the increase of temperature comes a decrease of oxygen in the water.
To remedy this type of pollution in lakes and the ocean, cool water must be diluted through diffuser systems. For smaller rivers, cooling towers have been proven effective to reduce the temperature of water.
Thermal pollution doesn't always affect humans.
Physical pollution is the introduction of harmful substances or forces in the environment through, for example, vibration, thermal alteration or electromagnetic radiation. Some examples are point source: dust, fires, humidity, whereas some are non-point source: radiation, mechanical stress, sound pollution, and electrical storms.
Chemical pollution occurs when compounds are left or disposed of in the environment. All chemical pollution is caused by humans- from either attempting to carry large amounts of oil across the ocean which may result in a leak or by purposely dumping chemicals such as Yanohydrin, Carbon Disulphide, Cresols, Naphthalene, Tetraethyl lead, Acrylonitrile, Carbon Tetrachloride, Ethylene Dichloride and Phenolbenzene, Styrene, Toluene, Xylene, Acetone, Phhosphoric acid and Tallow into the water. Said examples are point source methods of pollution. Non point source methods of chemical pollution are when pesticides from farms or oil from automobiles runs off and seeps into the groundwater.
The effects of chemical pollution are widespread and generally very harmful. If severely dangerous chemicals are introduced to the water, they have an immediate effect, generally rendering fish and similar organisms dead. In lower-level contamination, chemical pollution has subtler effects that are harder to notice.
Naturally, different chemicals have different effects on the ecosystem. For example, pesticides like DDT have been known to affect eagles by deteriorating the sufficient amount of calcium that a mother needs to produce strong egg shells. For humans, pesticides have many health risks. They can affect and damage the nervous system, cause liver damage, damage DNA and cause cancer, and cause reproductive and endocrine damage.
Another example of chemical pollution is that by oil and petroleum. When introduced to the water, some components of oil are degraded and dispersed, but some persist for years in shallow waters. Oil can adversely affect the ecology of an aquatic habitat and the physiology of marine animals, as well as be generally toxic to marine organisms at concentrations in the low parts-per-billion range. "Chronic exposure to PAHs (polycyclic aromatic hydrocarbons) can affect development of marine organisms, increase susceptibility to disease, and jeopardize normal reproductive cycles in many marine species." For humans,
some components of oil can cause gastrointestinal problems, kidney and liver damage, and adverse nervous system effects.
An especially detrimental chemical pollutant is mercury. Mercury gets into the water mainly by air pollution from coal-fired plants where it is then converted from elemental mercury to methylmercury by certain bacteria which are then eaten by small fish which are in turn eaten by bigger fish which are finally eaten by humans. Some health risks of mercury ingestion are central nervous system effects like Parkinson's disease, MS, and Alzheimer's disease; heart disease; and death or irreversible damage to the brain.
To avoid chemical pollution, carelessness must be ceased. Also, more precautions regarding the transfer of chemicals must be taken. Chemical pollution can be reduced or eliminated by legislation requiring that industries take heed to prevent chemicals from entering the water.
Chemical pollution affects environmental factors by disrupting ecosystems. In American culture, most people feel that corporations such as BP are essentially evil for their recent oil spill and subsequent harm of plant and animal life. Chemical pollution has therefore increased the awareness of people regarding pollution in general.
Biological pollution is the disturbance of an ecosystem by the accidental or deliberate introduction of a foreign organism, plant, or animal species into the environment. Generally, biological pollution refers to the entrance of alien species into the water. Invasive species occur for a number of reasons. Namely, invasive species possess specific traits that allow them to outcompete native species (the ability to reproduce both asexually as well as sexually, fast growth, rapid reproduction, high dispersal ability, phenotypic plasticity, tolerance of a wide range of environmental conditions, ability to live off a wide range of food types, association with humans).
Some examples of biological pollution are Bacopa mannien, amethyst gem clam, and the European green crab.
The introduction of the above stated, and other, species comes about by human activity. When land clearing and human habitation put pressure on local species, invasive species take the opportunity to move in. This severely disrupts the ecosystem in a number of ways. For example, the Bacopa mannien plant quickly covers surface mud, making it unsuitable for feeding birds in refuges.
Genetic pollution is uncontrolled hybridization and introgression which leads to homogenization or replacement of local genotypes as a result of either a numerical or fitness advantage of the introduced species. It can result in extinction by introducing rare species to abundant ones and having the abundant ones take over the rare ones.
To prevent biological pollution, species must not be carelessly introduced to ecosystems.
Biological pollution doesn't have an adverse affect on human health and therefore it doesn't affect cultural beliefs or socioeconomics.
Works Cited
" Google Image Result for http://www.scienceclarified.com/images/uesc_04_img0177.jpg." Google. N.p., n.d. Web. 8 June 2010.
"Biological Pollution: An Emerging Global Menace." CPL Press Online Bookshop. N.p., n.d. Web. 8 June 2010.
"Pollution Effects." Rainforests, Rainforest Animals, Other Environmental Issues And Practical Environmental Solutions . N.p., n.d. Web. 8 June 2010.
"Thermal Pollution - water, effects, environmental, United States, types, impact, industrial, wells, power, sources, use, Sources, Environmental Effects, Abatement." Pollution Issues. N.p., n.d. Web. 8 June 2010.
email. "Water Pollution Effects." Clean Funny Cartoons / Environmental Issues ... on Grinning Planet. N.p., n.d. Web. 8 June 2010.
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