Oil spill
An oil spill is the release of a liquid petroleum hydrocarbon into the environment due to human activity, and is a form of pollution. The term often refers to marine oil spills, where oil is released into the ocean or coastal waters. The oil may be a variety of materials, including crude oil, refined petroleum products (such as gasoline or diesel fuel) or by-products, ships' bunkers, oily refuse or oil mixed in waste. Spills take months or even years to clean up.
Oil is also released into the environment from natural geologic seeps on the sea floor. [1] Most human-made oil pollution comes from land-based activity, but public attention and regulation has tended to focus most sharply on seagoing oil tankers. [2]
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Environmental effects
The oil penetrates and opens up the structure of the plumage of birds, reducing its insulating ability, and so making the birds more vulnerable to temperature fluctuations and much less buoyant in the water. It also impairs birds' flight abilities, making it difficult or impossible to forage and escape from predators. As they attempt to preen, birds typically ingest oil that coats their feathers, causing kidney damage, altered liver function, and digestive tract irritation. This and the limited foraging ability quickly causes dehydration and metabolic imbalances. Most birds affected by an oil spill die unless there is human intervention.[3][4]
Marine mammals exposed to oil spills are affected in similar ways as seabirds. Oil coats the fur of Sea otters and seals, reducing its insulation abilities and leading to body temperature fluctuations and hypothermia. Ingestion of the oil causes dehydration and impaired digestion.
Largest oil spills
| Spill / Tanker | Location | Date | *Tonnes of crude oil | Reference |
|---|---|---|---|---|
| Gulf War oil spill | Persian Gulf | January 23 1991 | 136,000 - 1,500,000 | [5][6] |
| Ixtoc I oil well | Gulf of Mexico | June 3 1979- March 23 1980 | 454,000 - 480,000 | [7] |
| Atlantic Empress / Aegean Captain | Trinidad and Tobago | July 19 1979 | 287,000 | [8] [9] |
| Fergana Valley | Uzbekistan | March 2 1992 | 285,000 | [6] |
| Nowruz oil field | Persian Gulf | February 1983 | 260,000 | [10] |
| ABT Summer | 700 nautical miles (1,300 km) off Angola | 1991 | 260,000 | [8] |
| Castillo de Bellver | Saldanha Bay, South Africa | August 6 1983 | 252,000 | [8] |
| Amoco Cadiz | Brittany, France | March 16 1978 | 223,000 | [8] [6] |
| Amoco Haven tanker disaster | Mediterranean Sea near Genoa, Italy | 1991 | 144,000 | [8] |
| Odyssey | 700 nautical miles (1,300 km) off Nova Scotia, Canada | 1988 | 132,000 | [8] |
| Sea Star | Gulf of Oman | December 19 1972 | 115,000 | [8] [6] |
| Torrey Canyon | Scilly Isles, UK | March 18 1967 | 80,000 - 119,000 | [8] [6] |
| Irenes Serenade | Navarino Bay, Greece | 1980 | 100,000 | [8] |
| Urquiola | A Coruña, Spain | May 12 1976 | 100,000 | [8] |
a One tonne of crude oil is roughly equal to 308 US gallons, or 7.33 barrels.
Estimating the volume of a spill
| Air pollution |
| Acid rain • Air Quality Index • Atmospheric dispersion modeling • Chlorofluorocarbon • Global dimming • Global distillation• Global warming • Indoor air quality • Ozone depletion • Particulate • Smog |
| Water pollution |
| Eutrophication • Hypoxia • Marine pollution • Marine debris • Ocean acidification • Oil spill • Ship pollution • Surface runoff • Thermal pollution • Wastewater • Waterborne diseases • Water quality • Water stagnation • |
| Soil contamination |
| Bioremediation • Electrical resistance heating • Herbicide • Pesticide • Soil Guideline Values (SGVs) |
| Radioactive contamination |
| Actinides in the environment • Environmental radioactivity • Fission product • Nuclear fallout • Plutonium in the environment • Radiation poisoning • Radium in the environment • Uranium in the environment |
| Other types of pollution |
| Invasive species • Light pollution • Noise pollution • Radio spectrum pollution • Visual pollution |
| Inter-government treaties |
| Montreal Protocol • Kyoto Protocol • CLRTAP • OSPAR • Stockholm Convention |
| Major organizations |
| DEFRA • EPA • Global Atmosphere Watch • EEA • Greenpeace • American Lung Association |
| Related topics |
| Environmental Science • Natural environment • Acid Rain Program |
By observing the thickness of the film of oil and its appearance on the surface of the water, it is possible to estimate the quantity of oil spilled. If the surface area of the spill is also known, the total volume of the oil can be calculated.[11]
Oil spill model systems are used by industry and government to assist in planning and emergency decision making. Of critical importance for the skill of the oil spill model prediction is the adequate description of the wind and current fields. There is a worldwide oil spill modelling (WOSM) program.[12]
| Film Thickness | Quantity Spread | |||
|---|---|---|---|---|
| Appearance | in | mm | gal/sq mi | L/ha |
| Barely visible | 0.0000015 | 0.0000380 | 25 | 0.370 |
| Silvery sheen | 0.0000030 | 0.0000760 | 50 | 0.730 |
| First trace of color | 0.0000060 | 0.0001500 | 100 | 1.500 |
| Bright bands of color | 0.0000120 | 0.0003000 | 200 | 2.900 |
| Colors begin to dull | 0.0000400 | 0.0010000 | 666 | 9.700 |
| Colors are much darker | 0.0000800 | 0.0020000 | 1332 | 19.500 |
Methods of cleaning
A sheen is usually dispersed (but not cleaned up) with detergents which makes oil settle to the bottom. Oils that are denser than water, such as Polychlorinated biphenyls (PCBs), can be more difficult to clean as they make the seabed toxic.
Methods for cleaning up include:
- Bioremediation: use of microorganisms[13] or biological agents[14] to break down or remove oil
- Controlled burning can effectively reduce the amount of oil in water, if done properly.[15] But it can only be done in low wind, and can cause air pollution.[16]
- Dispersants act as detergents, clustering around oil globules and allowing them to be carried away in the water.[17] This improves the surface aesthetically, and mobilizes the oil. Smaller oil droplets, scattered by currents, may cause less harm and may degrade more easily. But the dispersed oil droplets infiltrate into deeper water and can lethally contaminate coral. Recent research indicates that some dispersants are toxic to corals.[18]
- Watch and wait: in some cases, nautural attentuation of oil may be most appropriate, due to the invasive nature of facilitated methods of remediation, particularly in ecologically sensitive areas.
- Dredging: for oils dispersed with detergents and other oils denser than water.
- Skimming: Requires calm waters
- Solidifying
Equipment used includes[15]:
- Booms: large floating barriers that round up oil and lift the oil off the water
- Skimmers: skim the oil
- Sorbents: large sponges that absorb oil
- Chemical and biological agents: helps to break down the oil
- Vacuums: remove oil from beaches and water surface
- Shovels and other road equipments: typically used to clean up oil on beaches
Prevention
- Secondary containment - methods to prevent releases of oil or hydrocarbons into environment.
- Oil Spill Prevention Containment and Countermeasures (SPCC) program by the United States Environmental Protection Agency.
- Double hulling - build double hulls into vessels, which reduces the risk and severity of a spill in case of a collision or grounding. Existing single-hull vessels can also be rebuilt to have a double hull.
See also
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References
- ↑ http://seeps.geol.ucsb.edu/
- ↑ 16. Petroleum: Oil Spill
- ↑ Dunnet, G., Crisp, D., Conan, G., Bourne, W. (1982) "Oil Pollution and Seabird Populations [and Discussion]" Philosophical Transactions of the Royal Society of London. B 297(1087): 413–427
- ↑ Untold Seabird Mortality due to Marine Oil Pollution, Elements Online Environmental Magazine.
- ↑ George Draffan. "Major Oil Spills" (HTML). Endgame. Retrieved on 2007-07-29.
- ↑ 6.0 6.1 6.2 6.3 6.4 "History" (HTML). The Mariner Group.
- ↑ John S. Patton, Mark W. Rigler, Paul D. Boehm & David L. Fiest (1981-03-19). "Ixtoc 1 oil spill: flaking of surface mousse in the Gulf of Mexico" (HTML). NPG (Nature Publishing Group). Retrieved on 2007-07-29.
- ↑ 8.0 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 8.9 "Statistics" (HTML) (in English). ITOPF. Retrieved on 2007-07-29.
- ↑ "Atlantic Empress/Aegean Captain" (HTML). Cedre (2006-04). Retrieved on 2007-07-29.
- ↑ "Oil Spills and Disasters" (HTML). infoplease. infoplease. Retrieved on 2007-07-29.
- ↑ Metcalf & Eddy. Wastewater Engineering, Treatment and Reuse. 4th ed. New York: McGraw-Hill, 2003. 98.
- ↑ Anderson, E.L., E. Howlett, K. Jayko, V. Kolluru, M. Reed, and M. Spaulding. 1993. The worldwide oil spill model (WOSM): an overview. Pp. 627–646 in Proceedings of the 16th Arctic and Marine Oil Spill Program, Technical Seminar. Ottawa, Ontario: Environment Canada.
- ↑ http://www.enviroliteracy.org/article.php/540.html
- ↑ http://www.epa.gov/oilspill/ncp/bagents.htm
- ↑ 15.0 15.1 "Emergency Response: Responding to Oil Spills". Office of Response and Restoration. National Oceanic and Atmospheric Administration (2007-06-20).
- ↑ Oil Spills
- ↑ "Detergent and Oil Spills" (HTML). NEWTON BBS (2002-10-12). Retrieved on 2007-07-29.
- ↑ Barry, Carolyn (2007). Slick Death: Oil-spill treatment kills coral, Science News vol. 172, p. 67.
Further reading
- The World Almanac and Book of Facts, 2004
- Oil Spill Case Histories 1967-1991, NOAA/Hazardous Materials and Response Division, Seattle WA, 1992
- Nelson-Smith, Oil Pollution and Marine Ecology, Elek Scientific, London, 1972; Plenum, New York, 1973
External links
- www.cedre.fr Centre of Documentation, Research and Experimentation on Accidental Water Pollution
- SINTEF's research on oil spill and response
- International Petroleum Industry Environmental Conservation Association - online publications
- oil spill and environmental clean-up news
- International Tanker Owners Pollution Federation
- Newsweek's Black Tides Timeline
- Industrial pollution information from the Coastal Ocean Institute, Woods Hole Oceanographic Institution
- Oil spill prevention program