An oil spill is the unintentional release of a liquid petroleum hydrocarbon into the environment as a result of human activity. Oil can refer to many different 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. Most man-made oil pollution comes from land-based activity, but the term often refers to the release of oil into the ocean or coastal waters. Public attention and subsequent regulation has tended to focus mainly on seagoing oil tankers.
Petroleum-based hydrocarbons can negatively impact marine life and seabirds even at low concentrations. Oil that is denser than water settles on and penetrates the seabed, and it may take months or even years to clean up. Some methods to clean up an oil spill include the use of bioremediation, dispersants, dredging, and skimming.
The lighter fractions of oil, such as benzene and toluene, are highly toxic, but they are also volatile and evaporate quickly. Heavier components of crude oil, such as polynuclear aromatic hydrocarbons (PAHs) appear to cause the most damage. Although they are less toxic than the lighter volatiles, they persist in the environment much longer.
A heavy oil spill can also blanket estuaries and shoreline ecosystems, such as salt marshes and tidal pools, preventing gas exchange and blocking light. The oil can mix deeply into pebble, shingle, or sandy beaches, where it may remain for months or even years.
Seabirds are severely affected by spills, as the oil penetrates and opens up the structure of their plumage, reducing the insulating ability of their feathers, making the birds more vulnerable to temperature fluctuations and much less buoyant in the water. The oiled feathers also impairs the birds' ability to fly, 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. The limited foraging ability coupled with the ingestion of oil quickly leads to dehydration and metabolic imbalances. Most birds affected by an oil spill die in the absence of supportive human intervention.
Marine mammals exposed to oil spills are affected in many of the same ways as seabirds. Oil coats the fur of sea otters and seals, reducing the natural insulation ability of their fur, leading to body temperature fluctuations and hypothermia. Ingestion of the oil also causes dehydration, and impaired digestion.
Some equipment used for cleanup:
Some methods used for cleanup:
|Acid rain • Air Pollution Index • Air Quality Index • Atmospheric dispersion modeling • Chlorofluorocarbon • Global dimming • Global warming • Haze • Indoor air quality • Ozone depletion • Particulate • Smog • Roadway air dispersion|
|Eutrophication • Hypoxia • Marine pollution • Ocean acidification • Oil spill • Ship pollution • Surface runoff • Thermal pollution • Wastewater • Waterborne diseases • Water quality • Water stagnation|
|Bioremediation • Herbicide • Pesticide •Soil Guideline Values (SGVs)|
|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|
|Clean Air Act • Clean Water Act • Kyoto Protocol • Water Pollution Control Act • Environmental Protection Act 1990|
|DEFRA • Environmental Protection Agency • Global Atmosphere Watch • Greenpeace • National Ambient Air Quality Standards|
For an oil spill on water, one can calculate the total volume of oil by measuring the surface area of the spill and the average thickness of the film.
|Film Thickness||Quantity Spread|
|First trace of color||0.0000060||0.0001524||100||1.461|
|Bright bands of color||0.0000120||0.0003048||200||2.922|
|Colors begin to dull||0.0000400||0.0010160||666||9.731|
|Colors are much darker||0.0000800||0.0020320||1332||19.463|
|Spill / Tanker||Location||Date||*Tonnes of crude oil||Reference|
|Gulf War oil spill||Persian Gulf||January 23, 1991||136,000 - 1,500,000|||
|Ixtoc I oil well||Gulf of Mexico||June 3, 1979 - March 23, 1980||454,000 - 480,000|||
|Atlantic Empress / Aegean Captain||Trinidad and Tobago||July 19, 1979||287,000|||
|Fergana Valley||Uzbekistan||March 2, 1992||285,000|||
|Nowruz oil field||Persian Gulf||February 1983||260,000|||
|ABT Summer||700 nautical miles (1,300 km) off Angola||1991||260,000|||
|Castillo de Bellver||Saldanha Bay, South Africa||August 6, 1983||252,000|||
|Amoco Cadiz||Brittany, France||March 16, 1978||223,000|||
|Amoco Haven tanker disaster||Mediterranean Sea near Genoa, Italy||1991||144,000|||
|Odyssey||700 nautical miles (1,300 km) off Nova Scotia, Canada||1988||132,000|||
|Sea Star||Gulf of Oman||December 19, 1972||115,000|||
|Torrey Canyon||Scilly Isles, UK||March 18, 1967||80,000 - 119,000|||
|Irenes Serenade||Navarino Bay, Greece||1980||100,000|||
|Urquiola||A Coruña, Spain||May 12, 1976||100,000|||
One metric ton of crude oil is roughly equal to 308 US gallons, or 7.33 barrels.
All links retrieved February 14, 2015.
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