Oil spill

Subsequent to an Oil Spill

An oil spill is the unintentional release of a liquid petroleum hydrocarbon into the environment as a result of human activity. The term often refers to marine oil spills, where oil is released into the ocean or coastal waters. 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. Spills take months or even years to clean up.

Oil is also released into the environment from natural geologic seeps on the sea floor. Most man-made oil pollution comes from land-based activity, but public attention and subsequent regulation has tended to focus most sharply on seagoing oil tankers.

Environmental effects

Studies of the Exxon Valdez oil spill have shown that the environmental damage caused by oil spills can be greater than was previously thought. Petroleum-based hydrocarbons can negatively impact marine life at concentrations as low as one part per billion. ^{[citation needed]}

Oiled birds

The lighter fractions of oil, such as benzene and toluene, are highly toxic, but are also volatile and evaporate quickly. ^{[citation needed]} Heavier components of crude oil, such as polynuclear aromatic hydrocarbons (PAHs) appear to cause the most damage; while 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. ^{[citation needed]} The oiled feathers 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. ^{[citation needed]} The limited foraging ability coupled with the ingestion of the oil quickly causes dehydration and metabolic imbalances. Most birds affected by an oil spill will die without 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, seals, reducing their furs natural insulation abilities, leading to body temperature fluctuations and hypothermia. Ingestion of the oil also causes dehydration, and impaired digestion.

Methods of cleaning an oil spill

A sheen can be dispersed (but not cleaned up) with detergents which makes oil settle to the bottom and makes the seabed toxic. It is very difficult to clean up oils denser than water as they settle to the bottom; PCBs are an example of such a pollutant.

Some of the equipment used in cleaning up include:

• Absorbent Boom, Sausage
• Containment Boom (except for gasoline where confinement can cause dangerous levels of fume buildup)^{[citation needed]}
• Skimmers
• Snares

Some of the methods used include:

• Bioremediation: use of biological agents to remove oil.
• Burning: It can be done only when it is not windy, the oil has not dispersed and there is a calm sea.
• Dispersants: Dispersants act as detergents, clustering around oil globules and allowing it to be carried away in the water. While this makes the surface look pretty, it only spreads the oil around. This can be a benefit since smaller oil droplets, scattered with currents, may cause less harm and may be easier to degrade. However, the dispersed oil droplets readily sink and can lethally contaminate coral. Moreover, recent research indicates that dispersants themselves are toxic to corals.
• Do nothing: Sometimes it is better to do nothing and let the oil evaporate or break down on its own than to make matters worse by attempting to clean up.^{[citation needed]} Cleanup by detergents pollutes the seabed. Shoreline cleanup can further disturb the ecology by bleaching all life from the area.
• Dredging: for oils dispersed with detergents and other oils denser than water.
• Skimming:It can't be done if there is a rough sea
• Solidifying ^{[citation needed]}

Spill Prevention

• Secondary Containment - methods to prevent releases of oil or hydrocarbons into environment.
• SPCC - Oil Spill Prevention Containment and Countermeasures program by US EPA.
• Double hulling - build double hull vessels and rebuild single hull vessels into double hull. A double hull reduces the risk and severity of a spill in case of a collision or grounding.

Estimating the volume of a spill

Pollution

Air pollution

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

Water pollution

Eutrophication • Hypoxia • Marine pollution • Ocean acidification • Oil spill • Ship pollution • Surface runoff • Thermal pollution • Wastewater • Waterborne diseases • Water quality • Water stagnation

Soil contamination

Bioremediation • 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

Government acts

Clean Air Act • Clean Water Act • Kyoto Protocol • Water Pollution Control Act • Environmental Protection Act 1990

Major organizations

DEFRA • Environmental Protection Agency • Global Atmosphere Watch • Greenpeace • National Ambient Air Quality Standards

Related topics

Natural environment

By observing the thickness of the film 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 known, the total volume of the oil can be calculated from this information.

	Film Thickness		Quantity Spread
Appearance	in	mm	gal/sq mi	L/ha
Barely visible	0.0000015	0.0000381	25	0.365
Silvery sheen	0.0000030	0.0000762	50	0.731
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

Largest oil spills

Volunteers cleaning up the aftermath of the Prestige oil spill.

Oil Spills of over 100,000 tonnes or 30 million US gallons, ordered by Tonnes^[a]

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 tonne of crude oil is roughly equal to 308 US gallons, or 7.33 barrels.

See also

• Hydrocarbon
• Oil
• Petroleum
• Pollution

References

ISBN links support NWE through referral fees

• Fingas, Mervin F., and Jennifer Charles. 2001. The Basics of Oil Spill Cleanup. Boca Raton, Fla: Lewis Publishers. ISBN 1566705371.

• Nelson-Smith, A. 1973. Oil Pollution and Marine Ecology. London, UK: Elek Scientific. ISBN 0236154117.

• Park, Ken ed. 2004. The World Almanac and Book of Facts. New York, NY: World Almanac. ISBN 0886879116.

• Reis, John C. 1996. Environmental Control in Petroleum Engineering. Houston, TX: Gulf Publ. ISBN 0884152731.

• Oil Spill Case Histories 1967-1991. NOAA/Hazardous Materials and Response Division. Retrieved December 7, 2007.

External links

• An educational website comprising texts, animations, diagrams, quizzes and video clips on oil spills. Retrieved December 7, 2007.
• www.cedre.fr Centre of Documentation, Research and Experimentation on Accidental Water Pollution. Retrieved December 7, 2007.
• International Tanker Owners Pollution Federation. Retrieved December 7, 2007.
• Newsweek's Black Tides Timeline. Retrieved December 7, 2007.
• How oil spill absorbent products Work. Retrieved December 7, 2007.
• Industrial pollution information from the Coastal Ocean Institute. Woods Hole Oceanographic Institution. Retrieved December 7, 2007.
• IncidentNews.gov - a NOAA site cataloguing major spills, April 14, 2005. Retrieved December 7, 2007.
• A Google map of the major oil spills since 1960. Retrieved December 7, 2007.
• Oil spill on Mississippi River after Hurricane Katrina. Retrieved December 7, 2007.
• 2000 Oil spill in Brazil. Retrieved December 7, 2007.
• Ashland oil spill in Floreffe, Pennsylvania in 1988 - considered one of the most severe inland oil spills in U.S. history. Retrieved December 7, 2007.
• Biodegradable Absorbents. Retrieved December 7, 2007.

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