These are the short-term effects of an oil spill. In the long-term, toxic materials from oil can remain in the water and on the land for many years. They can build up in the food chain to lethal levels, and destroy or disrupt and area's ecosystem. Petroleum is used as a vehicle fuel, heating source for homes and industry, for electricity generation, and as a feedstock for the chemical industry. Because of the huge demand for oil, enormous quantities are moved from production areas to where the oil is used.
Oil is pumped from the ground, refined, transported and stored.
There are many steps in this process during which oil can spill from well heads, drill rigs, tankers, pipelines and storage tanks. Oil may leak from ocean-going ships during accidental and deliberate spills. Spills can happen on land or water when oil is incorrectly handled, there are railway or truck accidents, tankers or barges collide, the insides of tankers are washed, and when natural oil deposits seep. Sometimes when people change the oil in their cars, they dump the used, dirty oil on the ground or down the storm sewer. The rain carries the oil with the metals and particles from the car engine into streams and creeks.