BP is now testing chemical dispersants in the vicinity of the deep-sea well that continues to spew more than 5,000 barrels of oil a day into the Gulf waters. The dispersants work just like dish soap does: they contain molecules that are attracted to oil at one end and to water at the other. The molecules break up the oil, reducing or eliminating its threat to shore-side aquatic life and beaches. BP plans to use the dispersants to cause the oil to sink to the sea floor, where bacteria can feast on it and distribute it harmlessly up the food chain.
The strategy, however, is not without its own risks. While the dispersant chemicals are low in toxicity, they expose more sea life to some contamination because they spread the oil over a larger area. Some environmental officials consider this tradeoff worthwhile because of the greater damage caused by oil slicks washing ashore. Oil that sinks to the sea floor is also likely to remain intact for a long time – up to thousands of years – before it is completely digested, though that time could be reduced somewhat if the oil is broken up into small enough clusters. Given the large amount of oil to be cleaned up, it is possible that using detergents to keep it off shore could end up destroying life on the sea floor instead.
BP and Environmental Protection Agency officials report that initial results from tests using about 3,000 gallons of dispersant injected into the well were promising, but Federal approval is needed before the strategy can be deployed on a large scale. The main dispersant being used is Corexit, a surfactant made by Nalco Company of Naperville, Ill. The company currently has more than 230,000 gallons of dispersant in stock and is making more. While Corexit is not toxic or carcinogenic, prolonged exposure to the chemical could cause eye, skin or respiratory inflammation in humans.
Time may be on BP’s side in this cleanup effort, as winds that threatened to blow the oil slick ashore have died down. The dispersant strategy is just one of several the company is using to try to keep the oil slick from washing ashore.
Written by Sandy Smith