Mississippi River pours as much dispersant into the Gulf of Mexico as BP

Every day during the Deepwater Horizon oil disaster, contractors sprayed an average 140,000 pounds of Corexit dispersant onto oil slicks on the surface of the Gulf of Mexico and into the oil being released a mile below.

But what few in the public understood was that an equivalent amount of similar surfactant chemicals -- the active ingredient in Corexit and in household soaps and industrial solvents -- enters the Gulf each day from the Mississippi River, with more flowing in from other rivers and streams along the coast.
22
0
232Share

Surfactants are only one of a myriad of potentially harmful chemical substances delivered by the Mississippi and other rivers and streams to the Gulf each day, scientists say.

"We have abused the Gulf for years," said George Crozier, executive director of the Dauphin Island Sea Lab and associate professor of marine science at the University of South Alabama. "We have our own versions of the dead zone in Mobile Bay. The most famous is the Jubilee, which is certainly caused by nutrient-fed algae blooms and low-oxygen driven."

The surfactants in the Mississippi and other rivers are the ingredients in dishwasher detergent and industrial solvents that cause oils to disperse. They get into the Mississippi from the disposal of wastewater to sewage treatment plants and directly to the river.

According to a 1996 U.S. Geological Survey report, the median concentration of surfactants in the river was .05 parts per million. Based on the river's average flow rate, that would result in 140,000 pounds of surfactant entering the Gulf each day, said David Dzombak, director of the Steinbrenner Institute for Environmental Education and Research at Carnegie Mellon University and chairman of a National Research Council committee that authored a 2008 study of Mississippi River water quality.

Based on information released by federal officials Wednesday, an average of 140,000 pounds of dispersant a day has been used during the first 104 days of the spill.

The 2008 study Dzombak chaired, like many others, pointed at nutrients as the most obvious threats to the Gulf's ecological health, as evidenced by this week's announcement by Louisiana Marine Consortium Director Nancy Rabalais that this summer's annual low-oxygen dead zone created by those nutrients ranks among the largest ever, almost as large as the state of New Jersey.

During the past 20 years, however, researchers with the Geological Survey also have identified a variety of what they refer to as "emerging contaminants" that may also be harming organisms in the Gulf.

These include a long list of pharmaceutical and household chemicals, ingredients used to make plastics, and new herbicides and pesticides.

Former Tulane University chemical engineer Glen Boyd found that the river's water contained measurable amounts of estrogen compounds from birth control pills and of the aspirin substitute naproxen.

more from the Times Picayune