It’s no secret that mercury pollution in our environment is a global health problem. The U.S. Food and Drug Administration has warned women of childbearing age and children to limit the amount and types of fish they eat, due to mercury contamination.

Governments around the world have issued similar warnings. Most mercury ingested by humans comes from contaminated fish. The contaminant can cause serious health problems, especially in children. A U.S. Environmental Protection Agency scientist estimated that one in six pregnant women has enough mercury in her blood to pose risks, such as brain damage, to her developing baby. But while many people are familiar with the mercury pollution problem, one of its largest sources has long been overlooked.

The chlorine industry is one of the nation’s top mercury polluters, according to Poison Plants, a report issued by Oceana. Oceana is an international ocean conservation organization. A typical plant using 19th-century mercury-based technology to produce chlorine releases five times more mercury into the air than the average mercury-emitting power plant. Nine antiquated chlorine plants across the nation are the top mercury-to-air polluters in six of the seven states in which they currently operate.

These rankings, however, are based only on reported emissions, which may not tell the whole story. The actual story may be far more disturbing.

‘Lost’ mercury

Oceana’s analysis of industry and government data has shown that the chlorine industry could not account for more than 130 tons of mercury between 2000 and 2004, in addition to the 29 tons it admitted emitting. If that “lost” mercury was in fact released to the environment, the chlorine industry would rival coal-fired power plants as the nation’s top mercury emitter.

The situation could be easily remedied by using currently available technology. In fact, more than 90 percent of U.S. chlorine is already being made using mercury-free technology, but production by the remaining facilities is responsible for the reported release of literally tons of mercury every year. The tremendous amount of mercury pollution released by these nine chlorine plants is both unnecessary and preventable.

EPA gives a free pass

Other governments have recognized the dangers and taken action. The European Commission has required the complete phase-out of mercury use by chlorine factories by 2007. The story in America is not so positive. Although Congress amended the Clean Air Act years ago to require companies to continually improve in order to cut down releases of hazardous chemicals like mercury, the EPA has given chlorine plants a free pass, allowing them to continue to release tons of mercury into the air every year.

Ironically, despite the EPA’s repeated warnings to U.S. citizens about the dangers of mercury, the agency has done little to promote the necessary shift in technology among the six companies that operate mercury-polluting chlorine plants. Those companies are the Olin Corp., Occidental Chemicals Corp., PPG Industries, ASHTA Chemicals, ERCO Worldwide and Pioneer Companies, Inc.

Jacqueline Savitz is Seafood Contamination Campaign director for Oceana,