It is well known that mercury is one of the most persistent, widespread, and dangerous of environmental pollutants. Exposure to this powerful toxin affects the senses, the brain, spinal cord, kidneys and liver. It causes an elevated risk of birth defects, making it particularly harmful to children and pregnant women. Until now, concerns about mercury contamination have focused largely on freshwater lakes, rivers, and streams. Our state of Maine is among 40 where mercury advisories warn pregnant women and young children to limit consumption of fish caught in these waters. In addition, mercury levels in Maine freshwater fish and the wildlife that feeds on them, such as loons and eagles, are among the highest in North America.
New research reveals that the threat of mercury contamination is even more widespread. I recently attended a presentation by the Biodiversity Research Institute of Gorham and the U.S. Fish and Wildlife Service in which findings were released showing elevated mercury levels in an insect-eating songbird that inhabits saltwater marshes in New England’s estuaries and national wildlife refuges.
This songbird – the saltmarsh sharp-tailed sparrow — is listed by the Fish and Wildlife Service as a “species of conservation concern,” and BRI scientists found evidence that fewer chicks survive in birds with higher mercury levels. This sparrow is an important indicator species for examining the impacts of mercury because approximately 95 percent of the global population breeds in the Northeast. This groundbreaking study was conducted at 11 sites in four New England states, including the Rachel Carson National Wildlife Refuge here in Maine.
This research demonstrates that mercury contamination is not limited to freshwater lakes or to species that eat fish. As Dr. David Evers, executive director of BRI and a co-author of the study, stated at the presentation, these findings “prompt the question of whether setting aside land as ‘refuges’ goes far enough to protect sensitive wildlife given that pollution doesn’t respect boundary lines.”
Pollution does not respect boundary lines for songbirds, or for people. Each new scientific study seems to find higher levels of mercury in more ecosystems and in more species than we had previously thought.
During my service in the Senate, I have made reducing this threat to our people and our wildlife one of my high priorities. In 2002, the Senate unanimously passed my legislation to ban the sale of mercury fever
thermometers, the source of some 17 tons of mercury to solid waste every year. In 2005, I led the fight to overturn a flawed Environmental Protection Agency regulation that allows coal-fired power plants – the single largest source of mercury pollution – to continue to emit unsafe levels of this toxin into the environment.
That flawed regulation was the result of flawed science. Many experts, including the EPA Inspector General, sharply criticized the science underlying the new regulation and recommended that EPA develop and implement a mercury monitoring plan. That was a major reason why this spring I introduced the Comprehensive National Mercury Monitoring Act.
This bipartisan legislation would establish mercury monitoring sites across the nation to measure mercury levels in the air, rain, soil, lakes and streams, and in plants and animals. It would fund research to form the scientific basis for a new mercury rule which adequately protects human health and environment. We must have more comprehensive information and we must have it soon; otherwise, we risk making misguided policy decisions.
The fish, loons, and eagles of our freshwaters are precious, as are the songbirds of our saltwater marshes. Most precious of all are the 600,000 American children born each year with unsafe levels of mercury in their blood. This important new research makes it clear that mercury contamination threatens the entire ecosystem. The legislation I have introduced will help provide the knowledge needed to address this threat, and to protect our wildlife and our people.
