California falcon eggs tainted with flame retardants

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SAN FRANCISCO -- The eggs of peregrine falcons living in California's big cities contain some of the highest levels ever found in wildlife of a flame retardant used in consumer products, a new study has found.Studies of peregrine falcon eggs and chicks by state scientists reveal that the birds hunting in San Francisco, Long Beach, Los Angeles and San Diego are ingesting the flame retardant called PBDEs, believed to leach out of foam mattresses, synthetic fabrics, plastic casings of televisions, electronics and other products. The research shows that the indoor chemicals can contaminate the outdoors and even humans.The predator birds feed on pigeons and other birds, which probably pick up the chemicals in the environment from sewage, landfills and runoff, scientists say. Humans can be exposed by inhaling household dust and absorbing the chemicals through the skin."Urban wildlife are the sentinel species that can tell us about chemicals of emerging concern that are coming from city exposures. Information from these species can be useful to us in protecting the sensitive members of our population like infants, children and pregnant women," said Kim Hooper, one of the leading research scientists with the California Environmental Protection Agency's Environmental Chemistry Laboratory.The work, which Hooper presented Thursday at the annual meeting of the Northern California Society of Environmental Toxicology and Chemistry at the University of California Berkeley, is part of the state's Wildlife Early Warning System supported by the California Department of Toxic Substances Control.The prevalence of PBDEs, or polybrominated diphenyl ethers, is raising worry among research scientists. The flame retardants are known as endocrine disrupters because they interfere with the function of the thyroid hormone, which is critical to the proper development of the brain and nervous system. Hooper is concerned that the levels of PBDEs in peregrine falcons are close to levels damaging developing neurological systems in lab rats and mice.Scientists compare the flame retardants to the notorious PCBs, or polychlorinated biphenyls, because of their potential for harming wildlife and humans, the persistence in the environment and the enormous amounts in commercial use. Three decades after PCBs were banned as insulators in transformers and capacitors, they are still found in San Francisco Bay, although their concentrations in birds and fish are diminishing as levels of PBDEs rise.Two years ago, California was the first state to ban two of the commercial mixtures of PBDEs -- octa and penta. State chemists Hooper and Myrto Petreas and their teams had found that women in Northern California had some of the world's highest PBDE levels in breast milk and tissue. Researchers also found that the flame retardants were contaminating the bay's harbor seals and seabirds, which feed on fish.A third mixture, called deca, is still in use and represents 70 percent of the PBDEs put into consumer products.State Assemblyman Mark Leno, D-San Francisco, has introduced a bill to ban all brominated and chlorinated flame retardants, a measure supported by environmental groups.The four major manufacturers of flame retardants -- Albemarle Corp. and Chemtura in the United States, Tosoh in Japan and Israeli Chemicals Ltd. -- oppose the legislation, as does the trade group Bromine Science and Environmental Forum.John Kyte, a forum spokesman in Washington, D.C., said the group maintains that deca is one of the most studied and effective chemical flame retardants available for electrical and electronic equipment and contributes to saving thousands of lives a year.One of the concerns over deca is that the amount in the environment is under-reported and might be more prevalent than is measured in the environment because it is unstable and breaks down to other forms of PBDEs.But the trade group's literature says the deca mixture is not a significant source of the wide array of PBDEs found in the environment.The state findings appear to contradict that argument. The state chemists found high deca levels when they measured the concentrations in peregrine falcons that live in California's big cities. Overall, the eggs from the birds in urban areas contained higher levels of PBDEs than eggs from coastal or inland regions.For information on PBDEs on the Web: www.epa.gov/oppt/pbdeE-mail Jane Kay at jkay(at)sfchronicle.com. (Distributed by Scripps Howard News Service, www.scrippsnews.com.)