The nationwide survey found that New York’s Hudson-Raritan Estuary had the highest overall concentrations of the chemicals, both in sediments and shellfish, but scientists with the National Oceanic and Atmospheric Administration found polybrominated diphenyl ethers, PBDEs, in all U.S. coastal waters.
These toxic chemicals are used as flame retardants in building materials, electronics, furnishings, motor vehicles, plastics, polyurethane foams and textiles.
The federal Agency for Toxic Substances says that the concentrations of PBDEs in human blood, breast milk, and body fat indicate that most Americans are exposed to low levels of PBDEs.
A growing body of research points to evidence that exposure to PBDEs may produce detrimental health effects in animals, including humans.
Toxicological studies indicate that liver, thyroid and neurobehavioral development may be impaired by exposure to PBDEs and they have been found to impair the immune systems of animals. These chemicals are known to pass from mother to infant in breast milk.
“This is a wake-up call for Americans concerned about the health of our coastal waters and their personal health,” said John Dunnigan, NOAA assistant administrator of the National Ocean Service.
“Scientific evidence strongly documents that these contaminants impact the food web and action is needed to reduce the threats posed to aquatic resources and human health,” he said.
Based on data from NOAA’s Mussel Watch Program, which has been monitoring coastal water contaminants for 24 years, the new findings are in contrast to analysis of samples as far back as 1996 that identified PBDEs in only a limited number of sites around the nation.
Individual sites with the highest PBDE measurements were found in shellfish taken from Anaheim Bay, California, and four sites in the Hudson-Raritan Estuary. This estuary, with its 650 miles of shoreline, hosts the Port of New York and New Jersey and is fed by waters from the Hudson, Hackensack, Passaic and Raritan Rivers, which drain major watersheds of New York and New Jersey.
High PBDE concentrations also were documented in the Southern California Bight, Puget Sound, the central and eastern Gulf of Mexico off the Tampa-St. Petersburg, Florida coast, and Lake Michigan waters near Chicago and Gary, Indiana.
PBDEs get into the environment from runoff and municipal waste incineration and sewage outflows, the report found. Other pathways include leaching from aging consumer products, land application of sewage sludge as bio-solids, industrial discharges and accidental spills.
The chemicals do not dissolve easily in water, but stick to particles and settle to the bottom of rivers or lakes.
Similar in chemical structure to polychlorinated biphenyls, or PCBs, the flame retardants have raised concerns among scientists and regulators that their impacts on human health will prove equally adverse.
PBDE production has been banned in a number of European and Asian countries. In the United States, production of most PBDE mixtures has been voluntarily discontinued.
The NOAA Mussel Watch survey found that the highest concentrations of PBDEs in the U.S. coastal zone were measured at industrial and urban locations. Still, the chemicals have been detected in remote places far from major sources, which NOAA says is evidence of atmospheric transport.
People may be exposed to PBDEs from eating foods or breathing air contaminated with the chemicals, according to the Agency for Toxic Substances.
Workers involved in the manufacture of PBDEs or products that contain PBDEs may be exposed to higher levels than usual. Occupational exposure also can occur in people who work in enclosed spaces where PBDE-containing products are repaired or recycled.
“We do not know whether PBDEs can cause cancer in humans,” says the Agency for Toxic Substances. “Rats and mice that ate food with decabromodiphenyl ether – one type of PBDE – throughout their lives, developed liver tumors. Based on this evidence, the EPA has classified decabromodiphenyl ether as a possible human carcinogen.” Environment News Service