Steep drop in S.F. Bay chemicals
Reductions in toxic flame retardant hailed as ‘success story’ for birds, fish
Ten years after government regulations forced an industry phaseout of once common but toxic flame retardants, a new study of San Francisco Bay has shown a steep decline in the presence of the chemicals in the bay’s wildlife.
A decade ago, the chemicals known as PBDEs were recorded in the bay at higher pollution levels than anywhere else in the world, but state and federal curbs that began in California in 2003 have averted a hazard that could have damaged bay birds, shellfish and fish for years to come, the study researchers said.
“This is quite a success story,” said Rebecca Sutton, the study’s lead author and senior scientist at the San Francisco Estuary Institute, which tracks chemicals in the bay. “We tie these results directly to the phaseout.”
Researchers found that the shorebirds nesting on bay islands, mussels living in sloughs and fish swimming in estuary waters have shed much of the contamination detected
in the early 2000s.
“Monitoring of wildlife ... indicated a decline in PBDE levels for all San Francisco Bay organisms under study,” the authors said.
The findings were published Sunday in the journal Environmental Science and Technology.
Popular starting in 1970s
Widespread use of PBDEs began in the mid-1970s when manufacturers introduced them into the foams of sofas and mattresses and the plastics used in computer casings and televisions as a flame retardant. But research, first observed in laboratory animals, has shown that exposure to the chemicals can disrupt the endocrine system, leading to developmental problems.
Researchers more recently and consistently have found that higher PBDE levels in pregnant women were associated with lowered IQs, attentiondeficit disorder and hyperactivity in their children.
The flame retardants enter the environment when the products that contain them degrade, and people pick them up by ingesting the dust. The dust also gets swept into sewage and storm drain systems, which pour wastewater into the bay. Fish and mussels absorb the poisons and pass them on to other wildlife.
The bay, which receives runoff flows from vast lands reaching up through the Sacramento and San Joaquin valleys, is the feeding and resting place for millions of shorebirds during migrations between North and South America, and for harbor seals and salmon runs.
Wide-ranging study
According to the new study, the two forms of PBDE that California banned have declined steeply in bay life. The fish-eating Forster’s terns once had the highest concentrations of PBDEs found in any wildlife in the world, but the levels fell 80 percent between 2002 and 2012. Levels in mussels dropped up to 95 percent. The chemicals in the bay bottom fell by 30 percent. In shiner surfperch, a popular sport fish, the chemicals declined by nearly 50 percent between 2003 and 2009.
A third form of PBDE, which wasn’t phased out until last year in a nationwide agreement with manufacturers, remains unchanged on the bay bottom, the one place where it was commonly detected.
What makes the study valuable is that it covers the period before and after the 2003 California phaseout and encompasses a range of species as well as water and sediments, scientists say.
California was a “hot spot” of contamination. Its 1975 product flammability standard was driving manufacturers to add PBDEs as a cheaper way to meet the specifications.
They used penta in polyurethane foam for cushions and octa in thermoplastics in electronic office equipment, TVs, telephones and computer casings. Deca, the third form, was added to plastics in electronics, furniture and carpet and drapery backing.
“Those products were sold all over the country, and California’s rule became the default rule,” said Carol Kraege, a manager at the Washington Department of Ecology.
In 2012, the Brown administration called for a new California flammability standard that wouldn’t require the use of flame retardants to meet safety requirements in furniture and some baby products. The standard went into effect this year. In January, a new law will require labeling the presence of flame retardants in upholstered furniture.
State got ball rolling
California’s 2003 legislative decision to phase out penta and octa set the stage for other states to act. The U.S. Environmental Protection Agency immediately pressured manufacturers to stop production, and restricted further use. But industry representatives, over the objections of environmental groups, successfully lobbied to exclude from the ban deca, the PBDE used in the greatest volume.
At first, scientists were cautious about attributing the decline of PBDEs directly to the regulatory actions of the past, said Myrto Petreas, chief of the Environmental Chemistry Branch of the California Department of Toxic Substances Control. She led the research 15 years ago that discovered that Bay Area women carried body concentrations of PBDEs about 10 times higher than women in Europe. The alarming finding led to international concern that the chemicals’ prevalence in the consumer products of everyday life could pose the same human health and ecological risks as harmful PCBs, DDT and dioxins, all now banned.
But this new bay study, along with separate studies on household dust as well as on women’s blood taken at San Francisco General Hospital, confirms the downward trend since the phaseout, Petreas said.
“The ban works. Manufacturers are not using PBDEs,” said Petreas, who did not participate in the study.
Industry representatives, who argued at the time of the 2003 California ban that the presence of the chemicals doesn’t mean they’re causing harm, agreed.
“It is expected that the levels of these substances would drop in biomonitoring studies,” after penta and octa were removed from the marketplace in the mid-2000s, said Bryan Goodman, spokesman for the American Chemistry Council.
New products in works
Manufacturers continue to innovate by bringing in new materials as flame retardants, and the EPA has the authority to review these chemicals, he said.
A ban alone is not always useful, said Arlene Blum, executive director of the Green Science Policy Institute in Berkeley, who worked to change the state’s flammability standard. “Industry wants to find another chemical as similar as possible. That leads to regrettable substitutions.”
New sampling of children’s products, indoor dust and humans indicates that manufacturers have replaced PBDEs with unregulated chlorinated tris, which has its own health risks, she said.
But changing the flammability standard will have a beneficial effect, said Mark Fellin, spokesman for the Juvenile Products Manufacturers Association.
“New products being assembled don’t have those chemicals,” Fellin said. “Consumers don’t want them.” Jane Kay is a freelance writer who specializes in environmental issues.