Environmental News several animal species by population, says Shelby. blocking production of andro"We are comfortable with Phthalate metabolites in humans gen, and this mode of action what the panel concluded," Urinary MBP (a metabolite of DBP) distribution in a is relevant for humans, says Shelby explains. human reference population. The creatininePaul Foster, a reproductive U.S. plastics industry adjusted MBP levels in spot urine samples were toxicologist at the Chemical representatives say the new Industry Institute of Toxicology. plotted for 289 subjects from the Third National data do not affect the panHealth and Nutrition Examination Survey (NHANES el's conclusions because The CDC results come III). Ten subjects (predominantly women of reproonly the few highest levels just months after a panel of ductive age) had urinary MBP levels >300 u.g/g in the CDC study exceeded experts, appointed by the creatinine. previous estimates. Most of U.S. government, concluded the data are also below levin July that most phthalates els estimated by the U.S. pose a "low, minimal, or Agency for Toxic Substances negligible" risk to human and Disease Registry and health. Only for DEHP did other health advisory the panel conclude that Raymond pregnant women, infants, David a toxicologist advisand children could be excesing the American Chemistry sively exposed. Council The highest urine metabolite levels for DBP and BBzP Even the highest values found in the CDC study are in the CDC data are at, or 10- to 15-fold higher than the below, levels that EPA has range of values used by the determined safe for daily federal panel, says Brock, exposures to these phthawho leads the CDC research Source: Adapted from Environmental Health Perspectives. lates, David writes in a letteam. For DBP, these levels ter also published in the are about 300 times lower than October issue of Environmental Institute of Environmental doses that cause effects in rats, Health Perspectives. The new CDC Health Sciences' Center for the asserts Foster. "In public health, data and public comments will be Evaluation of Risks to Human incorporated into the final packReproduction, which commisusually like to see a bigger of phthalate documents that cushion of safety" he says sioned the federal panel report. the National Toxicology Program Nonetheless, the federal panel The panel knew of the CDC data, will make available to regulatory will not reconvene to consider which include highly exposed the new data, says Michael individuals and most likely repagencies in Januarv REBECCA Shelby, who heads the National resent a small percentage of the RENNER
Increasing levels of flame retardants found in North American environment Levels of polybrominated diphenyl ether (PBDE) fire retardants are increasing in the Canadian and U.S. environments, according to a host of new data presented at Dioxin 2000 in August. Researchers also presented fresh data on PBDE concentrations in humans. PBDE flame retardants reduce the fire risk in such products as computers, furniture, and automobiles. Environmental trends continue to implicate PBDEs as emerging persistent organic pollutants worldwide, according to academic and government scientists at the meeting. The human data are part of preliminary attempts to study PBDE levels in humans, which began in 1998, when Swedish researchers showed for the first time
that concentrations of PBDEs in human breast milk collected from mothers, although low, have doubled every five years over the past 25 years. At the same time, levels of other persistent organic pollutants, such as polychlorinated biphenyls and DDT, were decreasing. Increasing levels have been also found in animals in northern Europe, but until now, North American data have been limited, according to Mehran Alaee, a research scientist at Canada's National Water Research Institute. "We are seeing increasing trends everywhere [in Canada]; in gull eggs, seals, fish, and beluga whales," says Alaee, who notes that Canadian and U.S. levels have been rising since the 1980s.
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These increases may be due to higher production and use of PBDEs in the United States and Canada, in particular, penta-BDE mixtures, which are used in flexible polyurethane upholstery foam, says Ake Bergman, professor of chemistry at Stockholm University, Sweden. Bergman notes that the demand for pentaBDE in the Americas—mostly in the United States—is much higher than in Europe, according to 1999 estimates by the Bromine Science and Environmental Forum, an industry group based in Brussels, Belgium (see table). Although few data exist for the United States, results presented at the meeting suggest that PBDE levels in the environment are compa-
Government Watch policy adviser. But she also points
TABLE 1
out that environmental research
The global brominated fire retardant market
is expensive, and being able to take advantage of work other
The worldwide demand for brominated fire retardants in 1999 was about
countries have already conducted
204,000 metric tons. Compound
"leverages our efforts in terms of Americas
Europe
Asia
Total
21,600 3100 24,300 1375 8290
13,800 8900 7500 450 210
85,000 3900 23,000 2000 -
121,300 15,900 54,800 3825 8500
doing investigations." Likewise, if an agreement can be reached,
TBBPA HBCD Deca-BDE (DBDPO) Octa-BDE (OBDPO) Penta-BDE (PBDPO)
Source: Bromine Science and Environmental Forum, Brussels. Note: Units are given in metric tons.
rable to, or greater than, those found in northern Europe, according to Bergman. For die San Francisco Bay area, Jianwen She, from die California Department of Toxic Substances Control's Hazardous Materials Laboratory, reported concentrations in harbor seal blubber ranging from 50 ppb to 7 ppm, comparable to those found in harbor seals from the Dutch coast. Some of the highest levels of PBDEs ever reported were found recently in fish in Virginia [Environ. Sci. Technol. 2000, 34 (7)) 163A). This surprising result prompted the Virginia Department of Health in July to set a fish consumption advisory of 5 ppm for 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) in fish fillets, says Khizar Wasti, director of Virginia's division of health hazard control. BDE-47, a main ingredient of penta-PBDE mixtures, is the component found at highest concentrations in the biosphere. Some PBDE congeners are ubiquitous in the environment, and some congeners are persistent and bioaccumlative. Rat toxicity studies conducted over the past two to three years suggest they may compromise endocrine and hepatic system function. Restrictions on use are being considered in Europe (Environ. Scii Technol. 2000, 34 (9), 223A-226A)) Research presented at Dioxin 2000 also added further information about human exposures. Christa Schroter-Kermani and colleagues from Germany's Federal Environmental Agency in Berlin reported mat from 1985 to 1999,
median PBDE concentrations in German blood samples increased from 3075 to 4687 pg/g lipid. In Canada, pooled human breast milk samples from 1981 to 1982 and 1992 show a difference in PBDE of almost 2 orders of magnitude from 0.21 to 16.24 ug/kg milk lipid, according to Jake Ryan of Healtii Canada's Bureau of Chemical Safety. Ryan also found significant regional differences in 1992 samples of breast milk from a low of 2.57 ug/kg milk lipid for Ontario composite samples to a high of 19.08 for a composite sample from the Maritime Provinces. As a result of the Swedish data, die U.S. Centers for Disease Control and Prevention are developing PBDE analytical metiiods to monitor human blood levels, according to Donald Patterson witii CDC's toxicology branch. Patterson's preliminary analysis of human blood serum samples identified 13-14 different congeners at levels high enough to pursue a monitoring program. The new data are sketching a clearer picture of the environmental distribution of the lower PBDE congeners, such as BDE-47, according to Alaee. The next challenge is to improve analyses of higher congeners, particularly deca-BDE (BDE-209), which is produced in significantly higher volumes than penta-BDE, but whose high molecular weight makes difficult analysis using mass spectrometry analyses. "It will take 3-5 years for us to get a good handle on deca-BDE," he predicts. —REBECCA RENNER
countries can present a unified front when discussing issues with automakers, giving domestic industries less room to persuade a government to back off on issues of importance, she says.
Cross-border pollution talks heat up Canada announced in August that it would meet or exceed U.S. standards for pollutants that cause ground-level ozone. With this commitment, Canada plans to hold up its end of the bargain on the Ozone Annex to the 1991 Canada-United States Air Quality Agreement, a treaty the two countries are negotiating to cut transboundary air pollution (Environ. Sci. Technoll.000,34
((),
115A). Canada is prepared to set enforceable emissions reduction targets to ensure tangible action from the United States, according to David Anderson, Canada's environment minister. The United States responded with commitments to implement stringent N0X reductions for power plants and vehicles. The Ozone Annex will help the Canadian government, which ordinarily has no authority to set provincial air standards, to reinforce lax provincial air programs by writing enforceable goals into the treaty, says Jack Gibbons of the Ontario Clean Air Alliance, a nonprofit advocacy group. For example, the province of Ontario pledged this year to reduce emissions of ozone-forming l\IO x 45% by 2010, but this "goal is too little, too late, and with no regulations in place to achieve it, it's just rhetoric," Gibbons says. This new treaty commitment will Continued on Page e455
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