Government Watch International vehicle standards?
Human phthalate study changes exposure picture For the first time, U.S. Centers for Disease Control and Prevention (CDC) scientists have collected uncontaminated measurements of a biomarker for phthalate exposure in humans. The data raise questions about whether phthalates pose low or negligible risk to humans. Phthalates, produced in high volumes in the United States and in other countries, include some that can cause cancer or birth defects in laboratory animals. In a controversial move last year, European countries b a n n e d the use of phthalates in baby toys, because the chemicals can leach out of plastic {Environ. Sci. Technol. 2000 34 (1), 11A). Previous measurements of phthalates in humans have been plagued by contamination problems because phthalates are ubiquitous constituents of plastic laboratory equipment. The CDC scientists solved these problems by measuring phthalate monoester metabolites in h u m a n urine.
According to CDC analytical chemist John Brock, their results show that exposure to the two phthalates—diisononyl phthalate (DINP) and di(2-ethylhexyl) phthalate (DEHP)—that have received the most attention to date is small compared to exposure to three other phthalates—diethyl phthalate (DEP), dibutyl phthalate (DBB), and benzyl butyl phthalate (BBzP) that 3X6 3.11 used 3S solvents For the study, scientists analyzed urine samples of adults aged 20-60 for seven phthalate metabolites (see figure). The samples were randomly selected from participants in a U.S. health survey conducted from 1988 to 1994, the Third National Health and Nutrition Examination Survey (NHANES-III). The results were published in Environmental Health Perspectives (2000 708 (10), 979-982). Although DEP has "next to no toxicity", DBB and BBzP produce reproductive tract birth defects in
Controversial EU phthalate ban here to stay? The European Commission (EC) has again extended its "emergency" ban on six phthalate softeners used in children's toys for another three months through Dec. 5. The temporary ban took effect throughout the EU late last year {Environ. Sci. Technol. 2000, 34 (1), 11 A) following a rejection by the European Union's Scientific Committee for Toxicity, Ecotoxicity, and the Environment (CSTEE) of two validated migration tests that had been developed to detect how much phthalate leaches from polyvinyl chloride toys—such as teethers and rattles—into saliva. "The reasons that motivated [last year's] decision . . . and its prolongation . . . are still valid, and it is therefore necessary to maintain the prohibition", the EC writes in its September decision. A draft directive is under discusssion to permanently ban phthalates in toys for children under the age of three, as well as an extension of the ban on the use of all phthalates in toys that children of any age could put in their mouths. Meanwhile, work continues on validating a reliable migration test method, upon which migration limit regulations could be based, rather than an outright ban on phthalates. The CSTEE is examining three in vitro test methods that measure diisononyl phthalate—one of the most ubiquitous phthalates—migration from toys and child care articles. —K.C.
Following the implementation in late August of an international agreement to develop uniform standards for motor vehicles, countries will meet in Geneva this month to hammer out which existing national and international regulations to harmonize first. The agreement is called the World Forum for Harmonization of Vehicle Regulations and sits under the auspices of the United Nations Economic Commission for Europe. Signatories include the most important car-producing countries United States Japan Germany France United Kingdom Canada and Russia as well as the European Union Korea is likely to sign on within the next As it stands now, countries approach safety and environmental concerns from different points of view with different stringencies in different areas, says Jan Jerie, U.N. spokesperson. Countries are seeking to work out uniform test procedures and test cycles, so that such issues as exhaust emissions and fuel consumption can be compared worldwide. Emerging issues such as how to effectively test hybrid electric vehicles are also likely to be on the agenda at the Geneva meeting Although the agreement does not obligate countries to adopt new standards it does ask them to t a k e hp r u l e i
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The harmonization effort "is worth countless millions [of dollars saved] to industry," which would like nothing better than to have one test to put vehicles through before selling the cars anywhere in the world, says Jane Armstrong, a senior U.S. EPA Continued on Page 453A
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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-
Goverment 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*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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