Why do PBDE levels vary widely? - Environmental Science

Concentration Distribution of PBDEs in House Dust on Si-Hwa Industrial ... Sjödin , Benjamin J. Apelberg , Frank R. Witter , Donald G. Patterson , Ro...
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Environmental▼News liter [µg/L] and 0.15 µg/L, respectively) significantly altered algal biomass yields. In contrast, tergitol, which has not been measured to date in the environment, at concentrations 1000-fold higher (200 µg/L) was found to lower the final yield of algae by 20% in both uncontaminated upstream and polluted downstream samples when compared with untreated cultures. However, the key finding was that all three compounds caused significant changes in the composition of the algal genera. Moreover, there were signs that prolonged exposure to triclosan and tergitol had already led some algae taken from

downstream of the WWTP to adapt to these pollutants. In a second experiment, Wilson collected algae only from the upstream site and grew them in the presence of varying concentrations of triclosan, ciprofloxacin, or tergitol. She found that biodiversity, as measured in the number of different genera, gradually declined with higher concentrations of each of these compounds. The results are significant because they mark the first time that the ecological impact of chemicals contained in personal care products have been measured quantitatively. Why these chemicals are chang-

ing the algal community isn’t yet known. Smith says that the compounds could be either directly toxic or selectively interfere with some aspect of the biochemistry such that certain algae can no longer compete effectively in the ecosystem. Smith next plans to place containers with the compound of interest directly in the river, allowing algal growth at ambient temperatures, nutrient concentrations, and solar conditions. “I worry that the loss of biodiversity in the [WWTP effluent] receiving waters may reduce the river’s resistance to other stressors and its resiliency,” says Smith. —ORI SCHIPPER

Why do PBDE levels vary widely? reported in Europe for workers in electronics recycling facilities. However, the PBDE levels recorded in the milk of 67 British women by a team led by Kevin Jones of the University of Lancaster ranged from less than 1 ppb to 69 ppb. More than half of the women in the study had levels of 6 ppb or above. LEONA KANASKIE

It is becoming increasingly clear that North American women are taking up high levels of a relatively new persistent organic pollutant (POP), polybrominated diphenyl ethers (PBDEs), and new data out of the United Kingdom show that women there are accumulating more than their peers on the continent. As the evidence grows, many scientists studying the issue are observing that some people are taking up far more of the flame retardant chemicals than others. The latest data come from England and three different areas of the United States: California, Indiana, and Texas. Arnold Schecter, a professor of environmental sciences at the University of Texas at Houston’s School of Public Health, revealed one of the largest collections of U.S. data amassed to date at the Society of Toxicology meeting in March. The PBDE levels Schecter found are “strikingly high compared to Europe,” he says. He analyzed 47 samples of milk from women in Texas and looked for 13 different PBDE compounds, or congeners. The samples contained anywhere from 6.2 to 419 parts per billion (ppb) of the PBDEs per gram of milk fat. In comparison, Bert van Bavel of Örebro University in Sweden reports that the lowest level in Schecter’s sample is equal to the highest levels

Researchers suspect that old furniture may be responsible for some people’s high levels of PBDEs.

The PBDE levels of North Americans are 10 times higher than the (non-U.K.) European levels, and some North Americans have levels 10 times higher than their peers, summarizes Linda Birnbaum, director of the Experimental Toxicology Division of the U.S. EPA’s National Health and Environmental Effects Research Laboratory, who says that the range of the data that


Schecter collected is roughly comparable with all of the data she has seen showing levels in North Americans (Environ. Sci. Technol. 2002, 36, 50A–52A). The European data also show that some individuals have significantly higher levels than their peers, van Bavel says. He routinely finds higher levels in 5% of the samples he analyzes from Sweden. The North American PBDE levels are notable for being orders of magnitude higher than human levels of dioxins in the parts-per-billion, rather than the parts-per-trillion levels, says Schecter, who has studied human exposure to dioxins. However, PBDE levels are generally an order of magnitude lower than those for polychlorinated biphenyls (PCBs), stresses Robert Hale, a professor in the Virginia Institute of Marine Science’s Department of Environmental & Aquatic Animal Health. The data on health effects from PBDEs are far from complete, but the chemicals are suspected endocrine disrupters, Birnbaum says. Rodent studies show that PBDEs may impair neurological functioning, and they appear to have additive effects with PCBs, she says. A new study out of Indiana University suggests that mothers may be transferring PBDEs to their babies in utero (Environ Health Perspect. 10.1289/ehp.6146). The researchers measured six different

the levels are “very similar.” One of the continuing mysteries surrounding the widely varying levels in humans is how these chemicals are taken up. Myrto Petreas, one of the California researchers who reported new data in March (Environ Health Perspect. 10.1289/ ehp.6220), speculates that diet cannot be the only source of PBDEs. Petreas suspects indoor dust. Previous reports have shown that levels of PBDEs in dust can be strikingly high, up to the parts-per-million level (Environ. Sci. Technol. 2001, 35, 274A–275A). The sources of PBDEs in dust include the flame retardants used in electronics products and in some polyurethane foam used as cushioning, says Hale. When the polyurethane foam in an old piece of furniture is exposed to the environment, it tends to crumble, he explains; this releases the PBDEs embedded within the foam. “Some people have nice, new furniture,” Hale points out. “Others are sitting on couches that are falling apart. When they vacuum, it re-suspends the material. If [someone is] chronically exposed to that, you can predict a spike in the[ir] blood level,” he says. —KELLYN BETTS

U.K. targets a 60% cut in CO2


In its much-anticipated plans for energy policy over the next 50 years, the United Kingdom has set an ambitious new goal of cutting CO2 emissions by 60% by 2050. In fact, Prime Minister Tony Blair says the European Union should spearhead a worldwide 60% reduction as part of a new international consensus to tackle climate change. For its part,

the British government plans to reach this target by expanding renewable energy and energy efficiency programs, but it has ruled out new nuclear power plants for now. Speaking at a United Nations Sustainable Development Commission conference in February, Blair set out the case for a worldwide 60% reduction. Calling climate change “unquestionably the most urgent environmental challenge”, he said that the international Kyoto Protocol was not radical enough. He stressed that technological development could help achieve low-carbon economies without causing economic damage, as feared by the U.S. government. The United Kingdom’s economy has grown by nearly 17%, and emissions have

News Briefs Warming could cool global markets Global warming will significantly impact financial markets as investors revalue companies based on their exposure to climate change risk, according to a survey of the 500 largest global companies by the U.K.-based Carbon Disclosure Project (CDP), a collaboration of 35 major institutional investors. Climate change would affect many sectors, including financial services and telecommunications, predicts the report, Carbon Finance and the Global Equity Market. The share price of heavy carbon emitters could fall by 40%, and those of banks could drop by 29% as they suffer economic losses from the natural disasters that are predicted to double every 10 years. The report can be found at www.cdproject.net.

Quantum jump for green energy technology Solar photovoltaics, wind turbines, and fuel cells will expand from a $9.5 billion market today to $89 billion by 2012, according to Clean Edge, Inc., a consulting firm. Clean Energy Trends 2003 predicts continued breakthroughs in producing hydrogen and it foresees that an increasing number of wind turbines and solar farms will reach 300 megawatts (MW). Japan and the European Union are investing most heavily in the green technologies, while the action in the United States has been mainly on the state and local levels, and the report suggests that the U.S. government’s lack of leadership will hurt its domestic green power industry. Large corporations are investing, despite the current economic downturn. To view a copy of the report, go to www.cleanedge.com.



PBDE congeners and found that the levels in 12 mothers ranged from 15 to 580 ppb per gram of fat in the blood, and the levels in their babies’ umbilical cords ranged from 14 to 460 ppb. Although researchers were looking for impacts on the thyroid, no such correlation between the PBDE levels and the infants’ thyroid levels was found. However, they say that their study shows that U.S. babies may be exposed to relatively high levels of PBDEs. Some PBDEs have been banned in Europe, and levels in countries where their use was already discontinued are dropping, which hints that the same could hold true in North America if the substances were banned, Schecter says. “Although the U.K. is subject to the same European Union bans, the U.K.’s fire regulations on the need for retardant treatments in furnishings, etc., were particularly stringent,” Jones notes. “The U.K. has also been a major manufacturer of PBDEs. Hence, the amounts ‘present in the U.K.’ are likely to be high, relative to other European countries.” He says that researchers in his lab have compared the level of PBDEs in the air with data collected by a group led by Ron Hites at Indiana University, and