Interview Hunting for persistent chemicals that might pollute the Arctic
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Spurred on by the 2001 Stockholm screens, Wania and Brown identiof the 23,000 chemicals on its DoConvention on Persistent Organic fied 4291 chemicals picked up by mestic Substances List, thereby Pollutants (POPs), which banned one or both methods, of which only becoming the first country to pri12 toxic substances, researchers 120 were high-production-volume oritize PBT chemicals. Environand regulators around the globe chemicals. Because the large proment Canada (EC) has identified have been trying to find quicker duction quantities increase the 2600 chemicals as medium-priand better ways to assess other exchemicals’ chances of traveling ority substances. Wania’s method isting chemicals for their risk to long distances, persisting in the encould help them look for potential human health and the environvironment, and accumulating in Arctic contaminants in that list, ment. Research published in says Mark Bonnell, senior ES&T (pp 5202–5209) offers science adviser at EC. “Ula new approach for a largetimately, chemical managescale assessment of the poment programs are interested tential of mass-produced in the potential for exposure chemicals to become POPs. and effects in the environIndustry produces more ment and humans,” says than 100,000 chemicals, yet Bonnell. “The advantage of few of these chemicals are this method is in its ability assessed for health risk, and to account not only for longeven fewer are regulated. range transport to remote reThe Stockholm Convention gions but also the potential required participating counfor deposition, uptake, and tries to review persistent, potential accumulation in Arctic ecosystems have become contaminated with POPs like PCBs, which are showing up at high levels in bioaccumulative, and toxic Arctic biota and humans.” (PBT) compounds and to add Arctic birds and mammals. The study could also new POPs to the convention. supplement existing moni“The issue of identifying POPs ecosystems, the authors settled on toring approaches, including the . . . has traditionally been done by these 120 as the most likely to pose U.S. Centers for Disease Control people going out and analyzing air, a risk to the Arctic environment. and Prevention’s National Biomonwater, polar bear livers, or seals or “It’s not that 120 are the final itoring Program, says Richard what have you,” says Donald Macword,” says Wania. “If you would Denison, senior scientist with the kay, the chemical fate and transvary certain aspects of our screenEnvironmental Defense Fund, an port pioneer at Trent University ing methods, you could end up environmental advocacy group. (Canada). “This is very much a hitwith a different number.” Because Almost all existing programs start or-miss, serendipitous approach.” of their reliance on top marine out by identifying chemicals that In recent years, however, the need predators like seals, whales, and are likely to pose a risk and then for a more comprehensive method walruses for food, people living in looking for them in people or in has grown, he says. the Arctic are especially vulnerparts of the environment, he says. In the study, Frank Wania and able to persistent organic contami“This [study] is flipping that on its his graduate student Trevor Brown nants, Wania adds. head and saying, ‘Well, it’s also imof the University of Toronto took The approach is “commendable” portant to know the full extent of two parallel approaches to screenand provides a “good shopping list” synthetic chemicals to which we ing 105,584 chemicals. They used of chemicals to watch out for, says may be exposed,’” he points out. the results of a global transport Mackay. Researchers and regula“The focus on just the Arctic model and a human bioaccumutors agree. “I think the paper will be here is limiting, because it cerlative model to determine which very important and will have a lot of tainly doesn’t address the concerns chemicals are likely to travel to the implications for the kind of screenabout the whole range of persistent Arctic and accumulate in the ening activity which we will see in the organic pollutants,” adds Denison. vironment and the food chain. By years to come,” says Geir Wing Ga“But it provides a useful way of subjecting the chemicals to a paralbrielsen, a toxicologist at the Northinking about how many chemilel screen for structural similarities wegian Polar Institute. cals . . . yet to be discovered in the to known Arctic contaminants and In September 2006, Canada Arctic may well be there [already].” by comparing the results of the two completed the initial assessments —RHITU CHATTERJEE 5034 ■ Environmental Science & Technology / July 15, 2008
© 2008 American Chemical Society
