Brominated and mixed halogenated dioxins in the Balticsand beyond
LILLEMOR ASPLUND
wastewater containing PBDEsscan of TCDD equivalents (TEQs). No A paper recently published in ES&T generate these dioxins in the presofficial toxic equivalency factors (2009, DOI 10.1021/es901705r) sugence of sunlight. (TEFs) exist for assessing internationgests that a freshwater spongesand/ Areas where informal recycling of ally recognized TEQs for any PBDDs or its associated microorganismss electronics products takes place, or Br/Cl-DDs. However, the World found in the brackish Baltic Sea is such as Guiyu, China, are also exHealth Organization’s 2005 re-evalucontributing the relatively high pected to have very high concentraation of dioxin-like TEFs states that quantities of polybrominated tions of PBDDs and Br/Cl-DDs, says “if the presence of PBDDs is more dibenzo-p-dioxins (PBDDs) being Kevin Brigden, an analytical found in Baltic biota. Lillemchemist at the University of or Asplund of Stockholm Exeter’s Greenpeace Research University’s Department of Laboratories (U.K.). Although Applied Environmental Scino measurements have been ence and her coauthors bepublished of PBDDs or Br/Cllieve that the research DDs in biota from informal presents the first report of recycling centers, researchers mixed brominated/chlorihave documented what nated dibenzo-p-dioxins Brigden terms “exceedingly (Br/Cl-DDs or PXCDDs) in high” concentrations in soil “background” biota not from Guiyu, on the order of known to be exposed Researchers suspect that nutrient-driven increases in through anthropogenic the Baltic Sea’s filamentous algae may increase concen- milligrams per kilogram. This trations of brominated and mixed halogenated dioxins. suggests that the concentrasources. A growing body of tions of PBDDs and Br/Cl-DDs research suggests that both that could be taken up by extensively demonstrated, there naturally and anthropogenically biotasincluding humanssin these would be a need for assigning TEFs produced PBDDs and Br/Cl-DDs areas may be far higher than what to these compounds.” This docuare an emerging environmental the new paper has reported in the ment also contains a similar stateproblem. sponges, he says. He adds that few ment about Br/Cl-DDs. Although the toxicology of PBBr/Cl-DD analytical standards exist, In earlier work, Asplund, HaDDs and Br/Cl-DDs has been the although nearly 1000 of the congeglund, and colleagues assessed subject of much less study than ners have the same configuration as relative TEQs for the concentrathat of the chlorinated dioxins 2,3,7,8-TCDD. tions of PBDDs in Baltic eels, her(PCDDs), the research conducted Although Asplund and her colring, and perch used as food, some to date suggests that they will have leagues say that they need more reof which are already so contamicomparable toxicity. In addition to search to know for sure, they believe nated with PCDDs that they cannot the Ephydatia fluviatilis sponge, that there may be an anthropogenic be sold in Europe. The researchers Asplund and her colleagues have basis for the natural dioxins they determined that the PBDDs “occur documented that some Baltic biota, have been detecting. If they can conat levels which may cause consuch as blue mussels and algae, firm that the dioxins are produced cern.” They also raised the possibilhave PBDD concentrations that can by a microorganism associated with ity that the relatively high be thousands of times higher than the sponge, this will suggest that the concentrations of PBDDs could be the allowable concentrations of nitrogen and phosphorus from causing ecotoxicological problems 2,3,7,8-TCDD, the most toxic dioxin wastewatersboth of which are by impairing the viability of young known, in food. The PBDD concenknown to enhance the Baltic’s filaperch, pike, and salmon, which aptrations in these Baltic organisms mentous algae and seasonal cyanopear to be in decline along the are higher than the PCDD concenbacteria algal bloomsscould be southeastern Baltic coast. trations in any marine area in the partially responsible. In other words, Researchers also plan to look for EU, except known PCDD pollution at least some of the PBDDs and Br/ PBDDs and Br/Cl-DDs in Minnehot spots, such as near incineraCl-DDs may be generated as a secsota, says Bill Arnold, associate protors, pulp mills, and facilities that ondary effect of the increased fessor of civil engineering at the produce halogenated pesticides, says production of filamentous algae and University of Minnesota. Arnold is paper coauthor Peter Haglund, a cyanobacteria, Asplund says. the co-leader of a research team professor of environmental chemisthat documented that OH-PBDEs try at Umeå University (Sweden). —KELLYN BETTS in freshwaterswhich they believe The allowable amount of dioxin to be produced by treatment of in EU food is 4 picograms per gram 9 ENVIRONMENTAL SCIENCE & TECHNOLOGY / December 1, 2009
10.1021/es903237t
2009 American Chemical Society
8712
Published on Web 11/04/2009
