Chlorinated Flame Retardant Travels The Globe

Zhiyong Xie

UBIQUITOUS Scientists aboard Germany’s Polarstern research ship found Dechlorane Plus in every air sample they collected between Greenland (shown here) and Antarctica.

In new research, Dechlorane Plus (DP), a widely used chlorinated flame retardant, emerges as a global pollutant.  Researchers from Germany's Helmholtz-Zentrum Geesthacht Institute of Coastal Research report detecting DP in every one of 20 air samples they collected during two cruises on the Atlantic Ocean between the Arctic and Antarctica (Environ. Sci. Technol., DOI: 10.1021/es103047n). 

Historically, DP was used in electrical connectors, commercial wire, and cables.  However, manufacturers may increasingly use it as a substitute for the brominated flame retardant decaBDE, which the European Union has banned in electronics and which American companies have agreed to phase out, says Axel Möller, a graduate student at the Institute of Coastal Research. More than 1 million pounds are manufactured each year of DP, which is long lasting and has raised concerns about human exposure.

Until now, the focus on DP in the environment has centered on the Great Lakes and China, where manufacturers of the chemical are located, says Ron Hites, distinguished professor of chemistry at Indiana University, Bloomington, who was first to detect DP in the atmosphere, in 2006 (Environ. Sci. Technol., DOI: 10.1021/es051911h). 

During research expeditions in 2008 and 2009, the German team captured samples using a high-volume air sampler aboard the Polarstern research ship.  Back on land, in a clean room, the scientists analyzed the air samples using gas chromatography and mass spectrometry. The researchers detected the highest concentrations, 4.2 picograms per cubic meter (pg/m³), at a site near Greenland. The lowest concentrations, 0.05 pg/m³, occurred at remote sites in the middle of the East Greenland Sea and the Southern Ocean near Antarctica.

The levels are much lower than those reported this year near a DP manufacturing plant near Huai'an, China. Led by Ed Sverko, of the organic analysis laboratory at Environment Canada's National Laboratory for Environmental Testing, researchers found air concentrations of up to 26,734 pg/m³ (Environ. Sci. Technol., DOI: 10.1021/es101224y).  Scientists have also detected DP in Canadian house dust, as well as in ocean water, freshwater sediments, sewage sludge, tree bark, Great Lakes fish, North American gull eggs, and European stork eggs.

The new work also provides "compelling evidence" that Western Europe is a major source of DP in the environment, says Gregg Tomy of Canada's Department of Fisheries and Oceans.  But DP is not manufactured in Europe. The new paper posits that the atmospheric DP comes from two sources in Europe: manufacturers that add the compound to goods as a flame retardant, and consumers that use and disposal of these products.  Sverko agrees the sources are plausible: DP could escape from them, he says, because it is not chemically bound to the products with which it is used.

The highly chlorinated flame retardant Dechlorane Plus consists of two stereoisomers.

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