Flame retardants take a vacation

Getting blood drawn may not be everyone’s idea of a vacation. Yet that’s just what some Swedish workers volunteered for. Researchers wanted to measure how bloodborne concentrations of polybrominated diphenyl ethers (PBDEs)–ubiquitous and potentially toxic flame retardants–changed during month-long respites from work. Other workers were tested in the workplace.

PBDEs escape from plastics, fabrics, and other materials (SN: 10/13/01, p. 238: Burned by Flame Retardants?). Potential health consequences are now being investigated (see “New PCBs?” in this week’s issue: New PCBs?). Kristina Jakobsson of Lund (Sweden) University Hospital and her coworkers focused on 11 PBDEs that show up frequently in human blood. The researchers reasoned that any drop in concentration during vacation was likely to have resulted from the absence of workplace exposures. Unchanged concentrations might reflect food and other nonoccupational sources. The researchers reported their results on 123 workers in late August at the Dioxin 2003 meeting in Boston.

All 11 PBDEs showed drops in blood concentration during the workers’ holidays. Blood concentrations of PBDEs fell faster as the size of the molecules increased. Values dropped 50 percent every 14 days for the largest PBDE, the 10-bromine BDE-209, Jakobsson reports. In contrast, her group calculated from the month long data collection that it would take nearly 2 years of vacation for concentrations of occupationally acquired 6-bromine BDE-153 to fall by half.

As expected, rubber workers who handle a powdered flame-retardant mix containing primarily the 10-bromine BDE-209 had concentrations of that chemical some 10 times as high as those in hospital cleaners or slaughterhouse workers. Jakobsson says she was “astonished,” however, that BDE-209 concentration in workers manufacturing rubber-coated electrical cable was 25 percent higher than that among the rubber workers. “Was it exposure to some fine rubber dust coming from wires as they were handled?” she wonders.

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