BUSPH Researchers Link Dust on Office Surfaces with Workers' Exposure to Banned Flame Retardants
Flame retardants now banned internationally as organic pollutants are widespread in Boston offices, and the chemicals’ concentrations in office dust are linked to traces found on workers’ hands and in their blood, a new BU School of Public Health study has found.
The authors of the study, published online June 30 in the journal Environmental Health Perspectives, found that the amount of polybrominated diphenyl ethers (PBDEs) on workers’ hands was a good predictor of how much was measured in their blood. Further, frequent hand-washing was found to reduce exposure to certain PBDEs, flame retardants that have been widely used over the past few decades.
While PBDEs have been the subject of a number of studies, this is the first peer-reviewed research to correlate levels of the chemicals on people’s hands to concentrations in their blood, said lead author Deborah Watkins, a Ph.D. candidate in BUSPH’s Department of Environmental Health.
In the study, PBDEs were detected in all 31 Boston offices that the research team tested. Certain PBDEs have been banned by the Stockholm Convention on Persistent Organic Pollutants, but because of slow turnover of products and the long half-life of PBDEs in the environment, human exposure to the compounds will continue for many years, the authors noted.
PBDEs were once widely used in computers and other electronics, as well as the polyurethane foam padding in office chairs, furniture and carpeting, so the chemicals are likely to be found in offices throughout the U.S. In recent years, epidemiologic studies have linked exposure to constituents of the PBDE formulation penta-BDE, which was used in polyurethane foam, with changes in people’s thyroid hormones, impaired fertility in women, lowered levels of testosterone in men, neuro-developmental deficits in children, and undescended testicles in babies.
U.S. manufacturers voluntarily discontinued production of penta-BDE and another PBDE formulation, known as octa-BDE, at the end of 2004. These formulations also are banned in the European Union. Manufacturers of a third formulation, deca-BDE, have agreed to discontinue production by the end of 2013.
Although scientists don’t know exactly how people accumulate PBDEs in their bodies, hand-to-mouth exposure is thought to play a significant role. In this study, workers who reported washing their hands with soap and water four or more times per day tended to have lower levels of penta-PBDEs on their hands than those who washed their hands less often. They also had, on average, three times lower concentrations of penta-PBDEs in their blood.
“This suggests that people’s hands play a key role in how they are exposed to PBDEs,” Watkins said. “This could be through hand-to-mouth behaviors such as eating oily food without washing your hands, or because the PBDEs are absorbed into the blood from the skin.”
Whatever the source, Watkins stressed that “good old-fashioned soap and water may be needed to remove the PBDEs.” The authors did not study whether use of alcohol-based hand sanitizers also was linked to lower hand levels of the compounds.
The concentrations of the PBDEs in the tested office dust varied dramatically, which Watkins said is consistent with other studies.
The authors did not investigate the sources of the PBDEs they detected, but Watkins noted that even offices in a new building with brand-new furniture had compounds associated with PBDEs in their dust. The 31 offices tested in the study, each housing one worker, were located in eight different buildings.
The City of Boston requires that all office furniture meet California fire safety standards, the strictest in the country. Some other cities have similar requirements, and office furniture is often manufactured to meet the California standard.
“Instead of producing two different kinds of office chairs, manufacturers often made just one chair model that met the California code,” Watkins explained. New office furniture meeting the standard — using fire retardants other than PBDEs — has a “TB-117” label on it, but those labels also are found on older furniture made with PBDEs.
Besides Watkins, other BUSPH researchers on the study include: Professors Thomas F. Webster, Michael D. McClean and Janice Weinberg, and former doctoral student Alicia J. Fraser. The work was supported by grants from the National Institute of Environmental Health Science.
Submitted by Lisa Chedekel