SPH Study Finds Toxic Dust in Boston Offices

SPH Study Finds Toxic Dust in Boston Offices

Residue from flame retardants in workers’ bodies also

Photo by Flickr user Lee Cullivan

Banned chemicals once widely used in computers and other electronics and in the polyurethane foam padding in office chairs, furniture, and carpeting are likely to be found in offices throughout the United States. Flame retardants now banned internationally are widespread in offices around Boston, and a new BU School of Public Health study has found that the chemicals’ concentrations in office dust are linked to traces found on workers’ hands and in their blood.

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. The BU researchers found PBDEs in all 31 Boston offices they examined. They also found that frequent hand-washing can reduce exposure to certain PBDEs in the widely used but now-banned flame retardants.

Lead author Deborah Watkins (SPH’11), a Ph.D. candidate in the environmental health department, says this is the first peer-reviewed research to correlate levels of the chemicals on people’s hands to concentrations in their blood.

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, the authors note, human exposure to the compounds will continue for many years.

PBDEs were once commonly used in office furniture and carpeting, as well as in computers and other electronics. In recent years, epidemiologic studies have linked exposure to constituents of the PBDE formulation penta-BDE, previously used in polyurethane foam, with changes in people’s thyroid hormones, impaired fertility in women, lowered levels of testosterone in men, neurodevelopmental 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.

Hand-to-mouth exposure
        Although scientists don’t know exactly how PBDEs accumulate in people’s bodies, hand-to-mouth exposure is thought to play a significant role. In the SPH study, workers who reported washing their hands with soap and water four or more times a day tended to have lower levels of penta-BDEs on their hands than those who washed their hands less often. They also had three times lower concentrations, on average, of penta-BDEs in their blood.

“This suggests that people’s hands play a key role in how they are exposed to PBDEs,” says Watkins. “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 stresses 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 levels of the compounds on hands.

The concentrations of the PBDEs in the tested office dust varied dramatically, which is consistent with other studies, she says.

The authors did not investigate the sources of the PBDEs they detected, but Watkins notes 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 in 8 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,” says Watkins. New office furniture meeting the standard—using fire retardants other than PBDEs—have “TB-117” labels on them, but those labels also are found on older furniture made with PBDEs.

Other SPH researchers on the study are Thomas F. Webster and Michael D. McClean, associate professors of environmental health, Janice Weinberg, an associate professor of biostatistics, and Alicia J. Fraser (SPH’10). Read more about PBDEs in Bostonia magazine.