Unwelcome Guest: PBDEs in Indoor Dust

Researchers have known for years that house dust is a major exposure route for lead and certain pesticides. Now attention is turning to another class of dustborne chemicals—polybrominated diphenyl ether (PBDE) flame retardants. A growing body of research documents that PBDEs and other brominated flame retardants (BFRs) released from many different consumer products can accumulate in people’s homes, cars, and workplaces. Moreover, certain segments of the population have extremely high concentrations of these substances in their bodies. However, hard data on the human health impact of these exposures are only just beginning to emerge, with many studies focusing on thyroid effects. PBDEs have been used extensively in the highly flammable plastic components of consumer goods including couches, mattresses, carpet padding, televisions, computers, cushions, car stereos, navigation systems, car seats, and padded dashboards. By 2001, a sufficient volume of data documenting PBDEs’ persistence, toxicity, and tendency to bioaccumulate had emerged that Europeans were calling for two PBDE formulations—pentaBDE and octaBDE—to be banned. Both formulations are mixtures of individual PBDE compounds, or congeners; they are named on the basis of the average number of bromine atoms making up the majority of each mixture. PentaBDE was used in cushioning material whereas octaBDE was used primarily in electronics including televisions, computers, and cell phones. Europe went on to ban both PBDEs in August 2004, and the bromine and flame retardant industries also voluntarily ceased production in North America by the end of that year. PentaBDE and octaBDE are now candidates for inclusion in the United Nation’s Stockholm Convention on Persistent Organic Pollutants (POPs), which globally bans chemical substances that bioaccumulate through the food web and pose a risk to humans and the environment. A third PBDE, an additive known as decaBDE, is used in electronic devices and textile backing. It remains in use today in North America, but was banned on 1 April 2008 by the European Court of Justice. The Bromine Science and Environmental Forum (BSEF), an industry group, is contesting that ruling, and writes on its website: “After 10 years of scientific research and more than 588 studies conducted and/or reviewed, both the environment and human risk assessment reports concluded that there is no significant risk [for decaBDE].” However, animal research suggests the compound may be carcinogenic and links it with developmental toxicity.