Older autos source of flame retardants.

Feb 04, 2009

Lagalante, AF, TD Oswald and FC Calvosa. Polybrominated diphenyl ether (PBDE) levels in dust from previously owned automobiles at United States dealerships. Environment International doi:10.1016/j.envint.2008.09.011.

Synopsis by Kim Harley, Ph.D.

Dust in used cars contains high levels of potentially toxic flame retardant chemicals, known as PBDEs, reports a study that measured them in older autos found at US dealerships.

The findings show that car interiors represent another source of exposure to the compounds. Levels of one type of PBDE -- called BDE-209 -- were particularly high. Its levels varied by the vehicle's year, manufacturer and country where it was made.

While there is increasing concern about PBDE exposure in the home, the levels in the cars tested were 10 times higher than in house dust. The authors estimate that, even though people spend much more time in their homes, most BDE-209 exposure is likely to come from the car.

The chemical-laden dust can be eaten and breathed. It may be more of a problem for children than adults because of their hand to mouth activity.

DecaBDE -- a mixture containing mostly BDE-209 -- is the only PBDE mixture that has not been banned or voluntarily phased out globally. Proposed bans in Maine and Washington states would not include vehicles and airplanes.

DecaBDE is used in television housing and other pre-formed plastics. Car interiors are likely to contain them in molded plastic parts, as well as seat cushion foam and electronics. The components release the chemicals as they age and are exposed to sunlight, extreme temperatures and other conditions.

The compounds are widely used to reduce the flammability of electronics, plastics and furniture. Animal studies link PBDEs to hormonal and neurodevelopmental disruption. One study has linked the compounds with reproductive birth defects in boys.

Inside, PBDEs do not break down quickly and can last for many years. Most people have some levels of PBDEs in their bodies. North Americans have higher levels than Europeans and Asians.

The current study measured PBDE levels in dust taken from the seats of 60 used cars from dealerships in New Jersey and Pennsylvania. A prior study found dust from new cars also had several kinds of flame retardants that could be a long-term source for people.