being in cars means inhaling flame retardants

Original article here


Science News
March 26, 2008
Spending time in vehicles can increase PBDE exposure
Air inside automobiles made by European, Japanese, and U.S. manufacturers can contain high concentrations of PBDEs.

The air inside automobiles can have very high concentrations of PBDE flame retardants, according to new research in ES&T (DOI: 10.1021/es7030533). The study documents that some cars manufactured as recently as January 2006 contain compounds, or congeners, associated with the lighter-weight Penta-BDE and Octa-BDE formulations, which have been banned from use in Europe since 2004.
To capture air samples from inside automobile passenger cabins, Manolis Mandalakis of the University of Crete constructed a custom-made sampler powered with a large battery (stored in the vehicle's trunk)
EURIPIDES STEPHANOU
To capture air samples from inside automobile passenger cabins, Manolis Mandalakis of the University of Crete constructed a custom-made sampler powered with a large battery (stored in the vehicle's trunk).

Air samples were taken from 33 cars owned by residents of Heraklion, Greece, including vehicles from 15 different European, Japanese, and U.S. manufacturers. Twenty of the cars were made after 2005, and the researchers collected air samples from inside the vehicles from February 2006 to July 2007. The concentrations of PBDEs in the tested cars ranged from 0.4 to 2644 picograms per cubic meter of air (pg/m3), with a median concentration of 201 pg/m3.

Some of the cars manufactured after the ban was in place had measurable or even elevated concentrations of the lighter-weight congeners associated with the banned formulations, says the paper's corresponding author, Euripides Stephanou of the Environmental Chemical Processes Laboratory at the University of Crete (Greece). He and his colleagues conducted additional tests with two cars purchased in January 2006; these tests "clearly indicat[ed] the presence of Penta-BDE in car interiors," according to the paper.

Stephanou's explanation for these findings is that "it is possible that there is a large inventory of PBDE-treated materials manufactured before 2004 that will continue to be used in the construction of vehicles until the end of stock. Alternatively, it is possible that the legislation for the ban of PBDEs has not been activated from all industries yet."

The authors argue that changes in the levels of two key molecules associated with Penta-BDE (BDE-47 and BDE-99) in some cars "could be attributed to the debromination of the highly brominated congeners, including [the main congener in Deca-BDE], BDE-209, to less brominated compounds." Deca-BDE is the only PBDE formulation still in widespread use, and PBDE experts agree that if it is conclusively shown to produce molecules associated with Penta-BDE, nongovernmental organizations are likely to call for it to be banned.

The new research documents significant variations among cars from the same manufacturer. For example, the PBDE concentrations recorded in three Fords ranged from 126 to 2644 pg/m3. Stuart Harrad of the University of Birmingham (U.K.), who also has measured PBDEs in automobile air and found widely varying concentrations, points out that the results highlight the complexity of modern automotive manufacturing. "Changes in market use of brominated flame retardants over time, different manufacturing origins of vehicles, and the impact of other goods, hi-fi, navigation systems, cushions, child seats," are just some of the factors that can affect automobiles' PBDE emissions, he says.

"The main factors governing the PBDE concentrations inside cars are vehicle age and car interior temperature," says the study's first author, Manolis Mandalakis, also of the University of Crete's Environmental Chemical Processes Laboratory. The ages of the vehicles tested varied from 1 month to 5.6 years, and the results suggest "significant outgassing of PBDEs from the interior surfaces of newer cars," Stephanou says.

The Greek researchers probably underestimated the presence of the Deca-BDE congener—which was found at high levels in some cars—because they did not analyze the dust inside the cars, says Myrto Petreas, chief of the environmental chemistry laboratory at the California Department of Toxic Substances Control. Deca-BDE is mainly associated with dust particles. As research recently published in ES&T makes clear, people may take up high concentrations of PBDEs from dust on their hands.

The new paper is the first to document the presence of polybrominated dibenzo-furans (PBDFs) (PDF Size: 47 KB) in automotive air. Mandalakis says that they decided to look for PBDFs and polybrominated dibenzo-p-dioxins (PBDDs) in cars because previous studies have shown that PBDEs can be photooxidized to produce PBDFs and commercial PBDE mixtures are known to contain PBDFs as impurities at microgram per gram levels. Although the researchers expected to find PBDFs in most of the samples, they found detectable PBDFs (61 pg/m3) in only one vehicle. The results suggest that PBDFs and PBDDs "are not important constituents of air in car interiors." However, Mandalakis says, further research is needed to explore the possible photodegradation of PBDEs to PBDFs and PBDDs, as well as the outgassing of PBDF impurities from interior surfaces. —KELLYN BETTS