Bromobenzene flame retardants in the Great Lakes atmosphere.

Seven bromobenzene flame retardants were measured in vapor-phase samples collected at five sites, all near the shores of the North American Great Lakes during 2008-2009, inclusive. The target compounds were hexabromobenzene (HBB), pentabromobenzene (PBBz), pentabromotoluene (PBT), pentabromobenzylacrylate (PBBA), pentabromobenzyl bromide (PBBB), tetrabromo-p-xylene (pTBX), and pentabromoethyl benzene (PBEB). Detection frequencies were, on average, higher than 50% for all of the compounds, with the exception of PBBA, which was detected only in 22% of all the samples. Considering all the sampling sites together, HBB showed the highest average concentration (4.6 ± 1.0 pg/m(3)), followed by PBBB (3.3 ± 0.5 pg/m(3)) and PBEB (1.0 ± 0.1 pg/m(3)). The concentrations of these compounds were generally significantly correlated with one another, with the exception of PBBA, which was correlated only to PBBB. The atmospheric concentrations of PBT, pTBX, PBBB, and PBBA tracked local human population density, suggesting that these compounds are or were used in a variety of commercial products. Unexpectedly, the concentration of PBEB was highest at the remote site of Eagle Harbor in northern Michigan, whereas that of HBB was highest at Sturgeon Point, ∼25 km southwest of Buffalo, New York. The lack of dependence of these two compounds' concentrations on human population suggests local point sources.