PBDEs in US and German clothes dryer lint: a potential source of indoor contamination and exposure

Polybrominated diphenyl ethers (PBDEs) are emerging persistent organic pollutants (POPs). Since the 1970s, PBDEs have been widely used as additive flame retardants in furniture and electronic equipment. Due to their wide use and persistent nature, these chemicals are found in the environment, human blood, breast milk and other tissues in increasing levels in recent decades. PBDEs are similar to polychlorinated biphenyls (PCBs) in structure and toxicity. However, unlike PCBs and PCDDs/PCDFs, the route of PBDE exposure is not almost exclusively through food. PBDE levels in US food are not markedly higher than in Europe, although US human blood and milk levels are an order of magnitude higher. For these reasons, other possible routes of PBDE exposure have been investigated to understand PBDE intake into humans. PBDE contaminated clothes dryer lint and household dust are indicators of indoor contamination and may be sources of human exposure through hand-to-mouth contact or dermal absorption. There are very few publications about PBDEs in US or European lint. Household dryer lint from 12 US and seven German homes were analyzed for PBDEs by gas chromatography coupled to high-resolution mass spectrometry. We found the median US total PBDE levels were more than 10 times higher than median German levels and the mean US levels were two times higher than mean German levels. The US levels ranged from 321 to 3073ngg(-1) (median: 803ngg(-1), mean: 1138ngg(-1)) and the German levels were from 330 to 2069ngg(-1) (median: 71ngg(-1), mean: 361ngg(-1)). PBDE contamination of lint was found in all samples; the source of the PBDEs may be from dryer electrical components and/or dust deposition onto clothing.