BACKGROUND: Hexabromocyclododecane (HBCD) is a brominated flame retardant used in polystyrene foams in thermal insulation and electrical equipment. The HBCD commercial mixture consists mainly of [alpha], [beta], and [gamma] stereoisomers. Health concerns of HBCD exposure include alterations in immune and reproductive systems, neurotoxic effects, and endocrine disruption. Stereoisomer-specific levels of HBCD have not been measured previously in U.S. food.
OBJECTIVES: We measured HBCD stereoisomer levels in U.S. foods from Dallas, Texas, supermarkets.
METHODS: Convenience samples of commonly consumed foods were purchased from supermarkets in Dallas in 2009-2010. Food samples included a wide variety of lipid-rich foods: fish, peanut butter, poultry, pork, and beef. Thirty-six individual food samples were collected in 2010 and analyzed for [alpha]-, [beta]-, and [gamma]-HBCD stereoisomers using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Ten pooled food samples previously collected in 2009 for a study of total HBCD levels using gas chromatography-mass spectrometry (GC-MS), were reanalyzed for [alpha]-, [beta]-, and [gamma]-HBCD stereoisomers using LC-MS/MS.
RESULTS: Of the 36 measured individual foods, 15 (42%) had detectable levels of HBCD. Median (ranges) of [alpha]- and [gamma]-HBCD concentrations were 0.003 (< 0.005-1.307) and 0.005 (< 0.010-0.143) ng/g wet weight (ww), respectively; [beta]-HBCD was present in three samples with a median (range) of 0.003 (< 0.005-0.019) ng/g ww. Median levels (range) for [alpha]-, [beta]-, and [gamma]-HBCD, in pooled samples were 0.077 (0.010-0.310), 0.008 (< 0.002-0.070), and 0.024 (0.012-0.170) ng/g ww, respectively.
CONCLUSIONS: [alpha]-HBCD was detected most frequently and at highest concentrations, followed by [gamma]-, and then [beta]-HBCD, in food samples from Dallas, Texas. Food may be a substantial contributor to the elevated [alpha]-HBCD levels observed in humans. These data suggest that larger and more representative sampling should be conducted.
KEY WORDS: Dallas, Texas; food; HBCD; hexabromocyclododecane; stereoisomers. Environ Health Perspect 120:1260-1264 (2012). http://dx.doi.org/10.1289/ehp.1204993 [Online 31 May 2012]
Hexabromocyclododecane (HBCD) is a brominated aliphatic cyclic hydrocarbon flame retardant (BFR) used in polystyrene foam for thermal insulation in buildings, upholstery textiles, and electrical equipment (Covaci et al. 2006). HBCD is a major BFR produced globally, and before the phase-out of certain polybrominated diphenyl ethers (PBDEs), it was the third most abundant BFR in North America, after tetrabromobisphenol A and PBDEs (Johnson-Restrepo et al. 2008). HBCD enters the environment during its production and by leaching from consumer products (Covaci et al. 2006). Human exposure occurs through dust inhalation and dust and food ingestion (Abdallah and Harrad 2009; Schecter et al. 2009; Thomsen et al. 2008). HBCD is hydrophobic and lipophilic, and it bioaccumulates with half-lives of 2, 60, and 240 days in air, water, and sediment, respectively (Abdallah and Harrad 2009; Germer et al. 2006; Haukas et al. 2009; Johnson-Restrepo et al. 2008; Kunisue et al. 2007; Thomsen et al. 2008; Tornkvist et al. 2011). Terminal elimination half-lives in nonoccupationally exposed humans were calculated to be on average 64 days (range 23-219 days) (Geyer et al. 2004), using the daily intake for total HBCD in adult humans based on a Swedish market basket study (Lind et al. 2002). The authors attributed the high variability observed in...