Hexabromocyclododecanes in indoor dust from Canada, the United Kingdom and the United States
Abou-Elwafa, Abdallah M.A.
Faculty of Pharmaceutical, Biomedical and Veterinary Sciences. Pharmacy
, p. 998-1001
University of Antwerp
Hexabromocyclododecane (HBCD) diastereomers were analyzed in house dust samples from Birmingham, UK (n=31); Amarillo/Austin, USA (n=13); and Toronto, Canada (n=8). Six samples of dust from UK offices were also studied. A ΣHBCD concentration of 110,000 ng/g was recorded in one of the UK house dust samples. Concentrations of ΣHBCD in house dust samples from each country were statistically indistinguishable, and concentrations in UK office samples fell within the range observed for UK homes. Ingestion of household dust is shown to constitute an important pathway of exposure to the UK population. The concentrations of α-HBCD in dust samples were generally higher than those present in the commercial formulations and it was the dominant diastereomer in a small number of samples. This is consistent with the thermal instability of HBCD, where at the temperatures used to incorporate the commercial formulations into treated goods (above 160 °C), γ- HBCD is partially converted to the α-isomer1. This together with the fact that cytochrome P450 preferentially metabolizes the γ- and β-diastereomers but not the α-diastereomer2 - provides a likely explanation for the observed dominance of the α-diastereomer in human tissues, compared to the dominance of the γ-diastereomer in the commercial formulations.