Serum levels of decabromodiphenyl ether (BDE-209) in women from different European countries and possible relationships with lifestyle and diet

To determine possible effects of lifestyle, diet, housing and professional activities on differences in individual levels of decabromodiphenyl ether (BDE-209) in serum of women, 20 to 40 years of age, in The Netherlands, the United Kingdom, Norway and Spain.BDE-209 was measured in serum of 145 female volunteers with no known occupational exposure from Norway, United Kingdom, The Netherlands and Spain. Blood levels of BDE-209 in a subgroup of 40 Dutch women were determined twice at a six months' interval. An extensive questionnaire was used to obtain detailed information about lifestyle factors that might contribute to BDE-209 exposure. Serum levels were used to determine margin of systemic exposure compared with a 28d rat toxicity study.Median BDE-209 serum concentrations were highest in The Netherlands and United Kingdom, respectively 8.8 and 9.3 pg/g ww. or 2.6 and 2.8 ng/g lipid. Median levels in Spain and Norway were lower, respectively 7.4 and 5.2 pg/g ww. or 3.3 and 0.8 ng/g lipid. Maximum levels in individual women were higher by one order of magnitude than the mean or median. The country of residence was the only variable significantly associated with BDE-209 levels; we found that the differences between countries could not be explained by any of the investigated exposure variables, and that these did not explain differences between individuals either. No consistent relationships were determined between diets, household, clothes, number and duration of use of electronics and occupational activities for the whole study group.We could not identify which of the multiple sources of exposure accounted for individual differences in blood levels. Although small differences in mean BDE-209 serum levels were recognized between countries, these differences are unlikely to cause a differential result with respect to risk assessment.