Residential Exposure to Deca-Polybrominated Diphenyl Ethers and Risk of Childhood Acute Lymphoblastic Leukemia: Effects of Adjusting for BDE209 Degradation

摘要

Background: Residential dust is a major source of polybrominated diphenyl ether (BDE) exposure. We estimated the risk of childhood acute lymphoblastic leukemia (ALL) associated with BDEs using carpet dust as an exposure indicator. Here, we compare results for DecaBDEs corrected and not corrected for BOE209 degradation during quantification. Methods: We studied 167 ALL cases 0-7 years of age and 214 birth certificate controls matched on age, sex, and race/ethnicity from the Northern California Childhood Leukemia Study in 2000-2006. We sampled carpets using a high volume surface sampler or we took dust from the home vacuum. We measured concentrations (ng/g) of 14 BDEs, including 4 DecaBDEs (206-209), using GC/MS. BDE209 standards were used to estimate degradation in the injector (temperature=290C) to BDE206-208. On a molar basis, conversion of BDE209 was 3%, 2%, and 1% to BDE206-208, respectively. Corrected and uncorrected odds ratios (ORs) were computed adjusted for demographics, sample year, and dust type. Results: BDE209 was detected in 100% of homes (corrected median (ng/g) [interquartile range]:946 [534-1682]; whereas, BDE206-208 were detected in 90, 74 and 76% of homes, respectively, and at low levels (28[15-41], 7[0.2-20], 4[0.2-10]). Correlations between corrected and uncorrected concentrations were 0.46, 0.48, 0.43, and 0.87 for BDE206-209, respectively. Correcting for BDE209 degradation and comparing the highest tertile to homes with no detections, we observed no association between BDE209 and ALL (OR=0.9, 95% CI 0.5-1.7); results were the same without correction. For BDE206, 207 and 208 corrected for BDE209 degradation, we observed significant two-fold risks with monotonic positive trends (p-trend=0.17, 0.05, 0.08, respectively). The respective uncorrected ORs were elevated but not significant (ORs=1.6,1.8,1.7) and there was no monotonic trend with increasing tertiles (p-trend=0.67, 0.34, 0.11). Conclusion: Correcting for estimated degradation of BDE209 resulted in stronger associations with ALL for BDE206-208.