Assessing Disparities in Americans' Exposure to PCBs and PBDEs based on NHANES Pooled Biomonitoring Data

The National Health and Nutrition Examination Survey (NHANES) has been continuously biomonitoring Americans' exposure to two families of harmful environmental chemicals: polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). However, biomonitoring these chemicals is expensive. To save cost, in 2005, NHANES resorted to pooled biomonitoring; that is, amalgamating individual specimens to form a pool and measuring chemical levels from pools. Despite being publicly available, these pooled data gain limited applications in health studies. Among the few studies using these data, racial/age disparities were detected, but there is no control for confounding effects. These disadvantages are due to the complexity of pooled measurements and a dearth of statistical tools. Herein, we developed a regression-based method to unzip pooled measurements, which facilitated a comprehensive assessment of disparities in exposure to these chemicals. We found increasing dependence of PCBs on age and income, whereas PBDEs were the highest among adolescents and seniors and were elevated among the low-income population. In addition, Hispanics had the lowest PCBs and PBDEs among all demographic groups after controlling for potential confounders. These findings can guide the development of population-specific interventions to promote environmental justice. Moreover, both chemical levels declined throughout the period, indicating the effectiveness of existing regulatory policies. for this article are available online.

Automated summary

The National Health and Nutrition Examination Survey (NHANES) has been continuously monitoring Americans' exposure to harmful environmental chemicals. In 2005, NHANES implemented a cost-saving measure of pooled biomonitoring. However, these pooled data have limited applications due to complexity and lack of statistical tools. The development of a regression-based method allowed for a comprehensive assessment of disparities in exposure to these chemicals, revealing age, income, and racial differences. These findings can inform targeted interventions for environmental justice, and chemical levels have declined over time, indicating the effectiveness of regulatory policies.