The association between residential proximity to brownfield sites and high-traffic areas and measures of immunity

The mechanisms by which neighborhood environmental exposures influence health are poorly understood, although immune system dysregulation represents a potential biological pathway. While many neighborhood exposures have been investigated, there is little research on residential proximity to brownfield waste. Using biomarker data from 262 participants in the Detroit Neighborhood Health Study (DNHS), we estimated the association between proximity to brownfields and heavy traffic and signal-joint T-cell Receptor Excision Circles (sjTRECs, a measure of naïve T-cell production), C-reactive protein (CRP, a measure of systemic inflammation), and interleukin 6 (IL-6, a proinflammatory cytokine). We assessed residential proximity ≤200 meters from brownfields and highways on all three biomarkers using multivariate regression. We demonstrated that living ≤200m from a brownfield site was associated with a 0.30 (95% CI = 0.59, 0.02, p = 0.04) log(e)-unit decrease in sjTRECs per million whole blood cells, as well as non-significantly elevated levels of CRP and IL-6. Heavy traffic was not associated with any biomarker. Persons living in close proximity to brownfield sites had significantly lower naïve T-cell production, suggesting accelerated immune aging. Decreased T-cell production associated with brownfield proximity may be caused by toxicant exposure in brownfield sites, or may serve as a marker of other neighborhood stressors