World Trade Center neurotoxicant exposure severity is associated with cortical thinning and regional brain atrophy: a neuroimaging study of general responders at midlife

Abstract INTRODUCTION Exposure to aerosolized pollutants is a risk factor for cognitive impairment and dementia, but the specific features of exposure‐related neurodegeneration remain unclear. METHODS We measured the World Trade Center Neurotoxicant Exposure Severity Index (WTC‐NESI) in 218 responders and unexposed controls aged 44‐65 years. The main outcome was cortical thickness. Correlation analyses reported unadjusted associations and multiple linear regression to adjust for correlates. Vertex‐wise analyses were used with threshold‐free cluster enhancement to examine associations after adjusting for cross‐vertex clustering in atrophy. RESULTS Cortical thickness was associated with WTC‐NESI ( R = −0.38, p < 0.001) that survived multivariable adjustment. Vertex‐wise analyses revealed reduced cortical thickness across much of the cortical surface that was associated with WTC exposure severity. Results were right‐hemisphere asymmetric and focused in the precentral regions (partial η 2 ≥ 0.07). CONCLUSION Our results provide an important reference for neurotoxicological investigators mapping the implications of airborne pollutant exposures. This study suggests that efforts to mitigate exposures in first responders might have long‐term implications for cerebral health.