World Trade Center Exposome: A novel, data-driven approach to modeling risk and protective factors for adverse mental and physical health outcomes among WTC Responders

Abstract

Background and Aim: Responders involved in rescue and recovery efforts following the 9/11 World Trade Center (WTC) attacks were exposed to hazardous working conditions and toxic agents. Previous studies associating WTC exposure with adverse health outcomes focus on a small number of risk factors selected a priori. We proposed a data-driven, exposomic approach to investigate the mixture of risk and protective factors experienced by WTC responders (i.e., a ’WTC exposome’) and its relation to responder health. Methods: We included 34,096 responders from the WTC Health Program (WTC-HP) with a physical and mental health evaluation and exposure assessment at first (post 9/11/01) visit. We used generalized weighted quantile sum (gWQS) regression to examine positive (i.e., risk) and negative (i.e., protective) associations between the "WTC Exposome” index containing 84 factors (i.e., dust and traumatic exposures, baseline health information, social support) and five WTC-related health outcomes as dichotomous (ever/never): post-traumatic stress disorder (PTSD), gastroesophageal reflux disease (GERD), respiratory problems, diabetes, and headaches. All models were adjusted for age, race, ethnicity, and gender. Results: The WTC exposome was associated with all five health outcomes (PTSD βrisk = 6.4, βprotective = 0.1; GERD βrisk = 4.4, βprotective= 0.5; respiratory problems βrisk = 3.9, βprotective = 0.6; diabetes βrisk = 1.6, βprotective = 0.7; headaches βrisk = 5.6, βprotective = 0.3; p<0.0001 for all models). The WTC exposomic profile (i.e., the mix of risk and protective factors) differed by health outcome. For example, working in an enclosed area contaminated with dust contributed most to PTSD risk while full-time employment post 9/11 appeared protective against PTSD. Conclusion: Understanding WTC-related risk and protective factors enable us to better identify responders vulnerable to adverse outcomes and identify factors that may protect against the development or progression of disease. This approach has potential for future disaster response studies.