Personal External Exposomes from Around the World

Abstract

BACKGROUND AND AIM: Industrial advances have led to a plethora of anthropogenic chemicals in our air, water, and soil. Exposures to a subset of these chemicals can lead to illnesses including respiratory illnesses, auto-immune disorders, inhibited immune response, and various cancers. Most studies focus on particulate matter or a select set of chemicals, missing chemicals of potential concern. Therefore, we have developed a personal exposure monitoring technology and workflow to comprehensively determine airborne chemical exposures of concern in populations across the globe. METHODS: Polydimethylsiloxane (PDMS) passive samplers placed in wristbands were deployed in South Africa, China, United States, Canada, and India, both in rural and urban regions. Samplers were shipped to Yale University and analyzed by direct thermal desorption gas-chromatography high-resolution mass spectrometry using a Q-Exactive orbitrap mass spectrometer. A software was developed to rank suspect screening annotations in terms of confidence, normalize for batch effects, filter out chemicals from background contamination, and remove redundant chemical annotations. Furthermore, a workflow implementing tools on the US EPA CompTox Chemicals Dashboard and prototype Hazard Comparison Dashboard was developed to automatically determine chemicals of most concern from a health perspective. RESULTS:Unique chemicals of concern, including pesticides used for malaria control in South Africa and for household pest control in China, fungicides deployed in the United States, and anti-microbial agents found in all populations, were determined. Participants were likely inhaling some of these chemicals, which poses health concerns. Chemical exposures were dynamic, with seasonal variation predominating any other factor among studies in different locations. CONCLUSIONS:We are finding that people around the world, from children in rural South African villages to the elderly in Chinese metropolis, to college students at Yale, are inhaling chemicals of concern, including biocides. These chemical exposures are dynamic, with season seeming to have the greatest influence on exposure profiles. KEYWORDS: Air pollution, external exposome, exposure assessment, omics technologies, mixtures, pesticides