Biomarker phenotypes of air pollution and cancer risk in India

ABSTRACT Chemical toxicants and carcinogens present in the polluted air are the likely causative agents in the associated cancers of aerodigestive tract in exposed individuals. Understanding the relationship between the level of exposure to these pollutants and the risk of cancer is key to identifying individuals or populations at risk and informing the development of preventive measures. The overarching goal of this study is to advance such understanding through a collaborative research between the Masonic Cancer Center, University of Minnesota and Centre for Cancer Epidemiology (CCE) in Mumbai, India. We will employ a panel of established and novel air pollution-related biomarkers to test our overall hypothesis that the uptake of air pollution-related chemical carcinogens is associated with the risk for LC and HNC in Indian nonsmokers. In Aims 1 and 2, we will conduct case-control studies to assess the association of air pollution-related biomarkers in plasma with LC and HNC, respectively, in Indian nonsmokers. To achieve the goals of these Aims, we will use available biological samples and questionnaire data from the corresponding epidemiological cohorts conducted by the CCE. We will develop capacity for biomarker measurements at CCE by transferring the U.S. team's expertise in this area. In Aim 3, we will recruit healthy nonsmokers with various levels of usual exposures to air pollution, based on their occupation or lifestyle. We will compare a panel of biomarkers of exposure and effect across the groups and correlate to pollutant levels collected through personal air sampling devices worn by a subset of participants. We will use specially designed air samplers to characterize the chemical profile of various air pollution scenarios. This aim will aid in the interpretation of biomarker data generated in Aims 1 and 2, and will inform future biomarker-based studies of air pollution in India. An important outcome of this study is the development of capacity for future biomarker research of cancer risk in India using CCE cohorts. Such research can be further expanded to other population subgroups (e.g., smokers or occupationally exposed individuals) and additional environmental and dietary exposures in India.