Environmental injustice and sexual minority health disparities: A national study of inequitable health risks from air pollution among same-sex partners.

Air pollution is deleterious to human health, and numerous studies have documented racial and socioeconomic inequities in air pollution exposures. Despite the marginalized status of lesbian, gay, bisexual, and transgender (LGBT) populations, no national studies have examined if they experience inequitable exposures to air pollution. This cross-sectional study investigated inequities in the exposure of same-sex partner households to hazardous air pollutants (HAPs) in the US. We examined cancer and respiratory risks from HAPs across 71,207 census tracts using National Air Toxics Assessment and US Census data. We calculated population-weighted mean cancer and respiratory risks from HAPs for same-sex male, same-sex female and heterosexual partner households. We used generalized estimating equations (GEEs) to examine multivariate associations between sociodemographics and health risks from HAPs, while focusing on inequities based on the tract composition of same-sex, same-sex male and same-sex female partners. We found that mean cancer and respiratory risks from HAPs for same-sex partners are 12.3% and 23.8% greater, respectively, than for heterosexual partners. GEEs adjusting for racial/ethnic and socioeconomic status, population density, urban location, and geographic clustering show that living in census tracts with high (vs. low) proportions of same-sex partners is associated with significantly greater cancer and respiratory risks from HAPs, and that living in same-sex male partner enclaves is associated with greater risks than living in same-sex female partner enclaves. Results suggest that some health disparities experienced by LGBT populations (e.g. cancer, asthma) may be compounded by environmental exposures. Findings highlight the need to extend the conceptual framework for explaining LGBT health disparities beyond psycho-behavioral mechanisms translating social stress into illness to include environmental mechanisms. Because psycho-behavioral and environmental factors may together exacerbate health disparities, we call for a shift toward interdisciplinary research on LGBT health that takes into account cumulative risks, including the role of environmental exposures.