Abstract
BACKGROUND AND AIM[|]A limited number of studies have investigated the impact of ambient air pollution on risk of cancers other than lung cancer among racially and ethnically diverse populations.[¤]METHOD[|]Among ~97,000 California participants of the Multiethnic Cohort Study (MEC) (35% African American, 39% Latino participants) who have been followed since cohort enrollment (1993-1996), we used Cox proportional hazards regression to examine associations between time-varying traffic-related air pollutants (gaseous and particulate matter (PM) pollutants) and risk of brain, breast, and pancreatic cancers as well as circulating levels of C-reactive protein (CRP) with adjustment for demographics, lifetime smoking, neighborhood socioeconomic status (nSES), and lifestyle factors. Subgroup analyses were conducted for race and ethnicity, nSES, and other factors.[¤]RESULTS[|]Exposure to fine particulate matter (PM2.5) was associated with a statistically significant increased risk of breast cancer in all females with no evidence of heterogeneity by race and ethnicity or hormone receptor status. Risk of pancreatic cancer also increased in association with exposure to PM2.5; the elevated risk was particularly prominent among Latino participants. Risk of malignant brain cancer increased with exposure to airport-related ultrafine particles (UFP) and the risk was statistically significant among African American participants, who had higher UFP exposures than other racial and ethnic groups. CRP levels measured in 7,860 California MEC participants from blood samples obtained in 1994-2016 showed that CRP levels increased with 12-month exposure to PM10 and other pollutants, providing support that air pollutants can harm health by promoting chronic inflammation in the body.[¤]CONCLUSIONS[|]These findings in large numbers of U.S. minoritized racial and ethnic populations support an association of ambient air pollution exposure with several cancer sites other than lung cancer. Further investigations of the biological mechanisms underlying air pollution-related carcinogenesis are a priority.[¤]