Jun Wu, Ph.D.
University of California, Irvine
Using several modeling approaches, NIEHS grantees found links between air pollutants near major roadways and increased breast cancer risk. Previous studies of air pollution and breast cancer have generally used one method of assessing exposure and have focused on white women, with inconsistent results. In this study, the researchers used three exposure assessment methods to investigate associations between long-term air pollution exposure and breast cancer risk for 57,589 women in the Southern California Multiethnic Cohort.
Using methods known as kriging, land use regression (LUR), and the California Line Source Dispersion model (CALINE4), the team estimated air pollution exposures of particulate matter and nitrogen oxides. Among all women, breast cancer risk was positively, but not significantly, associated with nitrogen oxides determined by kriging and LUR, as well as with particulate matter using kriging. However, among women who lived within 500 meters of major roads, the scientists observed significantly increased risks associated with nitrogen oxides and particulate matter as determined by kriging, as well as nitrogen oxides using LUR. No overall associations were observed using CALINE4.
When they analyzed subgroups within the population, stronger associations between nitrogen oxides and breast cancer risk among African Americans and Japanese Americans became apparent. According to the authors, further studies of multiethnic populations are needed using different modeling methods to confirm the effects of air pollution, particularly with near‐roadway exposures.
Citation: Cheng I, Tseng C, Wu J, Yang J, Conroy SM, Shariff-Marco S, Li L, Hertz A, Gomez SL, Le Marchand L, Whittemore AS, Stram DO, Ritz B, Wu AH. 2020. Association between ambient air pollution and breast cancer risk: The Multiethnic Cohort Study. Int J Cancer 146(3):699–711.