Abstract A119: Ethnic and sex differences in exposure to traffic-related air pollutants and lung cancer incidence: The Multiethnic Cohort
Authors: Cheng Iona , Conroy Shannon M. , Tseng Chiuchen , Yang Juan , Masri Shahir , Larson Timothy , Fruin Scott , Jain Jennifer , Marchand Loic Le , Samet Jonathan , Gomez Scarlett Lin , Setiawan Veronica Wendy , Park Sung-Shim Lani , Stram Daniel O. , Shariff-Marco Salma , Ritz Beate , Wu Jun , Wu Anna H. 
Published: August 2020

Introduction: California has one of the highest levels of air pollution in the nation. Vehicle exhaust contains a mixture of gases and particulate matter that are known to have mutagenic and carcinogenic effects. Our objective was to examine the association between specific traffic-related air pollutants and lung cancer risk by race/ethnicity and sex among participants of the Multiethnic Cohort Study (MEC), residing predominately in Los Angeles County.

Methods: Residential addresses from baseline, 1993-1996, through 2013 for over 112,000 California MEC participants were geocoded to latitude and longitude coordinates and used to estimate air pollutant exposures of NO2, NOX, PM10, CO, and O3 based on Bayesian kriging interpolation of state and national government air monitoring data. A total of 2,994 incident lung cancer cases (1,415 African Americans, 732 Latinos, 516 Whites, and 327 Japanese Americans) were identified by linkage to the California Cancer Registry. Cox proportional hazard regression was conducted to examine the long-term effects of NO2, NOX, PM10, CO, and O3 adjusting for age, race/ethnicity, sex, education, health behaviors, smoking, and other established lung cancer risk factors. Stratified analyses were conducted by sex, race/ethnicity, and smoking status.

Results: Lung cancer risk increased per 20 ppb NO2 among women (HR=1.29; 95% CI: 1.02-1.64) with consistent patterns of associations observed among African American, Japanese American, and White women. A slightly larger increased risk was observed among ever-smoking women (HR=1.33; 95% CI: 1.02-1.74), particularly ever-smoking African American women (HR=1.54; 95% CI: 1.06, 2.24). In addition, a statistically significant increased lung cancer risk was observed per 10ug/m3 increase in PM10 among ever-smoking women (HR=1.16; 95% CI: 1.01-1.34) and per 100 ppb increase in CO among women (HR=1.05; 95% CI: 1.01-1.09). No significant associations with lung cancer were detected among men.

Conclusion: These preliminary findings suggest that women of diverse racial/ethnic groups may be particularly vulnerable to the effects of long-term exposures of NO2, PM10, and CO on lung cancer risk. These findings among women in contrast to men may relate to differences in residential exposures with higher sensitivity or more time spent in residential neighborhoods for women in comparison to men. Future analyses will examine associations with other pollutants using different exposure assessment approaches and examine differences in associations by neighborhood- and individual-level factors.

Citation Format: Iona Cheng, Shannon M. Conroy, Chiuchen Tseng, Juan Yang, Shahir Masri, Timothy Larson, Scott Fruin, Jennifer Jain, Loic Le Marchand, Jonathan Samet, Scarlett Lin Gomez, Veronica Wendy Setiawan, Sung-Shim Lani Park, Daniel O. Stram, Salma Shariff-Marco, Beate Ritz, Jun Wu, Anna H. Wu. Ethnic and sex differences in exposure to traffic-related air pollutants and lung cancer incidence: The Multiethnic Cohort [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr A119.