Ambient air pollution and lung cancer risk among never-smokers in the Women's Health Initiative

Shilpa N Gowda; Anneclaire J DeRoos; Rebecca P Hunt; Amanda J Gassett; Maria C Mirabelli; Chloe E Bird; Helene G Margolis; Dorothy Lane; Matthew R Bonner; Garnet Anderson; Eric A Whitsel; Joel D Kaufman; Parveen Bhatti

doi:10.1097/EE9.0000000000000076

Ambient air pollution and lung cancer risk among never-smokers in the Women's Health Initiative

Environ Epidemiol. 2019 Oct 25;3(6):e076. doi: 10.1097/EE9.0000000000000076. eCollection 2019 Dec.

Authors

Shilpa N Gowda^{1

2}, Anneclaire J DeRoos³, Rebecca P Hunt⁴, Amanda J Gassett¹, Maria C Mirabelli⁵, Chloe E Bird⁶, Helene G Margolis⁷, Dorothy Lane⁸, Matthew R Bonner⁹, Garnet Anderson⁴, Eric A Whitsel¹⁰, Joel D Kaufman¹, Parveen Bhatti^{11

12}

Affiliations

¹ Department of Environmental & Occupational Health Sciences, School of Public Health, University of Washington, Seattle, Washington.
² Workplace Health and Wellness, MaineGeneral Health, Augusta, Maine.
³ Department of Environmental and Occupational Health, Dornsife School of Public Health, Drexel University, Philadelphia, Pennsylvania.
⁴ Women's Health Initiative Clinical Coordinating Center, Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington.
⁵ Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia.
⁶ RAND Corporation, Santa Monica, California.
⁷ Department of Internal Medicine, School of Medicine, University of California, Davis, California.
⁸ Department of Family, Population & Preventive Medicine, School of Medicine, Stony Brook University, Stony Brook, New York.
⁹ Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, University at Buffalo, Buffalo, New York.
¹⁰ Department of Epidemiology, Gillings School of Global Public Health and Department of Medicine, School of Medicine, University of North Carolina, Chapel Hill, North Carolina.
¹¹ Cancer Control Research, BC Cancer, Vancouver, British Columbia, Canada.
¹² Program in Epidemiology, Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington.

Abstract

Background: Ambient air pollution is classified as a human carcinogen by the International Agency for Research on Cancer (IARC). However, epidemiologic studies supporting this classification have focused on lung cancer mortality rather than incidence, and spatial and temporal resolutions of exposure estimates have varied considerably across studies.

Methods: We evaluated the association of outdoor air pollution and lung cancer incidence among never-smoking participants of the Women's Health Initiative (WHI) study, a large, US-based cohort of postmenopausal women (N = 65,419; 265 cases). We used geospatial models to estimate exposures to fine particulate matter (PM_2.5) and nitrogen dioxide (NO₂) based on residential addresses at baseline and throughout follow-up. We also characterized exposures to traffic-related air pollution by proximity to major roadways. We estimated hazard ratios (HRs) for the risk of lung cancer in association with these exposure metrics using Cox proportional hazards regression models.

Results: No compelling associations of PM_2.5 and NO₂ exposures with lung cancer risk were observed. An increased risk of lung cancer was observed when comparing those individuals with residences <50 versus ≥200 meters from a primary limited access highway (HR = 5.23; 95% confidence interval = 1.94, 14.13).

Conclusions: Our results do not exclude lung cancer risk estimates observed in association with PM_2.5 and NO₂ exposures identified in previous studies. Our results suggest that residential proximity to major roadways may be a proxy for carcinogenic exposures not correlated with PM_2.5 or NO₂ levels. New studies of air pollution and lung cancer incidence should characterize additional aspects of proximity to major roadways.

Keywords: Adenocarcinoma; Air pollution; Distance to roadway; Lung cancer.