Spatial Health Lab

Lung and female breast cancers are highly prevalent worldwide. Although the association between exposure to ambient fine particulate matter (PM ) and lung cancer has been recognized, there is less evidence for associations with other common air pollutants such as nitrogen dioxide (NO ) and ozone (O ). Even less is known about potential associations between these pollutants and breast cancer. We conducted a population-based cohort study to investigate the associations of chronic exposure to PM , NO , O , and redox-weighted average of NO and O (O ) with incident lung and breast cancer, using the Ontario Population Health and Environment Cohort (ONPHEC), which includes all long-term residents aged 35-85 years who lived in Ontario, Canada, 2001-2015. Incident lung and breast cancers were ascertained using the Ontario Cancer Registry. Annual estimates of exposures were assigned to the residential postal codes of subjects for each year during follow-up. We used Cox proportional-hazards models adjusting for personal- and neighborhood-level covariates. Our cohorts for lung and breast cancer analyses included ~4.9 million individuals and ~2.5 million women, respectively. During follow-up, 100,146 incident cases of lung cancer and 91,146 incident cases of breast cancer were diagnosed. The fully adjusted analyses showed positive associations of lung cancer incidence with PM (hazard ratio [HR] = 1.02 [95%CI:1.01-1.05] per 5.3 μg/m ) and NO (HR = 1.05 [95%CI: 1.03-1.07] per 14 ppb). No associations with lung cancer were observed for O or O . Relationships between PM and NO with lung cancer exhibited a sublinear shape. We did not find compelling evidence linking air pollution to breast cancer. This article is protected by copyright. All rights reserved.