Breast Cancer Risk in Association with Atmospheric Pollution Exposure: A Meta-Analysis of Effect Estimates Followed by a Health Impact Assessment

BACKGROUND: The epidemiological literature of associations between atmospheric pollutant exposure and breast cancer incidence has recently strongly evolved. OBJECTIVES: We aimed to perform a) a meta-analysis of studies considering this relationship, correcting for publication bias and taking menopausal status and cancer hormone responsiveness into account; and b) for the pollutants most likely to affect breast cancer, an assessment of the corresponding number of attributable cases in France and of the related economic costs. METHODS: We conducted a literature review and random-effects meta-analyses of epidemiological studies examining the association of fine particulate matter with aerodynamic diameter less than or equal to [Formula: see text] ([Formula: see text]), particulate matter with aerodynamic diameter less than or equal to 10 μm ([Formula: see text]), and [Formula: see text] long-term exposure with breast cancer incidence; additional analyses were stratified on menopausal status and on tumor hormone responsiveness status. The resulting dose–response functions were combined with modeled atmospheric pollutant exposures in 2013 for France, cancer treatments costs, lost productivity, and years of life lost, to estimate the number of breast cancers attributable to atmospheric pollution and related economic costs in France. RESULTS: The review identified 32, 27, and 36 effect estimates for [Formula: see text] , [Formula: see text] , and [Formula: see text] , respectively. The meta-analytical relative risk estimates of breast cancer corrected for publication bias were 1.006 [95% confidence interval (CI): 0.941, 1.076], 1.047 (95% CI: 0.984, 1.113), and 1.023 (95% CI: 1.005, 1.041), respectively. [Formula: see text] estimated effects appeared higher in premenopausal than in postmenopausal women and higher for hormone responsive positive ([Formula: see text]) than negative ([Formula: see text]) breast cancers. Assuming a causal effect of [Formula: see text] , we estimated that 1,677 (95% CI: 374, 2,914) new breast cancer cases were attributable to [Formula: see text] annually in France, or 3.15% (95% CI: 0.70, 5.48) of the incident cases. The corresponding tangible and intangible costs were estimated to be € [Formula: see text] (low, high: 570, 1,080) per year. CONCLUSION: These findings suggest that decreasing long-term [Formula: see text] exposure or correlated air pollutant exposures could lower breast cancer risk. https://doi.org/10.1289/EHP8419