Long-term atmospheric exposure to particulate matter and breast cancer risk: findings from a nested case-control...

Airborne particulate matter (PM) is a complex mixture of particles thought to be associated with a range of adverse health effects, including female breast cancer. Current evidence on the association between PM and female breast cancer risk is inconsistent.

This study investigated the association between long-term exposure to PM and breast cancer risk in a nested case-control study within the French E3N-Generation cohort including 5222 breast cancer cases identified over the 1990-2011 follow-up period and 5222 individually matched controls. Annual mean concentrations of PM₁₀ and PM_2.5 at participants' residential addresses, were estimated using a land use regression model. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using conditional logistic regression models.

ORs for each 10 µg/m³ increase in the average of PM_2.5 and PM₁₀ were 1.14 (95% CI: 0.99-1.30) and 1.08 (95% CI: 0.98-1.18), respectively. When restricted to invasive ductal and lobular carcinomas, ORs were 2.74 (95% CI: 1.05-7.15) for PM_2.5 and 2.05 (95% CI: 1.11-3.78) for PM₁₀. Comparable effects of PM exposure estimated by a chemistry transport model reinforces these findings.

This study suggests a potential association between PM_2.5 and PM₁₀ exposure and breast cancer risk.