Women living in areas with poor air quality—especially those near heavy traffic—face a higher risk of developing breast cancer, according to a large-scale study involving more than 400,000 women. The research, published in the American Journal of Public Health, found that even modest increases in nitrogen dioxide, a pollutant linked to car emissions, were associated with a 3% rise in breast cancer cases.
Veronica Irvin of Oregon State University, one of the study’s authors, emphasized the significance of this finding. “It’s often not realistic for people to leave their homes and relocate in areas with better air quality in search of less health risk,” she said. “So we need more effective clean air laws to help those who are most in need.”
The study also revealed that higher levels of fine particulate matter (PM2.5) were linked to increased rates of hormone receptor-negative breast cancer—a more aggressive and harder-to-treat form of the disease. These findings are particularly concerning for communities of color and low-income neighborhoods, which are often situated near highways and industrial zones.
Despite pollution levels falling within current EPA guidelines, the health impact remains significant. Irvin called for policies that reduce car traffic and promote alternative transportation to protect vulnerable populations.
With breast cancer already the second leading cause of cancer death among women in the U.S., the study adds urgency to addressing environmental health disparities that disproportionately affect minority communities.
See: “Outdoor air pollution linked to higher incidence of breast cancer” (October 27, 2025)
