Sept. 12, 2023 – New research links living amid high levels of air pollution to an increased risk of breast cancer.
Women whose homes were in areas with high air pollution had an 8% greater chance of getting the disease, compared to women who lived in areas with lower pollution levels. The findings were published Monday in the Journal of the National Cancer Institute.
“Although this is a relatively modest increase, these findings are significant given that air pollution is a ubiquitous exposure that impacts almost everyone,” study author Alexandra White, PhD, an environment and cancer expert at the National Institute of Environmental Health Sciences, said in a statement. “These findings add to a growing body of literature suggesting that air pollution is related to breast cancer.”
More than 500,000 people were recruited in the mid-1990s. Those who took part in the study were men and women who were members of the American Association of Retired Persons (now called AARP) and lived in one of six states or one of two metropolitan areas. The states were California, Florida, Louisiana, New Jersey, North Carolina, and Pennsylvania, and the cities were Atlanta and Detroit. They completed follow-up questionnaires in 2004 and 2005.
During the 20-year follow-up period, there were 15,780 cases of breast cancer among nearly 200,000 women who had no history of the condition. Researchers analyzed the women’s air pollution exposure during the 10 to 15 years before they enrolled in the study based on national air quality data near their homes.
The researchers specifically studied a type of air pollution called particulate matter, which is a mixture of solid particles and liquid droplets found in the air. Particulate matter can be grouped according to the size of particles, and for the study, researchers focused on PM2.5 pollution, which is so small, it can be deeply inhaled into the lungs. Sources of PM2.5 pollution include motor vehicle exhaust, combustion of coal or oil, wood smoke, and industrial emissions, the authors noted.
The study also showed that exposure to high levels of particulate matter pollution was significantly linked to a type of breast cancer called hormone-positive breast cancer. The researchers said their data was not able to indicate heightened risk levels based on the geographic area where someone lived, but their results showed this could be an important area of future study.
One limitation of the study, the authors noted, was that most of the women in their analysis were older and post-menopausal.
About 240,000 women and 2,100 men are diagnosed with breast cancer annually in the U.S., according to the CDC.
