Breast Cancer Prevention: A Focus on Air Pollution

By: All for the Breast Editorial Team, June 19, 2017

BY ALEXANDRA GOHO

Every day, women come into contact with hundreds of potentially hazardous chemicals where they live and work, whether it’s from consumer products or contaminants in the environment. Many of these chemicals have been linked with breast cancer. However, which ones pose the greatest risk and how can we reduce our exposures? These are questions scientists at Silent Spring Institute, a beneficiary of the Avon Breast Cancer Crusade, are trying to answer through an innovative research program on environmental health and breast cancer prevention.

For more than 20 years, Silent Spring Institute based in Newton, Mass. has been investigating the role of environmental factors in the development of breast cancer. A large part of their work centers on endocrine disrupting chemicals (EDCs) in everyday products that mimic or interfere with the body’s natural system of hormones. Now, the organization is extending its work to include air pollutants as growing evidence suggests that many of the components of air pollution may also increase breast cancer risk.

Back in 2014, with support from the Avon Foundation, Silent Spring evaluated more than a hundred common chemicals that cause mammary tumors in laboratory studies. From that list, the researchers identified 17 types of chemicals as top priorities for breast cancer research and prevention. These include things like flame retardants, stain-resistant chemicals, paint removers, disinfection byproducts in drinking water, and estrogen mimics. The analysis also singled out chemicals in vehicle exhaust as potential risk factors.

“Despite progress over the last 30 years, air pollution from traffic and other sources continues to have a major impact on our environment and our health,” says Ruthann Rudel, Silent Spring’s director of research. Studies show that proximity to highways and other busy roads can expose communities to a toxic mix of chemicals that place residents at an increased risk for a variety of health problems including asthma, heart disease, and cancer. According to the Environmental Protection Agency, more than 45 million people in the U.S. live within 300 feet of a major road or transportation facility.

To better understand the impact of traffic-related pollution on breast cancer, Silent Spring has begun an innovative study involving workers in the trucking industry in the United States. With funding from the Avon Breast Cancer Crusade, the Institute is analyzing blood and urine samples from 90 truck drivers in conjunction with air samples collected inside their vehicles during their shifts.

“There’s lots of overlap between what truckers are exposed to and what people living near high-traffic roadways are exposed to, so we can use this information to better understand the impact of air pollution on breast cancer in other communities,” says Rudel. Using metabolomics, a method involving advanced statistical tools, she and her team hope to identify molecular changes in the body—or signatures—that result from exposure to vehicle exhaust, and then link these molecular signatures with early markers of breast cancer risk.

The findings could also have important implications for addressing health disparities. Over the years, studies increasingly show that low-income and minority communities tend to have higher exposures to harmful air pollutants than more affluent neighborhoods. One of the main reasons for that is that poorer communities tend to be clustered around industrial sites, truck routes, and high-traffic roadways. Low-income communities also tend to have less access to health care, and suffer disproportionately from exposures to environmental contaminants linked with cancer.

“That’s why prevention efforts that include reducing exposures to harmful air pollutants are so important, not only for reducing the incidence of breast cancer, but also for reducing health disparities by addressing vulnerable populations,” says Julia Brody, executive director and senior scientist at Silent Spring.

Brody hopes her team’s research will lead to new prevention strategies that focus on creating healthier environments. Lower-emissions standards for vehicles, increased protections for communities living near high-traffic roadways such as vegetation barriers and better air filtration systems in buildings, and policies that discourage construction of housing near freeways could make a real difference, she says.

“No one should get breast cancer from breathing in bad air,” says Brody. “Luckily, there are things we can do to make our environment healthier… and help us breathe a bit easier.”

The Avon Breast Cancer Crusade is proud to support this groundbreaking research project. To learn more about Silent Spring Institute, visit www.silentspring.org.