Exposures to environmental hazards can have a broad range of impacts on our health, from asthma attacks in poor air quality to heat-related illness in vulnerable populations during heatwaves, as well as a possible increased risk of developmental disabilities and neurological diseases. They’ve also been linked with an increased risk of certain cancers, and a new study finds in one state, this is reflected in breast cancer rates by county.
Research recently published in the journal Scientific Reports investigated how multiple exposures to environmental contaminants impact breast cancer risk. Using data on breast cancer diagnoses and regional environmental quality in North Carolina, the team found that in counties with poor environmental quality, there were more cases per 100,000 residents. Higher rates of early-stage cancer were also found in areas with poor land quality, especially in urban counties. The researchers say their study highlights the need to better understand how cumulative environmental exposures may impact breast cancer figures.
Dr. Gayathri Devi, the study’s senior author and Program Director of the Duke Consortium for Inflammatory Breast Cancer at the Duke Cancer Institute, says, “Individual environmental contaminants have long been associated with breast cancer, but we have limited understanding of how multiple exposures simultaneously affect this disease.
“Our study explored the incidence of breast cancer within the context of the Environmental Quality Index (EQI) – a county-by-county assessment of air, water, land, built environment, as well as the sociodemographic environment. This type of data analysis allows for a high-level look at broader environmental factors and health outcomes.”
In addition to data from the Environmental Quality Index, the team looked at breast cancer incidence rates from the North Carolina Central Cancer Registry, along with data on cancer stages within rural areas versus urban areas.
The researchers found that counties with poor overall environmental quality had 10.82 more cases of breast cancer per 100,000 people than those with good environmental quality. This was mostly driven by early-stage breast cancer. Meanwhile, areas with poor land quality, especially cities, saw a link between environmental exposures and higher total breast cancer rates. Those environmental land exposures include pesticides and toxic industrial and agricultural releases.
The team hopes that their findings ultimately help tackle higher rates of breast cancer in such communities.
Larisa Gearhart-Serna, lead author and Ph.D. candidate at Duke, says, “Our analyses indicate significant associations between environmental quality and breast cancer incidence, which differ by breast cancer stage and urbanicity, identifying a critical need to assess cumulative environmental exposures in the context of cancer stage. This has the potential to develop measures to reduce disease incidence in vulnerable communities.”
Past research has also found a link between levels of forever chemicals PFAS and hormone-related cancers, like breast cancer. You can read more on that here.