Air Pollution Linked With Higher Risk of Childhood Cancer, But Green Spaces Could Counteract It
Michelle Milliken
Exposure to certain environmental factors has been linked with an increased risk of childhood cancers. Those exposures include tobacco smoke, pesticides, and air pollution. In fact, 2022 research showed that traffic-related air pollution is linked specifically with childhood leukemia. Researchers from the University of Minnesota recently investigated the impacts of air pollution on cancer risk and whether or not the greenness of a child’s neighborhood could counteract it.
The study, published in the Journal of the National Cancer Institute, looked at data from childhood cancer patients in Texas between 1995 and 2011, along with data from their cancer-free peers, to see how exposure to traffic-related air pollution and green space may have impacted their health. The goal was to work toward identifying exposures that could be addressed to lower a child’s risk of developing cancer, a topic which isn’t currently all that well understood.
Dr. Lindsay Williams, lead researcher and assistant professor at University of Minnesota’s Medical School, explains, “As a childhood cancer epidemiologist, I am always concerned with identifying factors that increase risk of cancer development in kids. There is growing evidence that air pollution during pregnancy and fetal development increases the risk of developing some diseases in children, including cancer.”
Dr. Williams and her team examined health data from more than 6,000 childhood cancer patients up to age 16, along with just under 110,000 controls. They looked specifically at the average particulate matter (PM2.5) and vegetation density at the children’s home address during their birth year.
The researchers found that higher exposure to PM2.5 during a child's birth year was linked with a higher risk of all childhood cancers, specifically lymphoid leukemias, Hodgkin and non-Hodgkin lymphomas, thyroid carcinoma, retinoblastoma, and the brain cancer ependymoma.
On the other hand, increased vegetation density near their homes was associated with a lower risk of ependymoma and another brain cancer, medulloblastoma. However, children in such green spaces also faced a higher risk of malignant melanoma and Langerhans cell histiocytosis.
The researchers say the findings “highlight the complexity between PM2.5 and [vegetation density] in cancer etiology.” However, the study also suggests that air pollution exposure and nearness to green spaces may be modifiable risk factors that can be addressed through policies promoting more tree planting and mitigating environmental concerns.
The team is now working on further research to see how the timing of exposures during pregnancy and other air pollutants may impact childhood cancer development.
