Researchers found the risk for respiratory hospitalisation was significantly higher among the survivors who received chemotherapy compared to the cancer-free group. (Photo: ANI)

Washington: A recent study claims that air pollution puts young cancer survivors at higher risk of hospitalisation due to respiratory issues. The details were published in the Journal of Environmental Research and Public Health.

Better treatments developed through research have resulted in a dramatic increase in the rates of childhood cancer survival; today, nearly 80 per cent of children diagnosed with cancer will survive their disease.

However, these survivors may experience long-term detrimental health issues related to their cancer treatment. In this project, researchers sought to better understand what a polluted environment means for the health of cancer survivors who may already be at a higher risk for illness because of the type of cancer treatment they received.

The team examined the medical records of nearly 4,000 childhood, adolescent, and young adult cancer survivors. They tracked when and how often those survivors required emergency room treatment or were admitted to a hospital due to respiratory illness.

The study was divided into three groups: those who received chemotherapy as part of their cancer treatment, those who didn't receive chemotherapy, and a cancer-free group. The researchers found the risk for respiratory hospitalisation was significantly higher among the survivors who received chemotherapy compared to the cancer-free group.

Researchers were specifically looking at what happened to survivors on unhealthy air days. The study found the risk for hospitalisations among cancer survivors was significant when air pollution (PM2.5) was below the standard for sensitive groups implying that levels below that protective standard may still contribute to respiratory problems for cancer survivors.

This is the first study to report a connection between PM2.5 levels and childhood cancer survivors requiring emergency treatment or hospitalisation for respiratory issues. Survivors of childhood cancers may have a higher vulnerability to high levels of PM2.5 because of lung damage and potential immune suppression resulting from cancer and treatment with chemotherapy.

"This study has wide application to cancer survivors in Utah as well as nationwide," said Judy Ou, Ph.D., a cancer epidemiologist at HCI and lead author on the study.

"There are approximately 17 million cancer survivors in the United States, and statistics show about 40 per cent of the US population lives in places that are considered polluted at certain times of the year. This study provides valuable information to the medical community about how air pollution affects young survivors of cancer. We can use this to inform strategies to address this risk."

Anne Kirchhoff, Ph.D., HCI cancer researcher and associate professor of paediatrics at the U of U, said, "We really haven't thought about how environmental exposures may affect long-term healthcare needs and health outcomes. We may need to rethink guidelines, both on air pollution notifications from public health agencies as well as guidelines we're giving cancer patients," said Judy Ou, Ph.D., a cancer epidemiologist.