Living near benzene release sites increases cancer risk

Living near a benzene release site – such as a refinery or plant that releases the chemical into the air or water supply – puts people at a higher risk for contracting non-Hodgkin lymphoma, according to a new study.

Risk factors for non-Hodgkin lymphoma are not well known, though the disease is more common in older individuals. Nearly 70,000 new cases appear in the United States each year, leading to nearly 20,000 deaths annually – and incidences of non-Hodgkin lymphoma are only expected to increase as the U.S. population ages.

“For many more common cancers like breast, lung or colon we have well-known associations and can describe risk factors,” study author Dr. Christopher Flowers, associate professor of hematology and medical oncology at the Emory University School of Medicine, told FoxNews.com. “But for lymphomas, those have not been nearly as well described, and it is becoming important to identify those risk factors as the population ages.”

In a study published in the journal Cancer, Flowers and his colleagues gathered data on benzene release sites in Georgia from the Environmental Protection Agency’s (EPA) Toxics Release Inventory and compared it to data on incidences of lymphoma gathered from the Georgia Comprehensive Cancer Registry.

Researchers have long known that workers exposed to elevated levels of benzene – such as factory workers – often develop adverse health effects, and in vitro studies of the chemical have revealed it to be a known carcinogen.  However, this study was the first to analyze the effects of benzene at the population level, looking at the distance and clustering of non-Hodgkin’s lymphoma around sites of benzene exposure.

After analyzing the data, researchers found that incidences of non-Hodgkin lymphoma were significantly greater than expected surrounding benzene release sites. Additionally, the population’s risk for contracting non-Hodgkin lymphoma decreased by .31 percent as their distance from the site increased by each one-mile interval.
 
“We can’t say directly that benzene is causing the cancer,” Flowers said. “But the residential proximity to the sites are associated with higher incidences of cancers.”

Though more research needs to be conducted before measures can be taken to limit people’s exposure to benzene release sites, the EPA is currently required to keep track of benzene exposure sites throughout the United States.

“There are a number of sites of exposure; some could potentially be factories, some were benzene release sites, because they were sites of toxic chemical dumping in underground stores, and some were released from other types of plants,” Flowers said.

In the future, the study’s authors hope to use their research to develop methods for decreasing exposure to lymphoma risk factors, like benzene, in the wider population.

“Our hope is that we can identify these risk factors and try to create population level approaches that could decrease risk for exposure by limiting or restricting sites of release,” Flowers said. “Another would be to provide general information to the public and population to try and identify where those risks might be increased.”

Flowers and his colleagues at the Winship Cancer Institute of Emory University are part of the International Lymphoma Epidemiology Consortium (InterLymph), an organization that is striving to better understand the risk factors for the different subtypes of lymphomas.

To locate benzene release sites near you, visit the  EPA’s Toxic Release Inventory.