Radon and Cancer
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Geospatial and temporal information about radon in Maine water and bedrock will be among the first data sets entered in the new Maine Cancer Geographic Information System (MeCancerGIS), being developed by University of Maine and Jackson Laboratory researchers as part of Biobank of Maine.

Since the early 1970s, the radioactive element has been the focus of pioneering research at the University of Maine led by nuclear physicist Charles Hess. He and UMaine geologist Steve Norton were among the first in the nation to clearly link high radon concentrations and granite and high-grade metamorphic bedrock. Their work helped establish state and federal Environmental Protection Agency standards for radon levels, and contributed to better understanding of the health risks posed by the naturally occurring gas.

"Early studies showed geology made a big difference," says Hess, who also collaborated in those early years of research with experts such as UMaine hydrologist and civil engineer Willem Brutsaert. "In those days, radon was known about but largely ignored. It was known to be a problem in mines. Those who worked silver mines got lung cancer, what they called mountain sickness. They found radon gas was the cause."

Since then, radon has been established as a risk factor for lung cancer, but its correlation to other cancers is still debated.

"Radon causes more than 50 percent of the total radiation exposure (to humans) each year," Hess says. "When it's in the water, it causes the most damage to the lungs and inner organs."

The most recent radon study out of Hess' lab was conducted by then physics graduate student Paul Smitherman. In 2006-07, Smitherman collaborated with a Columbia University research team studying arsenic in well water in the Augusta area. Arsenic also is a known carcinogen for lung cancer.

Smitherman tested for radon in more than 1,000 wells, mapping the measurements against the geology. The trends he found are expected to be published in the journal Environmental Science and Technology. They also will be entered into MeCancerGIS.

"Mapping gives us a tool for data visualization to begin analysis. Especially when working on some advanced statistical analysis, it provides a technique for understanding the data in space and time," says Smitherman, now a research assistant in the Department of Spatial Information Science and Engineering, where he is doing computer programming and data analysis on MeCancerGIS.

"In the long run, we will be able to see what really are the highest risk factors for cancer," Smitherman says. "There are a lot of theories, but the risk factors are hard to determine when the lag time for cancer is 10-20 years, from exposure to onset of disease. We have some data now and we want to keep it going over time. More data will allow us to get more precise in our anaylsis of the risk factors and zero in on prevention. We're hoping to fine tune the cancer epidemiological process, including what to look at."

Smitherman's radon research involved more sophisticated averages by geological unit and other criteria than the groundbreaking studies of radon in water in Wiscasset and Sebago, Maine, says Hess. But the health concerns about radon remain.

"The risk is not in parts per million. With radon, it's parts per hundred, which makes toxicologists and public health people nervous," Hess says. "Radon is a problem all over the world, but there's tremendous apathy.

The apathy, says Hess, is due in part to the fact that radon is colorless, odorless and pervasive throughout the environment, including the air. The problem comes when people live in areas where the geology - especially high-grade rock like granite - results in particularly high levels of radon. It's then that high radon levels can threaten the value of many people's biggest investments - their homes.

"One of the unsolved problems is how to convince people of something that's known to be a problem," says Hess. "People think it couldn't possibly be found in their homes, that it's someone else's problem."

Hess urges homeowners to monitor the radon levels in their houses and drinking water and, if found to be high, take steps to mitigate the risk.