C.Thomas Hess, University of Maine professor of physics. (Photo courtesy of the University of Maine)

ORONO, Maine — "You will not find bears unless you hunt for bears," says University of Maine physics professor C. Thomas Hess. Likewise, he said, people who don’t test their homes for the presence of radon might never identify the presence of the potentially deadly gas. But that doesn’t mean it isn’t there.

Hess, an early researcher into the presence of radon in homes, says most people are insufficiently concerned about their everyday exposure to the radioactive gas.

While radon was identified more than 100 years ago as a cancer-causing hazard for uranium miners in the U.S., Canada and Europe, he said, the recognition of its presence at high levels in many homes is much more recent.

In the early 1970s, Hess was testing the area around the Maine Yankee nuclear power plant in Wiscasset for radiation escaping from the reactor. He and other researchers were staying at local farms and discovered that radiation levels were high in the air inside the homes and the well water piped into them.

“There was 100 times more radiation there than anything coming from the reactor,” he said. “I thought, ‘I’m studying the wrong thing.’”

A discussion with a state geologist revealed that the Panther Point area near Wiscasset was rich in a type of granite also plentiful in the areas around Mount Katahdin, Prospect, Mount Desert Island and Red Beach in Calais, among other areas. Hess and his team theorized that radiation from the breakdown of uranium in the formations was accumulating in the air and water of the homes built in those areas.

Hess’ team shared its preliminary findings with the federal Environmental Protection Agency and Department of the Interior and in 1978 obtained funding to study the correlation among certain geologic deposits, radon in groundwater and lung cancer rates.

“We studied radiation all over Maine,” Hess said. The results, he said, were “dynamite” — showing a clear correlation between radon in well water and lung cancer cases here.

National research followed, including a landmark study of elevated radon levels in homes built along the uranium-rich Reading Prong formation that stretches from western Pennsylvania into Connecticut.

“This was a revolution, that’s what it was,“ Hess said. “We had been neglecting this thing, but all of a sudden we weren’t neglecting it anymore.”

But despite ongoing academic interest in the issue, Hess is frustrated that radon has not gotten more attention from the public health world.

“If you have granite, I’m willing to bet you have radon,” he said. Limestone is another type of radon-releasing rock that is plentiful in Maine, he noted.

Hess’ early research continues to inform the issue and is currently being entered into the database of a new mapping partnership between the Maine Institute for Human Genetics and Health in Brewer and the Old Town-based James W. Sewall Co.