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Published October 18, 2010, 01:18 PM

Study: Mineral on Western ND Roads Changes Lungs

A study has found that an asbestos-like mineral used on western North Dakota gravel roads can cause changes in the lungs consistent with commercial asbestos exposure that could lead to breathing problems.

By: Associated Press,

BISMARCK, N.D. (AP) — An asbestos-like mineral used on western North Dakota gravel roads can cause changes in workers' lungs consistent with commercial asbestos exposure that could lead to breathing problems, a study has found.

The erionite investigation did not find an increase in mesothelioma cancer — a serious disease associated with exposure to asbestos-like dust — but the results are inconclusive about whether there is an increased risk, the state Health Department and U.S. Environmental Protection Agency said Monday.

Scientists in Turkey have linked the fibrous erionite to mesothelioma. Officials said the western North Dakota tests are inconclusive on that cancer because the population is small and there is still the possibility cases could develop in the future.

State Geologist Ed Murphy, 53, who has worked in the region for three decades and notified state and federal officials about the use of erionite there in 2006, said he worries about the long-term effects of the mineral.

"You always have to be aware of it," he said. "There's likely a long wait-and-see period between exposure and when (health problems) show up. I'll probably do a CT scan in five to 10 years."

Hundreds of miles of roads in western North Dakota are covered with gravel containing erionite, found in chalky white rock mined for decades in Dunn, Slope and Stark counties.

In March 2009, officials began testing 34 volunteers who had long-term exposure, including Murphy. The testing conducted by medical investigators from the University of Cincinnati found that occupational exposure to road gravel containing erionite, especially for workers employed in road maintenance or gravel pits, can result in changes to the tissue of the lung or to the membrane that lines the outside of the lungs and the inside of the chest.

"These type of lung changes could be consistent with the same type of non-cancer effects that might happen with asbestos ... impair breathing ability, those sorts of things," said Scott Radig, the health department's waste management director.

Radig said issues such as whether someone driving down a gravel road might be at risk were not addressed in the study.

"The idea of this study was, you would look at the people who had the highest exposure," he said. "There were a couple of participants in the study who did have some lung changes that were observed. They were ... in the category of gravel pit workers and road construction."

State health officials continue to recommend that efforts be made to keep erionite gravel dust exposure as low as possible and plan to work with local, federal and University of Cincinnati officials to develop plans to further address that issue.

However, Radig said the Health Department cannot ban the gravel with erionite because it is not regulated by the state or federal governments like asbestos. He said the matter could come up before the Legislature next year.

Murphy said he thinks the results "justify the state shutting down and restricting the use of gravel that contains erionite."

Three years ago, the Health Department recommended discontinuing the use of gravel containing erionite. The state Transportation Department now bans such gravel for its state road projects. Dunn, Slope and Stark counties are working to follow the state recommendations and identify alternative sources of gravel, state officials said.

The city of Killdeer has removed affected gravel from several public areas, including a baseball diamond and a swimming pool parking lot.

Murphy said his department will take steps to reduce erionite exposure for workers who travel on gravel roads in western North Dakota.

"Sometimes just the common sense of not following right behind another vehicle; when hammering into rocks to have the wind at your backs, those kinds of things," he said.