Health officials have determined an asbestos-like mineral found on 100 miles of Dunn County roads can be breathed into the lungs.

The Environmental Protection Agency, along with the State Health Department, will meet with the public and Dunn County residents at 6:30 p.m. Tuesday at the Killdeer school to talk about its findings on eronite and what the future holds.

The mineral eronite occurs naturally in the Killdeer Mountains and in other counties. Health officials have known since 2006 that the potentially cancer-causing mineral is found in gravel deposits that have been mined and used on public roads and parking lots.

Dunn County officials have adhered to a State Health Department recommendation to not use any more of the eronite gravel for now.

The EPA collected and tested samples, and found that the eronite in Dunn County does have a "complete exposure pathway."

Scott Radig, the health department's director of waste management, said that means the mineral particles are the right microscopic size to collect in lung tissue; neither too small to be exhaled, nor too large to be airborne in the first place.

Inhalation of eronite has been linked to lung diseases, including cancer, in Turkey.

However, it is not regulated by the EPA.

Radig said exposure would occur from breathing eronite-laden dust raised by vehicle traffic, raking or extreme wind gusts.

The State Health Department hopes to reduce human exposure over the long term, once more is known about the eronite.

EPA community coordinator Libby Faulk said agency representatives want to tell the public about the sampling already done and its plans to do more sampling and testing. She said nothing is known about the health risk for individuals.

Radig said the point of the meeting will not to be to set off a panic, but to let people know there is a potential problem if eronite is airborne.

"It can be breathed in," he said.

He said it's more possible the state would recommend dust control measures than removing all those miles of road gravel.

In time, other gravel on road surfaces could eventually cover the eronite.

A map on the Health Department's Web site shows that eronite, a residue of volcanic ash, is found in capstone rock in the Killdeer Mountains, the "little Badlands" southwest of South Heart in Stark County, in White and Chalky buttes in Slope County, and elsewhere in southwestern North Dakota counties.