This week the North Dakota Department of Health and the Environmental Protection Agency (EPA) announced the completion of a study that measured the risk of inhaling dust from gravel containing the mineral fiber erionite.
Mark Dihle, environmental scientist for the department of health’s division of air quality, said, “We didn’t find an increase in mesothelioma, but it [the study] does suggest that possible high exposure to road gravel can possibly lead to [lung] changes.”
The study, which began in March 2009, did not discover an increase in mesothelioma incidence, but did report occupational exposure to erionite gravel can cause lung tissue damage. The type of lung tissue changes found in the study were similar to those found in occupational asbestos exposure.
Mesothelioma is a rare form of cancer caused almost exclusively by asbestos exposure. Because there is no cure for this disease, the mesothelioma life expectancy for most patients averages between four and 18 months after diagnosis.
Due to its resemblance to asbestos, many believe exposure to erionite may lead to the development of mesothelioma. Ed Murphy, a geologist in North Dakota, first notified the EPA about the erionite in western North Dakota several years ago upon learning the mineral was being linked to mesothelioma in Turkey.
Although the erionite in North Dakota is slightly different than erionite in Turkey, health officials were concerned about the possible connection between exposure and mesothelioma. In Turkey, erionite is considered to be a carcinogen and scientific studies have linked it with mesothelioma.
The EPA reports erionite is found in at least 12 states in the western United States, but not to the same degree found in western North Dakota (where the mineral has been used on many rural roads). The EPA also reports that erionite has been shown to cause cancer in lab rats, but the mineral remains unregulated by the agency.
Initially, state health officials and the EPA hoped for 50 people to sign up for the study to receive chest X-rays and CT scans, which were sent to a team of researchers at the University of Cincinnati. A total of 33 participants with erionite exposure were gathered for the study.
“We didn’t have as large of a group as we would have liked, but we still had a diverse group participate in the study. Even before the medical study, based on our recommendations, the counties have been working to remove gravel from affected areas, and the EPA has been working to help identify areas,” Dihle commented.
Additional information about mesothelioma may be found through the mesothelioma Center.