Erionite in road gravel associated with interstitial and pleural changes--an occupational hazard in western United States.

OBJECTIVE

To determine the rate of chest radiographic abnormalities among residents of North Dakota potentially exposed to road gravel containing the fibrous mineral erionite.

METHODS

Participants (n = 34) completed a questionnaire, chest radiograph, and high resolution computed tomography scan to assess the rate of interstitial and pleural changes consistent with fibrous mineral exposure.

RESULTS

Interstitial, pleural, or both changes typically associated with asbestos exposure were observed by high resolution computed tomography in seven (21%) individuals. The primary exposure pathway for six of these was from gravel pits, road maintenance, or both. Three participants (8.8%) demonstrated bilateral localized pleural changes with calcification; two of these also had accompanying interstitial changes. All three reported extensive work in gravel pits, road maintenance, or both.

CONCLUSIONS

These results indicate that occupational exposure to erionite contained within road gravel in the United States represents a potential health hazard.

CLINICAL SIGNIFICANCE: This study identifies chest radiographic changes among residents of North Dakota occupationally exposed to road gravel containing erionite. Public health officials and physicians in affected areas should be aware of the potential health effects of erionite exposure. Precautionary measures should be taken to limit occupational exposure to gravel containing erionite.