Calling erionite "an emerging North American hazard," the National Institue for Occupational Safety and Health (NIOSH) says a growing body of evidence links the substance to serious health effects includng lung disease.
Until recently, there was little recognition of the exposure risk and potential health hazards of erionite, a naturally occurring mineral found in volcanic ash that has been altered by weather and groundwater. Disturbance of the material can generate airborne fibers that can cause health effects similar to those caused by asbestos. Another similarity to asbestos: erionite deposits are present in many Western states.