Erionite exposure and mesotheliomas in rats

Area of Science:

• Environmental Science
• Toxicology
• Pathology

Background:

• Epidemiological surveys in Turkey linked village mesothelioma cases to zeolite fibers from volcanic tuff.
• Unusually high mesothelioma rates, despite low ambient fiber concentrations, suggested high biological activity of these zeolites.

Purpose of the Study:

• To investigate the hypothesis of high biological activity for zeolite fibers.
• To assess the carcinogenic potential of erionite from Turkey and Oregon.

Main Methods:

• Experimental studies involving intrapleural inoculation and inhalation techniques in rats.
• Comparison of erionite fibers with non-fibrous zeolites (natural and synthetic).

Main Results:

• Erionite samples from Oregon and Turkey induced a very high incidence of tumors.
• Intrapleural inoculation with Oregon erionite and Turkish fiber led to mesothelioma in nearly all rats.
• Inhalation of Oregon erionite also caused a high incidence of mesothelioma.

Conclusions:

• Erionite is a potent inducer of mesothelioma in experimental studies.
• This research identifies erionite as a significant potential human health hazard in regions beyond Turkey.