What Is Erionite?
Erionite is a fibrous mineral that is found naturally and belongs to a class of minerals known as zeolites. It typically appears in volcanic ash that has undergone weathering and groundwater-induced changes. A.S. Eakle initially identified erionite in 1898 as white, fuzzy, fibrous masses in rhyolite lava cavities at Durkee, Oregon. Erionite has a molecular structure that resembles that of chabazite. Erionite forms fibrous masses inside hollows of rock formations that are brittle and look like wool. Erionite and asbestos have similar characteristics and properties. However, the U.S. Environmental Protection Agency does not currently regulate erionite, and there are no occupational exposure restrictions for erionite.
Where Is Erionite Found?
Erionite is widely spread and distributed in all continents. Erionite is found in numerous places, but it has received the most attention in Turkey and the western states of the United States of America (USA). However, comprehensive information about locations and extent of erionite in different parts of the world is hard to find. According to reports, certain volcanic tuff (volcanic ash) contains erionite.
Does Erionite Cause Cancer?
Yes, unfortunately, erionite is a known carcinogen (cancer-causing agent). The International Agency for Research on Cancer has classified erionite as a Group 1 carcinogen since it is known to cause cancer in humans. Erionite's carcinogenicity in animal studies has been sufficiently demonstrated. Mesotheliomas were common in rats treated to erionite by inhalation, injection, or intraperitoneal injection.
In three Turkish villages where erionite exposure was extensive, descriptive research found an increase in the number of deaths by mesothelioma (cancer of the tissues lining several organs). In two of the three erionite-contaminated villages, a higher-than-average rate of lung cancer was also noted. Respirable erionite fibers were found in lung tissue samples taken from mesothelioma patients as well as in air samples taken from the affected villages.
The erionite found in Central Anatolia, Turkey, has been studied for its carcinogenic properties, but when it was compared to the erionite acquired in North Dakota, USA, no difference in their carcinogenic capacity was identified.
Which Cancer Is Associated With Erionite?
Cancers that are commonly associated with erionite exposure are:
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Mesothelioma: Mesothelioma is a cancer that originates in the lining that protects and covers the outer surface of several organs of the body. Mesothelioma is known to occur due to asbestos exposure, but it also occurs due to erionite exposure.
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Lung Cancer: Lung cancer is a form of cancer affecting the lungs. This type of cancer is generally reported in chronic smokers, but it may also occur due to several other causes.
How Are People Exposed to Erionite?
In the past, erionite mining and industrial operations exposed workers to the substance. Erionite, however, is no longer mined or sold commercially. Erionite occupational exposure nowadays mostly happens during the mining and manufacture of other zeolites. It has also been claimed that erionite is a minor ingredient in a few commercial zeolites. Therefore, the general public and employees who utilize zeolites in a range of processes and products may be exposed to erionite due to the usage of other zeolites. Other naturally occurring zeolites are used commercially as gas absorbents, pet litter, soil conditioners, animal feed, and wastewater treatment systems.
In an open-pit zeolite mine in Arizona that also contained some erionite, miners' total exposure to dust ranged from 0.01 to 13.7 mg/m3 (milligram per cubic meter), and the area's respirable dust concentration ranged from 0.01 to 1.4 mg/m3.
Road construction and maintenance employees who may have been exposed to erionite-containing gravel used on road surfaces have been documented to have a high incidence of erionite-related disease.
How Can Erionite Exposure Be Reduced?
Erionite fibers in the air are not subject to any regulations, standards of agreement, or occupational exposure restrictions. It could be possible to restrict the production and inhalation of dust that is known or suspected to be contaminated with erionite by following the U.S. Occupational Safety and Health Administration's guidelines for working with asbestos. Since asbestos exposure occurs in the same way as erionite exposure, and they also cause similar health hazards, it will be best to follow similar guidelines to restrict erionite exposure.
Conclusion:
Erionite is a naturally found element that belongs to a class of silicate minerals known as zeolites. It is typically present in volcanic tuff (ash) that is altered by weathering and groundwater effects. Fibrous erionite is carcinogenic, and it is frequently associated with mesothelioma and lung cancer. There are no occupational exposure limits (OEL) or regulatory or consensual standards for airborne erionite fibers. Control suggestions should concentrate on lowering the possibility of exposure to airborne erionite fibers since erionite fibers only become hazardous when disturbed and become airborne.
