Soil Mineral Linked to Mesothelioma Deaths in Mexico

Concerns continue to grow over the health threat posed by a mineral called erionite. There is new evidence that erionite dust may be responsible for the elevated mesothelioma and lung cancer death rates in a remote Mexican village.

Malignant mesothelioma is usually caused by exposure to asbestos, a naturally-occurring fibrous mineral that was once heavily used in several industries. While the lungs can typically rid themselves of other types of irritants, asbestos dust fibers are small and sharp and tend to lodge in the tissue, causing cancer years later.

In recent years, a less prevalent but similarly-shaped mineral called erionite has been suspected of doing the same thing. Mesothelioma rates hundreds of times higher than average have been found in Turkish villages where erionite is prevalent, making Turkey a focal point for many mesothelioma researchers. Now, a new study finds that erionite may also be behind many mesothelioma deaths in the village of Tierra Blanca, Mexico.

Researchers with the Universidad Nacional Autonoma de Mexico examined the causes of 14 deaths from lung cancer or mesothelioma in the village between 2000 and 2012. Although asbestos-linked mesothelioma does not typically occur until people are in their 60s or 70s, the mesothelioma cases in Tierra Blanca occurred in people between 30 and 54, suggesting that their exposure happened early in life. The numbers revealed a mesothelioma mortality rate of 2.48 for men and 1.05 for women. In the U.S., mesothelioma accounts for only 12.8 deaths per million people.

“Erionite fibres were found in exposed rocks and soils, which can easily become airborne and be carried into streets and recreational areas near schools and homes,” writes Dr. M. Adrian Ortega-Guerrero.

Although the scientists did find some other cancer-causing elements in the village, including quartz dust and asbestos cement, these were found in only trace amounts and were also found in neighboring villages where the rates of mesothelioma and lung cancer were not as high. Dr. Ortega-Guerrero and colleagues conclude that erionite is the main cause of mesothelioma deaths in Tierra Blanca.

In the U.S., erionite has been found in 11 Western states and the CDC calls it “an emerging North American hazard”. Erionite has been heavily used to make road gravel in North Dakota, where road workers are now being monitored for signs of health problems.

Sources:

Ortega-Guerrero, MA et al, “High incidence of lung cancer and malignant mesothelioma linked to erionite fibre exposure in a rural community in Central Mexico”, September 17, 2014, Occupational and Environmental Medicine, Epub ahead of print

Weissman, D and Kiefer, M, “Erionite: An Emerging North American Hazard”, NIOSH Science Blog, Centers for Disease Control and Prevention website