Environmental asbestos may be to blame for higher-than-expected numbers of mesothelioma cases among younger people and women in Nevada. That conclusion comes from a newly-published report from top cancer researchers.
Malignant mesothelioma is caused almost exclusively by the mineral asbestos and affects the membrane that surrounds the lungs, heart, or abdominal organs. Although it is extremely rare, it is also highly lethal. Since the regulation of asbestos in industries like construction and manufacturing in the 1970s, most mesothelioma cases now occur in older men who were exposed on the job decades ago.
But the story is different in Nevada. Whereas occupational asbestos exposure typically causes mesothelioma at a rate four to eight times greater in men than in women, mortality data between 1999 and 2010 shows that men and women in southern Nevada are contracting the deadly cancer in about equal numbers. Mesothelioma is also being diagnosed there in a higher-than-normal percentage of people under 55. Both trends are more consistent with environmental than occupational asbestos exposure.
Driven by these trends, and given the fact that Nevada never had any major asbestos industries, a research team including scientists from Hawaii, Nevada, and Pennsylvania studied the state’s geology, looking for carcinogens. They found a range of natural toxins in Nevada’s soil including both asbestos and erionite, another mineral linked with mesothelioma.
According to a new article in the Journal of Thoracic Oncology, residents of two southern Nevada counties appeared to be at particular risk for mesothelioma. “We discovered that, compared with the U.S. and other Nevada counties, Clark and Nye counties in southern Nevada had a significantly higher proportion of malignant mesothelioma that occurred in young individuals and in women,” states senior author Michele Carbone of the University of Hawaii Cancer Center.
Asbestos and erionite in the soil can be released by human activities such as digging or even hiking. Natural processes such as wind and water can also cause these minerals to become airborne, which increases the risk of mesothelioma. Both asbestos and erionite are “biopersistent”, meaning that it is difficult or even impossible for the body to rid itself of these irritants once they have been inhaled or ingested.
The authors recommend further research to identify the highest risk areas in Nevada and to determine what activities are responsible for releasing environmental asbestos.
Baumann, F et al, “The presence of asbestos in the natural environment is likely related to mesothelioma in young individuals and women from Southern Nevada”, February 7, 2015, Journal of Thoracic Oncology, Epub head of print