Weis addresses industrial hygiene group on mineral fibers
By Eddy Ball
NIEHS Toxicology Liaison Chris Weis, Ph.D., was on the road last month speaking on the link between hazardous mineral fibers and an epidemic of respiratory ailments, including mesothelioma, lung cancer, asbestosis, and non-malignant pleural disease.
Weis addressed an audience of professionals concerned about workplace safety and public health on the final day of the 37th annual meeting of the Yuma Pacific Southwest section of the American Industrial Hygiene Association (AIHA) (http://www.aiha.org/Pages/default.aspx) Jan. 18-20 at the Crowne Plaza in Irvine, Calif. Weis was a presenter during a special session titled “Fourth Wave: Ambient Exposures to Asbestos and Elongated Mineral Particles.”
Weis is among a growing number of toxicologists, biomedical researchers, and regulators striving to raise awareness of the ongoing hazards associated with occupational and environmental exposure to asbestos and asbestos-like fibers found in natural deposits, and in engineered nanomaterials (ENMs), which are used in a growing number of consumer and medical products.
“Over the past two decades, between 100,000 and 200,000 deaths have been attributed to fiber inhalation,” Weis told the audience. “Between the 1960s and 1990s, asbestos mortality increased nearly 20 fold and rates of mesothelioma continue to rise.”
Opening the asbestos box
Weis emphasized that researchers, industrial hygienists, and occupation medicine specialists need to look beyond the narrowly employed definition of asbestos, to better understand the potential health consequences of inhalation of micro- and nano-sized fibers. While there is general awareness of the hazards of asbestos exposure, he said, there is much less awareness of potential health effects from exposure to other naturally occurring minerals, such as erionite (see story (http://www.niehs.nih.gov/news/newsletter/2011/november/science-erionite/index.cfm) ) and some ENMs, which behave in ways similar to asbestos and, like erionite, could turn out to be even more dangerous.
Moving beyond the well-known link between asbestos and cancer, Weis summarized ongoing research into the molecular basis of inflammation and autoimmunity triggered by mineral fiber exposure. He also described NIEHS efforts with partners in government, nonprofits, and private enterprise to find better ways to define the mechanisms of fiber bioactivity, persistence, and distribution in mammalian models.
“We don’t have definitive answers yet,” Weis concluded, “but we have reasons to keep looking at these fibers.” He pointed to the likelihood of additional discoveries of deposits of erionite and other zeolite minerals, as well as the many unanswered questions about the potential effects of the physical, chemical, and electrical characteristics of ENMs and other nano-sized fibers that are capable of crossing protective barriers in the human body.