Asbestos fibers occur in two basic forms: amphiboles, which are straight needle-like fibers, and serpentine asbestos, whose fibers are curled and more flexible. Chrysotile or white asbestos is the most commonly encountered form of asbestos, accounting for approximately 95% of the asbestos in place in the United States, and the commonest means of exposure for workers in industries which use asbestos.
Early studies had suggested that only amphiboles caused cancer. Considerable epidemiological research has established that inhalation of Chrysotile fibers, which are serpentine, can cause mesothelioma.
The hearings, held by the EPA's panel of 20 scientists, were to gather testimony about changes the agency was proposing in the way it measured chrysotile concentrations. The changes were made in response to pressure from industries which still manufacture or use asbestos, and also from the White House. The changes would have ignored decades of solid epidemiological studies documenting the high toxicity of chrysotile.
Leading asbestos scientists, public health experts, physicians who treat mesothelioma, and asbestos victim's advocates testified at the July hearings against the agency's plan to change how it estimates potential cancer risk for those who have inhaled microscopic asbestos fibers.
The Scientific Advisory Board's report agreed that there are differences in toxicity among the six forms of asbestos, but said the EPA's data were weak, and did not provide justification for changing the current standards.
The report dealt a significant loss to the industries that had pushed for the change as a defensive tool in the thousands of asbestos injury cases they still face. The EPA's decision to override its own advisory panel's report is likely to meet with stiff resistance within the asbestos victims' community.
Frederick Schenk, a leading San Diego mesothelioma lawyer has been representing victims of asbestos caused disease for more than 20 years. His team of attorneys, paralegals and investigators work closely with medical professionals and industry consultants to provide the highest quality of services for those facing a mesothelioma diagnosis.