Asbestos defendants are frequently faced with medical causation testimony from the plaintiff that asserts that, because there is no “safe” level of asbestos exposure, any exposure above some ill-defined “background” level is a substantial contributing factor to the plaintiff’s asbestos-related injury. This theory has become the centerpiece of modern asbestos litigation and discourages minimal exposure cases from going to the jury. However, a strong defense can be mounted to a minimal exposure case, particularly if plaintiff alleges exposure to chrysotile asbestos fibers.
For the toxic tort defense lawyer, an understanding of the two major families of asbestos is critical. From a toxicity standpoint, amphibole asbestos fibers are more potentially toxic than fibers of the serpentine family. Amphiboles tend to: (1) be acid resistant; (2) be persistent in the body; (3) be straight fibers; and (4) contain iron. By comparison,chrysotile asbestos, a member of the serpentine family, has a much more lower toxicity profile, particularly in low exposure settings. Chrysotile: (1) breaks down in the body; (2) is acid soluble; (3) has a soft pliable curly shape; and (4) contains dissolvable magnesium.