Cardno ChemRisk publishes updated analysis on “no-effect” levels for chrysotile asbestos for mesothelioma and lung cancer

Pierce et al. published “An updated evaluation of reported no-observed adverse effect levels for chrysotile asbestos for lung cancer and mesothelioma” in the online version of the Critical Reviews in Toxicology journal last month. This article is an update to the review article published in 2008 titled “An evaluation of reported no-effect chrysotile asbestos exposures for lung cancer and mesothelioma.”

The general findings of the updated study are:

· Based on our review of 16 eligible groups of chrysotile-exposed workers, we determined a best-estimate NOAEL range for lung cancer of 89-168 fibers/cc-years and for pleural mesothelioma of 208-415 fibers/cc-years. 

· None of the studies of workers exposed to medium and short (grade 4 – 7) chrysotile reported an increased risk of either disease at any exposure level.  This supports that medium and short fiber chrysotile, which was used in hundreds of products (e.g., automotive brakes, and clutches, gaskets, roofing products, joint compound, etc.) may have no carcinogenic potential.

· Of the seven cases of peritoneal mesothelioma reported in all studies combined, none were observed in the analyses of medium and short chrysotile-exposed workers in the absence of crocidolite exposure.

The abstract of the article is available here.

Please contact Jennifer Pierce for more information.