UK Chief Science Adviser Completes Chrysotile Review
This type of asbestos is currently classified as a Class 1 carcinogen, and Sir John Beddington concluded there's no justification for an imminent change in that classification.
The chief science adviser to the British Government, Sir John Beddington, has finished a requested review of the classification of chrysotile asbestos as a Class 1 carcinogen. After convening experts and reviewing the scientific literature, Beddington concluded there is no justification for making an imminent change in that classification.
The Health and Safety Executive posted Beddington's report and also meeting notes from a March 7 meeting in London with the expert panel. They concluded there is consistent evidence that chyrsotile causes lung cancer, "though there is less consistent evidence and more uncertainty with regard to causation of mesothelioma, particularly at low levels of exposure." This supports the current classification, they agreed. An annex in the notes lists peer-reviewed papers, books, and other resources the panel considered, as well as some papers referenced at its meeting but not circulated among the members beforehand.
It is not possible to determine a threshold level below which exposure to "pure" chyrsotile is safe for human health, and this is also true for exposure to chyrsotile from cement during remediation and disposal activities, they concluded. Chyrsotile readily breaks down in the lungs and is less biopersistent than other amphibole forms of asbestos, but there is insufficient evidence presently to determine the toxicological action of chyrsotile, the notes indicate.
The panel concluded the relative risk of lung cancer from chrysotile cement exposure during remediation and disposal is low when compared with mining or textile production.