A survey of the health problems associated with the production and use of high density chrysotile products

Chrysotile asbestos has been used in high density cement and friction products for nearly one hundred years. Since this paper is not presented as a definitive history of asbestos in all its guises and since early developments in friction products involved textiles among a variety of other materials and a quite different technology to that used today it seems reasonable to restrict the contents to those products developed and used in the last 50 years. In that time, of all the world production of chrysotile some 90% has been used in asbestos-cement products such as pipes, plates, sheets, mouldings and shingles (tiles). Some 7% is used for friction products such as brake linings and clutch facings and only 3% is used in other materials including textiles, clothing, electrical insulation materials, gaskets, paper products, vinyl sheet and vinyl floor tiles – where chrysotile has been used as a filler – and as a filler in cement, plastics, roof coatings and various mastic and caulking compounds.

Health and safety records for workers in the chrysotile industry have been kept for perhaps only the last 60 years. They show few health problems among those involved in the manufacture and use of these products even in the early days when there was little attempt at dust suppression. This has been borne out by every health study of chrysotile cement or friction product workers that has ever been carried out. Concerns about the use of chrysotile in such products have been raised by those who have used health statistics from other forms of asbestos or from mixed fibre exposures or who have failed to understand the confounding role of smoking in the epidemiology. The concerns have been compounded through reliance on questionable mathematical models, rather than actual worker health data. It is relevant at this point to note that no such risk models have been used to calculate worker health risks from the use of substitute fibres in these products. In fact regulators have, at times, deliberately avoided the issues of toxicity for substitute fibres and not questioned the claims that they are safe. This ‘turning a blind eye’ has strengthened the call for a ban for all asbestos products in a number of countries. Such a ban has been successfully carried in the EU, but failed in countries including the US, Canada, Brazil and India. The ban in the EU extends to all forms of asbestos regardless of type and regardless of product. ‘Alternative materials’, production of which is largely seated in the countries keenest on a ban, give an economic rationale. In the EU there is cynicism in the official reason that the ban was to protect the health and safety of workers. Anyone truly concerned would have taken heed of the following:

  • An INSERM report [5; p. 2] on the health effects of several asbestos substitutes notes: “Because the fibre structure of asbestos is a major pathogenic factor, any new fibre proposed as an asbestos substitute (or for any other use) should automatically be suspected of being pathogenic because of its structure.”
  • The Scientific Committee of the European Commission’s Directorate General DG XXIV stated in a February 1998 report that: “…there is no significant epidemiology base to judgethe human health risks (of substitutes) …….hence the conclusion that specific substitute materials pose a substantially lower risk to human health, particularly public health, than the current use of chrysotile, is not well founded…..” [12].

Misinformation about asbestos is not the prerogative of the official world but is particularly rife in the public domain. The media in their constant search for sensationalism have created a climate where the word “asbestos,” now causes immediate panic verging on hysteria. As with some other environmental problems, heavy occupational exposure to asbestos is counted equal with very low environmental exposure. The level of disease, which at the worst occurs in less than 10% of those exposed occupationally is translated by many, and particularly the media, to a death sentence following the tiniest exposure in the public arena. While it is true that asbestos, particularly blue and brown asbestos, in even modest quantities, are a significant health risk for those occupationally and also para-occupationally exposed this is not the case for chrysotile (white asbestos). Dangerous levels of exposure can result from those who just live near blue asbestos mines where fine weather and mine tailings used as road metal keep high concentrations of fibres in the air. However, studies (Camus…) of the very large population who live near chrysotile mines or on chrysotile ore bodies has shown that there is no excess asbestos-related disease in these areas. Even industrially the comparatively small danger posed by the present low levels of exposure to chrysotile in the industry cannot be shown to produce a significant risk of disease.

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