| Ralls statement that countervailing human data on the carcinogenic effects of
chrysotile asbestos (including large numbers of mesotheliomas among Canadians)
exist is reminiscent of a similar claim by Nicholson et al. (7) in which his
exaggerated numbers were correctly put into perspective by the epidemiologists
studying the Canadian workers (8). His unreferenced conclusion that
mesotheliomas are largely from chrysotile exposure in insulation workers and
family members who were exposed to low doses ignores the fact that these
individuals encountered mixed exposures to chrysotile and amphiboles at much
higher concentrations than levels of asbestos (predominantly chrysotile)
occurring in homes and public buildings today. Moreover, Rall does not
acknowledge the significant content of amphibole fibers in the lungs of these
workers (9) as well as recent studies showing a correlation between the lung
burden of tremolite, but not chrysotile, in the lungs of Canadian miners with
mesothelioma (. |
| Dr. Finkelstein also cited five cases of mesothelioma among former
Holmes workers. Three of the five workers died at less than fifty years
of age and all were less than sixty years old! |
| The analysis of 335 cases of mesothelioma observed at the Ramazzini
Foundation and the Bologna Institute of Oncology has
shown: 1) a high percentage of correlation of these tumours with
asbestos exposure; 2) a large number of population categories
potentially exposed to asbestos fibres and therefore at risk of
developing mesothelioma; and 3) the high risk of mesothelioma
among people exposed in various circumstances to asbestos used in
railroads and sugar refinery plants.
______________________________________________________
Med Lav 1997 Jul-Aug;88(4):316-20 |
| We reviewed the certificates of 39,650 deaths which occurred in the
period 1975-1988 in Leghorn and of 45,900 in La Spezia
(Italy) in the period 1958-1988. In total 262 cases have been
recorded as pleural mesothelioma. The main occupational
exposures occurred in the shipbuilding industry. Regarding
non-occupational exposures to asbestos, 13 cases of mesothelioma
were found in women who had washed the work clothes of their
relatives at home; we also found other domestic uses of
asbestos which were rarely or never discussed previously in the
literature: six cases might be explained by the installation of
fireproof or non-conductive materials in the domestic environment.
These exposures probably are more frequent than realized until now.
__________________________________________________________
Am J Ind Med 1992;21(4):577-85 |
| Our 1990 article reported on recent papers in the peer-reviewed literature and
two international symposia, one at the International Agency for Research on
Cancer (2) and the other at Harvard University (3), all concluding that
chrysotile fibers are less active than amphibole types (crocidolite, amosite,
tremolite) of asbestos in the causation of mesothelioma in man. In his summary
of the IARC meeting, Sir Richard Doll, an eminent epidemiologist, concluded
there is the difference between the effects of chrysotile and amphiboles, which
is so great in relation to mesothelioma that it is possible to argue that
chrysotile does not cause mesothelioma at all (2). This observation has been
supported by numerous peer-reviewed papers and working groups subsequently
(4-6). |
