Publications - G Berry
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Health effects of asbestos - effect of elimination on mesothelioma rate
A theme that was developed during work on the health effects of asbestos was the concept that the
elimination of asbestos from the lungs after initial deposition was important in the later mesothelioma
incidence. The rapid elimination of chrysotile from the lungs was noted in an inhalation experiment [32].
Paper [100] was the first to note that elimination could explain apparent discrepancies between
mesothelioma rates and lung contents. The consequences of elimination on future mesothelioma
incidence were explored in papers [111, 118 and 122]. In 1999 a detailed paper was published in
Inhalation Toxicology [143]. In this paper the consequences of elimination were modeled and
explored in detail. It was shown that the slow rate of elimination of amphibole fibre from the
lungs, coupled with the faster rate for chrysotile, could be an important factor in explaining the
higher rate of mesotheliomas in people exposed to amphibole compared with chrysotile, whilst also
being consistent with the similar rates in shorter-lived experimental animals.
The effect of elimination on the relationship of the incidence of mesothelioma with time since
exposure is given by an extension of the usual power relationship, which includes a term to
incorporate a gradual elimination of asbestos from the lungs as time since exposure finished increases.
where µ is the rate of elimination [111]. This model was discussed further in 1995 [122] and
in more detail in 1999 [143]. There is good evidence that elimination of crocidolite fibre does take
place at a slow rate, in the range of 10 to 15% a year [143], and this evidence has been strengthened
by the finding [173] that the number of mesotheliomas occurring in former miners and millers at the
Wittenoom crocidolite asbestos mines and mills during 1987 to 2000 was similar to that predicted in [111]
based on observed numbers up to 1986 when an elimination model was used. Failure to allow for
elimination gave a much higher prediction than was observed. The most recent follow-up [195] shows that the
number of mesotheliomas up to 2008 remained fairly similar to the predictions based on the elimination
model, although the number during 2001 to 2008 was higher than predicted (74 observed compared with 63 predicted).
32. WAGNER, J.C., BERRY, G., SKIDMORE, J.W. & TIMBRELL, V. (1974). The effects of the inhalation of asbestos in rats. Br. J. Cancer, 29, 252-69.
100. BERRY, G., ROGERS, A.J. & POOLEY, F.D. (1989). Mesotheliomas asbestos exposure and lung burden. In: Non Occupational Exposure to Mineral Fibres, eds. J. Bignon, J. Peto & R. Saracci, 486-96. IARC Scientific Publications No. 90, Lyon.
111. BERRY, G. (1991). Prediction of mesothelioma, lung cancer, and asbestosis in former Wittenoom asbestos workers. Brit. J. ind. Med., 48, 793-802.
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118. BERRY, G. (1993). Mesothelioma incidence and time since exposure to asbestos, In: Health Risks from Exposure to Mineral Fibres: An International Perspective - Proceedings of the International Symposium on the Health Effects of Low Exposure to Fibrous Materials, Kitakyushu, Japan, 26-27 November 1991, ed. G.W. Gibbs, J. Dunnigan, M. Kido & T. Higashi, 40-48. Captus University Publications, North York, Ontario, Canada.
122. BERRY, G. (1995). Environmental mesothelioma incidence, time since exposure to asbestos and level of exposure. Environmetrics, 6, 221-228.
143. BERRY, G. (1999). Models for mesothelioma incidence following exposure to fibers in terms of timing and duration of exposure and the biopersistence of the fibers.
Inhal. Toxicol., 11, 111-130.
173. BERRY, G., de KLERK, N.H., REID, A., AMBROSINI, G.L., FRITSCHI, L., OLSEN, N.J., MERLER, E., & MUSK, A.W. (2004). Malignant pleural and peritoneal mesotheliomas in former miners and millers of crocidolite at Wittenoom, Western Australia. Occup. Environ. Med. 61, e14, 1-3. (http://www.occenvmed.com/cgi/content/full/61/4/e14).
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195. BERRY, G., REID, A., ABOAGYE-SARFO, P., DE KLERK, N.H., OLSEN, N.J., MERLER, E., FRANKLIN, P.
& MUSK, A.W. (2012). Malignant mesotheliomas in former miners and millers of crocidolite at
Wittenoom (Western Australia) after more than 50 years follow-up.
Br. J. Cancer 106, 1016-1020.
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