Cancer Mortality among Workers Exposed to Amphibole-free Chrysotile Asbestos

Abstract

The issue of whether exposure to chrysotile asbestos alone, without contamination from amphibole asbestos, causes lung cancer and mesothelioma was investigated in a 25-year longitudinal study (1972-1996) in Chongqin, China. The study cohort comprised 515 male asbestos plant workers exposed to chrysotile only; the control cohort included 650 non-dust-exposed workers. The results of analysis in which the proportional hazards model was used indicated that mortality due to all causes, all cancers, and lung cancer was related to asbestos exposure; the relative risks, adjusted for age and smoking, were 2.9, 4.3, and 6.6, respectively. Fiber concentrations in the raw material section and the textile section of the plant were 7.6 and 4.5 fibers/ml, respectively. Because of differences between the study and control plants, the authors also compared various sections of the asbestos plant that had different levels of dust exposure. The adjusted relative risk of lung cancer was 8.1 for workers exposed to high versus low levels of asbestos. Two cases of malignant mesothelioma, one pleural and the other peritoneal, were found in the asbestos cohort. These results suggest that heavy exposure to pure chrysotile asbestos alone, with negligible amphibole contamination, can cause lung cancer and malignant mesothelioma in exposed workers.

Cancer mortality in a cohort of asbestos textile workers

“…Cohort studies found increased incidence and mortality from mesothelioma among (chiefly male) asbestos workers employed in mining (Piolatto et al, 1990;McDonald et al, 1993), but mainly textile and manufacture (Newhouse and Berry, 1979;Berry et al, 2000;Yano et al, 2001), insulation (Selikoff et al, 1979) and asbestos-cement factories (Tulchinsky et al, 1999;Ulvestad et al, 2002). Mesothelioma risk varied widely among different studies, according to types of asbestos involved (chrysotile, amosite or crocidolite) (Hodgson and Darnton, 2000) and levels of exposure (Doll and Peto, 1985).…”

Peritoneal Mesothelioma and Asbestos: Clarifying the Relationship by Epidemiology

“…This finding is contrary to other studies that claim a lesser causal relationship between asbestos exposure and peritoneal mesothelioma in women as compared to men [20]. There have been other reports of peritoneal mesotheliomas in occupational groups exposed to chrysotile asbestos from all over the world including China [44,45] Italy [46,47] Australia [48] and Canada [42,49].…”

The Rough Path to the Compensation of Asbestos Damages in China

“…While in cases in which the employers compensate the injured worker for the medical costs with a lump sum, calculated on the previous earning power, the workers needing a continuous medical treatment could not be able to afford all the medical care expenses [134] (pp. [12][13][14][15] and [136,137].…”