An update of a mortality study of talc miners and millers in Italy

Our plain-English summary of An update of a mortality study of talc miners and millers in Italy, by M. Coggiola, D. Bosio, E. Pira, et al (American Journal of Industrial Medicine, 2003).

The study

• Authors: M. Coggiola, D. Bosio, E. Pira, P.G. Piolatto, C. La Vecchia, E. Negri, M. Michelazzi, A. Bacaloni
• Journal: American Journal of Industrial Medicine
• Published: 2003;44(1):63-9
• Cited by: 62 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: While talc containing asbestiform fibers is considered a human carcinogen, only limited animal and human data are available on non-asbestiform talc. To provide further evaluation on the issue, we updated the analysis of an Italian cohort of talc miners and millers in Val Chisone; talc found here is free from asbestiform fibers.

Methods: The cohort was comprised of 1,795 men who had worked for at least 1 year in the mine and/or in the factory between 1946 and 1995. Vital status and death certificates were obtained from registration offices in the municipality of death or of birth. Employment, termination of employment, and detailed job history were obtained from personnel records at the plant.

Results: No excess was found for total cancer mortality, nor mortality for lung cancer. No case of mesothelioma was reported. There was a significant excess mortality from non-neoplastic respiratory diseases (SMR 228.2, 95% CI 190.2-271.5). Mortality excess for non-neoplastic respiratory diseases was mainly due to silicosis.

Conclusions: This study provides additional support for an association between talc in mining and milling and non-neoplastic respiratory diseases, while showing no significant excess risk for lung cancer and mesothelioma. The results also provide additional information of interest to evaluate the potential association between silica and lung cancer.

Copyright 2003 Wiley-Liss, Inc.

In plain English

This study updated follow-up of talc miners and millers in Val Chisone, Italy, where the authors state the talc was free from asbestiform fibers. Of 1,974 men employed at least one year between 1946 and 1995, 1,795 were analyzed; 880 died by the end of 1995. No case of mesothelioma was reported. Lung cancer showed no excess: 44 deaths against 46.9 expected, a standardized mortality ratio (SMR; 100 means as many as expected) of 93.8 (95% confidence interval 68.1 to 125.9). Deaths from all causes (SMR 119.7, 95% CI 111.9 to 127.9) and from non-cancer respiratory diseases (127 observed, 55.7 expected, SMR 228.2, 95% CI 190.2 to 271.5) were significantly higher than expected. The respiratory excess, mainly silicosis (62 deaths), was confined to miners. Oral cavity and esophageal cancer deaths were also raised, which the authors considered likely due to alcohol and smoking (no smoking data were available); they took a cirrhosis excess as suggesting elevated drinking. The authors concluded that no association was found between talc containing no asbestos fibers and lung cancer or pleural mesothelioma.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Retrospective (historical) cohort mortality study, updating an earlier follow-up of the same cohort
• Who was studied: Men who had worked at least 1 year in the talc mine and/or mill in Val Chisone (Turin, Italy) between 1946 and 1995. Of 1,974 men, 179 with no follow-up information were excluded, leaving 1,795 for analysis: 1,244 miners (mine only, or mixed mine and plant work) and 551 millers and other plant-only workers. Follow-up ran from 1 January 1946 to 31 December 1995, with 880 deaths and 50,701 man-years.
• Exposure: Non-asbestiform talc dust from mining and milling. The authors state the talc was free from asbestiform fibers; miners were also exposed to quartz, radon and, from 1991, diesel exhaust.
• Main results:
  • No deaths from mesothelioma (pleural or peritoneal) in the cohort
  • Whole cohort, lung cancer: 44 observed, 46.9 expected, SMR 93.8 (95% CI 68.1 to 125.9)
  • Whole cohort, lung cancer by duration of exposure: no statistically significant increase in any of the four duration groups
  • Whole cohort, all cancers: 185 observed, 186.5 expected, SMR 99.2 (95% CI 85.4 to 114.5)
  • Whole cohort, all causes of death: 880 observed vs. 735 expected, SMR 119.7 (95% CI 111.9 to 127.9), significantly higher than expected
  • Whole cohort, non-cancer respiratory tract diseases: 127 observed, 55.7 expected, SMR 228.2 (95% CI 190.2 to 271.5), a significant excess
  • The respiratory excess was mainly due to silicosis (62 deaths); with silicosis excluded, the SMR for non-malignant respiratory disease was 116.6
  • The excess in all-cause and respiratory tract disease mortality was confined to miners
  • Silicosis deaths: 58 in miners compared with 4 in millers
  • Miners only: a direct trend of risk with duration of exposure was seen only for non-neoplastic respiratory diseases
  • Whole cohort, oral cavity cancer: 31 observed vs. 6 expected, SMR 514.4 (95% CI 349.4 to 730.1)
  • Whole cohort, esophageal cancer: 10 observed, 4.7 expected, SMR 212.9 (95% CI 101.9 to 391.6)
  • Whole cohort, liver cirrhosis: 55 observed, 31.2 expected, SMR 176.3 (95% CI 132.8 to 229.4)
  • The authors considered the excess of oral cavity and esophageal cancers likely due to alcohol consumption and cigarette smoking
  • The authors took the excess of liver cirrhosis deaths as also suggesting elevated alcohol drinking in the cohort
• The authors' conclusion: The authors concluded that no association was found between exposure to talc containing no asbestos fibers and lung cancer or pleural mesothelioma. They attributed the respiratory disease excess in miners to past mixed exposure to quartz.
• Limitations the authors state:
  • No information on smoking habits was available
  • About 7% of deaths were of unknown cause, so the authors note that SMRs for various causes may be somewhat underestimated

Topics

The National Library of Medicine indexes this study under subjects our site covers: Talc and vermiculite, Throat and laryngeal cancer.

Medical terms in this study, explained in our Lexicon: Talc, Asbestiform, Non-Asbestiform, Death Certificate, Lung Cancer, Mesothelioma, Silicosis.

Related studies

• Mortality of Talc Miners and Millers From Val Chisone, Northern Italy: An Updated Cohort Study — E. Pira, M. Coggiola, et al. (2017)
• Mortality in the cohort of talc miners and millers from Val Chisone, Northern Italy: 74 years of follow-up — C. Ciocan, E. Pira, et al. (2022)
• An update of cancer mortality among chrysotile asbestos miners in Balangero, northern Italy — G. Piolatto, E. Negri, et al. (1990)
• Exposure to chrysotile mining dust and digestive cancer mortality in a Chinese miner/miller cohort — S. Lin, X. Wang, et al. (2014)
• Evaluation of respiratory effects in miners and millers exposed to talc free of asbestos and silica — D.H. Wegman, J.M. Peters, et al. (1982)
• Malignant mesothelioma incidence among talc miners and millers in New York State — M.M. Finkelstein (2012)

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