The impact of asbestos exposure in Swedish construction workers

Our plain-English summary of The impact of asbestos exposure in Swedish construction workers, by B. Järvholm, A. Englund (American Journal of Industrial Medicine, 2014).

The study

• Authors: B. Järvholm, A. Englund
• Journal: American Journal of Industrial Medicine
• Published: 2014;57(1):49-55
• Cited by: 20 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Objective: To study the occurrence of pleural mesothelioma as a measure of the impact on health from asbestos exposure in the construction industry.

Methods: The occurrence of pleural mesothelioma in different occupations, time periods and birth cohorts was studied in a cohort of construction workers. They were prospectively followed after they had participated in health examinations between 1971 and 1993. The analysis was restricted to men and in total 367,568 men was included in the analysis.

Results: In total there were 419 cases of pleural mesotheliomas between 1972 and 2009. As expected the age adjusted incidence was high in insulation workers and plumbers (39 and 16 cases per 100,000 person-years, respectively). However, only 21% of the pleural mesotheliomas occurred in those occupational groups. Occupational groups with many cases of pleural mesothelioma were concrete workers (N = 56), wood workers (N = 55), painters (N = 32), electricians (N = 48), and foremen (N = 37). The highest risk was in birth cohorts born between 1935 and 1945. Between 1995 and 2009 around one-third of all male cases in the country occurred in this birth cohort. The risk seemed to decrease considerably in men born after 1955.

Conclusion: In Sweden a considerable proportion of pleural mesotheliomas occur among construction workers; and not only in jobs traditionally associated with asbestos exposure such as insulators and plumbers but also among electricians, for example. The results shows that asbestos exposure occurs in many occupational groups, indicating that safe handling of asbestos is a very difficult or even impossible task in the construction industry.

© 2013 Wiley Periodicals, Inc.

In plain English

This Swedish cohort study followed male construction workers examined by their industry's health service (Bygghälsan) from 1971 to 1993 (367,568 men in the abstract, 367,988 in the main table). They were linked to the Cancer Register through 2009 and grouped by first-examination job. There were 419 pleural mesotheliomas from 1972 to 2009. In the last two decades, cohort cases were about 20% of Swedish male cases. Age-adjusted incidence was highest in insulators (39.3 per 100,000 person-years, 95% confidence interval 22.9 to 62.9; 16 cases). Plumbers and pipe fitters had 15.5 (12.1 to 19.5; 72 cases), and these two groups had only 21% of cases. Many cases occurred in large groups: concrete workers (56), wood workers (55), electricians (48), foremen (37) and painters (32). Men born 1935 to 1944 had the highest risk. At ages 20 to 54, men born after 1955 had lower risk than men born 1945 to 1954 (relative risk 0.1; interval 0.01 to 0.68). The authors concluded that exposure occurred in many construction jobs and that asbestos control led to a decrease in risk. They noted the cohort covered about 80% of the workforce.

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: Prospective cohort study of construction workers followed after occupational health examinations. Cancer cases were identified through register linkage, and relative risks were estimated by Poisson regression.
• Who was studied: Male Swedish construction workers aged 15 to 65 at examination, examined between 1971 and 1993 by the construction industry's national occupational health service (Bygghälsan). Pleural mesothelioma was tracked through the Swedish Cancer Register from 1971 through 2009. Women were excluded. The article gives two cohort sizes: 367,568 men in the abstract and a total of 367,988 in Table I. The Table I figure matches 369,714 men minus the reported age exclusions.
• Exposure: Asbestos exposure in the construction industry, measured indirectly by occupational group at first examination (22 groups). No individual exposure measurements were made. The authors state that chrysotile was the major asbestos type in Swedish construction and that amosite was used for spraying.
• Main results:
  • There were 419 cases of pleural mesothelioma in the cohort between 1972 and 2009. The authors state that cohort cases made up about 20% of all cases in Sweden during the two most recent decades. Figure 2 shows this comparison against Swedish males.
  • Age-adjusted incidence was highest in insulators: 39.3 per 100,000 person-years (95% CI 22.9 to 62.9), from 16 cases among 2,860 men. Plumbers and pipe fitters had 15.5 per 100,000 person-years (12.1 to 19.5), from 72 cases. Together these two groups had only 21% of the cases.
  • Refrigeration repairers had a rate of 19.6 per 100,000 person-years (4.0 to 57.3). This rate was based on only 3 cases, and the authors describe its precision as low.
  • Many cases occurred in large occupational groups: concrete workers (56 cases), wood workers (55), electricians (48), foremen (37) and painters (32). Electricians had an incidence of 10.7 per 100,000 person-years (7.9 to 14.2). Sheet-metal workers had 11.4 (6.5 to 18.5), from 16 cases.
  • In the Poisson regression, plumbers and pipe fitters were the reference group. Relative risks compared with them were:
• insulators: 2.84 (95% CI 1.65 to 4.90)
• electricians: 0.70 (0.48 to 1.02)
• sheet-metal workers: 0.69 (0.40 to 1.21)
• painters: 0.40 (0.25 to 0.63)
• concrete workers: 0.33 (0.23 to 0.48)
• wood workers: 0.30 (0.21 to 0.43)
• foremen: 0.30 (0.20 to 0.46)
  • The lowest incidence was in men who mainly worked outdoors. Asphalt workers had 0 cases among 3,974 men. Machine operators had 0.78 per 100,000 person-years and rock workers 0.9.
  • Men born 1935 to 1944 had the highest risk and were the reference group. Relative risks for the other birth cohorts were:
• born 1915 to 1924: 0.40 (0.28 to 0.57)
• born 1925 to 1934: 0.68 (0.51 to 0.91)
• born 1945 to 1954: 0.60 (0.41 to 0.88)
  • In a Poisson analysis restricted to ages 20 to 54 years, men born after 1955 had a smaller risk than men born 1945 to 1954: relative risk 0.1 (95% CI 0.01 to 0.68).
  • From 1997 to 2009, the number of pleural mesotheliomas in this cohort was similar to or higher than the number of fatal occupational accidents in Swedish construction. In the 2000s there were about 15 mesotheliomas a year in the cohort, against about 10 fatal accidents a year in the industry.
  • Job turnover between first and last examination was low except among insulators. 35% of insulators reported a change of job, compared with 0% to 18% in the other groups examined.
• The authors' conclusion: The authors concluded that a considerable proportion of pleural mesotheliomas in Sweden occur among construction workers, including in jobs not traditionally linked to asbestos, such as electricians. They concluded that safe handling of asbestos is very difficult or impossible in construction, and that asbestos control has led to a decrease in risk.
• Limitations the authors state:
  • Workers were classified only by their job at the first examination.
  • The cohort represents only about 80% of the construction workforce of the period.
  • Occupational titles and tasks differ between countries, so the findings may not transfer to other countries.
  • The start of exposure for these workers was not known.
  • Some workers may have been exposed to asbestos in other industries during their careers.
  • Only pleural mesothelioma was analysed. Lung cancer, peritoneal mesothelioma (29 cases in the cohort), asbestosis and pleural disease were not included.
  • The rate for refrigeration repairers was based on few cases and had low precision.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Construction, Mesothelioma.

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Pleural Mesothelioma, Insulator.

Related studies

• Smoking, occupational exposures, and idiopathic pulmonary fibrosis among Swedish construction workers — M. Andersson, P.D. Blanc, et al. (2021)
• The risk of lung cancer after cessation of asbestos exposure in construction workers using pleural malignant mesothelioma as a marker of exposure — B. Järvholm, E. Aström (2014)
• Occupational exposures and risk of esophageal and gastric cardia cancers among male Swedish construction workers — C. Jansson, A.L. Johansson, et al. (2005)
• Multiple myeloma and diesel and other occupational exposures in swedish construction workers — W.J. Lee, D. Baris, et al. (2003)
• Cancer incidence among Swedish pulp and paper mill workers: a cohort study of sulphate and sulphite mills — E. Andersson, H. Westberg, et al. (2013)
• Respiratory cancer incidence in Swedish construction workers exposed to man-made mineral fibres and asbestos — G. Engholm, A. Englund, et al. (1987)

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