Variations in exposure to carcinogens among shift workers and non-shift workers

Our plain-English summary of Variations in exposure to carcinogens among shift workers and non-shift workers, by S. El-Zaemey, R.N. Carey (American Journal of Industrial Medicine, 2019).

The study

• Authors: S. El-Zaemey, R.N. Carey
• Journal: American Journal of Industrial Medicine
• Published: 2019;62(4):352-356
• Cited by: 6 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: There is limited information on whether the prevalence of exposure to workplace carcinogens varies among shift workers and non-shift workers.

Methods: This analysis used data from the Australian Work Exposures Study-Cancer, a telephone survey which examined exposure to carcinogens in the workplace. Workers were classified as shift workers if they indicated that their usual roster ever included work between the hours of midnight and 5 am. Modified Poisson regression was used to estimate the adjusted prevalence ratios (aPRs) and 95% confidence internals (CIs).

Results: Among the 5425 workers, 6.88% reported being exposed to shift work. Overall, shift workers were more likely to be exposed to any carcinogen (aPR = 1.16; 95% 1.06-1.26) and to specific carcinogens such as asbestos (aPR = 1.93; 95% 1.33-2.83) than non-shift workers.

Conclusions: Our study shows that there are differences in exposure to carcinogenic agents among shift and non-shift workers, and so there is a need for prevention programs in order to reduce these discrepancies.

© 2019 Wiley Periodicals, Inc.

In plain English

This brief report analysed data from the Australian Work Exposures Study-Cancer, a 2011 national telephone survey of workers aged 18 to 65. It asked whether exposure to workplace carcinogens differed between shift workers and other workers. It did not study cancer cases. Shift workers were those whose usual roster ever included work between midnight and 5 am. Exposure was assessed from job-specific task questions given to 2745 respondents. Another 2748 had jobs judged unlikely to involve carcinogens. The article does not say which types of asbestos were involved. Of 5425 workers analysed, 6.88% were shift workers. Of these, 10.19% of shift workers and 2.30% of non-shift workers were assessed as exposed to asbestos. After adjusting for demographic factors and occupational group, the prevalence ratio was 1.93 (95% CI 1.33-2.83). Exposure to any carcinogen other than shift work was 60.05% among shift workers and 33.71% among non-shift workers (adjusted ratio 1.16, 95% CI 1.06-1.26). Wood dust and chromium VI exposure were less common among shift workers. The authors noted that tasks were self-reported and the response rate was low. The authors concluded that exposures differ between the groups and that prevention programs are needed.

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: Cross-sectional analysis of data from a national telephone survey (brief report)
• Who was studied: 5425 current Australian workers aged 18 to 65 surveyed in 2011: 373 shift workers and 5052 non-shift workers. The survey response rate was 52.6%. Of 5493 usable respondents, 68 were excluded for missing age or education data.
• Exposure: Shift work meant a usual roster that ever included work between midnight and 5 am. The survey covered current occupational exposure to 38 known or probable carcinogens, including asbestos (fiber type not specified). Respondents in 13 job categories judged unlikely to involve carcinogen exposure (n = 2748) were screened out. The remaining 2745 were assigned job-specific task modules (OccIDEAS), which were used to assess exposure. Specific carcinogens were analysed only if at least 3% of workers were exposed.
• Main results:
  • Assessed as exposed to asbestos: 10.19% of shift workers versus 2.30% of non-shift workers. Unadjusted prevalence ratio 4.44 (95% CI 3.12-6.30). Adjusted prevalence ratio 1.93 (95% CI 1.33-2.83).
  • Exposed to any carcinogen (excluding shift work): 60.05% of shift workers versus 33.71% of non-shift workers. Adjusted prevalence ratio 1.16 (95% CI 1.06-1.26).
  • Exposed to two or more carcinogens: 43.16% of shift workers versus 26.44% of non-shift workers. Adjusted prevalence ratio 1.17 (95% CI 1.06-1.30).
  • Wood dust and chromium VI exposure were less prevalent among shift workers, including after adjustment. Adjusted prevalence ratio 0.53 (0.28-0.97) for wood dust and 0.37 (0.17-0.82) for chromium VI.
  • After adjustment for demographic factors and occupational groups, exposures to solar UVR, lead, environmental tobacco smoke and formaldehyde were no longer significantly more prevalent among shift workers.
• The authors' conclusion: The authors concluded that exposure to carcinogenic agents differs between shift and non-shift workers. They also concluded that prevention programs are needed to reduce exposure to carcinogens among workers who do shift work.
• Limitations the authors state:
  • Exposure assessments were based on self-reported tasks and may be subject to recall bias or social desirability. The authors considered this unlikely to matter much, because only current job tasks were asked about.
  • The response fraction was low (53%), and some groups were under-represented, mainly younger age groups and people living in regional areas.

Topics

Medical terms in this study, explained in our Lexicon: Carcinogenic.

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