Cancer and all-cause mortality among United States union poultry workers.

Abstract

Objectives: Several industry-specific hazards are present in the poultry working environment. It is not well known whether risk factors unique to poultry working increase all-cause and cancer mortality relative to other industry types. The study objective was to compare all-cause and cancer mortality among poultry workers to non-poultry food workers.

Methods: Occupational data for 30 411 poultry and 16 405 non-poultry workers were obtained from United Food and Commercial Workers union records and matched to the National Death Index up to 31 December 2019 to conduct a retrospective cohort study. Unadjusted and adjusted hazard ratios (aHR) and their 95% CIs from time-stratified Cox proportional hazard regression models were run to compare all-cause and cancer mortality among poultry and non-poultry workers.

Results: Across the full cohort, no statistically significant elevation in all-cause or cancer mortality among poultry workers was observed (all-cause: aHR 0.98, 95% CI 0.95 to 1.01; cancer: aHR 1.05, 95% CI 0.97 to 1.13); however, time-period sensitivity was evident. After accounting for calendar time, poultry workers hired before 1960 had a 62% greater cancer mortality hazard compared with non-poultry workers (aHR 1.62, 95% CI 1.25 to 2.11). Poultry workers hired between 1980 and 1989 had a 59% (aHR 1.59, 95% CI 1.40 to 1.79) and 86% (aHR 1.86, 95% CI 1.39 to 2.48) greater all-cause and cancer mortality risk, respectively.

Conclusions: Union poultry workers hired in the United States during the 20th century faced greater all-cause and cancer mortality compared with non-poultry workers; however, this elevation was period-sensitive, varying by employment start date.