Impact of Interventions to Prevent Asbestos-Related Respiratory Disease in an Exposed Worker Registry Using a Simplified G-computation

DeBono NL, Everest L, Richardson DB, Berriault C, Yeo RE, Meeds MA, Arrandale V, Demers PA. Impact of Interventions to Prevent Asbestos-Related Respiratory Disease in an Exposed Worker Registry Using a Simplified G-computation. American Journal of Epidemiology 2025. https://doi.org/10.1093/aje/kwaf040

ABSTRACT: The Ontario Asbestos Workers Registry is a regulatory exposure registry obligating employers to report the number of work hours with asbestos containing materials for each of their workers. Currently, each worker is notified of the need for a medical examination once they have accrued 2,000 reported hours of work with asbestos. We sought to evaluate the impact on disease prevention of alternative policies limiting asbestos work hours among registry participants. A cohort of 26,164 asbestos workers were followed for cancer and non-malignant disease diagnoses between 1986 and 2019. Analyses of the association between cumulative asbestos work hours and respiratory disease incidence rates showed substantially elevated disease rates well before reaching 2,000 asbestos work hours. Using a simplified application of parametric G-computation (G-POSH), limiting cumulative asbestos work hours to 100 hours would have prevented 76 asbestosis, 36 pulmonary fibrosis, 27 mesothelioma, and 79 lung cancer cases at the end of follow-up compared to the observed risk in the cohort. Limiting exposure to 2,000 asbestos work hours had a smaller but still substantial impact on disease prevention, particularly among workers in the construction industry. Regulatory agencies should intervene sooner to prevent respiratory disease among workers in the registry.