Evaluation of occupational exposure risk experienced by a cohort of workers exposed to acrylonitrile using a register-based information system.

Objectives: This study aims to explore the extent of exposure to acrylonitrile in workplaces in Italy and its potential implications for workers' health.

Methods: Exposure measurements data (n = 31,599) on acrylonitrile reported in the period 1996 to 2022 to the Italian national register of occupational exposures, called SIREP, were collected and analysed. Concurrent exposures with other occupational carcinogens were investigated using SPSS 2-step cluster analysis. A retrospective register-based cohort mortality study was performed, and standardized mortality ratios (SMRs) were calculated linking exposure data to national mortality statistics in the period 2005 to 2020.

Results: Most of the exposures occurred in the chemical industry (88%). Exposure to multiple occupational carcinogens was detected frequently (92% of exposed workers). Elevated proportions of deaths from lung and brain cancer, as well as Parkinson's disease, were found among exposed male workers (SMR = 1.3, CI: 1.0 to 1.7; SMR = 1.8, CI: 1.0 to 3.2; and SMR = 2.8, CI: 1.2 to 6.8, respectively). Among other cancers, increased proportions of deaths from multiple myeloma (SMR = 2.9, CI: 1.4 to 5.7), leukemia (SMR = 3.7, CI:1.2 to 11.4), and mesothelioma (SMR = 4.2, CI: 2.2 to 8.1) were also found.

Conclusions: The monitoring of occupational exposures for the prevention of related risks is the main goal of epidemiological surveillance systems such as SIREP. Some acrylonitrile exposure circumstances deserve special attention, especially in the chemical and plastic industries. The excesses mortality from Parkinson's disease, lung cancer, and brain cancer constitute an actual concern for acrylonitrile exposed workers and warrant the implementation of further prevention measures and investigation.