8253455 Job-exposure matrices for estimating historical occupational exposures to trichloroethylene, perchloroethylene, and formaldehyde in China

<h3>Objectives</h3> Occupational exposure assessment is critical for understanding the health risks associated with chemical agents in epidemiological studies. While individual-level exposure measurements may be conducted in occupational cohorts, they are often impractical in general population-based studies. Job-exposure matrices (JEMs) provide a systematic approach to estimate exposures retrospectively based on job title, enabling exposure assessment in the general population. However, there is a notable lack of JEMs tailored to the Chinese context for common industrial solvents such as trichloroethylene (TCE), perchloroethylene (PCE), and formaldehyde. This study aims to construct semi-quantitative JEMs for TCE, PCE, and formaldehyde exposure by integrating multiple data sources, demonstrating the principles and methodological considerations during the process. <h3>Material and Methods</h3> We synthesized data from published literature that reported occupational exposure levels, routine industrial hygiene monitoring datasets, existing international JEMs, and expert assessments to inform the exposure estimates. The final JEMs were structured across three dimensions: job title codes (3-digit and 4-digit ISCO-88), chemical agents (TCE, PCE, formaldehyde), and four calendar periods (≤1990, 1991–2000, 2001–2010, ≥2011). For each job title-chemical-period combination, estimates of exposure prevalence and level were assigned using a harmonized semi-quantitative scale. <h3>Results</h3> The resulting matrices covered over 500 job title codes and provided prevalence and level of occupational exposure with temporal resolution, enabling evaluation of exposure-response relationships for these exposures and disease outcomes in epidemiological studies. <h3>Discussion</h3> Despite the individual variations, the semi-quantitative JEMs balanced expert judgment and empirical data, enhancing reproducibility and applicability. These JEMs are essential resources for general population-based studies in China investigating the relationships between long-term occupational exposure and chronic health outcomes. Our experience and principles could serve as a model for future JEM development for other occupational exposures and in other geographic regions.