The Epidemiology of Working Life: Reorganizing Occupational Health Science Around Work-Structured Exposure Systems

Occupational epidemiology has played a central role in identifying workplace hazards and informing prevention. However, its focus on discrete exposures, bounded worksites, and linear models is insufficient to capture how contemporary work shapes health. Many risks arise not from isolated hazards, but from cumulative, interacting exposures generated by work organization that extend beyond the workplace and accumulate across working life. This paper proposes the Epidemiology of Working Life (EWL) as a framework for reorganizing occupational health science. Anchored in the working-life-exposome, EWL centers analysis on work-structured exposure systems-structures that generate recurring configurations of co-occurring exposures under specific employment conditions. EWL changes what counts as exposure, how risk is analyzed, and where prevention can act. Rather than treating work as a setting of discrete hazards, EWL treats it as a system that generates and distributes risk across working life. EWL shifts the unit of inference from individual hazards to recurring exposure configurations and the systems that generate them. This shift enables earlier detection of risk and identifies intervention points that reduce multiple harms simultaneously-less visible in hazard-by-hazard approaches. EWL yields three prevention-oriented outputs: (1) recurrent exposure configurations associated with elevated risk, (2) upstream drivers that generate and sustain them, and (3) early-warning indicators for anticipatory intervention. Proof-of-concept scenarios illustrate how EWL reveals prevention opportunities obscured when exposures are examined in isolation. By centering occupational health science on work-structured exposure systems, EWL strengthens alignment between epidemiological evidence and prevention in contexts where risks are cumulative, interacting, and structured by employment conditions.