8235025 Occupational exposure assessment for burden of disease studies – critique of the WHO/ILO approach

<h3>Objective</h3> The World Health Organisation (WHO) and the International Labour Organisation (ILO) are producing joint estimates of the occupational disease burden for several workplace risk factors. Prevalence and intensity of occupational exposures are key input parameters determining the burden of occupational disease. This paper evaluates the methodology for generating exposure estimates for several agents (dusts and solar UV) used by WHO/ILO. <h3>Methods</h3> Two publications (Schlünssen et al 2023; Pega et al 2023) were reviewed for potential biases on the exposure estimates. <h3>Results</h3> Schlünssen et al (2023) estimated the prevalence and intensity of exposure for asbestos, respirable crystalline silica and coal dust, based on a systematic review of the peer-reviewed literature. Two major concerns were identified: i. non-representativeness of published exposure data and ii. the exposure prevalence estimate based on the ratio of number of measurements above and below the limit of detection of the measurement. Pega et al (2023) estimated the number for non-melanoma skin cancer (NMSC) for many countries. The calculated number of NMSC deaths in the UK was based on an estimate of 21 million people occupationally exposed to solar UV radiation. This appears to be a gross overestimate of the number of UK workers exposed at sufficiently high cumulative levels. <h3>Conclusion</h3> Determining the burden of occupational disease is important but also very challenging. Robust methods for estimating exposures are required which should be based on all reliable sources of data and should include estimates of exposure for those sectors where no exposure data are available. Furthermore, it is important to ensure that exposure estimates for the burden calculations are aligned (acquired with similar methods) with the exposure measures used in the epidemiological studies that provide the risk estimates.