Balazs Adam, Daniele Mandrioli, Ben Nemery, Paul T.J. Scheepers

Abstract

Objective Reliable and transparent assignments of occupational exposure prevalences and levels are crucial for estimating the global burden of disease when occupational exposures contribute to etiology. In this presentation we present an example of using a systematic approach and meta-analysis, done at the initiative of WHO/ILO, to assess global prevalence and levels of exposure to inhaled silica, asbestos and coal dust. Materials and Methods A systematic review was conducted of studies of any type, published between 1960 and 2018, if they had been done in working-age populations (≥15 years), provided objective dust or fibre measurements, and directly or indirectly reported an estimate of the prevalence and/or level of occupational exposure to silica, asbestos and/or coal dust. Being exposed was defined as a personal sampling result being above the limit of detection. Results For dust/fibres, 88 studies (>2.4 million measurements, 23 countries, all WHO regions represented) were included, all performed among manual workers. Most studies were performed in construction, manufacturing and mining. Overall, the degrees of evidence for the three exposures varied by the industrial sector between very low and moderate quality of evidence for exposure prevalence, and between very low and low for exposure level. None of the studies included covered the entire workers’ population in each of the industrial sectors. Conclusion Prevalence and level estimates for occupational exposures based on a systematic review approach were probably overestimated in most industrial sectors, thus leading to a need of more representative studies. A way forward for improving exposure estimates in disease burden estimates is to apply different methods, with different assumptions. Still, using the transparent systematic review approach including meta-analysis and quality of evidence evaluation presents an important further step complementing existing approaches for global exposure assessment.

John Cherrie; Hans Kromhout

Abstract

Objective: 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.

Methods: Two publications (Schlünssen et al 2023; Pega et al 2023) were reviewed for potential biases on the exposure estimates.

Results:  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. 

Conclusion: 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.

Nadia Vilahur, Xabier Irastorza

Abstract

Objective The European Agency for Safety and Health at Work (EU-OSHA) carried out an exposure survey to cancer risks factors, based on an adaptation of the Australian Workplace Exposures Study (AWES). The survey provides prevalence and semi-quantitative levels of occupational exposure to 24 known risk factors in the last working week, for example silica dust, UV radiation, benzene, diesel exhaust, different metals, or wood dust; as well as demographic and job-related information for each worker. Material and Methods The survey was held with 24,402 respondents, representing 98.5 million European workers. The exposure assessment was conducted with the Occupational Integrated Database Exposure Assessment System (OccIDEAS) which was first developed for AWES and adapted for Europe by national experts from the six countries covered. Results The survey presents a few limitations considering the partial geographic coverage of the EU (Finland, France, Germany, Hungary, Ireland and Spain), and the limited time of the fieldwork (September 2022 to February 2023), thus not covering all seasonal working circumstances and all European workplaces. The expert assessment was conducted with the existing knowledge at the time, while work circumstances are constantly changing and new information about exposure levels in different jobs is regularly published. A gender bias was identified since the beginning, given the selection of the 24 risk factors and the existing knowledge better covering male-dominated occupations. The survey provides information on multiple exposures over the same working week and self-reported use of workplace prevention measures, mainly local exhaust ventilation and respiratory protection, but also specific protection measures when dealing with radiation, or strictly regulated substances like asbestos. Conclusion WES is a cross-sectional survey providing estimated occupational exposure to 24 cancer risk factors at a given point. The survey data is not meant to be used for establishing causal relations with current occupational cancer outcomes.