Experiencing a probabilistic approach to clarify and disclose uncertainties when setting occupational exposure limits

• Authors: David Vernez , Sandrine Fraize-Frontier , Raymond Vincent , Stéphane Binet , Christophe Rousselle

Abstracts

EN

Objectives Assessment factors (AFs) are commonly used for deriving reference concentrations for chemicals. These factors take into account variabilities as well as uncertainties in the dataset, such as inter-species and intra-species variabilities or exposure duration extrapolation or extrapolation from the lowest-observed-adverse-effect level (LOAEL) to the noobserved- adverse-effect level (NOAEL). In a deterministic approach, the value of an AF is the result of a debate among experts and, often a conservative value is used as a default choice. A probabilistic framework to better take into account uncertainties and/or variability when setting occupational exposure limits (OELs) is presented and discussed in this paper. Material and methods Each AF is considered as a random variable with a probabilistic distribution. A short literature was conducted before setting default distributions ranges and shapes for each AF commonly used. A random sampling, using Monte Carlo techniques, is then used for propagating the identified uncertainties and computing the final OEL distribution. Results Starting from the broad default distributions obtained, experts narrow it to its most likely range, according to the scientific knowledge available for a specific chemical. Introducing distribution rather than single deterministic values allows disclosing and clarifying variability and/or uncertainties inherent to the OEL construction process. Conclusions This probabilistic approach yields quantitative insight into both the possible range and the relative likelihood of values for model outputs. It thereby provides a better support in decision-making and improves transparency. Int J Occup Med Environ Health 2018;31(4):475–489

Keywords

EN

risk management; chemical toxicity; assessment factors; uncertainty distributions; probabilistic methods; occupational exposure limits

• Publisher: Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
• Journal: International Journal of Occupational Medicine and Environmental Health
• Year: 2018
• Volume: 31
• Issue: 4
• Pages: 475-489

Dates

published

2018

Contributors

author

David Vernez

• University of Lausanne and Geneva, Lausanne, Switzerland (Institute of Work and Health (IST))

author

Sandrine Fraize-Frontier

• French Agency for Food, Environmental and Occupational Health and Safety (ANSES), Maisons-Alfort, France

author

Raymond Vincent

• National Institute for Research and Security for the Prevention of Occupational Accidents and Diseases (INRS), Vandoeuvre-lès-Nancy, France

author

Stéphane Binet

• National Institute for Research and Security for the Prevention of Occupational Accidents and Diseases (INRS), Vandoeuvre-lès-Nancy, France

author

Christophe Rousselle

• French Agency for Food, Environmental and Occupational Health and Safety (ANSES), Maisons-Alfort, France

Identifiers

DOI

10.13075/ijomeh.1896.01184

Biblioteka Nauki

2159984