How to Obtain a Reliable Estimate of Occupational Exposure? Review and Discussion of Models' Reliability.

Spinazzè Spinazzè,Cattaneo Cattaneo,Rovelli Rovelli,Borghi Borghi,Fanti Fanti,Keller Keller,Campagnolo Campagnolo,Cavallo Cavallo

doi:10.3390/ijerph16152764

Abstract

Evaluation and validation studies of quantitative exposure models for occupational exposure assessment are still scarce and generally only consider a limited number of exposure scenarios. The aim of this review was to report the current state of knowledge of models’ reliability in terms of precision, accuracy, and robustness. A systematic review was performed through searches of major scientific databases (Web of Science, Scopus, and PubMed), concerning reliability of Tier1 (“ECETOC TRA”-European Centre for Ecotoxicology and Toxicology of Chemicals Targeted Risk Assessment, MEASE, and EMKG-Expo-Tool) and Tier2 models (STOFFENMANAGER® and “ART”-Advanced Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) Tool). Forty-five studies were identified, and we report the complete information concerning model performance in different exposure scenarios, as well as between-user reliability. Different studies describe the ECETOC TRA model as insufficient conservative to be a Tier1 model, in different exposure scenarios. Contrariwise, MEASE and EMKG-Expo-Tool seem to be conservative enough, even if these models have not been deeply evaluated. STOFFENMANAGER® resulted the most balanced and robust model. Finally, ART was generally found to be the most accurate and precise model, with a medium level of conservatism. Overall, the results showed that no complete evaluation of the models has been conducted, suggesting the need for correct and harmonized validation of these tools.

Highlights

To comply with the REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) regulation (EC 1907/2006), manufacturers and importers of chemical substances must conduct quantitative occupational exposure studies for identified and selected exposure scenarios
The use of occupational exposure assessment models should follow a tiered approach: the evaluation should be organized into a first phase of evaluation (Tier1) in which simple tools should be used for exposure assessment
Following the REACH recommendation, in the event that the estimated exposure value is not controlled, indicating that the potential presence of risk in the exposure scenario, or whenever some concern persists in a worker’s exposure to a chemical, it is necessary to proceed with a second evaluation phase (Tier2), in which more advanced tools are used for exposure estimation, or environmental monitoring could be used to confirm the estimated exposure [1,11]

Summary

Introduction

To comply with the REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) regulation (EC 1907/2006), manufacturers and importers of chemical substances must conduct quantitative occupational exposure studies for identified and selected exposure scenarios. The exposure assessment process can be based (1) on measured exposure data or (2) on the use of exposure assessment tools. The use of exposure modeling for the assessment of exposure to chemicals by inhalation is considered in a recent EU standard (EN 689: 2018) that request of appraisers to produce reliable exposure estimates using appropriate and validated models or algorithms. When exposure modeling is used, the European Chemical Agency (ECHA) suggests the use of exposure-specific tools for the evaluation of exposure assessment, following a tiered approach. The tiered approach involves the use of simplified and conservative exposure models in the first step of the evaluation. Public Health 2019, 16, 2764; doi:10.3390/ijerph16152764 www.mdpi.com/journal/ijerph

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