February 20, 2020

“WebExpo” Project Publishes Algorithms for IH Calculations

The research organization IRSST has created a public repository of algorithms that can be used in some of the most frequently performed calculations in industrial hygiene risk assessment, IRSST said in a press release. The goal of the project, which is called “WebExpo,” is to simplify the interpretation of occupational exposure measurements, according to IRSST.

The algorithms make use of Bayesian statistical techniques, which IRSST says can facilitate risk communication due to the ease with which Bayesian inferences can be presented as probabilities. An accompanying report explains how the algorithms were developed and serves as documentation for their use.

“Bayesian methods were chosen because they provide direct answers to questions such as ‘What are the chances of this group of workers being overexposed?’ or ‘What are the chances of my intervention reducing exposure by half?’” said Jérôme Lavoué, principal investigator and associate professor in the department of Environmental and Occupational Health at the University of Montreal. “This type of information makes it much easier to communicate risks to non-specialists.”

The WebExpo report states that industrial hygienists have been slow to adopt statistical tools for IH calculations. One possible reason for this hesitance, according to the report, is the difficulty of explaining the output of current IH statistical tools to workers and other laypeople.

Lavoué said that applying Bayesian techniques to exposure measurements also allows industrial hygienists to account for errors in measurement and for values reported by analytical laboratories as “non-detects.” More information is available from IRSST, the Institut de recherche Robert-Sauvé en santé et en sécurité du travail.

Related: Free software tools developed by AIHA’s Exposure Assessment Strategies Committee are available on the AIHA website. These tools include IHMOD, a mathematical modeling spreadsheet for estimating occupational exposure; IHSTAT, which calculates exposure statistics, assesses fit tests, and graphs exposure data; and IHSkinPerm, which estimates dermal absorption. Many of the committee’s tools have been translated into multiple languages.