Exposure simulation is a process used to collect relevant data by measuring chemicals released under re-created current or historical conditions. More specifically, exposure simulation is a technical approach to filling data gaps using modern sampling and analytical methods and controlled conditions. Exposure simulation studies have recently become popular in evaluating historical exposures, particularly to products that are no longer manufactured or commercially available, and where empirical measurements of chemical concentrations are inadequate or absent. In some of these cases, although industrial hygiene data may exist, these data are often limited due to outdated sampling methods or confounding factors prevent interpretation of the data for a specific product. For current exposure to chemicals in consumer products, often there are no data available.
Exposure simulation allows a researcher to quantitatively bracket the range of possible concentrations to which an individual or population may have been exposed by using actual measured data for activities or products rather than relying on mathematical modeling and/or extrapolations to understand exposures. In this way, exposure simulation is a direct approach to gathering relevant data and provides a more quantitative approach to characterizing the magnitude of historical exposures. Exposure simulation provides several benefits, including production of a substantial amount of relevant data based on the best available sampling and analytical methods; ease of describing the methods, sampling design, and relevance to historical exposure conditions; and ability to provide photo or video documentation of exposure conditions re-created and experienced during the simulation.
Exponent has conducted and published exposure simulation on several chemicals, including asbestos, benzene, cadmium, ethylbenzene, formaldehyde, lead, and volatile organic chemicals.
Specific Experience
Exponent’s staff has conducted numerous exposure simulations and reconstructions for a variety of products and chemicals. For example:
Ammonia in household cleaning products
- Asbestos in mastics and adhesives
- Asbestos in phenolic molding compounds/resins
- Asbestos roofing materials
- Benzene in parts-washing solvents , and industrial products
- Cadmium polyvinyl chloride (PVC) cables
- Cyanoacrylates in adhesives
- Ethylbenzene in marking pens
- Formaldehyde in nail-hardening products
- Lead in PVC cables and jewelry
Exposure Simulation Publications
Malzahn D, Mowat F, Armstrong P. Simulation of asbestos release during dismantling of a residential sectional boiler. Accepted for presentation at the American Industrial Hygiene Conference & Expo (AIHce), Minneapolis, MN, June 2–5, 2008.
Mowat F, Weidling R, Sheehan P. Simulation tests to assess occupational exposure to airborne asbestos from asphalt-based roofing products. Ann Occup Hyg 2007; 51:451–462.
Sheehan P, Malzahn D, Goswami, E, Mandel J. Simulation of Benzene Exposure during Use of a Mineral Spirit Solvent to Clean Elevator Bearing Housings. Human and Ecological Risk Assessment 2008; 14:421-432.