Estimation of human equivalent exposure from rat inhalation toxicity study of silver nanoparticles using multi-path particle dosimetry model

Abstract

Respiratory tract dosimetry is a useful tool to estimate the exposure concentrations of an inhaled substance that will produce the same result at a target site of the respiratory tract in both rats and humans. Thus, to enable the results of animal inhalation studies to be extrapolated to human equivalent exposure levels, the MPPD (multi-path particle dosimetry) model was used to estimate the differences in the respiratory dosimetry of rats and humans. In our previous study, when animals were subchronically exposed to silver nanoparticles over a period of 90 days, a no observable adverse effect level (NOAEL) of 100 μg m⁻³ was suggested. Therefore, this study used results from a previous animal study, including the test aerosol information and estimated clearance rate of silver nanoparticles after a 90 day inhalation toxicity test. As a result, the human equivalent workplace exposure concentration of silver nanoparticles was estimated as 59 μg m⁻³ compared to the rat NOAEL of 100 μg m⁻³.