Hydrogen Sulfide: Integrative Analysis of Acute Toxicity Data for Estimating Human Health Risk⋆

The purpose of this article is to present a specialized applied review of the information available for evaluating human health risk from acute exposure to hydrogen sulfide. This article discusses a categorical regression approach to performing an integrative analysis of information and data from multiple studies for the derivation of benchmark concentrations useful for establishing health-protective reference concentrations. The underlying basis of this analysis is a severity categorization from judgment-based evaluations and assignments of the individual responses observed in the various toxicity studies. Specifically, this article provides a general introduction to acute toxicity of hydrogen sulfide (H2S), and to categorical regression analysis in the form of the US EPA's CatReg software program; presents a general description of CatReg and its capabilities related to analysis of exposure–response data; illustrates the data and information available for H2S in individual toxicity studies, both animal and human; and demonstrates the extent and capacity of outputs available from CatReg to achieve the goal of estimating acceptable exposure levels to hydrogen sulfide for humans over different durations from the totality of the available data.