Influence of Short-Term Concentration Peaks on Exposure Risks in the Vicinity of an Episodic Release of Hydrogen Sulphide

摘要

In order to propose a methodology by which the influence of short-term concentration peaks on exposure risks could be estimated in the vicinity of an atmospheric release of hydrogen sulphide (H sub 2 S), an extensive and up-to-date review of H sub 2 S toxicity was conducted, with emphasis on acute and sub-acute poisoning. The literature on animal studies and cases of human exposure were used to derive a lethal dose relationship(concentration-exposure time) appropriate for the general population. A statistical model was developed which calculates the probability of short-term concentrations exceeding the lethal level given the downwind range from the release, the short-term averaging time of interest, the long-term average concentration, and metereological and terrain conditions. Results were obtained for passive releases of H sub 2 S under a range of hypothetical conditions. Interpretation of these results is given in terms of the overall probability of lethal exposure during a 30-minute episode. The likely influence of heavy water plant gas dispersion systems is also addressed. (Atomindex citation 12:632469)