Two fatalities by hydrogen sulfide poisoning: Variation of pathological and toxicological findings

We report the simultaneous deaths of two individuals by inhalation of hydrogen sulfide (H2S), produced either by the putrefaction of a large quantity of sweet corn or by heavy oil that flowed out of the fuel tank of a large stranded cargo vessel. Ten workers went into a water ballast tank of the vessel to remove remaining heavy oil and suddenly felt unwell. Two of the ten workers (patient A, a male in his early thirties, and patient B, a male in his early sixties) died. Autopsies of the two patients revealed a partial green discoloration of the skin and pulmonary edema. Toxicological analysis revealed high levels of thiosulfate in the blood (0.089 mmol/L in patient A and 0.142 mmol/L in patient B). From these findings, we concluded that the cause of death in both patients was H2S poisoning. In addition, the autopsy of patient A revealed petechiae of the palpebral conjunctiva and the mucous membrane of the mouth and erosion of the respiratory tract. The autopsy of patient B failed to reveal these observations. We presumed that patient B may have been exposed to higher H2S levels, and that the circulation and respiration of patient B may have arrested faster than patient A. Thiosulfate levels in the blood may reflect the levels of H2S exposure. This case suggests that the pathological and toxicological findings of H2S poisoning vary from case to case.