An adult Japanese man (A) entered a pit to remove sludge in a drainage pipe at a
dye works in Japan. When he took off a joint of the pipe, the sludge in the pipe flowed into the pit. As he suddenly lost consciousness, three colleagues (B, C, D) entered the pit to rescue him. All of these (A, B, C and D) lost consciousness in the pit, and died soon after the accident. Since
hydrogen sulfide gas was detected in the sludge of the pit,
gas poisoning was suspected. Toxicological analyses of
sulfide and
thiosulfate, a metabolite of
sulfide, in blood and urine of the victims were made, using the extractive alkylation technique combined with gas chromatography/mass spectrometry.
Sulfide and
thiosulfate were detected in whole blood of the four workers at levels of 0.32-9.36 mg/l and 0.11-0.23 mmol/l, respectively. These concentrations were at least 6-187 times higher in
sulfide and 37-77 times higher in
thiosulfate than those in healthy persons, and were similar to values found in fatal cases of
hydrogen sulfide poisoning.
Thiosulfate was not detected in the urine of four workers, which indicated acute death. Based on these results, all four patients were victims of
hydrogen sulfide poisoning, who died soon after the exposure.