An Overview of Hydrogen Sulfide Suicides in Yamagata Prefecture, Japan

Background: Hydrogen sulfide (H2S) is one of the major toxic gases and the second most common cause of death in workplaces among toxic gas-related morbidities. H2S suicides using hospital-based data were studied in 2008. However, most cases did not involve ambulance transfer to the hospital because the victims of H2S suicide were usually found dead at the scene. H2S suicide-related data elucidating an overview of the patients were therefore not available. To clarify the mechanism of poisoning, H2S suicide victim data were obtained from the Yamagata prefectural police office. Methods: H2S suicide data from the Yamagata prefectural police office for the period 2007 to 2013 were obtained. All H2S suiciderelated data in Yamagata Prefecture were collected, including sex, age, location of suicide, source of hydrogen sulfide, and methods Results: In this study, a total of 41 cases (29 men and 12 women) were included for analysis. The number of H2S suicides reached a peak in April 2008, with 14 cases being reported, followed by 10 in 2009, 10 in 2010, 3 in 2011, and 4 in 2012. The mean age of the victims was 31.8 ± 12.2 years (range: 18–77 years), and the median age was 28 years. Sources of H2S gas included cars (23 cases; 54%), rooms (8 cases; 20%), and bathrooms (5 cases; 12%). We also identified several cases of a novel suicide method, wherein H2S was generated in a plastic garbage bag that the victim would then place over their head or body into the bag. Conclusion: Most cases of H2S poisoning are not registered at hospital, therefore, the data on these victims need to be analyzed from police office data. H2S-related suicides are known to occur in confined places including cars or toilets; however a new form of H2S suicide using a sealed plastic bag is increasingly prevalent, possibly due to widespread sharing of this method on the internet.