The Suicide Pandemic of Hydrogen Sulfide Poisoning in Japan

Hydrogen sulfide (H2S) suicides have been frequent in Japan in recent years. This study was performed to describe the epidemiologic profile of an outbreak of H2S suicides in Japan. In September 2008, questionnaires about patients involved in H2S suicides were sent to 250 hospitals in Japan. Data collected from each patient included gender, age, clinical manifestations, date of event, location of suicide, source of H2S, treatments and neurological outcome. A total of 90 subjects (60 men, 30 women) were enrolled in this study. In this outbreak, the first case was reported in September 2006 and subsequent cases reached a peak in April 2008. There were 60 cases of attempted suicide by generating H2S gas (suicide group) and 30 cases of secondary exposure (secondary exposure group). The suicide group included mostly subjects in their twenties. Cardiopulmonary arrest at the scene was reported in 39 cases (65%). Clinical features of the suicide group inpatients included coma (14 cases), convulsion (1 case), and lung edema (1 case). Patients in suicide group were significantly younger than secondary exposure group (P < 0.001). The development of cardiopulmonary arrest was significantly higher in suicide group (65% vs. 10%; P < 0.001). Death was more frequent in suicide group (70% vs. 10%; P < 0.001) and patients with secondary exposure were discharged with better neurological outcomes (Table 1). Suicide with H2S poisoning has recently been a serious social problem especially in younger generation in Japan. There is extensive information on H2S suicide methods on the internet. Management of access to websites describing suicide methods is an immediate necessity together with counseling for suicide prevention.