An Outbreak of Carbon Monoxide Poisoning in Yamagata Prefecture Following the Great East Japan Earthquake

Background: in the aftermath of the great east japan earthquake, most of the areas in yamagata prefecture experienced a serious power failure lasting for approximately 24 hours. a number of households were subsequently poisoned with carbon monoxide (co) due to various causes. in this study, we conducted a survey of co poisoning during the disaster.methods: a questionnaire regarding co poisoning associated with the disaster was sent to 37 emergency hospitals in yamagata prefecture.results: a total of 51 patients were treated for unintentional co poisoning in 7 hospitals (hyperbaric oxygen chambers were present in 3 of the hospitals). the patients (18 men, 33 women) ranged in age from 0 to 90 years. the source of co exposure was charcoal briquettes (23 cases; 45%), gasoline-powered electric generators (18 cases; 35%), electric generators together with oil stoves (8 cases; 16%), oil stoves (1 cases; 2%), and automobile exhaust (1 cases; 2%). blood carboxyhemoglobin levels ranged from 0.5% to 41.6% in 49 cases. of these, 41 patients were treated by normobaric oxygen therapy, while one was intubated for artificial respiration. additionally, 5 patients (10%) were treated by hyperbaric oxygen therapy, and 3 patients (6%) experienced delayed neuropsychiatric sequelae.conclusion: co sources included gasoline-powered electric generators and charcoal briquettes during the disaster. storm-related co poisoning is well recognized as a disaster-associated accident in the united states, but not in japan. we emphasize that public education is needed to make people aware of the dangers of co poisoning after a disaster. in addition, a pulse co-oximeter should be set up in hospitals.