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

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. A questionnaire regarding CO poisoning associated with the disaster was sent to 37 emergency hospitals in Yamagata prefecture. 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. 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.