Unintentional Carbon Monoxide Poisoning Outbreak from 2 to 9 October 2019 in Ulaanbaatar, Mongolia

Carbon monoxide poisoning (COP) from 2 to 9 October 2019 was a major public health concern in Ulaanbaatar, Mongolia, after a transition from consumption of raw coal to upgraded briquette fuel. During the period, a total of 186 residents, which is 16 times more than the previous years, were exposed to COP and 6 persons died at home. We conduct a cross-sectional study by using registration data and medical history of all hospitalized patients with a diagnosis of COP from 2 to 9 October 2019 and had an in-depth interview. 144 (77.4%) people from 85 households registered as potential cases and 124 (86.1%) people were diagnosed with COP. All households used upgraded briquettes, and 41 households (48.2%) used them for the first time. In 50% of cases, the stove was broken, the chimney was short, not heated, and the clay joint connecting the wall stove was broken. The majority of interviewees were unaware of COP and improperly used briquettes, and the safety of chimneys and stoves was insufficient which caused unintentional COP. It is necessary to provide information to the local population about the potential risks of COP, install CO alarms in households, and educate the population. In further, a well-established poisoning surveillance system is an important aspect of public health emergency preparedness in Mongolia.