According to experts, poor air ventilation systems  can be a factor in the spread ofCOVID-19 among apartment residents. In Mongolia, this appears to be the case; health officials have issued a quarantine in the Bayangol District of Ulaanbaatar and conducted coronavirus tests. These measures took place among residents between 8 and 9 January. As a result, eight people from four families who live in the same apartment in Bayangol District tested positive for coronavirus. The families live on the 2-5 floors of the same block in the 6 story apartment. The family members said that they can smell food or cigarettes smoke through the air vents from other apartments.