Since inhabitants spend much time sitting on the ground around the stove, which is put in the middle of the tent/house, we chose a sampling site close to their breathing zone. The BC and PM2.5 monitors were placed approximately 0.5 m above the ground and 1 m horizontally away from the stove. Generally, residents get up around 7 am, light the stove, and cook breakfast. Men, rarely women, leave the tent/house and start herding sheep and yak around 10 am. Lunch is prepared around noon and dinner around 7 pm. The stove is then used mainly for heating and boiling until around 11 pm, when residents go to bed . Fuels are added every 15e20 min while the stove is lit, and more frequently when cooking. The start and end times of the measurement period at each household varied depending on several logistical reasons.