Wintertime pollution level, size distribution and personal daily exposure to particulate matters in the northern and southern rural Chinese homes and variation in different household fuels.

This study investigated and compared wintertime air pollution and personal exposure in the rural northern and southern Chinese homes. Daily indoor and outdoor particle samples were simultaneously collected by using stationary samplers, and personal exposure was directly measured using portable carried samplers. The daily average concentrations of indoor and outdoor PM were 521 ± 234 and 365 ± 185 μg/m in the northern village, that were about 2.3-2.7 times of 188 ± 104 and 150 ± 29 μg/m in indoor and outdoor air in the southern villages. Particle size distribution was similar between indoor and outdoor air, and had relatively smaller difference between the two sites, relative to the particle mass concentration difference. PM contributed to ∼80% of the TSP mass, and in PM, near 90% were PM. In homes using electricity in the southern villages, outdoor air pollution could explain 70-80% of the variation in indoor air pollution. The daily exposure to PM measured using personal carried samplers were 451 ± 301 μg/m in the northern villages with traditional solid fuels used for daily cooking and heating, and in the southern villages without heating, the exposure to PM were 184 ± 83 and 166 ± 45 μg/m, respectively, for the population using wood and electricity for daily cooking. Time-weighted daily average exposure estimated from area concentration and time spent indoor and outdoor was generally correlated the directly measured exposure.