Research on influencing factors and improvement methods for air pollution in rural houses of severe cold region of China

Self-sufficient energy system leads to high levels of indoor pollution, accompanied by fuel burning processes indoors. Many factors have potential impacts and relations among factors and indoor air pollution are complicated. Exploration on revealing the relations in rural-houses of severe cold region of China is still insufficient. This paper attempted to comprehensively explore influences of factors composed of building layout, building envelope, heating feature, outdoor climate on indoor air pollutants. Field measurement and questionnaire survey were conducted in thirty-nine villages located in Shenyang, China. Temporal data for indoor air pollutants, including PM2.5, PM10, CO2 and CO in winter were measured. For each pollutant, 51,110 pieces of data were obtained. Statistics for percentage distributions of pollutants in different concentration intervals showed that 80 % of day-time was in serious pollution situation. Associations between factors and indoor air pollution were investigated utilizing multifactorial logistic regression. The values of OR and CI showed that these factors had significant effects on four kinds of pollutants. Overall, variations of factors in the four dimensions were found to have the greatest impact on CO2 concentration. Further, the influence of different heating scenarios composed of multiple factors on indoor air pollution level were analyzed. Twenty heating scenarios were suggested for heating in rural houses of severe cold region. Time-series data of air pollutants, indoor air temperature and humidity were detrended to study the correlations while eliminating the influence of time. It was found that indoor temperature fluctuated earlier than air pollutants and thus should not be taken as the indicator of estimating fuel burning time. The research results are helpful to deepen the understanding of the influence of various factors on complex indoor environment of rural houses in severe cold region. In addition, yielded results will provide basis to formulate strategies for improving living environment of rural-house and help to eliminate the health inequities caused by poverty.