Investigation of yearly indoor/outdoor PM2.5 levels in the perspectives of health impacts and air pollution control: Case study in Changchun, in the northeast of China

Campus environment, especially campus indoor environment, will directly affect the health of college students. Through one-year real-time monitoring of PM2.5 indoor and outdoor in colleges and universities in Northeast China, the annual PM2.5 indoor and outdoor concentration was analyzed. Questionnaires were used to investigate students' lifestyles, and the health effects of PM2.5 pollution on students in university packed areas were assessed using the DALY model and the USEtox model. The monitored results show that PM2.5 concentration was the highest in winter, 41.59 mu g/m(3) indoor and 105.85 mu g/m(3) outdoor, the lowest concentration was 11.15 mu g/m(3) and 18.71 mu g/m(3) in summer. There is a significant Correlation between indoor and outdoor PM2.5 concentrations. The contribution value of outdoor PM2.5 to indoor air pollution was 11.22 mu g/m(3) and 14.28 mu g/m(3) respectively in autumn and winter, and 7.30 mu g/m(3) and 3.61 mu g/m(3) respectively in spring and summer. The contribution rate of autumn and winter was 26.47% and 27.00% respectively, and that of spring and summer was 48.13% and 65.63% respectively. Among 145,200 students in this area, 109-134 died prematurely due to PM2.5 pollution, 71-75 of which were attributed to indoor PM(2.5 )pollution. Indoor and outdoor PM2.5 pollution resulted in 42 chronic bronchitis, 2565 medical outpatient visits, 19 cardiovascular diseases and 5 respiratory diseases. These findings should further arouse our attention to come up of effective solutions for indoor air pollution control, such as sources control, purification equipment mounting etc..