Study Of Organic Pollutants In Air Aerosol (PM 2.5) Of Lanzhou City

Air aerosol is a sort of pollutant which poses a negative effect on human health, environment and climate change. Research concerning aerosol takes up the trend which attaches more importance to fine particle, namely PM2.5. The reason is that fine particle does more harm to human health than coarse particle and causes low atmosphere visibility. By means of research on PM2.5, we could know more about overall air quality. Especially, research of organic pollutants could provide scientific evidence for air quality improvement and air pollution control. Equipped with GC-MS method, air samples were collected from the summer of 2008. Pollution condition resulting from PM2.5 in summer, autumn, winter were assessed. Meanwhile pollution status of PM10 in winter was also observed. Results indicate that concentration of PM2.5 and PM10 is generally beyond national limit (there is no standard for PM2.5 in China, so we apply the criterium for PM2.5 of the U.S.). PM2.5's proportion over PM10 is increasing. From above, we could see that PM2.5 research is of vital importance to atmosphere analysis while there is no national standard we could depend on, which worsens the current situation. 32 organic pollutants were observed. Alkane occupies the biggest part, while alkene with a second large proportion. Ester, ketone, alcohol were within the group. Summer and winter do not differ a lot in concrete organic pollutants while winter is quite different, which can be partly explained by use of coal for heating in winter time. The 32 pollutants are all chemicals used in chemical synthesis or as by-product. They mainly originate from chemical synthesizing process or vehicle exhaust. They act as stimulus to human respiratory system. Pneumonia, edema, tuberculosis, asthma, bronchitis are possible consequences if certain amount of these pollutants are inhaled. Gansu has a high incidence of lung disease and suffers a lot from it. And there might be a relation between lung diseases and organic pollutants' existence. Compared with another research in Changchun city (Jilin province), a conclusion could be drawn that part of these pollutants, mainly alkane and alkene, come from vehicle exhaust.