Daily Variation Characteristics Of Small Air Ions And Radon And Its Correlation Analysis

Atmospheric ions produced by radon exhalation from the Earth’s surface can play a vital role in the electrification of atmosphere. It has been now recognized that atmospheric ions not only play important role in determining the electrical state of atmosphere, but also can affect the aerosol and cloud properties and ultimately on climate. Therefore, it is significantly important for academic study and human health to explore the characteristics of variation and the correlations of between small air ions and radon, atmospheric particles(PM2.5/PM10).In this thesis, measurements were performed of outdoor and indoor in Chang’an University. The concentrations of small air ions, radon and atmospheric particles(PM2.5/PM10) were measured by using COM-3600 F air ion monitor, RAD7 and PC-3A(S), respectively. The emphasis here was on the characteristics of variation of small air ions, radon and atmospheric particles(PM2.5/PM10), and the correlations of between small air ions and radon, atmospheric particles(PM2.5/PM10). Moreover, the prediction model of small air ion concentrations were also studied preliminary.The results show that radon is the major source of the small air ions of outdoor and indoor air, and PM2.5/PM10 concentrations was found to be the important parameter influencing the lifetime of small air ions. The concentrations of small air ions and radon revealed a strong positive correlation in enclosed rooms(P<0.01), correlation coefficient between air ions and radon were R(Rn, n+)=0.878 and R(Rn, n-)=0.865, respectively; there was negative correlation between air ions and PM2.5(PM10)(P<0.01), correlation coefficient between air ions and PM2.5(PM10) were R(PM2.5(PM10), n+)=-0.985(-0.982) and R(PM2.5(PM10), n-)=-0.947(-0.976), respectively. It has been found that the correlation coefficient of the outdoor measurements is lower than indoor, correlation coefficient were R(Rn, n+)=0.670(P<0.01), R(Rn, n-)=0.401(P<0.05) and R(PM2.5, n+)=-0.479(P<0.05), R(PM2.5, n-)=-0.589(P<0.01), respectively.The concentrations of the indoor small air ions, radon and PM2.5 were affected significantly by human activity(burning cigarettes) and air flow. Generally the number of small air ions was lower when the concentrations of PM2.5 was increasing due to burning cigarettes, but there was little influence for radon. A decline greatly of the indoor air ions and radon concentrations is attributed to air flow, while the indoor PM2.5 concentrations was as same as the outdoor concentrations.Small air ions, radon and PM2.5 concentrations in the different weather conditions was: moderate rainy>after the rain cloudy>light rainy>before the rain cloudy; before the rain cloudy≈after the rain cloudy>rainy; before the rain cloudy>after the rain cloudy>rainy, respectively.