Study On Pollution Characteristics Of The Atmospheric Particle Matters (PM₁₀,PM_2.5) On Haze And Non-haze Days In Shanghai

By analyzing on chemical components in airborne particles, the pollution characteristics and influence factors were explored, thus the process of atmospheric pollution, environmental effect and control management had more in-depth understanding. Providing a scientific basis on haze pollution formation process and haze pollution controlling.Atmospheric particulate matter(PM_2.5, PM₁₀) had manual sampled haze and non-haze days of filters on the seventh floor roof of Shanghai Xuhui District Environmental Monitoring Station during November 2012 to March 2013. After analyzing and processing the data, the water soluble inorganic ions and heavy metals pollution characteristics of particulate matter(PM_2.5, PM₁₀) were compared and analyzed, and evaluating heavy metals of particulate matter(PM_2.5, PM₁₀) on human health risk, mainly obtained the following conclusions:Results showed that average mass concentrations of PM_2.5 and PM₁₀ during haze days were（ 114.0±36.9） and（162.7±53.2）μg/m3, 2.72 and 2.48 times greater than those in non-haze days, the average concentrations of water-soluble anions of PM_2.5 and PM₁₀ during haze days were 51.0μg/m3 and 60.6μg/m3, 2.70 and 2.58 times greater than those in non-haze days. So it was also said that they greatly enriched in haze days, especially the concentrations of water-soluble anions in PM_2.5 highly enriched than those in PM₁₀.According the concentration ratio of NO₃^- / SO₄^2- was >1 in haze days higher than that in non-haze days, which showed the mobile emission sources（traffic emission） had great roles on the haze days in the city. The dynamic process of haze pollution showed that the mass concentration of particles, water-soluble anions such as NO₃^-, SO₄^2- and Cl- had changed significantly. The longer the duration of the haze period, the concentration of PM_2.5, NO₃^-, C1- accumulated more.The average concentration of six kinds of heavy metals of particulate matter(PM_2.5, PM₁₀) during haze and non-haze ranked from descending order:Fe>Zn>Pb>Cu>Cr>Cd. During the haze the average concentration of heavy metals such as Zn,Cu,Cr,Cd in PM_2.5 and PM₁₀ were higher than those in non-haze period, the results showed that the heavy metal elements in the haze period significantly enriched. By means of enrichment factor analysis, the enrichment factor values of heavy metals（such as Zn, Pb and Cd） are more than 40. Moreover the enrichment factors of heavy metals of PM_2.5（Zn, Pb, Cu, Cr, Cd） were higher than those of PM₁₀, therefore the enrichment effect of heavy metals in fine particles was more obvious, so the damage of fine particles is more harmful. Use the Index of Geoaccumulation（Igeo） to evaculate the heavy metals in PM_2.5, the results showed that the heavy metals of particulate matter（Pb,Cu,Cd,Zn） were all contaminated except Cr. The level ranked from low to high as follow:Cu<Zn<Pb<Cd.Haze and non-haze during heavy metals PM₁₀ and PM_2.5 are basically the same ecological hazards, as follow:Cd>Pb>Cu>Zn>Cr.During Haze and non-haze in PM₁₀ and PM_2.5, Cr, Cd did not have the risk of cancer. The non-carcinogenic hazard index of 5 kinds of heavy metals were less than 1, which can be considered the risk was small and would not cause harm to human body.