Distribution Characteristics Of Polychlorinated Biphenyls (PCBs) In Main Urban Atmospheric Particles Of Inner Mogolia

Polychlorinated biphenyls（PCBs）are one of the typical persistent organic pollutants（POPs）.They were also one of the first batch of 12pollutants of POPs which have banned in《Stockholm Convention on persistent Organic Pollutants》（simply named《Convention》）.Because Japanese rice bran oil occurred in 1968,PCBs become a hotspot of research in worldwide.According the further research,PCBs had been detected vary from different degrees in many environmental mediums of various countries.However,as atmosphere is a better transport medium,so it can provide a good foundation for the PCBs contamination,diffusion and migration in worldwide.Besides atmospheric particles can provide a good carrier for taking in PCBs,which is easily to enter the body through the respiratory system.Therefore,the research of PCBs about the concentration,distribution characteristics,sources and other aspects in atmospheric particulate matter has a positive meaning.The concentration levels,distribution characteristics and sources of PCBs in atmospheric particles of Inner Mongolia Autonomous Region were studied in this paper.The samples of atmospheric TSP and PM₁₀0 particles were collected from four cities（Hohhot city,Ordos city,Chifeng city and Tongliao city）of Inner Mongolia during the winter of 2012 and the summer of 2013,and 219 samples were collected totally.After Soxhlet extraction,concentration and a series of pre-treatment process,eight kinds PCBs in the samples were analyzed by GC-MS finally.PCB in atmospheric TSP and PM₁₀0 particles in Inner Mongolia Autonomous Region of four cities has the following characteristics:1.In four cities of Inner Mongolia Autonomous Region,the concentration rang of total PCBs in the TSP samples in summer and winter is44.36-74.43 pg/m³ and 101.13-176.64 pg/m³,respectively;the concentration rang of total PCBs in the PM₁₀0 in summer and winter is 11.36-37.37 pg/m³and 108.48-162.71 pg/m³,respectively.2.The concentration of PCBs in TSP was higher than that of in PM₁₀0 and mostly detected PCBs is low chlorine-based PCB in atmospheric particles,which are PCB-1,PCB-5,PCB-29 and PCB-47.3.In Inner Mongolia Autonomous Region of four cities for sampling,the concentration rang of PCBs in atmospheric particulate samples in summer is nd-144.44 pg/m³;the concentration rang of total PCBs in atmospheric particulate samples in winter is nd-430.30 pg/m³.Which was exhibited one trend is winter（29）summer.4.The day and night PCB concentration levels in PM₁₀0 In winter were monitored.The results show that the concentration of PCBs in the day and night is 108.48-162.71 pg/m³ and 28.80-61.69 pg/m³,respectively.It is apparent that the concentration of PCBs in the day is higher than that of the night.5.The concentration of PCBs of atmospheric particulate in above four cities,namely,Hohhot,Ordos,Chifeng and Tongliao,of Inner Mongolia Autonomous Region,is 96.67-125.53 pg/m³,73.40-97.61pg/m³,71.42-77.80pg/m³ and 68.66-101.71 pg/m³,respectively.