利用中子活化分析法(NAA)研究了2004年11-12月上海嘉定地区大气中总悬浮颗粒物(TSP)和可吸入颗粒物(PM10)中可萃取有机卤素污染物(EOX)和持久性可萃取有机卤素污染物(EPOX)。分析结果表明,该地区大气中EOX的质量分数(ω)顺序为EOCl〉〉EOBr〉EOI,EOCl均占到EOX的87%以上,说明大气中有机卤素污染物主要为有机氯污染物;TSP中六六六(HCHs)、滴滴涕(DDTs)和多氯联苯(PCBs)的平均质量浓度分别为7.4,30.4,21.9pg/m^3,PM10中的平均质量浓度分别为3.7,19.5,13.1pg/m^3。TSP和PM10中,(ρ(p,p'-DDE)+ρ(p,p’-DDD))与ρ(p,p’-DDT)的质量浓度比值范围分别为0.8~2.3和0.9~4.4,说明大气中DDTs主要来自历史的残留,同时发现上海嘉定地区大气中新近有DDTs的输入。TSP和PM10中分别约有59%~93%和33%~69%的PCBs为五氯至八氯取代物。
TSP and PM10 samples were simultaneously collected at Jiading district, Shanghai between November and December 2004 and analyzed by neutron activation analysis (NAA) for extractable organohalogens (EOX) and extractable persistent organohalogens (EPOX) and by GC ECD for organochlorinated pesticides (OCPs) and polychlorinated biphenyls (PCBs). The results show that the mass fraction of EOX in TSP and PM10 are in the order of EOCl〉〉EOBr〉EOI, and more than 87% of EOX is EOCl, which indicate that EOCl is the major component of organohalogens in the particulate matter. The mass concentrations of HCHs, DDTs and PCBs in TSP are 7.4, 30.4 and 21.9 pg/m^3, respectively, and are 3.7, 19.5 and 13.1 pg/m^3 in PM10, respectively. The ratios of the sum of ρ(p,p'-DDE) and ρ(p,p'-DDD) to ρ(p,p' DDT) in TSP and PM10 are 0.8-2.3 and 0.9-4.4 respectively, which imply that DDTs mainly originated from the past residues in the environment, and there is new input of DDTs in Jiading district, Shanghai. C15PCBs-C18PCBs are the most abundant isomers in this study, which account for about 59%-93% and 33%-69% of total PCBs in TSP and PM10, respectively. Higher chlorinated PCBs are the major PCBs in particulate matter, which originate mainly from leakage of transformer oils and disposal of capacitors.