福州城郊冬夏两季大气中HCHs和DDTs分布特征

2010年冬、夏两季,利用大流量采样器采集了福州市大气样品,并用气相色谱-电子捕获检测器(GC-mECD)分析其中六六六(HCHs)和滴滴涕(DDTs)残留水平、分布特征及来源.结果表明,大气ΣHCHs浓度范围为28.04~413.0 pg/m3,总体而言,城区高于郊区,夏季高于冬季,气相高于颗粒相;气相中HCHs浓度夏季高于冬季,颗粒相中则相反;夏季气相中HCHs浓度显著高于颗粒相,而冬季气相与颗粒相中HCHs浓度基本相当.4种HCHs异构体中,气相与颗粒相中均是δ-HCH相对含量最高.大气ΣDDTs浓度范围为146.5~897.8 pg/m3,总体而言,郊区高于城区,冬季高于夏季,颗粒相高于气相;气相中DDTs浓度夏季高于冬季,颗粒相中则相反;冬季颗粒相中DDTs浓度显著高于气相,而夏季颗粒相与气相中DDTs浓度无显著差异.4种DDTs异构体/同系物中,气相中o,p′-DDT的相对含量最高,颗粒相中o,p′-DDT和p,p′-DDT相对含量较高.来源解析表明,福州城郊大气中HCHs非历史污染,存在林丹的使用或输入;大气中可能存在DDTs输入,并可能有大量三氯杀螨醇的输入.

Distribution characteristics of HCHs and DDTs in the atmosphere in winter and summer in the urban and suburban of Fuzhou

Air samples in urban and suburban in Fuzhou were collected by Hi-vol air sampler in winter and summer in 2010, and concentrations of HCHs and DDTs were analyzed by GC-μECD. The concentrations of ΣHCHs ranged from 28.04 to 413.0 pg/m3. In general, the residue level of HCHs in air in Fuzhou was as follows: urban > suburban, summer > winter, the gaseous phase > the particle phase. Concentrations of HCHs in summer were higher than those in winter in the gaseous phase while the particle phase had the opposite trend. Concentrations of HCHs in the gaseous phase were significantly higher than those in the particle phase in summer, while the concentrations of HCHs in the gaseous phase were almost equal to those in the particle phase in winter. δ-HCH had highest relative content in all samples. The concentrations of ΣDDTs spanned the range of 178.3~897.8 pg/m3. In general the residue level of DDTs was as follows: suburban > urban, winter > summer, the particle phase > the gaseous phase. Concentrations of DDTs in winter were higher than those in summer in the particle phase while the gaseous phase had the opposite trend. DDTs concentrations in the particle phase were significantly higher than those in the gaseous phase in winter, while there were no significant differences between particle and gaseous phases in summer. o,p′-DDT had highest relative content in the gaseous phase while o,p′-DDT and p,p′-DDT in the particle phase. Source analysis indicated that HCHs was not historic pollution in Fuzhou atmosphere, and the use or newly input of lindane might exist. There maybe newly input of DDTs and large amount input of dicofol in Fuzhou.