苏南地区香樟树皮中有机氯农药(OCPs)的污染水平及来源解析

Levels and Possible Sources of Organochlorine Pesticides( OCPs) in Camphor( Cinnamomum camphora) Tree Bark from Southern Jiangsu,China

利用树皮作为被动采样介质，2012年8月于苏南地区采集了33个香樟树皮进行有机氯农药（OCPs）的分析．结果表明，苏南地区香樟树皮中六氯苯（HCB）、滴滴涕（DDTs）和氯丹（Chlordanes）的含量范围（以干重计）分别为0．31-1．81、0．40-17．3和n．d．-1．03ng·g^-1．由于六氯苯挥发性较强，其含量的空间差异性不明显．同其它研究结果相比，苏南地区树皮中六氯苯含量相对较低．苏南地区DDT主要来源于工业DDT的历史残留和三氯杀螨醇的使用．根据反式氯丹（Tc）／顺式氯丹（CC）的比值判定，苏南地区城区中氯丹可能来源于近期的直接使用，而乡村地区则来源于历史残留．

Thirty-three camphor tree bark samples were collected from Southern Jiangsu in August 2012. They were analyzed for organochlorine pesticides （ OCPs ） , including hexachlorobenzene （ HCB ） , DDTs （ o,p＇-DDE, p,p＇-DDE, o, p＇-DDD, p,p＇-DDD, o,p＇-DDT and p,p＇-DDT）, trans-chlordane and cis-chlordane. The concentrations of HCB, ∑ 6DDTs and ∑Chlordanes ranged （dw） from0.31 ng.g-~ to 1.81 ng.g-t, 0.40 ng.g-i to 17.3 ng＇g-1 and n.d. to 1.03 ng＇g-1, respectively. Due to the high volatility, the spatial distribution of HCB in Southern Jiangsu was uniform. Compared to the other results, the HCB concentration in Southern Jiangsu was lower. The historical usage of technical DDT mixture and the dicofol-type DDT were the major sources of DDTs in southern Jiangsu. The TC/CC ratio is usually used to distinguish between aged and fresh chlordane. According to the ratio of TC/CC, the chlordane in the urban area was derived from the fresh application of technical chlordane, and that in the rural area was attributed to the historical usage.