小海湾水体有机氯农药的浓度水平和特征

以海南省万宁市小海湾为研究区,按照美国EPA8080A方法,使用仪器GC-ECD对小海湾海水和汇入其中地表水中样品的OCPs含量进行分析,样品中18种有机氯农药均出,以HCHs和DDTs为主,它们的和占到OCPs含量的60%。外海HCH含量0.26ng/L,DDTs含量0.53ng/L,OCPs含量1.34ng/L。海水中HCHs含量范围:2.39～4.59ng/L,平均值是3.31ng/L;DDTs含量范围:0.27～6.34ng/L,平均值是3.42ng/L;OCPs含量范3.63～17.01ng/L,平均值是11.15ng/L。地表水中HCHs含量范围:0.95～3.46ng/L,总含量是9.70ng/L;DDTs含量:0.96～2.86ng/L,总含量是9.70ng/L;OCPs含量范围3.71～17.16ng/L,总含量是59.13ng/L后山村河以及桥头村河的OCPs含量高出其它河流很多,周围是农田、居民点。由数据及小海湾的地理状况,得出海水中OCPs来源于地表径流,小海湾是OCPs巨大的储存库,OCPs主要汇集在沉积物中。

Concentration and Distribution of Organochlorine Pesticides Residues in a Bay of Hainan Province

Levels of organochlorine pesticides (OCPs) in both sea water and surface water from Xiaohai Bay, Hainan Province were determined. Most of OCPs were DDT, HCH and their metabolite residues, with concentration up to 60% of OCPs. In offshore, the concentration of HCHs residues, DDTs residues and OCPs was 0.26ng/L, 0.53ng/L and 1.34ng/L. In seawater, the concentration of HCHs residues, DDTs residue and OCPs was in the range of 2.39-4.59ng/L, 0.27 -6.34ng/L and 3.63-17.01ng/L, with average of 3.31ng/L, 3.42ng/L and 11.15 ng/L. In surface water, the concentration of HCHs residues, DDTs residues and OCPs was in the range of 0.95-3.46 ng/L, 0.96-2.86ng/L and 3.71-17.16ng/L, with total 9.70ng/L, 9.70ng/L and 59.13ng/L respectively. OCPs entry to seawater mainly comes from surface runoff. The Bay is a huge storeroom of OCPs which is stored in sediments.