Institute of Environmental Science, Engineering, and Management, Industrial University of Ho Chi Minh City, 12 Nguyen Van Bao, Go Vap District, Ho Chi Minh City, Vietnam.
Graduate University of Science and Technology, Viet Nam Academy of Science and Technology, Hanoi, Vietnam.
Arch Environ Contam Toxicol. 2019 Nov;77(4):514-526. doi: 10.1007/s00244-019-00653-6. Epub 2019 Jul 11.
The goals of the current study were (1) to examine seasonal and spatial variation of selected OCPs concentrations and (2) to identify potential sources of the pollutants in the lower reaches of the Dong Nai River system. Forty-eight water and sediment samples were taken from 12 stations in the dry and rainy seasons to determine the concentrations of dichlorodiphenyltrichloroethane and its metabolites (total DDTs), hexachlorocyclohexane isomers (total HCHs), heptachlor, aldrin, dieldrin, and endrin. The concentrations of total DDTs (0.30), total HCHs (0.29), Aldrin (0.068), heptachlor (0.04, µg L) in water, and total DDTs (8.04), total HCHs (4.51), and Aldrin (1.52, µg kg) in sediment were significantly higher in the rainy season than in the dry season (0.14, 0.12, 0.008, 0.009 in water and 3.49, 2.29, and 0.4 in sediment, respectively). Cluster analysis grouped 12 sampling stations into 2 groups, of which group 1 (3 stations) had higher concentrations of total DDTs, total HCHs, Aldrin, heptachlor, and dieldrin in both water and sediment than in group 2. Compositional analysis of total DDTs revealed that DDT residue could be decomposed significantly for the past years and that anaerobic decomposition could be predominant. Principal component analysis/factor analysis (PCA/FA) indicated that the potential sources of OCPs in the study stations could come from residential and agricultural areas located in the upper catchment or areas surrounding the studied stations. In short, OCPs concentration in the studies area could depend on seasonal, spatial variation, and transport of OCPs from upper parts or surrounding areas.
（1）考察选定的 OCPs 浓度的季节性和空间变化；（2）确定在湄公河下游系统中污染物的潜在来源。在旱季和雨季，从 12 个站点采集了 48 个水样和沉积物样，以测定二氯二苯基三氯乙烷及其代谢物（总滴滴涕）、六氯环己烷异构体（总六氯环己烷）、七氯、艾氏剂、狄氏剂和异狄氏剂的浓度。水中总滴滴涕（0.30）、总六氯环己烷（0.29）、艾氏剂（0.068）、七氯（0.04μg/L）的浓度在雨季明显高于旱季（分别为 0.14、0.12、0.008、0.009μg/L），而沉积物中总滴滴涕（8.04）、总六氯环己烷（4.51）和艾氏剂（1.52μg/kg）的浓度在雨季也明显高于旱季（分别为 3.49、2.29 和 0.4μg/kg）。聚类分析将 12 个采样站分为 2 组，其中第 1 组（3 个站）的水中和沉积物中总滴滴涕、总六氯环己烷、艾氏剂、七氯和狄氏剂的浓度均高于第 2 组。总滴滴涕的组成分析表明，滴滴涕残留物在过去几年中可能发生了显著分解，而厌氧分解可能占主导地位。主成分分析/因子分析（PCA/FA）表明，研究站 OCPs 的潜在来源可能来自上游集水区或研究站周围的居民区和农业区。总之，研究区 OCPs 的浓度可能取决于季节性、空间变化以及 OCPs 从上游或周围地区的迁移。
