Abstract:In order to investigate the occurrence characteristics and transmission laws of organochlorine pesticides (OCPs) in Luhu Lake, a typical suburban lake in the middle reaches of the Yangtze River, water and sediment samples were collected from 40 sites in Luhu Lake, located in Jiangxia District, Wuhan, China. 24 kinds of OCPs were determined by gas chromatography (GC-ECD) to analyze the pollution characteristics, sources and multi-medium transmission laws. The results showed that, all 24 kinds of OCPs were detected in the study area, and the total amounts of OCPs ranged 0.64 to 6.97 ng·L-1 in dissolved phase, 0.06 to 5.61 ng·L-1 in suspended particulate matter, 0.47 to 14.16 ng·g-1 in surface sediments, respectively. Compared with other lakes, the OCPs concentrations were at a low level. HCHs accounted for the largest proportion in dissolved phase, while HCHs, DDTs and Aldrin were the main pollutants in suspended particulate matter and sediment. The results of characteristic ratio traceability analysis showed that HCHs and DDTs were mainly historical residues in the study area. The main sources of HCHs in water and sediment were agrolindane application and mixed sources respectively, and DDTs were mainly degraded in an anaerobic environment. The multi-medium transmission of OCPs was analyzed by the cosine theta similarity metric, partition coefficient and fugacity approach. The distribution coefficient (Kd) between dissolved phase and suspended particulate matter showed that OCPs in water were more easily to be adsorbed by suspended particulate matter with an increase in the octanol-water partition coefficient (KOW). The fugacity fraction between water and sediment (ffSW) decreased with an increase in KOW, indicating that the sediments in the study area were sinks of OCPs with high KOW such as HCB and Aldrin.