investigation of persistent organic pollutants residue in sediments of international anzali wetland, iran

anzali wetland is one of the most important aquatic ecosystems of iran located in south of the caspian sea. this wetland is a habitat for valuable fishes and aquatic animals which have an important role in life cycle of this ecosystem. agroup of the pollutants entering these wetlands is the persistent organic pollutants. this pollutants has a wide range of ingredients in the environment and are known as a global pollution problem. due to the high solubility of these compounds in fat and their stability in the environment they can make accumulate in the body of the aquatic organisms and transfer through the food chain. in this studsy durig winter and spring of 2008 the levels of organo chlorinated pesticides (ocps) in the sediments was investigated. the concentration of hchs ?cyclodiene ddts and hcb in the sediments of winter were in the range of 1/17 4/21 ng/g dw nd 5/08 ng/g dw 1/43 8/51 ng/g dw and 0/06 0/35 ng/g dw and in the spring were in the range of 1/08 4/78 ng/g dw 1/27 5/97 ng/g dw 2/15 9/92 ng/g dw and 0/06 0/38 ng/g dw respectively. among hchs ?cyclodane and ddts ? hch endosulfan and p p/ dde with the concentration of 0/47 2/12 ng/g dw nd 1/7 ng/g dw and 1/43 3/47 ng/g dw were the dominant detected congeners in the winter while in the spring ? hch endosulfan and p p/ dde with the concentration of 0/46 2/58 ng/g dw 0/44 1/96 ng/g dw and 1/32 4/78 ng/g dw were the dominant detected ones respectively. . in the samples of spring the mean ocps concentrations were higher than winter. moreover the significant difference was observed among investigated stations (p < 0/05).