Determination of organochlorine pesticide residues in the sediments of Rasht Rivers and their hazard assessment

In this study, some samples of bed sediments from Rasht rivers were obtained and 19 organochlorine pesticides (OCPs) were determined for specifying the contamination profiles, distribution characteristics, effective factors and hazard of carcinogenic compounds. OCPs as Persistent Organic Pollutants (POPS) haskhown vast distribution, persistence and accumulation in the environment. Their high toxicity to humans and non-target organisms are a significant threat to human health and biodiversity.

Identify and determine the concentrations of organochlorine pesticides analysis were conducted on bed sediment samples by liquid-liquid micro extraction method and then by gas chromatography flame ionization (GC-FID) and via external standard calibration curve drawing.

Based on the analysis, total concentration of OCPs is in the range of 2.6-60.2 ng/g, with an average of 20 ng/g. The main sources of pollution are Heptachlor, HCHs, DDTs and Endosulfans and highest contamination of the dominant pollutant DDE isomers belonges to sediments of Pir Bazar River.

The results are showed that there were various amounts of new and past entries. The analysis shows that the potential source of high levels of DDTs and HCHs residues of pesticides returns to the pastconsumptions.