Occurrence of pesticide residues in freshwater and estuarine fishes of Thamirabarani river

Abstract

Background: Studies pertaining to the presence of OCP residues in the freshwater and marine fishes caught from the Thamirabarani river basin region are not available to analyze the extent of bioaccumulation to assess their safety for human consumption. Hence, this study was undertaken as a maiden work to examine the OCP residues in the fishes collected from five sites spanning from the source to mouth region of the Thamirabarani river system, along with other related niches to examine the effect of environment pollution. Methods: Pesticides from fish muscle and their organs were extracted as per AOAC 2007.01 using QuEChERS method. A Gas Chromatograph model Perkin Elmer - equipped with Ni Electron Capture Detector of activity 15 MCi was used for the analysis. A volume of 1.0 μl of the extracts was injected. The operating conditions were capillary column Elite-5 capillary column, 60 m × 0.25 mm, 1.00 μm temperature programme: 70°C (2 min) to 180°C (I min) 25°C/min to 300°C 5°C/min, Injection temperature: 270°C, Detector temperature: 300°C, Carrier gas: Nitrogen at 1.0 mL/min, Make up gas: Nitrogen at 29 mL/min. Result: Among fishes, rohu accumulated maximum of 0.4014 to 0.605 ug/kg of DDT in station IV and V respectively. Dhananjayan and Muralidharan (2010) reported OCPs in 156 fishes sample from Kaveri river. The average concentration of DDT ranged between 0 and 0.605 ug/kg. Bhuvaneshwari and Babu rajendran (2012) also reported 2.8 ug/g of DDT in fishes from Kaveri river. The low occurrence of DDT in the presence study is mainly due to their rapid degradation with living organisms.