Multiresidue screening of endocrine disrupting chemicals (pesticides & Pcbs) in the marine environment of Karachi: Evaluating the bioconcentration evidences and preferred sources of these chemicals

Pakistan has rich living and non-living resources in its coastal zone which produce about 6,21,980 metric tons of fish and shrimp and exports about 131,000 metric tons of fish worth rupees 7.272 billion. only karachi port handles 90-95% of sea food catch and seaborne trade of the country. but karachi being an industrial city is facing severe pollution along its coastline. in this study endocrine disrupting chemicals (edcs); twelve pesticides and nine pcbs were analyzed using methodology by environmental protection agency (epa) with gas chromatography-electron capture detector (gc-ecd) in 38 different species of fish,crabs,mollusks,echinoderms and shrimps from six different locations of karachi coastline. concentration levels of edcs at all sampling locations were below the extraneous residue limit and maximum residue limits of codex alimentarious commission of fao-who and us-fda. but according to the epa screening guidelines,concentration levels of σddts and σpcbs were found higher than their set limits in samples from two locations; korangi creek and fish harbor. higher pp'-ddt residues levels compared with pp'-dde levels were observed in this study indicating the fresh input of ddt in the study zone. whereas lindane and pcb-18 were also problem,having average highest concentration about 680ng/g and 32ng/g respectively,comprising of 58 and 36 % of total edcs concentration,respectively. bioconcentration evidences for pcbs have been observed in the area. study concludes the samples collected from coasts are rather less contaminated with the said pollutants than the samples taken from market and harbor area.