Bioaccumulation and Excretion of Some Pesticides by Freshwater Fish Oreochromis niloticus

Shehata E. Elowa

Department of Zoology, Faculty of Science, Helwan University, Helwan, Egyipt

Corresponding author: Dr. Shehata, E. Elowa
    Department of Zoology
    Faculty of Science
    Helwan University
    Helwan, Egypt
    Telephone: 002/02/4535765
    Fax number: 002/02/5552468
    E-mail: shehataa2000@yahoo.com

CEJOEM 2003, Vol.9. No.1.: 67–80


Key words:
Bioconcentration factor (BCF), excretion, LC50, fenthion, carbofuran, cypermethrin, excretion rate (k), half life (t½), Oreochromis niloticus


Abstract:
In Oreochromis niloticus exposed to the pesticides fenthion, carbofuran, or cypermethrin for 96 h, the static bioassay yielded LC50 values of 50, 80 and 45 µg∙L–1, respectively. The bioconcentration factor (BCF) of the pesticides studied were somewhat higher for the liver (8.5, 1.62, and 2.25, respectively) than for the muscle (7.0, 1.4, and 2.31, respectively). The record hepatic concentrations amounted to 170, 220, and 180 ng∙g–1 and the muscular ones to 185, 155 and 140 ng∙g–1, respectively. The excretion rates of the three pesticides only showed minor differences (liver: 0.006, 0.007, and 0.006 ml∙g–1∙h–1; muscle: 0.008, 0.0061, and 0.0051 ml∙g–1∙h–1, respectively), while their uptake rate constants were found to be 0.088, 0.017, and 0.023 h–1, respectively, for the liver and 0.072, 0.040, and 0.12 h–1 , respectively for the muscle. It can be concluded that the accumulation and/or excretion of a pesticide and its impact could be assessed in fish. Consequently laboratory exposure of fish to pesticides could provide useful information on the proper use of pesticides and how to facilitate their elimination.


Received: 15 November 2002
Accepted: 5 November 2003

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