Volume No. 7 Issue No.: 4 Page No.: 1322-1332 April-June 2013

 

ASSESSMENT OF CYTOTOXIC AND GENOTOXIC POTENCY OF Cr(VI)-DOPED RIVER WATER OF NEN-SHKODRA LOWLAND, ALBANIA, ON Allium cepa L.

 

Kopliku Ditika* and Mesi Anila

Department of Biology and Chemistry, Faculty of Natural Sciences University of Shkodra “Luigj Gurakuqi”, Shkodra (ALBANIA)

 

Received on : November 05, 2012

 

ABSTRACT

 

The increase of metal concentration in water bodies by mining effluents has caused a great environmental and ecological concern. In this paper the Allium cepa L. bio-test was used to assess the toxicological tendency of some riverside water samples taken in Nen-Shkodra lowland (North-West Albania) and to evaluate the cyto/genotoxicological potency of chromium (VI), experimentally added to analyzed natural waters. The Cr(VI) toxic effective concentration (EC50) per each sample was assessed by using K2Cr2O7 salt and a preliminary root growth inhibition test for 96 h, and then the onion roots were grown for 48 h in river samples mixed with three doses, representing the corresponding ¼ EC50, ½ EC50 and EC50 Cr(VI) concentrations. There were evaluated some microscopic endpoints of onion roots grown in natural and experimental samples : mitotic and phase indexes, interphase nuclear volume, DNA content, micronuclei formations and chromosomal aberration rate and types. There was noted a certain difference of cytogenetic endpoints between two groups of natural samples, demonstrating a possible amelioration of river water quality down streaming Nen-Shkodra lowland into sea. The results showed obvious Cr(VI) concentration-dependence : cyto/genotoxicological effects on root cells came increasing with addition of chromium salt. Cr(VI) EC50 doped samples caused a reduction in the mitotic and metaphase indexes, interphase nuclear volume and DNA content of 48-56%, 53-66%, 34-41% and 28-37%, respectively, and a considerable increase in micronuclei and chromosomal aberrations frequencies. Stickiness, c-mitosis, bridges, fragments and laggard chromosomes were mostly detected. Being a sensitive, short-term and low cost alternative, the Allium test and in general the bioassays should be an integral tool in quality monitoring of water bodies, soil and air, especially in developing countries as Albania.

 

Keywords : Albania, Mining effluents, Water pollution, Allium cepa L. bio-test, Cytotoxicity, Genotoxicity, Cr(VI)

 

 

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