Volume No. 6 Issue No.: 1 Page No.: 1-11 July-Sept 2011

 

EVALUATION OF TOTAL TOXICITY OF EFFLUENTS FROM SEVERAL WASTE WATER TREATMENT STATIONS AND MAJOR WATER SOURCES OF CYPRUS USING Xenopus Laevis AS A MODEL ORGANISM

 

Maria Andreou, Iro Eleftheriou, Anna Eleftheriou, Neophytos Christodoulou, Ioanna Antoniades, Andr

Department of Biological Sciences, University of Cyprus, Nicosia (Cyprus)

 

Received on : April 27, 2011

 

ABSTRACT

 

The evaluation of total toxicology is achieved by using FETAX (Frog Embryo Teratogenesis Assay). This method is applied in many toxicological studies and is a rapid test for the identification of developmental toxicants. Due to the sensitivity of embryonic and early life stages, FETAX provides information that can be useful in determining the chronic toxicity of a test material on aquatic organisms. This method has been established and tested using chemicals which are known to cause specific phenotypes in Xenopus laevis embryos. In this study, water samples were collected from 26 dams and reservoirs throughout Cyprus and in addition the assay was applied to determine water quality from both small and large scale biological wastewater treatment plants. Dams and reservoirs are the major water sources of the island. During the water sample collection; temperature, pH and conductivity were measured on site. All the samples were subsequently measured for nitrates, phosphates, carbonates, magnesium and calcium salts and were used to carry out FETAX in order to test for developmental toxicity. Overall the tested samples showed very low levels of developmental toxicity using the FETAX assay. Out of 26 dams only two that are located near agricultural areas (of which the watershed encompasses substantial agricultural areas) and they may contain a very high concentration of pesticides. In addition a reservoir that is very close to an old pyrite mine was identified to have extremely high developmental toxicity. Embryos exposed to water from this reservoir died or developed severe abnormalities. The samples taken from the waste water treatment plants showed that despite clear developmental toxicity of the incoming water, the outgoing water from all tested systems had very low levels of developmental toxicity. This is a good indication that water treatment methods used at these stations are effective in producing water suitable for agricultural use without adversely affecting the development of living organisms.

 

Keywords : Ecology, Toxicology, Water pollution, Effluent, Xenopus laevis

 

 

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