BIOACCUMULATORY, HEPATOTOXIC AND GENOTOXIC POTENTIAL OF CHRONIC FLUORIDE EXPOSURE ON CAT FISH, CLARIAS BATRACHUS Purva Mishra* and Aditi (Niyogi) Poddar SOS in Life Science, Pt. Ravishankar Shukla University, Raipur-492 010, India. *e-mail : purvamishra49@gmail.com (Received 28 October 2019, Accepted 22 November 2019) ABSTRACT : Fluorine is the most reactive and highly electronegative element in the periodic table and is not available in its free form due to its high reactive property. Being a soluble and easily transportable inorganic pollutant, it gets accumulated in various organs of aquatic organisms and adversely affects many physiological functions. Clarias batrachus were exposed to different sub lethal concentrations of NaF (Sodium fluoride) for 60 days (chronic exposure). Bioaccumulation status of fluoride was estimated in blood and tissues (Liver, Kidney & Muscle). Highest concentration was found in liver tissues ranging from 0.018 to 0.069 mg Kg -1 .Liver enzymes GOT (Glutamic oxaloacetic Transaminases) & GPT (Glutamic pyruvic Transaminases) were analyzed for their activities, which ascertained hepatotoxic effects of fluoride accumulation. DNA damage was also estimated using COMET assay technique, in which percent DNA was calculated using visual scoring method. Percent DNA damage was found to be high in fluoride exposed fishes. All the results were found to be highly significant, performed by statistical analysis, two way ANOVA (P<0.05). Key words : Fluoride, bioaccumulation, liver damage, genotoxicity. INTRODUCTION Fluorine is the most reactive and highly electronegative element in the periodic table and is not available in its free form due to its high reactive property. It exhibits an oxidation state of -1 and is combined chemically in the form of inorganic (F - ) and organic fluorides (Freons). Fluoride occurs in variety of minerals like fluorspar (CaF 2 ), cryolite (Na 3 AlF 6 ), apatite [Ca 10 F 2 (PO 4 ) 6 ] and hornblende with percent occurrence of 0.06- 0.09 in the earth’s crust (WHO, 1994). It is generally used in steel, glass and fiber industries and is also released during the production of bricks, ceramics, tiles and phosphate fertilizers. Although, an essential element, long term exposure to fluoride in concentrations above the reference level (1.5 mgL -1 according to WHO) in drinking water can lead to deformities in bones (skeletal fluorosis) and adverse effects on tooth enamel (dental fluorosis). Fluoride intoxication is very common in aquatic ecosystems. Being a soluble and easily transportable inorganic pollutant, it gets accumulated in various organs of aquatic organisms and adversely affects many physiological functions (Singh et al, 2015). Besides, it also accumulates in both soft tissues and bones in fishes. Concentration of fluoride accumulation in muscles differs from species to species (Sigler et al, 1972). Fishes are aquatic and poikilothermic animals. Hence, their existence and performance is dominated by the quality of their environment. All species of fish perform best under certain optimal conditions, but the amplitude of such conditions is quite narrow (Wedemeyer, 1970; Wedemeyer and Wood, 1974). Various stress conditions, like low dissolved gases, change in temperature, pH, density, pressure, light, etc. lower the resistance power of fishes. As a result, the organism undergoes a series of morphological, biochemical & physiological changes that constitute the General Adaptation Syndrome (GAS). These changes allow the organism to maintain its state of homeostasis in an unfavorable condition (Wedemeyer et al, 1999). MATERIALS AND METHODS Exposure of NaF : Experimental fishes, Clarias batrachus were purchased from local market and acclimatized with continuous water and oxygen supply for 15 days. After acclimatization fishes were divided into three groups including, one control and two experimental groups (E1 & E2). Fishes of control group were exposed to normal tap water, while those of the experimental groups E1 and E2 to 10 mgL -1 & 20 mgL -1 NaF solution, respectively for 60 days (chronic exposure). Collection of blood and tissues : Fishes were J. Exp. Zool. India Vol. 23, No. 1, pp. 259-264, 2020 www.connectjournals.com/jez ISSN 0972-0030