www.iaset.us editor@iaset.us GENOTOXIC POTENTIAL OF NONYLPHENOL IN FRESHWATER FISH, OREOCHROMIS MOSSAMBICUS VIDYA BALAKRISHNAN, K. P. ASIFA & K. C. CHITRA Department of Zoology, University of Calicut, Thenhipalam, Kerala, India ABSTRACT Nonylphenol is the breakdown product of alkylphenol ethoxylates (APEs), which are an important class of non- ionic surfactants used for a variety of industrial, household and commercial applications including plastics, cosmetic products, inks, paints and textiles. Genotoxic potential of nonylphenol is evaluated by micronucleus and Ames test in Oreochromis mossambicus. Median lethal concentration of nonylphenol (1.5 mg/ L) was computed on the basis of probit analysis. Fishes were treated for 24 h, 96 h and 7 days with one-tenth of the concentration to represent the sublethal dose. Nuclear abnormalities such as micronuclei, and other nuclear malformations as fragmented apoptotic cells, binucleated cells and sticky adherent cells are noticed after nonylphenol exposure. In the present study Ames test reports more colonies in one-tenth of the test dose compared with the controls. Thus the present findings reports that nonylphenol is mutagenic and causes genotoxicity in O. mossambicus. KEYWORDS: Ames Test, Genotoxicity, Micronucleus, Nonylphenol, Oreochromis, Salmonella INTRODUCTION Aquatic toxicity is the lethal consequence of any compounds with suspected detrimental effects and that are usually determined on any organisms with several endpoints. Any man-made or the natural environmental chemicals present in the aquatic environment are able to interfere with the various systems in the aquatic organisms and has been shown to cause adverse effects on growth, behavior, reproduction, immune system or may cause genotoxicity. Some of such environmental toxicants listed as genotoxicants have been known to be released into the environment that is produced during post-emission chemical or biological transformation. Consequently, it is not surprising that during the past decade there has been increasing concern regarding the genotoxic hazards associated with the release of complex industrial wastes and effluents. According to research, approximately 300,000 tones of alkylphenols are produced per year and 60% are known to be released into the environment. This is then converted into the biodegradation products as nonylphenol and octylphenol, which are more toxic than alklyphenol itself (Schrenk-Bergt and Steinberg, 1998). Nonylphenol is more persistent in the environment than the parent nonylphenol ethoxylate. Nonylphenol bioaccumulates in aquatic organisms, especially on fish and the breakdown products of these compounds are persistent in the environment. The bio concentration factor (BCF) of nonylphenol in fish varies from 3 to 1300 (Ahel et al., 1993) and relatively low concentrations of nonylphenol and/ or nonylphenol ethoxylates has been shown to cause death in fishes (Cox, 1996). One of the studies has reported that nonylphenol shows positive genotoxic effects with increased nuclear abnormalities on Oreochromis spirulus fish (Al-Sharif, 2012). On contrary, another literature reported that nonylphenol did International Journal of Applied and Natural Sciences (IJANS) ISSN(P): 2319-4014; ISSN(E): 2319-4022 Vol. 3, Issue 2, Mar 2014, 81-88 © IASET