CHAPTER ONE  
INTRODUCTION   
1.1  BACKGROUND OF STUDY   
Leachate is any liquid that in passing through matter, extracts solutes, suspended solids or any other component of material through which it has passed, introducing environmentally harmful substances (Wikipedia, 2010). Leachates normally enter the environment from waste disposal sites. The lack of proper management of solid waste has been a major environmental issue in Nigeria. Solid wastes are often disposed of in uncontrolled and undesignated public places rather than in the few and probably inadequate designated dump sites. Increase in urbanization and population growth are likely to increase the annual generation of municipal solid waste estimated at 29.78 x 109kg (Ojoloet al., 2004). Leachate contains a range of chemical compounds, which may leach into the environment particularly into nearby water sources (Christensen et al., 2001). Leachate may also contain pathogenic microbes some of which are capable of producing toxins that may have public health implications (Donnelly et al., 1988). Studies on the possible hazards of solid waste leachate and its effects on aquatic organisms have been reported (Wong, 1989, Wick and Dave, 2006, Koshyet al., 2007). Leachate has been reported to impact negatively on water quality parameters of the aquatic ecosystem. Leachate contamination of water bodies can result in increase of water turbidity, limiting the amount of light penetration which reduces photosynthesis and production of dissolved oxygen (Pillay, 1992). Leachate has also been reported to increase water alkalinity and hardness (Dupree and Huner, 1984). Leachate may clog fish gills reducing resistance to diseases, lowering growth rate and affecting egg and larval developments (Ovre and Adeniyi, 1990). Few reports are available on the effect of leachate-contaminated water on tropical fish species especially cat fish which are hardy and can withstand more stress than other tropical fish species (Holden and Reed, 1978). This study investigates the growth and survival of Clariasgariepinuscat fish in different concentrations of domestic leachate.   
1.2   OBJECTIVES OF THE STUDY 
In this studies, leachate simulated from domestic waste, its physio-chemical characteristics and the changes or effects in the serum of African catfish where assessed. The objectives of the investigation include: 
·        To evaluate the effect of simulated leachate on the haematological parameters 
·        To determine effect of simulated leachate onthe serum cholesterol concentration 
·        To determine the effect of simulated leachate on the protein concentration of the African catfish. 
·        Determination of potential risk posed on aquatic animals domestic leachate contamination of their habitat since blood parameters are considered pathopysiological indicators of the whole body and therefore are important in diagnosing the structural and functional of fish exposed to toxicant.
·        To serve as reference material for further investigation of haematological effects of simulated leachate on aquatic organism and the environment in general.        
1.3   RELEVANCE OF STUDY 
The relevance of this study is to show the adverse effect of simulated domestic leachate at different concentration at 5% and 10% in tissues such as the blood, kidney, liver, the gills of the African catfish and the possible effect it will have on human. Claris garipinus is commonly known to be a very good source of high quality protein containing essential amino acid in the amount and proportion required for nutrition. It also provides a good source of vitamins and minerals. And to also know if the leachate will alter the biochemical properties of the amino acid, to what extent with reference to the control A.