HEAVY METAL CONTAMINATION OF WELL WATER

Abstract
The determination of heavy metal composition of onu-asata well water has been carried out using standard analytical procedure. This result of the heavy metal determination of Onu-asata well water revealed that the concentration of lead in the water is 2.2mg/L, iron (5.3mg/L), Zinc (2.1mg/L), Copper (O.5m/L), Nickel  (O.2mg/L), Cadmium (O.001mg/L), manganese (0.130mg/L), and chromium (0.02mg/L). The result of the analysis has shown that some of the heavy metal concentration in the water is within the limit of WHO and SON while some such as lead, and iron is above the limit stated by WHO and SON. Adequate treatment measure must be carried out on the water before using them so as to reduce the concentration of lead and iron in the water, hence with the result of the heavy metal concentration of the well water the water is not ideal for drinking, but it can be used for mixing of concrete and washing.
 
CHAPTER ONE
INTRODUCTION
1.1   BACKGROUND OF THE STUDY
Water is essential to all forms of life and make up 50-97% by weight of all plants and animal and about 70% of human body (Allan, 1995). Water is also a vital resource for agriculture, manufacturing, transportation. Despite its importance, water is the most poorly managed resource in the world (Chutter, 1998). The public health significance of water cannot be over emphasized. Many infectious diseases are transmitted by water through the fecal oral route. Diseases contacted through drinking water kills about 5million people annually and make 1/6th of the world population sickness (WHO, 2004). Water is vital for the existence of life and its importance in our daily life makes it imperative that thorough microbial, physico-chemical and heavy metal examination of water should be concluded on water used for various purposes to reduce the risks of water borne diseases emanation from such water. Portable water is the water that is free from disease–producing micro-organisms chemical substances that are dangerous to health (laminkera, 1999). In Nigeria, majority of the in the rural and urban area do not have access to portable water and therefore depend on well, stream and river water for domestic use. The bacterial and heavy metal content of well water in Nigeria have been reported to be unsatisfactory; with coliform count exceeding the recommendation by WHO (Edema et al; 2001). Water is the second important resource to human life after air. Man can survive longer without food than without water. Water is an important constituent of biotic community, it occurs naturally on land, underground, in the atmosphere and biomass (Narayanan, 2007). Water pollution should be a concern to every citizen because water accounts for about 70% of the weight of a human body, out of the estimated.
1,011 million km3 of the total water present on 400m3 is available for drinking, agricultural purposes, domestic and industrial uses. The rest of the water is locked up in ocean of salt underground. These qualities of water and its effect are characterized by its physical, chemical and microbial properties (Narayanan, 2007). The problem associated with chemical constituents of drinking water arises primarily from their ability to cause adverse health effects after prolonged period of exposure of a particular contaminant that have cumulative toxic properties such as heavy metals and substances that are carcinogenic (Uduma ,2014).
Heavy metals are chemical elements with a specific gravity (S.G) at least 5 times that of water. The specific gravity of water is I at 4oC. Some well known toxic metals with a specific gravity of 5 or more than that of water are cadmium (8.65), iron (7.9) Lead (11.34) and mercury (13.546), (Lide, 1992). Heavy metals are produced from varieties of natural and anthropogenic (man-made activities like mining, disposal of effluents from industries and indiscriminate use of fertilizers and pesticides in cultivation (Amman et al, 2002).
Investigation of the spatial distribution of levels of arsenic, lead and cadmium in Rivers, in kumasi (Ghana) revealed that most of the aquatic life have gone extinct due to the toxicity of the heaving metal to the aquatic organisms in the water (arpong et al; 2009). In aquatic ecosystem, heavy metal pollution can result from atmosphere deposition of geological weathering or through the discharge of waster. Metals like CU, Fe, Mn, Ni and Zn are essential micronutrients for life processes in plants and micro organisms while other many metals like Cd, Cr and pb have no known physiological activity, but have been proved to be detrimental beyond certain levels (Marschner, 1995).
1.2    STATEMENT OF THE PROBLEM
Many androgenic activities have been going on almost at all points in obiagu, Enugu. Onu-Asata being the peak of them all is where many toxic chemicals are produced; by these activities, they are leached into the well water used in this area, which has prompted for this research works on the determination of heavy metal contamination of well water; heavy metals such as pb, Fe,Zn,Cu,Ni,Cd,Mn,Cr.
1.3    OBJECTIVE OF THE STUDY
1.  To determine the heavy metal contaminants such as pb, Fe, Zn, Cu, Ni, Cd, Mn,and Cr in well water sample collected from onu-asata, obiagu, Enugu.
2.  To ascertain the level of heavy metals contaminants in the well water sample.
3.  To educate the people using the water on the health impacts of the water depending on the level of heavy metals present in it.
1.4 SIGNIFICANT OF THE STUDY
The result of this research work would be useful in the determination of heavy metals in well water samples, it also would disclose the level of heavy metal contaminants in the well water sample collected from Onu –asata thereby creating awareness on the health implication of using the well water.
1.5 SCOPE OF THE STUDY
Due to some financial constraints, this research work is limited to the determination of heavy metal contaminants such as Pb,Fe,Zn,Cu,Ni,Cd,Mn and Cr  in Onu-asata well water.