Effect of Leachate-contaminated Groundwater on the Growth and Blood of Albino of Rats

摘要

The results of effect of daily consumption of leachate-contaminated groundwater for 65days on rats' Packed Cell Volume (PCV), Haemoglobin (Hb), White Blood Cell (WBC), Red Blood Cell (RBC), neutrophil and platelet are presented. The PCV (%) of rats treated with leachate was found to be 26±4 while that of animals treated with control tap water was 40±2. Hb (g/dl) of control rats was observed to be 14.3±0.3 while that of leachate treated rats was 10.9±0.3. The experimental results indicated that consumption of leachate-contaminated groundwater may lead to ill health particularly anaemia. Introduction Pollutants can escape from improperly designed landfill in a variety of ways (Carla, 2000). If soil above or below a landfill is permeable, leachate can escape to contaminate groundwater (Carla, 2000). Recent studies indicate that small landfills (waste volume up to 50,000yd 3 ) may impact groundwater (Friedman, 1988 and Bagchi, 2004).Once the groundwater is polluted, the pollution may be difficult to correct or even to detect. Carla (1997) predicted that in the next few decades, more contaminated aquifers will be discovered, new contaminants will be identified, and more polluted groundwater will discharged into wetlands, streams, and lakes as this groundwater passes through the hydrologic cycle. By the time groundwater pollution is detected, it may be very widespread, and the exact extent of the problem may not be readily determined without the drilling of many monitoring wells across the affected area (Bagchi, 2004). Even the source can be hard to identify unless the chemistry of the contamination is distinctive (Carla, 1997).Contaminants carried in leachate are dependent on solid waste composition and on the simultaneously occurring physical, chemical and biological activities within the landfill (Monroe, 2001). Heavy metals such as lead, mercury, chromium, copper and cadmium, together with household chemicals and poisons can be concentrated in groundwater supplies beneath landfills (Wagner and Rhyner, 1984). These contaminants have been reported to possibly cause growth retardation and haematological abnormalities (Hogson, 2004).In Lagos, Nigeria exists a typical landfill located in Ojota area (Detail of location described elsewhere (Adeyemi et al., 2007)). The landfill is not lined and receives both hazardous and non-hazardous wastes without prior consideration for their highly polluting effect on the surrounding groundwater. Residential houses with groundwater (Wells and Boreholes) as only source of water were constructed at about 1.5km radius to the landfill. These groundwater sources are continually being consumed by home owners without the knowledge of the possible hazardous effect which the landfill leachate can have on the water quality and public health. Reports presented at seminars and conferences also attested to the prevalence of water related diseases in the inhabitants (LAWMA, 2000). The present study, therefore, examines the effect of such leachate-contaminated groundwater on the growth and blood of rats. Materials and methods Chemicals and solvents are of analytical grade and are products of Sigma-Aldrich, inc., St. Louis, U.S.A. The experimental water for the study was collected from the residential areas located within the vicinity of Odo Iya Alaro landfill in Ojota, Lagos, Nigeria. The water samples were obtained from two different wells located at about 1 and 1.5km respectively from the landfill; and two boreholes located at about 1 and 1.5km respectively from the landfill. The water samples were collected using stainless steel buckets. Solid wastes were collected at the Odo Iya Alaro landfill located in Ojota, Lagos, Nigeria in December, 2004. Leachate simulation was carried out following the ASTM method (Perket et al, 1982). In this method a sample (0.3kg) of the landfill waste was shredded and packed in a 2l glass flask. A volume of distilled water, four times the sample weight, was added. The resulting sa