Assessment of some heavy metals and physico-chemical properties of soils within the vicinity of University Of Port Harcourt Teaching hospital medical dumpsite, Port Harcourt, Rivers State, Nigeria

Abstract

It is imperative to assess the toxicity of the medical waste on areas prone to contamination in order to ascertain their present level and offer some remediation or preventive measures. Soil samples TS (0-15cm) and SS (15-30cm) were collected from a sample point using hand auger, four samples were collected around the dumpsite in a grid format with a control point, that is about 100m away from the dumpsite and were characterized using standard methods. The results shows that the area was alkaline with pH ranging from 10.48-11.78 for the dumpsite and 10.04-10.83 for the control point., Electrical conductivity (EC) ranges from 58-200 μS/cm, Cation Exchange Capacity (CEC) ranges from 0.30-1.08meq/100g, Total Nitrogen 0.22-1.31mg/kg, Total Phosphorus was low ranging from 0.01-0.1mg/kg, Total organic matter 0.24-0.62%,Total carbon 0.26-0.36% with sand particles ranging from 67-79.4%, silt particles represented 7.8-12.2% and Clay particles with 8.2-22.8%.The mean value results of some of the heavy metals are: Ni 1.46mg/kg, Fe 20.26mg/kg, Pb 1.11mg/kg, Cr 0.14 mg/kg, Cd 0.040mg/kg, Mn 11.24mg/kg, Zn 1.24mg/kg, Cu 1.26mg/kg. These values can be attributed to the nature of medical waste with high percentage of non-biodegradable materials, periodic burning of the waste that have a way of adding potash to the soil, age of the dumpsite and vertical movement of leachates and plume. These values are all far below the maximum tolerable levels set by Food and Agriculture Organization (FAO) and World Health Organization (WHO, 1992) for agricultural soil. The study revealed that the dumpsite and the control area lack adequate soil nutrients, hence low levels of metals should eventually be converted to agricultural farmland.

Keywords: Heavy Metals, Physicochemical Properties, UPTH, Medical Dumpsite.