HAZARDOUS EARTH PROCESSES IN PARTS OF NIGERIA:THEIR CAUSES AND ENVIRONMENTAL IMPLICATIONS

Parts of Bauchi, Gombe,and most of the South-Eastern States of Nigeria experience passive subterenian movement of varying intencities with attendant destruction. Residential buildings have been cut, causing foundations to rotate, jamming doors and windows. Lithomonitoring programme put in place in these areas since 1985 has aided control and prediction of changes in the geological medium under the influence of extreme seasonal changes. Hydrogeological bases of prevention and control of gulley erosion have been adopted and metculously applied to ensure dependable prediction mechanism andy and and attain toxic levels hence guarantee protection of lives and properties

Soil chemical data show that the soils are rich in illite(20-35)%; montmorillonite (60-75)%, and kaolinite(45-73)%. Plasticity Index(PI) determination on these soils are high(>13.4%) indicating that the soils are potentially harzadous. The attendant hazards and huge losses to the States are blamed on the expansive nature of the soils.

Investigation of the concentration of selected heavy metals (Cd, Co.Pb and Ni) in soils and water, conducted in the mining districts of Nassarawa, Plateau, and Ebonyi States of Nigeria, show that Pb and Cd in the soils are generally higher than the normal soil average of 35mg/kg and 0.35mg/kg respectively and attain toxic levels in majority of the samples. North of Abakaliki, in the Middle Benue Trough, Pb-poluted ground water effeect is evident in the deplorable health conditions of the inhabitants, especially the children. Ni and Co are present in elevated amounts but do not attain toxiicity level. Ni concentration in the majority of samples exceed the WHO recommended limit of human tolerance. Risk to human health by higher than normal amounts of these metals is real and the need to control the intake by man is urgent.