Geology

Biography

Biography: Akobundu Amadi

Abstract

Groundwater contamination by fluoride in Hong area, North-eastern Nigeria was investigated in this study. Groundwater samples, soil samples and rock samples were collected in both dry and wet seasons and subjected to field and laboratory analysis to determine the physico-chemical characteristics of groundwater with emphasis on fluoride. Results of analysis were compared with World Health Organisation and Nigerian Standard for Drinking Water Quality. The hydrochemical facies analysis indicate the water type in the area as Ca-Mg-HCO3 type, fluoride concentration in groundwater in Hong area ranged from 0.08 mg/l to 2.58 mg/l as against the maximum permissible value of 1.5 mg/l for a safe drinking water. The analysis of the rock and soil samples revealed the presence of sodium-calcium-phosphate-fluoride, a fluoride bearing mineral called nacaphite (Na2CaPO4F) in granitic rocks from the area. This implies that the high fluoride concentration in groundwater system in the area is from geogenic source as a result rock/soil-water interaction, bedrock dissolution, chemical weathering, infiltration and leaching processes. Children and adults in the area are having dental fluorosis presently. Results of rock, soil and groundwater analysis shows high fluoride concentration above the tolerable limit of 1.5 mg/l. The results obtained from the study lead to the production of dental fluorosis prevalence map and health risk map for the area. The study further revealed that a total of 16,600 people in 8 villages out of 123,865 in 13 villages in the area have dental fluorosis while 112,165 people are potential dental fluorosis carriers. It was recommended that government should as a matter of urgency provide another source of drinking water for the household and community within the fluoride endemic zone.