Comparative Analysis of Fluoride Occurrence in Groundwater Systems of Hong and Zango Area, Northern Nigeria

Abstract

Groundwater can be contaminated through rock-water interaction, anthropogenic activities or a combination of both factors. Fluoride when taken in small quantities (less than 05 mg/L) causes dental caries, non-formation of dental enamel and deficiency of mineralization of bones among children below the age of 5. When taken in excess of 15 mg/L it could lead to dental and or skeletal fluorosis The presents study examines fluoride accurrence in groundwater systems in Hong and Zango area northern Nigeria and the view of establishing the source and degree of pollution of the groundwater in these area The geological mapping of Hong and Zango communities revealed that the area is partly underlain by granitic rock as well as other rock types. Petrographic study of the granitic rock domiciled in Hong and Zango areas showed quartz feldspar mica and some accessory minerals while the laboratory analysis using XRD indicates the presence of nacaphite (NazCaPO4F) in the granite sample Interestingly, the nacaphite, which is a fluoride bearing mineral was conspicuously absent in the other rock samples analyzed. An integration of the results of laboratory analysis from Hong and Zango areas against the respective geology further revealed that water samples collected from areas underlain by grantic rock showed higher concentration of fluoride (20 mg/L compared to the water samples obtained from areas underlain by other rock types This amplies that the high fluorice concentration in groundwater system in Hong and Zango communities are from natural source due to bedrock dissolution and weathering processes Gobs plat also confirmed that rock-water interaction and precipitation are the geochemical processes responsible for groundwater evolution and composition in these areas. They use of water in the grante dominated zone for drinking and domestic purposes in Hong and Zango communities should discontinue and alternative source of water should be provided for inhabitants in the interim pending when remediation processes targeted at extracting the unde from the groundwater systems in these settlements are executed