Variation of Fluoride Levels in Surface Geology: A Study of River Njoro Catchment, Kenya

Abstract

Fluoride levels in water that is higher than the World Health Organization (WHO) recommended levels of 1.5mg/l have raised concerns to the health of human. Subsequently fluoride contamination in water is a pertinent matter that calls for concern by all people and government. This study sought to investigate variation of fluoride levels in surface geology in river Njoro catchment. This study adopted purposive longitudinal survey research designs. In this research, rock samples were collected from 11 purposively selected points along the river Njoro and its tributaries to analyse fluoride levels in the laboratory. The research adopted descriptive data analysis in evaluating fluoride changes as contained in the rocks. The study observed that despite different types of volcanic rock outcrops along Njoro River, there were minimal variations in the levels of fluoride in the river Njoro. The study identified Superficial Deposits of Volcanic Soils with highest fluoride levels (1.575 mg/l) while eutracite Welded Tuffs had the lowest fluoride levels (0.678 mg/l). In Conclusion the rocks within the River Njoro catchment have insignificant contribution to the known elevated fluoride levels contained in sub surface and water in the ground in Njoro River catchment.