Assessment of Fluoride and selected heavy metals in food chain around Fluorspar mining Plant, Kenya

Abstract

The purpose of the research was to assess the levels of fluoride and selected heavy metals in caprine, mutton, and vegetation around the Fluorspar mining plant in Kerio Valley. Previous studies have reported contamination of water and soil by acidic factory discharges laced with hazardous heavy metals and fluoride in Kerio Valley, Kenya. However, there is no data on Fluoride and selected heavy metals in food chain around Fluorspar mining Plant. This formed the motivation behind the study to avail the data on the level of contamination. The experimental design was an entirely randomized design where mutton, caprine, and plant (leaves, grass, corn maize) samples were randomly collected from the three locations (Tumeiyo, Choff, and Kimwarer) in three replicates and Turesia which was selected as the reference or control site. Sample preparations and analyses were done according to recommended methods. Fluoride levels were 6.34±2.45 mg/Kg and 9.58±6.03 mg/Kg in caprine and mutton, respectively. Heavy metals ranged between 0.06±0.02-0.06±0.03 mg/Kg for Pb, 0.06±0.03-0.09±0.06 mg/Kg for Cd, 3.31±1.90-3.66±2.41 mg/Kg for Zn, 0.51±0.32-0.82±0.55 mg/Kg for Fe and 0.44±0.28-0.54±0.33 mg/Kg for Cr. Fluoride levels in vegetation ranged between 4.77±2.52 and 6.27±3.40 mg/Kg, while heavy metal levels ranged between 0.01±0.01- 0.04±0.02 mg/Kg for Pb, 0.02±0.02-0.05±0.03 mg/Kg for Cd, 0.26±0.21-0.48±0.30 mg/Kg for Zn, 0.21±0.15-0.50±0.34 mg/Kg for Fe and 0.19±0.14-0.23±0.18 mg/Kg for Cr. Zn, Fe and Cr levels in meat and fluoride surpassed the WHO/FAO maximum limits while Pb and Cd in all the samples were within allowable limits. Conclusively, meat recorded higher analytes concentrations compared to vegetation. The fact that the levels of key chemical analytes in the assessed samples were availed and the contamination status indicated, presented the primary significance of this research.   Keywords: heavy metals; caprine, mutton; food chain; Fluorspar mining Plant