Assessment of Fluoride Concentration in Drinking Water in Gedaref Town and its Uptake by Some Vegetable Plants

Abstract

This study was carried out on fifteen wells in Gedaref Town to determine their concentration of fluoride. These wells are a source of drinking water for two stations in Abu Naga and Alazaza. Fluoride concentration in water was determined using spectrophotometric methods. Hardness, Calcium and Magnesium concentration were determined using Titrimetric methods. Four vegetable plant species, irrigated with water containing 2.67 mg F/l, were analyzed for fluoride contents in leaves, roots and fruits of Hibiscus esculentus (Okra) and leaves and roots of Corchorus olitorius (Molokhaya), Cajanus cajan (Lobya) and Lycopersicon esculentum (Tomato) utilizing the Ion Selective Electrode Potentiometric method. All water samples showed higher fluoride concentration than the standard level (1.5-mg F/l) permitted by Sudanese and WHO standards. The results showed that there are no significant differences in calcium in the two areas but Alazaza showed higher concentration of magnesium than area A. These waters are described as hard water. Significant differences (P<0.05) in fluoride levels in roots, leaves and fruits of Hibiscus esculentus were encountered. Significant differences (P< 0.05) were found in roots and leaves of Corchorus olitorius and Cajanus cajan. No significant differences (P >0.05) were encountered in fluoride levels in leaves and roots of Lycopersicon esculentum. No toxic symptoms were observed on either of the four species.