Distribution of fluoride in beans and maize grown along the slope of Mount Meru, Tanzania

Abstract

This study assessed the uptake and distribution of fluoride in maize and beans grown in fluoride contaminated soils, (Ngarenanyuki) around Mount Meru in Northern Tanzania during the rainy season. The study revealed that fluoride uptake increases with increasing fluoride concentration in soils except in a stem and root part of maize and beans respectively. It was observed that fluoride accumulation followed the order of soil >roots > leaves >stem >grain > cob for maize, while the order soil> root> grain> stem was observed for the beans. when the soil contained 116.93ppm of fluoride, the corresponding plants harvested had the mean fluoride accumulation (ppm dry weight) in root, leaves, stem, grain, and cob of maize of 38.560, 24.251, 10.629, 7.7756 and 2.100 respectively, while the soil with 129.2ppm mean fluoride concentration, the accumulation in root, grain, and stem of beans were 16.27, 11.328 and 8.459 respectively. It was reported that beans plant had a higher efficiency in fluoride uptake to bean grain than maize plant. Maize and bean grain collected from Ngarenanyuki contains higher fluoride levels than other fluoride endemic areas. It was also reported that fluoride in the soil samples has a strongly positive correlation with sodium (p-0.000). This suggests that there is a high possibility of fluoride to be present in the form of NaF. Significant accumulation of fluoride in both bean and maize were observed in this study at p≤ 0.05.