Fluorosis in children and sources of fluoride around Lake Elementaita region of Kenya

Abstract

During a project to determine the fluoride levels of milk in Lake Elementaita region, the authors were astonished by the high levels of fluorosis in children living in the area. With special reference to children, a study was designed to establish and describe the levels of dental fluorosis and also to determine other sources of fluoride to the community. The levels of dental fluorosis were recorded using Thylstrup and Fejerskov classification method (TF) for children aged between 2-14 years. Biodata information, feeding habits and details of fluoride history were collected using a questionnaire form filled out with the help of teachers and/or parents. Results pertain to both continuous and non-continuous residents for both primary and permanent dentition. The high fluorosis level of 95.8% was associated with the fluoride concentration in the community water supply and food. Food samples analysed for fluoride include cows milk (the major source of nutrients for the children in the area), vegetables and water. Fluoride levels in drinking water from different boreholes were high, varying from 2.0-20.9 pg/mL-1. Milk fluoride levels in samples from seven localities ranged from 0.05-0.22 pg/mL-1 (mean) and an individual animal range of 0.02-0.34 pg/g-1 . Vegetables had fluoride levels between 7.9-59.3 pg/g-1 with an exception of one with 296.6 pg/g-1 . The soils in which the vegetables are grown had over 1000 ppm. This being a landscape formed by the process of faulting and volcanic activity, the dust from Lake Elementaita also had high fluoride concentration of 2300 pg/g-1. Key words: Dental fluorosis; Fluoride sources; Kenya; Milk; Water.