Comparison of two village primary schools in northern Tanzania affected by fluorosis

High fluoride levels in drinking water sources are a problem throughout the East African Rift Valley and can lead to dental fluorosis (DF) and skeletal fluorosis (SF) in exposed local populations. Two villages in the Hai District of northern Tanzania in which fluoride has been identified as a problem were investigated in a pilot study. Fluoride levels in drinking water sources were measured and the prevalence of DF and deformities due to SF were assessed in children attending school in the two villages. The assessment also recorded the source of drinking water as well as children's height, weight and 3-day food diaries. Over one-quarter of the children in both villages had skeletal deformities, despite one village having much higher levels of fluoride in its drinking water sources. More than 90% of children in both villages had DF. SF and DF are major problems in this area. Deformities relating to SF are common, but the reasons for individual susceptibility remain unclear and may include a low calcium diet, ingestion of magadi (local salt) with high fluoride, or genetic factors.