 Kuopio is the only community in Finland with at least 70,000 people that has ever had water fluoridated.Kuopio stopped fluoridation in 1992.In regions with rapakivi bedrock (small, but densely populated regions), 22% of well waters and 55% of drilled well waters exceed the legal limit of 1.5 mg/l; generally, surface and well waters have 0.5-2.0 mg/l fluoride in affected regions.