Flourosis and Flouride Removal: Fluorosis worldwide

Fluoride in water is mostly of geological origin. Waters with high levels of fluoride content are mostly found at the foot of high mountains and in areas where the sea has made geological deposits.

Known fluoride belts on land include: one that stretches from Syria through Jordan, Egypt, Libya, Algeria, Sudan and Kenya, and another that stretches from Turkey through Iraq, Iran, Afghanistan, India, northern Thailand and China. There are similar belts in the Americas and Japan. In these areas Fluorosis has been reported.

Fluorosis in India
Fluorosis is endemic in large areas of India, mostly rural. This is because more than 90% of the rural population in India
  ground water for domestic use, predominantly for drinking and cooking.

Nearly 65 million people in 160 districts and 17 states across India drink water contaminated by excess fluoride (over 1.5ppm). Rajasthan in India has fluoride levels as high as 44 mg/l in the ground water which is used for domestic purposes in several districts.

Geochemistry of Fluoride in Karnataka
Karnataka contains high levels of Fluoride in India. The sedimentary formation of Bhima group is constituted by conglomerates, sandstones, shales and limestones. The formation in the Southern regions is subjected to tectonic disturbances and hence traversed by shear and fractured zones. These zones are occupied by pegmatite veins filled with fluorite-associated minerals.

The alluvium is of Recent age and is limited to certain river courses draining the districts. It consists of unconsolidated sediments as gravel, sand, clay, silt and pebbles. These sediments contribute to the water fluoride content.