Addis Ababa (Ethiopia) An estimated 8.5 million people, or 11% of the population of Ethiopia, are at risk from high concentrations of fluoride in water used for domestic consumption.
When consumed in high concentrations fluoride is toxic and spoils the natural colour and texture of teeth, said Dr. Berhanu Gizaw, a geological survey expert at the Ethiopian ministry of mines and energy.
He said studies indicate that the volcanic rocks of East Africa are richer in fluoride than analogous rocks in other parts of the world.
Gizaw said fluoride has various impacts on health, depending on the amount of concentration in the water supply.
Water with a fluoride concentration of between the range of 1.5 and 3.5 mg/l causes a kind of enamel hyperplasia known as dental flourosis if consumed during the period of enamel maturing.
This results in the destruction of ameloblasts and the production of abnormal mottled enamel, he said.
If the concentration is between the range of 3.6 and 10 mg/l skeletal flourosis, a kind of bone disease, which alters the size and structure of its crystal, will result.
“If it exceeds 10 mg/l, skeletal crippling will occur,” he said.
In areas where alternative water sources are not readily available, water treatment is the only option to control flourosis though it is expensive, he noted.