High fluoride content found in Khordha, Nayagarh groundwater

Context

A study has found the high fluoride concentration in groundwater in parts of Khordha and Nayagarh districts in Odisha. This can be a serious threat to human health.

Key highlights

• The high fluoride concentrations have also been recorded in groundwater near geothermal regions in Telangana, Rajasthan and Gujarat.
• The region in Eastern Ghats comprises deformed metamorphic and igneous rocks, containing fluoride-bearing minerals.

Permissible limit

• Bureau of Indian Standard permissible limit of fluoride is 1 mg / l. and some samples had more than 3.5 milligrams per litre (mg / l), much above the permissible limit.

What are the reasons behind the accumulation?

• The accumulation of fluoride in water is not due to evapotranspiration or due to calcite precipitation. Fertilizers are sources of fluoride contamination.

How it can be treated?

• Defluoridation using coagulation precipitation
• Membrane-based techniques

Why it is useful fluoride?

• Adding fluoride to the water supply reduces the incidence of tooth decay.
• Fluoride protects teeth from decay by demineralization and remineralization.

Harmful impacts of high concentration

• Dental fluorosis, Skeletal fluorosis, Neurological problems, cardiovascular problems,Fluoride poisoning. Acute, high-level exposure to fluoride can lead to:abdominal pain, excessive saliva, nausea and vomiting, seizures and muscle spasms