It could come as a great relief to millions of people living in fluoride-hit areas.
A team of Indian researchers has found that the leaves and stem of the tulsi plant can detoxify water with high fluoride content, and make it safe for human consumption. The quality of the treated water will be on par with the norms prescribed for fluoride content by the Bureau of Indian Standards.
Tulsi or ocimum sanctum has natural bio-absorbent properties, that is, the leaves and stem of this Indian herb serve as a natural magnet to adsorb (attach) fluoride molecules in the water. All one has to do is dip the leaves or stem of the tulsi in a glass of water for 20 minutes, remove the plant pieces and drink the water.
A team from the department of environmental sciences, Sardar Patel Mahavidyalaya, Chandrapur, have successfully demonstrated defluoridation of water using tulsi. They used fresh and dried tulsi leaves, stem pieces and extract from the fresh leaves.
“With initial fluoride concentration of 5 ppm, it was observed that maximum 94 per cent of fluoride can be removed at a dose of 75 mg of fresh basil leaves for a sample of 100 ml for a contact period of 20 minutes,” Mr Kamble said.
Fresh basil stems with a dose of 100 mg/100 ml had a removal efficiency of 75 per cent, whereas for dry leaves and dry stems at a dose of 250 mg/100 ml, the removal efficiency was 78 per cent and 74 per cent respectively.
“This makes the fluoride concentration within the permissible limit of Indian standard for drinking water (IS 10500:1991, Fluoride 1.0-1.5 ppm). The absorption of fluoride ion was affected by pH, quantity and size of tulsi parts used. This technique is cost effective, environment friendly and easy to understand and can be adopted in rural as well as urban areas throughout the year,” he added.
About 10 lakh people in 500 villages in Nalgonda district alone are affected by the high fluoride content in water. The ground water fluoride content in the district is between 0.4 ppm to 20 ppm.