A recent study has found that over a third of drinking water sources in Dhanbad district's Gharbar panchayat are contaminated with fluoride, sometimes up to 10 times the permissible limit, affecting over 14,000 villagers. The research, conducted by the School of Environmental Studies at Jadavpur University, Kolkata, in collaboration with Megh Pyne Abhiyan (MPA), an NGO, was published in the journal Environmental Science & Technology (ES&T) of the American Chemical Society (ACS).
Extent of Contamination
Researchers tested 315 drinking water sources across six villages and found that over 36% exceeded the safe limit of 1.5 milligrams per litre (mg/l). The contamination levels ranged from 0.02 mg/l to a maximum of 16.2 mg/l. Nearly 28% of the water sources recorded fluoride levels between 1.5 and 4 mg/l, while around 8% showed concentrations between 4 and 10 mg/l. Approximately 1% of the sources crossed the extreme threshold of 10 mg/l.
Health Impact on Residents
The research team also tested 162 urine samples and conducted health assessments of 60 schoolchildren. The analysis revealed an average urinary fluoride concentration of 3.9 mg/l among the population, with some residents recording a high of 16 mg/l. Urinary fluoride levels peaked at 21 mg/l among schoolchildren.
Eklavya Prasad, managing trustee of MPA, stated, "Fluoride contamination has translated into substantial human exposure. Urine analysis revealed elevated fluoride concentrations among residents and schoolchildren. Children belong to the most vulnerable population group as around 50% of those studied showed signs of both dental and skeletal fluorosis."
Prolonged exposure has left a visible mark on locals, with both adults and children suffering from dental fluorosis, discolouration and mottling of teeth, skeletal fluorosis, joint pain, and bone and mobility-related problems.
Source of Contamination
The study established that the contamination is purely geogenic, meaning it originates from natural geological formations of the Chotanagpur plateau rather than industrial effluents. This specific finding complicates mitigation efforts, officials said.
Prasad added, "This means that drilling new borewells cannot be assumed to provide safe drinking water. Every drinking water source requires testing and verification before being considered safe for consumption."
