What if you were told that your drinking water can affect the Intelligence Quotient (IQ) of your child? Strange as it may sound—as many of us drink RO purified water at our homes or buy bottled water—the villagers in the Gharbar gram Panchayat, Baliapur block of Dhanbad district in Jharkhand depend on groundwater to meet their drinking and irrigation needs.
Their water is causing various health conditions, including low IQ in school-going children, because it is laced with high-fluoride beyond the World Health Organization’s (WHO) maximum safe limit of 1.5 milligram per litre (mg/L) of fluoride in drinking water.
A groundbreaking new study has established an association between long-term exposure to high fluoride in groundwater and the local crops of Gharbar Panchayat block with the prevalence of diseases such as dental and skeletal fluorosis among villagers. It has also uncovered an impact on the cognitive abilities of school-going children. Fluoride is known to cross the blood-brain barrier, potentially leading to neurotoxic effects and affecting mental and cognitive development in children.
The key findings of this joint study by the School of Environmental Sciences (SOES), Jadavpur University, Kolkata; and Megh Pyne Abhiyan (MPA), a public charitable trust working on issues of water distress in east India, are concerning.
Of the total 315 groundwater samples tested in 20 habitations of six revenue villages in Gharbar Panchayat, 36 per cent exceeded the permissible limit of 1.5 mg/L. In one of the six revenue villages named Gharbar, fluoride concentrations in groundwater were the highest at 16.2 mg/L, which is more than ten times the safe limit. Young children are at the highest risk because their bodies and brains are still developing.
Nearly half of the schoolchildren examined as part of the joint study exhibited signs of dental and skeletal fluorosis, which affects teeth and bones, respectively. Shockingly, urinary fluoride levels among some children were found to be as high as 21 mg/L. Researchers also observed associations between elevated fluoride exposure and lower cognitive performance in students.
“There is no normal level or recommended value of fluoride in human urine. However, since the permissible level for fluoride in drinking water is 1.5 mg/L, the same can be treated as normal level of human urine. Exceeding it can be measured as acute fluoride toxicity,” Tarit Roychowdhury, co-author of the study, and Professor at SOES, Jadavpur University, told Kashmir Times.
The study—Groundwater Fluoride Dynamics and Potential Risk of Fluorosis in Schoolchildren: An Extensive Study from the Fluoride Endemic Region of Chota Nagpur Plateau, Jharkhand, India—was published in the international journal ACS ES&T Water in May 2026.
Speaking on the impact of fluoride on cognitive development of children, Ayan De, the first author of this research publication, said: “Our study identified a significant negative association between fluoride exposure and IQ, supported by concurrent evidence from previous epidemiological investigations.”
According to him, the certainty of linking IQ reduction solely to fluoride ingestion is limited because cognitive development is influenced by numerous factors, including genetics, nutrition, parental education, socio-economic status, and other environmental exposures.
“However, given the observational nature of the study and the potential for residual confounding, the results should be interpreted as evidence of an association rather than a definitive causal relationship. Further longitudinal studies controlling for major confounding variables are needed to establish causality more conclusively,” said De.
Against the WHO’s permissible limit of 1.5 mg/L, the fluoride concentrations in groundwater in the six revenue villages were found to be highest in Gharbar (0.02−16.2 mg/L), followed by Kalajhor (0.37−7.47 mg/L), Shivpur (0.16−7.31 mg/L), Kalipur (0.05−4.94 mg/L), Kharikabad (0.13−1.59 mg/L), and Simpathar (0.13−1.32 mg/L).
Importantly, fluoride in drinking water standard under the Bureau Of Indian Standards (BIS) is more stringent than the WHO’s guideline value. The BIS standard for fluoride is divided into two parts—an acceptable limit of 1 mg/L, and a permissible limit of 1.5 mg/L in the absence of an alternate source.
Researchers of the study did not limit the testing to water quality alone. They also sampled 104 varieties of locally grown crops and vegetables, such as rice, wheat, lentils, and a range of leafy and non-leafy vegetables. The team also collected 48 soil samples from agricultural fields, and 102 urine samples from the general population and 60 additional samples from schoolchildren aged 4 to 12 years.
Fluoride concentrations in food crops ranged from 0.04 to 129 milligram per kilogram (mg/kg). Among leafy vegetables, the highest concentration was found in coriander. The soil analysis showed highest fluoride concentration in a radish field at 455 mg/kg.
“These findings indicate that dietary intake, particularly through leafy vegetables, represents an important exposure pathway in addition to drinking water…,” reads the joint study.
Poisoned Lives
According to Eklavya Prasad, Managing Trustee of MPA, and a leading member of the research team, “The tragedy of Gharbar Panchayat is not that the fluoride contamination remained undiscovered. The tragedy is that the contamination was identified, documented, scientifically validated, and repeatedly brought to the attention of authorities since the past one decade, yet effective protection of public health has remained inadequate.”
According to him, over the years, multiple rounds of testing by government agencies, civil society organisations, and academic institutions confirmed widespread fluoride contamination in drinking water sources of Gharbar Panchayat.
“Yet, most villagers continue to drink high-fluoride groundwater because no reliable alternative source of safe drinking water has been made available to them,” Prasad pointed out.
But, how did fluoride enter the groundwater? The Baliapur block is situated on the Archean-aged rocks of the Chota Nagpur Plateau, which are rich in minerals like fluorite, apatite, and mica. Through weathering-induced dissolution, the groundwater reacts with these rocks. The water in this region is typically alkaline, with high levels of sodium and bicarbonate, which creates a chemical environment that facilitates the release of fluoride from the minerals into the aquifer.
The joint study was necessitated by the fact that while naturally-occurring fluoride contamination had been reported in the Chota Nagpur Plateau previously, detailed information required for the precise identification of contaminated zones and the assessment of associated health risks was missing.
This research study plugs that gap. It moves beyond mere water testing to provide a comprehensive "total exposure" assessment. It examines how a geogenic toxin (fluoride) moves from the earth’s crust into the water, then into the soil and crops, and finally into the human body, where it manifests as physical deformity and neurological impairment (see map).
It Started With Jitendranath Sarkhel…
Till mid-1980s, villagers in Gharbar depended on open dugwells and the nearby Damodar River for drinking water. After 1990, the government began installing hand pumps at the Panchayat level and soon people switched over entirely to groundwater accessed through these hand pumps.
A couple of years later, many villagers began experiencing acute joint pains and difficulty in moving around. No one could identify the disease or pinpoint the cause of the health problem.
In 2013, Jitendranath Sarkhel from Gharbar Panchayat visited Sai Diagnostics in Dhanbad city to seek medical help. Doctors reviewed his X-Ray reports and suggested that fluoride contamination in groundwater could be the cause of his stiff bones and excruciating joint pains.
Community meetings, petitions, and protests followed as villagers demanded action. They approached elected representatives, the then officials of the Public Health Engineering Department (PHED), and the district administration for access to safe drinking water.
Water Quality Tests, But Zero Action
In 2014, water quality testing was conducted by teams from the Dhanbad district administration and the Government of Jharkhand. The results confirmed that groundwater sources across Gharbar village contained high levels of fluoride. Contaminated sources were marked in red and villagers were advised not to use them for drinking purposes. However, no alternate safe source of drinking water was provided to them. Villagers were forced to continue drinking high-fluoride water.
The crisis became increasingly evident over the following years. Villagers reported widespread stained teeth (dental fluorosis) among children and chronic joint pain (skeletal fluorosis) in adults. Dental and skeletal fluorosis are caused due to excess intake of fluoride over a period of time.
Beginning 2017-18, Prasad, along with his colleague Kumod Kumar Das, started to systematically document water quality testing across Baliapur block. “Testing undertaken in 2018 confirmed fluoride contamination in multiple Panchayats, including Gharbar. Databases of contaminated sources were prepared, affected habitations were mapped, and repeated submissions were made to district and state authorities,” said Prasad.
To further build scientific evidence and push for urgent action, MPA collaborated with the SOES, Jadavpur University, to undertake a comprehensive scientific study in Gharbar Panchayat 2022-23. Its results were recently published in May 2026.
“Our study shows that approximately 14,162 people continue to depend on fluoride-contaminated groundwater sources. An entire generation of kids has grown up consuming water that was known to be unsafe,” said Prasad.
Cursed Childhood
The biological evidence found in the urine samples was perhaps the most alarming. The mean urinary fluoride concentration in the studied population was 3.9 mg/L, but in children, this figure was significantly higher, averaging 5.56 mg/L.
Schoolchildren of Utkramit Prathamik Vidyalaya in Kalajhod showed the highest urinary fluoride levels at 21 mg/L. The study warns that children are most vulnerable to fluoride exposure due to their developing physiological systems and higher water intake relative to their body weight.
Another important aspect of this study is the association between long-term exposure to high fluoride and the IQ of children. By using the Raven’s Standard Progressive Matrices, a non-verbal test for cognitive ability, the researchers found a significant inverse correlation between urinary fluoride concentrations and IQ scores.
In simpler terms, as the concentration of fluoride in a child’s body increases, their cognitive performance decreases. The study found that 67 per cent of the affected schoolchildren had only "average" (Grade III) intelligence, suggesting that the toxin is not just damaging their bodies but is also limiting their future potential by impairing their mental development.
Systemic Failure
Prasad pointed out the systematic failure to supply safe drinking water. Way back in 2014-15, a multi-village drinking water project, supported by NABARD, was launched to draw treated surface water from Damodar River. The project, implemented under the Mega Rural Water Supply Program (MRWSP) of the Department of Drinking Water and Sanitation, was designed as a long-term solution for the fluoride-affected Panchayats.
Under this initiative, 15 out of the 23 Panchayats were brought under the scheme. The project involved an investment of Rs 71.96 crore. “However, delays in implementation meant that affected communities continued to depend on fluoride-contaminated groundwater for years,” said Prasad.
“Even after the commissioning of the scheme, villagers reported irregular and intermittent water supply. As a result, many households were forced to return to hand pumps and other unsafe groundwater sources,” he added.
Incidentally, data from the Indian government’s Jal Jeevan Mission (JJM) shows 99.66 per cent coverage of functional tap water connection in rural households of Baliapur block in Dhanbad. On paper, five of the total six revenue villages covered under the joint study have 100 per cent tap water coverage as on June 11, as documented on JJM’s dashboard.
“Although the JJM dashboard reports high functional tap water coverage in the study area, our field surveys indicated that many households continued to rely on groundwater as their primary source of drinking water,” said Roychowdhury.
According to him, the local residents reported that the supplied tap water was generally not considered suitable for drinking purposes and was mainly used for domestic activities. “Consequently, groundwater remained the principal source of potable water and the dominant pathway for fluoride exposure,” Roychowdhury added.
Act Now
Addressing the fluoride crisis in Gharbar Panchayat requires a dual-track strategy focusing on immediate relief and sustainable security. In the short term, the priority is to ensure a regular, reliable supply of safe piped water to end the community's dependence on contaminated hand pumps. This must be accompanied by systematic testing and marking of all water sources, alongside strengthening community institutions like the Village Water and Sanitation Committees, Paani Samitis, and other community institutions.
“To support community-led management, we need to develop a cadre of trained local volunteers known as Bhujal Doots. These volunteers would assist in groundwater monitoring, awareness generation, community mobilisation, and dissemination of information regarding safe water practices,” said Prasad.
Long-term goals necessitate a shift away from contaminated groundwater by restoring traditional dug wells and implementing large-scale rooftop rainwater harvesting, particularly in schools. Finally, establishing a permanent monitoring system and a comprehensive Panchayat-level mitigation framework is vital to ensuring that future generations are protected from this invisible poison.
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