New Delhi,January 16: A three-year survey by the Fluorosis Research and Rural Development Foundation has found that 34.8 per cent of the children, below the age group of 8 years, living in Palam are afflicted with dental fluorosis. The levels of fluoride in the drinking water here was found to be higher than permissible limits — sometimes even by 12 times.

The study, carried out under the aegis of the Ministry of Environment and Forests, sourced its data through eight schools in the area, screening 7,407 students in the process.

‘‘We thought of conducting a survey on this area, since more and more children were reporting problems related to high intake of fluoride,’’ said a Ministry official.

Fluoride content in drinking water from 576 sources — brought by students from both homes and schools — were tested. Out of this, 112 sources were found to be contaminated, with fluoride levels ranging from 1.1 milligrams per litre to 12.45 mg/l. The permissible limit in India is 1 mg/l.

The blood and urine of 45 children afflicted with dental fluorosis were also tested and 42 were found to be consuming fluoride-contaminated ground water.

The study also found that fluorosis was endemic in areas like Maharani Enclave, Mohan Garden, Deepak Vihar, Palam Extension, Om Vihar, Sureksha Vihar, Hastal village.

The report says that when the health of 335 families living in these seven areas were assessed, the researchers found an ‘‘alarmingly high level’’ of symptoms suggestive of fluorosis — pain in joints, gastro-intestinal discomfort, excessive thirst, excessive tendency to urinate, fatigue and muscle weakness and frequent headache.