Published Paper Details:

In order to study the seasonal variation of fluoride in surface and ground water, samples were collected from eighteen villages near the bank of Thovalai and Nanchilnadu Puthanar Channel in Kanyakumari District, Tamilnadu. The period of study was divided into three seasons (Southwest monsoon, Northeast monsoon and Summer) for two years. The concentration of fluoride was estimated by Ion Selective Electrode method. Fluoride intake may be associated with a number of adverse health effects. Dental fluorosis and effects on bones (increased fragility and skeletal fluorosis) are the two well documented adverse effects of fluoride intake. However, it is considered to be beneficial in the prevention of dental caries (tooth decay). Fluoride is a persistent and non-degradable toxin that is accumulating in water, soils, plants and wildlife. The emerging picture from all risk assessments conducted on fluoride is that there exists a narrow margin between the recommended intakes for the prevention of dental caries and the upper limits of exposure. The result showed that fluoride content of surface water ranged from a minimum of 0.10 mg/L during southwest monsoon to a maximum of 0.72 mg/L during summer. Similarly, the ground water showed the fluoride content ranged from 0.25 mg/L during southwest monsoon to 3.97 mg/L in bore well water collected from Nalloor village during summer season. The study revealed low fluoride concentration during monsoon seasons compared to summer season; this may be due to dilution with rain water. All the surface water samples were found to exhibit fluoride contents well within permissible limit prescribed by WHO (0.5 -1.0 mg/L). However, most of the ground water samples were found to have these values well above the permissible limit and hence unsuitable for drinking purpose. Overall ground water quality was found unsatisfactory for drinking purpose without any prior treatment.