Fluoride concentration and other parameters in groundwater from 261 villages in Tehsil Kheragarh of District Agra were assessed and attempts were made to observe the relationship between fluoride and other water quality parameters.

The natural contamination of drinking water by arsenic needs to be urgently addressed.

In Bangladesh, arsenic in groundwater above 0.05 mg/1, the maximum permissible limit laid down by WHO, was found in 41 out of 64 districts. People suffering from arsenicosis have been identified in 20 districts out of 21 districts we have surveyed so far.

The arsenic affected areas of West Bengal are lying on a sediment of Younger Deltaic Deposition (YDD). The same sediment extends eastwards towards Bangladesh, covering the approximate area of 34 districts out of a total of 64 districts in Bangladesh. We suspect that the groundwater of these 34 districts of Bangladesh may be arsenic contaminated.

Arsenic has been found in groundwater in seven districts of West Bengal covering an area 37,493 km having about 34 million population. Our survey indicates that 560 villages are arsenic-affected and more than a million people are drinking arsenic contaminated water and more than 200,000 people are suffering from arsenic-related diseases.

Argues that excessive fluorides in groundwater are a serious water quality problem in some parts of Sri Lanka. The incidence of dental fluorosis shows a high correlation with the presence of groundwater in certain areas. Tube wells constructed in various rock types have shown different fluoride concentrations, possibly due to the different mineral constituents in these rocks and their relative capability of releasing fluoride ions into groundwater. It has been observed that the tube wells located in the dry zone have higher fluoride concentrations than those in the wet zone.