The Indian Guideline for fluoride in drinking water :
The guideline for fluoride in drinking water is 1.0 mg fluoride/liter; it is the maximum the that body may tolerate; less the better as fluoride is injurious to health.
It is the observation in India, that there are safe and unsafe water sources existing in the villages.
Testing for fluoride should apply to cent percent sources. This would enable to identify safe sources existing in a village and the maximum contaminant level of fluoride in a village.