The BIS (Indian Standard) acceptable limit for fluoride in drinking water is 1.0 mg/L, and the permissible limit (in absence of alternative) is 1.5 mg/L. Fluoride concentration above 1.5 mg/L for prolonged periods causes which condition?
- A Dental and skeletal fluorosis ✓
- B Blue baby syndrome (methaemoglobinaemia)
- C Arsenicosis (chronic arsenic poisoning)
- D Itai-itai disease (cadmium toxicity)
Correct answer: A. Dental and skeletal fluorosis
Explanation
Fluoride > 1.5 mg/L causes dental fluorosis (pitting and mottling of enamel); levels > 3–6 mg/L cause skeletal fluorosis (osteosclerosis and ligament calcification). This is endemic in India in states like Rajasthan, Andhra Pradesh, Gujarat, and Karnataka. The acceptable limit is 1.0 mg/L to optimise caries prevention without causing fluorosis.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.