A rural health centre reports several children with genu valgum and dental mottling. Groundwater analysis shows elevated total dissolved solids and a specific ion. Which additional finding in the water sample would most strongly support fluorosis as the diagnosis?
- A Fluoride level >1.5 mg/L ✓
- B Nitrate level >45 mg/L
- C Arsenic level >10 μg/L
- D Hardness >600 mg/L as CaCO₃
Correct answer: A. Fluoride level >1.5 mg/L
Explanation
Dental mottling and skeletal deformities in children in a rural setting strongly suggest endemic fluorosis. The diagnosis is confirmed by fluoride concentration in drinking water exceeding 1.5 mg/L (WHO guideline) or >1.0 mg/L (BIS). Nitrate >45 mg/L causes methemoglobinaemia, not fluorosis. Arsenic causes skin lesions. High hardness causes scaling but not mottling.
Reference: Park's Textbook of Preventive and Social Medicine, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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