A public health team investigating mottled brown discoloration of teeth among schoolchildren in a rural village analyses drinking water samples. Endemic dental fluorosis is characteristically associated with drinking water fluoride levels exceeding:

• A 0.5 mg/L
• B 1.0 mg/L
• C 0.1 mg/L
• D 1.5 mg/L ✓

Explanation

Fluoride concentrations of about 0.7 to 1.2 mg/L in drinking water are considered optimal for caries prevention. Levels consistently above 1.5 mg/L are associated with dental fluorosis (mottled enamel), while prolonged exposure to much higher levels causes skeletal fluorosis. In India, high-fluoride groundwater belts in states such as Rajasthan and Andhra Pradesh account for most endemic fluorosis. Option B represents the upper end of the beneficial range, not the toxicity threshold.

Reference: WHO Guidelines for Drinking-water Quality and 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.