This fact is from Water Fluoridation & Fluoride Toxicity in Public Health Dentistry. It is a commonly tested concept in NEET MDS examinations. Understanding this fact is crucial for answering MCQs correctly.
Optimal fluoride = 0.7ppm current CDC recommendation
Certainly Lethal Dose = 32-64 mg/kg NaF
Safely Tolerated Dose = CLD divided by 4
Chronic fluoride toxicity = Dental and Skeletal fluorosis
Deans Index for dental fluorosis = 7 categories
Defluoridation methods = Nalgonda technique activated alumina
Community water fluoridation = most cost effective public health measure.