The benchmark of 1 mg/L is somehow an “optimal level” because a committee within an organization like WHO says so. In reality the way of thinking resulting in such a claim that an optimal level exists at all has become institutionalized over time. In short the assumptions not the science drive the conclusion. There are many studies showing that health effects increase as fluoride intake increases. This is to be expected.
Sebastian ST, Soman RR, Sunitha S. Prevalence of dental fluorosis among primary school children in association with different water fluoride levels in Mysore district, Karnataka. Indian journal of dental research 2016 Mar-Apr;27(2):151-4. doi: 10.4103/0970-9290.183126.
BACKGROUND: Fluoride intake at optimal level decreases the incidence of dental caries. However, excessive intake, especially during developmental stages can cause adverse effects such as dental and skeletal fluorosis.
AIM: To assess the prevalence and severity of dental fluorosis in primary school children born and raised in three villages of Mysore District. The three selected villages have different water fluoride concentrations.
MATERIALS AND METHODS: Three villages namely, Nerale (water fluoride 2.0 ppm), Belavadi (1.2 ppm) and Naganahally (0.4 ppm) were selected for the study. Then, a total of 405 children, 10-12-year-old (204 [50.4%] males and 201 [49.60%] females) were selected from three schools of the villages. Dean’s fluorosis index recommended by World Health Organization was used to evaluate fluorosis among the study population.
RESULTS: The overall prevalence of dental fluorosis was found to be 41.73%. An increase in the community fluorosis index (CFI) was higher among those living in high water fluoride area.
CONCLUSION: A significantly positive correlation was found between CFI and water fluoride concentration in drinking water.