Hygiene Atlas

Atlas · Plate XV · Caries and Preventive Agents · 04

Water fluoridation

Community water fluoridation began in Grand Rapids, Michigan, in 1945 and cuts caries by roughly 25% in children and adults. The US Public Health Service level has been 0.7 mg/L since 2015, and the EPA caps fluoride at 4.0 mg/L. Utah and Florida banned it statewide in 2025, but exam items still follow the established science.

High-yield facts · 6

  1. The US Public Health Service recommended level has been 0.7 mg/L since 2015 (it was 0.7-1.2 mg/L before).S32
  2. The EPA's maximum contaminant level is 4.0 mg/L (to prevent skeletal fluorosis); the secondary standard is 2.0 mg/L (to prevent moderate dental fluorosis).S33
  3. Community water fluoridation reduces caries by roughly 25% in children and adults.S32
  4. Grand Rapids, Michigan began the first community water fluoridation in 1945.S32
  5. The "halo" (diffusion) effect: foods and drinks made with fluoridated water carry benefits to nearby nonfluoridated areas.S33
  6. Water fluoridation is policy-sensitive: Utah and Florida passed statewide bans in 2025 (see curriculum.md).S32

Facts are written in our own words; each tag links to its source. Values marked "sources vary" differ between references, so check the one your program uses.