Water fluoridation
Health and dental organizations worldwide have endorsed its safety and effectiveness. Its use began in 1945, following studies of children in a region where higher levels of fluoride occur naturally in the water. Further research showed that moderate fluoridation prevents tooth decay.
Fluoridation by country
In 2013, a Hamilton City Council committee voted to remove fluoride from late June 2013. A referendum was held during the council elections in October 2013 with approximately 70% of voters voting for fluoride to be added back into the water supply, and in March 2014, the council voted 9 to 1 to re-introduce fluoride into the supply. In a 2007 referendum about half of voters in the Central Otago, South Otago and the Southland Region did not want fluoridation and voters in the Waitaki District were against water fluoridation for all Wards. Ashburton and Greymouth also voted against fluoridation.