Community Water Fluoridation Questions and Answers

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1 Community Water Fluoridation Questions and Answers Taken from the Ministry of Health (MoH) website on 27 September 2012: Is there a difference between fluoride found naturally in water and fluoride that is added to water? It is important to know there is no difference. The fluoride ions in water are exactly the same regardless of whether they come naturally from rocks or are added as calcium fluoride or sodium silicofluoride. The dental benefits of fluoridated water occur no matter the source of the fluoride. Is non-fluoridated water more pure than fluoridated water? No. All natural waters contain many different minerals and compounds, including fluoride. The amount of each mineral and compound depends on where the water comes from. Fluoride occurs naturally in most waters and cannot be considered an impurity. This was confirmed by a Privy Council decision in 1963 that stated the addition of fluoride adds no impurity and the water remains not only water but pure water and becomes greatly improved and still natural water containing no foreign elements. How does fluoride help my teeth? Fluoride works in three ways. Fluoride makes teeth more resistant to decay by strengthening the tooth surface. Fluoride interferes with the growth of the bacteria that cause cavities. Fluoride helps to repair the early stages of tooth decay. Fluoride can help strengthen baby teeth before they come through the gums by building fluoride into their structure. The main effect is when teeth erupt through the gums. If fluoride is present in saliva, teeth will continually be exposed to small levels of fluoride, which helps strengthen the tooth surface. Fluoridated water is the best way to achieve this. Do fluoride tablets work as well as fluoridated water? No. The benefit of fluoride tablets is limited as they don t provide constant small doses throughout the day and are more expensive over time than water The fluoride in the saliva from a tablet lasts only three hours, and would give less than 1 percent of the fluoride available from food and drink in a fluoridated area. How do we know water fluoridation is effective? The effectiveness of water fluoridation has been documented in scientific literature for well over 50 years. Data from the 1930s and 1940s shows that even before fluoridation, children drinking naturally fluoridated water had lower decay rates than children consuming water without fluoride. Studies have also shown that when communities stop fluoridation, there is a reversal of the benefits, an increase in decay rates and a large increase in the number of baby teeth extracted. Most recent studies continue to show that the difference between fluoridated and non-fluoridated areas continues to be significant throughout life. The World Health Organisation has reviewed the data available and the Public Health Commission (PHC) in New Zealand published an extensive review of water fluoridation in 1994 and supports In September 2000 the MoH released a report, written by Environmental Science and Research Ltd (ESR), evaluating recent evidence of the safety and effectiveness of water In 2003 the Public Health Advisory Committee (PHAC) also reviewed evidence of the effect of water fluoridation with respect to reducing inequalities in oral health. It strongly recommended increasing the proportion of the New Zealand population receiving fluoridated water. Does fluoridation cause health problems? The weight of scientific evidence supporting the safety and effectiveness of fluoridation is overwhelming and it is clear the majority of reputable health, scientific and medical bodies agree with its use.

2 Many parts of the world have received naturally fluoridated water for thousands of years. Large human populations have now been exposed to community water fluoridation for many decades and no persuasive evidence links optimal fluoridation with any adverse health effects. With hundreds of millions of people continuing to receive the benefits of fluoride in drinking-water, the absence of documented adverse health effects is particularly convincing. Can fluoridated water cause toxic effects? It is impossible to experience fluoride toxicity from drinking-water optimally fluoridated at levels between 0.7 ppm to 1 ppm. It would require drinking more than 5000 glasses of fluoridated water at one time. Anything is toxic if you take too much of it, including many common substances that are essential to health, for example, water, iron, vitamins A and D or even oxygen. In excessive quantities fluoride too can be toxic, but, at the very low concentrations (0.7 ppm to 1 ppm) used in water fluoridation it is not toxic, even when used over a lifetime. What if people have health conditions like kidney disease? There is no research evidence of increased kidney disease or dysfunction in humans drinking up to 8 ppm fluoride; nor is there any evidence that existing kidney disease is made worse. What if people use a fluoridated toothpaste as well, will that be too much fluoride? Studies show that water fluoridation provides benefits above and beyond those from other fluoride vehicles alone (for example, toothpaste or tablets). Conversely, fluoride toothpastes provide additional benefits beyond water Water fluoridation is not a replacement for toothbrushing with fluoride toothpaste, as brushing helps to remove the bacteria (found in plaque) and keeps gums healthy. Rather, the two work hand in hand to help prevent tooth decay, and provide an additional benefit above that of fluoridated water alone. This requires the ingestion of much larger amounts of fluoride than anyone in New Zealand would be exposed to. What is the benefit of fluoride to teeth when it is ingested instead of applied topically? Fluoride ingested and applied topically, such as drinking-water and brushing teeth with a fluoridated toothpaste, go hand in hand as effective measures to help prevent tooth decay. Sugar intake constantly flowing past teeth needs good levels of fluoride in plaque and saliva to be the first line in tooth decay prevention. Human beings are well adapted to living in an environment with natural fluoride. Some of the fluoride we ingest is taken up by bones and teeth. The fluoride taken in to the teeth also helps to prevent dental decay by strengthening the teeth and reducing enamel demineralisation. Our kidneys excrete excessive fluoride from the body, so to protect teeth over our lifetime it is important to have small, regular amounts such as is provided in fluoridated water and fluoridated toothpaste. When fluoride is ingested regularly when teeth are developing, it is deposited across the tooth s entire surface and this slows down decay. Because of this, tooth decay in fluoridated areas progresses more slowly. What is the difference (in any form of measurement) between a safe intake and potentially harmful intake of fluoride? The Drinking-Water Standards for New Zealand focus on defining safety standards to prevent adverse health effects. The recommended maximum acceptable value (MAV) for fluoride is proposed as 1.5 mg/l. The guidelines also recommend the adjustment of water fluoride to between 0.7 mg/l and 1.0 mg/l for oral health reasons. Because the dosage is over half the MAV, this automatically makes the water supply a priority 2 under the standards. This means the supply must be monitored to demonstrate compliance with the standards. Can a person have too much fluoride in their body? Yes, in the same way that a person can have too many vitamins and other dietary supplements. In other parts of the world, where there are extremely high levels of fluoride, it can cause skeletal fluorosis. For more Ministry of Health questions and answers visit the Taranaki DHB Website -

3 Water Fluoridation Facts Prepared by the National Fluoridation Information Service (NFIS) Key Facts Community water fluoridation is the adjustment of natural fluoride levels in drinking water to a level that will give extra protection against tooth decay. The recommended level of fluoride in New Zealand community water supplies is 0.7 to 1mg per litre. Almost all water sources used in New Zealand to supply drinking water contain low levels of naturally occurring fluoride from the rock and sediment they flow over. Some countries have excessively high naturally occurring levels of fluoride and they use treatment processes to adjust this down to a safe level. Fluoride is added to the water supply by feeder and pump systems and is monitored on at least a weekly basis by water suppliers who need to meet standards set out in the New Zealand Drinking Water Standards Currently about 56% of New Zealanders receive fluoridated drinking water supplies. Australia also has naturally low levels of fluoride in drinking water sources. Currently more than 80% of Australians have access to drinking water supplies with community water fluoridation programmes. Countries with widespread community water fluoridation schemes include the U.S.A., Canada, the U.K., Ireland, Spain, Israel, Brazil, Chile, Argentina, Colombia, Hong Kong, South Korea, Singapore and Malaysia. Many European countries and some Central and Southern American countries with naturally low levels of fluoride in water sources, use fluoridated salt widely. Milk fluoridation schemes also exist in several countries. In some countries community water fluoridation is not practical due to the complex and very old water systems without a single point to add fluoride. The Centre for Disease Control and Prevention rate community water fluoridation as one of the top ten public health achievements in the 20 th century. The World Health Organisation (WHO) restated its support for community water fluoridation in 2007, in its Global Policy for improvement of oral health. Benefits The optimal level of fluoride in New Zealand community water supplies is 0.7 1mg per litre. This is the lowest amount at which the benefits to dental health can be achieved, while minimising any risk of dental fluorosis. Because of its role in dental health, fluoride is considered a nutrient by the National Health and Medical Research Council and the New Zealand Ministry of Health. The 2009 New Zealand Oral Health Survey showed that overall children and adults living in fluoridated areas had significantly lower lifetime experience of dental decay than those in nonfluoridated areas. The risk of dental decay is highest for lower socio-economic groups, who can least afford dental care. It is also these groups that benefit most from decay prevention due to community water Most New Zealand studies since 1980 have continued to show benefits of water A 1994 review found 2 studies showed no benefit. The remaining 13 studies showed benefits ranging from 14% to 36% reductions in tooth decay for older children and from 12% to 56% reductions in affected tooth surfaces for younger children. The National Health and Medical Research Council of Australia commissioned a review in 2007 to evaluate scientific data on The review affirmed that community water fluoridation remains the most effective and socially equitable means of achieving the dental decay preventative affects of fluoride.

4 Safety Many substances we use every day are beneficial in small amounts, but may be harmful in large amounts for example salt and water. Adding fluoride to the water to prevent dental decay can be compared to other nutritional measures such as adding Vitamin D to margarine to maintain healthy bones, folic acid to breakfast cereals to reduce the risk of babies being born with neural tube defects and iodine to salt for thyroid health. Other preventative public health measures include smoking restrictions, compulsory seat belts, and immunisation. Almost all water sources and additives to treat drinking water contain small levels of chemicals which is why they are monitored routinely to meet the New Zealand Drinking Water Standards From birth to the age of about seven years when teeth are forming excessive fluoride intake may result in altered formation of the tooth enamel, called dental fluorosis. This looks like white specks in the tooth enamel while more serious forms look like brown stains or pitting. In New Zealand there is a low prevalence of mild and moderate fluorosis and no reported evidence of the more severe forms of fluorosis. There is no established link between water fluoridation and the risk of bone cancer (osteosarcoma). Published reviews have also stated that there is no consistent evidence of an association between community water fluoridation and ill-health or death due to cancer in general. There is no current credible evidence of a link between community water fluoridation and thyroid disease. There is no evidence linking reduced Intelligence Quotient (IQ) scores with community water There have been studies linking low IQ with naturally high fluoride in water supplies although they are problematic due to a number of influences on the study samples. No evidence exists that community water fluoridation poses any health risk for people with chronic kidney disease, although only limited relevant studies are available. Extracts from February and July 2012 issues of the NFIS Newsletter. These can be found on the NFIS website New Zealand Oral Health Survey 4906 New Zealanders participated in the New Zealand Oral Health Survey, including 1961 Maori, 622 Pacific and 755 Asian respondents. The survey showed large improvements in oral health have occurred for children, with the proportion of year olds surveyed who were decay-free almost doubling since the last oral health survey in Adolescents aged years had worse oral health than the younger age groups surveyed. Children and adults living in areas with community water fluoridation had significantly lower lifetime experience of dental decay than those living in nonfluoridated areas. The majority of adults (18 and over) surveyed had some natural teeth, with 88.6% having 21 or more natural teeth. Two in three (65%) adults surveyed brushed their teeth with fluoride toothpaste at least twice a day. Only 43% of 2-17 year olds brushed their teeth twice daily with fluoride toothpaste. The survey found no significant difference in the prevalence of fluorosis between people living in fluoridated and nonfluoridated areas. What s happening elsewhere? In 2011 approximately 56% of New Zealanders were receiving fluoridated drinking water. Whakatane District Council, and Hastings District council are holding referendums about whether to continue with their community water fluoridation programmes during their 2013 local body elections. Lower Hutt City Council and Dunedin City Council have decided to continue with community water Waikato District Council is considering expanding their community water fluoridation programme. Clutha District Council commenced community water fluoridation in Tapanui and Milton in late 2010, and in Kaitangata in February The Ranfurly Community Board in the Central Otago District Council agreed to commence water fluoridation and are expected to have fluoride added to their water supplies in late 2012 after the instalment of the necessary equipment and monitoring systems.

5 Where can I go for more information? Taranaki District Health Board You can find further information on Community Water Fluoridation on the TDHB website: If you want to talk to someone about water fluoridation contact your Dentist or phone TALK TEETH ( ). National Fluoride Information Service The National Fluoride Information Service (NFIS) is an association funded by the Ministry of Health (MoH). Led by Regional Public Health, it also includes the Hutt Valley DHB Community Dental Services, Environmental Science and Research, Centre for Public Health Research at Massey University and the National Poisons Centre. There is ongoing research and monitoring around the world looking at the effectiveness and safety of water fluoridation programmes. NFIS has been established to monitor and assess this work and to provide advice on these issues. NFIS offers robust and independent scientific and technical information around water fluoridation to District Health Boards (DHBs) and Territorial Local Authorities (TLAs). Website: Ministry of Health The Ministry of Health leads New Zealand s health and disability system, and has overall responsibility for the management and development of that system. Website: New Zealand Dental Association The New Zealand Dental Association (NZDA) is the professional association for New Zealand dentists. NZDA is the one body able to speak on behalf of NZ dentistry as a whole. They also provide information and advice to consumers. Healthy Smiles is the New Zealand Dental Association website for the public, students, teachers, health professionals and the media. Follow this link: Victoria Government Health Information - Fluoridation The Department of Health, Victoria, Australia, Victorian Government Health Information website is a gateway to information on community water Follow this link: World Health Organisation Visit their website: