water fluoridation in the united states water fluoridation in the united states as with some other countries, water fluoridation in the united states is a contentious issue. as of may 2000, 42 of the 50 largest u.s. cities had water fluoridation. on january 25, 1945, grand rapids, michigan, became the first community in the united states to fluoridate its drinking water to prevent tooth decay. u.s. residents served with community water fluoridation, 1992 and 2006. the percentages are the proportions of the resident population served by public water supplies who are receiving fluoridated water. fluoridation became an official policy of the u.s. public health service by 1951, and by 1960 water fluoridation had become widely used in the u.s., reaching about 50 million people. by 2006, 69.2% of the u.s. population on public water systems were receiving fluoridated water, amounting to 61.5% of the total u.s. population. near the end of 2012, 67.1% of the u.s. population were getting water from community water systems (cws) supplying water that had fluoride at or above recommended levels. those included the 3.5% of the population that were on cws with naturally occurring fluoride at or above recommended levels. 74.6% of those on cws were receiving water with fluoride at or above recommended levels. u.s. regulations for bottled water do not require disclosing fluoride content. a survey of bottled water in cleveland and in iowa, published in 2000, found that most had fluoride levels well below the 1 mg/l level common in tap waters. history main article: history of water fluoridation 1909 photograph by frederick mckay of greene vardiman black (left) and isaac burton and f.y. wilson, studying the colorado brown stain. community water fluoridation in the united states is partly due to the research of dr. frederick mckay, who pressed the dental community for an investigation into what was then known as "colorado brown stain." the condition, now known as dental fluorosis, when in its severe form is characterized by cracking and pitting of the teeth. of 2,945 children examined in 1909 by dr. mckay, 87.5% had some degree of stain or mottling. all the affected children were from the pikes peak region. despite the negative impact on the physical appearance of their teeth, the children with stained, mottled and pitted teeth also had fewer cavities than other children. mckay brought this to the attention of greene vardiman black, and black's interest was followed by greater interest within the dental profession. initial hypotheses for the staining included poor nutrition, overconsumption of pork or milk, radium exposure, childhood diseases, or a calcium deficiency in the local drinking water. in 1931, researchers from the aluminum company of america (alcoa) concluded that the cause of the colorado stain was a high concentration of fluoride ions in the region's drinking water (ranging from 2 to 13.7 mg/l) and areas with lower concentrations had no staining (1 mg/l or less). pikes peak's rock formations contained the mineral cryolite, one of whose constituents is fluorine. as the rain and snow fell, the resulting runoff water dissolved fluoride which made its way into the water supply. dental and aluminum researchers then moved toward determining a relatively safe level of fluoride to be added to water supplies. the research had two goals: (1) to warn communities with a high concentration of fluoride of the danger, initiating a reduction of the fluoride levels in order to reduce incidences of fluorosis, and (2) to encourage communities with a low concentration of fluoride in drinking water to add fluoride in order to help prevent tooth decay. by 2006, 69.2% of the u.s. population on public water systems were receiving fluoridated water, amounting to 61.5% of the total u.s. population; 3.0% of the population on public water systems were receiving naturally occurring fluoride. in april 2015, fluoride levels in the united states were lowered for the first time in 50 years, to the minimum recommended levels of 0.7ppm, because too much fluoride exposure has become a common issue for children teeth, visible in the form of white splotches. the basis were the results of two national surveys (1999–2004 nhanes) which assessed the prevalence of dental fluorosis, and found that two out of five adolescents had tooth streaking or spottiness on their teeth - an increase of mostly very mild or mild forms. early studies h. trendley dean set out in 1931 to study fluoride's harm, but by 1950 had demonstrated the benefits of small amounts. a study of varying amounts of fluoride in water was led by dr. h. trendley dean, a dental officer of the u.s. public health service. in 1936 and 1937, dr. dean and other dentists compared statistics from amarillo, which had 2.8 – 3.9 mg/l fluoride content, and low fluoride wichita falls. the data is alleged to show fewer cavities in amarillo children, but the studies were never published. dr. dean's research on the fluoride-dental caries relationship, published in 1942, included 7,000 children from 21 cities in colorado, illinois, indiana, and ohio. the study concluded that the optimal amount of fluoride which minimized the risk of severe fluorosis but had positive benefits for tooth decay was 1 mg per day, per adult. although fluoride is more abundant in the environment today, this was estimated to correlate with the concentration of 1 mg/l. in 1937, dentists henry klein and carroll e. palmer had considered the possibility of fluoridation to prevent cavities after their evaluation of data gathered by a public health service team at dental examinations of native american children. in a series of papers published afterwards (1937–1941), yet disregarded by his colleagues within the u.s.p.h.s., klein summarized his findings on tooth development in children and related problems in epidemiological investigations on caries prevalence. in 1939, dr. gerald j. cox conducted laboratory tests using rats that were fed aluminum and fluoride. dr. cox suggested adding fluoride to drinking water (or other media such as milk or bottled water) in order to improve oral health. in the mid-1940s, four widely cited studies were conducted. the researchers investigated cities that had both fluoridated and unfluoridated water. the first pair was muskegon, michigan and grand rapids, michigan, making grand rapids the first community in the world to add fluoride to its drinking water to try to benefit dental health on january 25, 1945. kingston, new york was paired with newburgh, new york. oak park, illinois was paired with evanston, illinois. sarnia, ontario was paired with brantford, ontario, canada. in 1952 nebraska representative a.l. miller complained that there had been no studies carried out to assess the potential adverse health risk to senior citizens, pregnant women, or people with chronic diseases from exposure to the fluoridation. a decrease in the incidence of tooth decay was found in some of the cities which had added fluoride to water supplies. the early comparison studies would later be criticized as, "primitive," with a, "virtual absence of quantitative, statistical methods...nonrandom method of selecting data and...high sensitivity of the results to the way in which the study populations were grouped..." in the journal nature. water fluoridation main article: water fluoridation as of may 2000, 42 of the 50 largest u.s. cities had water fluoridation. according to a 2002 study, 67% of u.s. residents were living in communities with fluoridated water at that time. the u.s. centers for disease control has identified community water fluoridation as one of ten great public health achievements of the 20th century. the cdc recommends water fluoridation at a level of 0.7–1.2 mg/l, depending on climate. the cdc also advises parents to monitor use of fluoride toothpaste, and use of water with fluoride concentrations above 2 mg/l, in children up to age 8. there is a cdc database for researching the water fluoridation status of neighborhood water. in 1998, 70% of people polled in a survey conducted by the american dental association (ada) believed community water should be fluoridated, with 18% disagreeing and the rest undecided. in november 2006, the ada began recommending to parents that infants from 0 through 12 months of age should have their formula prepared with water that is fluoride-free or contains low levels of fluoride to reduce the risk of fluorosis. the issue of whether or not to fluoridate water supplies frequently arises in local governments. for example, on november 8, 2005, citizens of mt. pleasant, michigan voted 63% to 37% in favor of reinstating fluoridation in public drinking water after a 2004 ballot initiative ceased water fluoridation in the city. at the same time, voters in xenia, ohio; springfield, ohio; bellingham, washington; and tooele city, utah all rejected water fluoridation. in skagit county in the state of washington, the county commissioners in 2007 voted 2 to 1 to order the local public utility district to begin fluoridating the public water supply by jan. 2009. $1.2 million was to be provided by the privately funded washington dental service foundation to begin building the equipment needed to add fluoride to the judy reservoir, which supplies the majority of skagit valley's water customers. the source and type of fluoride to be added to the drinking water of more than 70,000 citizens had not been disclosed. however, in february 2009, skagit county commissioners rescinded the 2007 order, citing costs and possible lawsuits. the cost of adding fluoridation to the water of 44 florida communities has been researched by the state health office in tallahassee. in communities with a population of over 50,000 people, fluoridation costs were estimated at 31 cents per person per year. the estimated cost rises to $2.12 per person in areas with a population below 10,000. unintended consequences, such as equipment malfunction, can substantially raise the financial burden, as well as the health risks, to the consumer. in the u.s., hispanic and latino americans are significantly more likely to consume bottled instead of tap water, and the use of bottled and filtered water grew dramatically in the late 1990s and early 2000s. decisions about water fluoridation many political and popular entities and activities determine whether fluoride is added to water supplies. those include courts, local governments, popular referendums, and water authorities. court cases fluoridation has been the subject of many court cases wherein activists have sued municipalities, asserting that their rights to consent to medical treatment and due process are infringed by mandatory water fluoridation. individuals have sued municipalities for a number of illnesses that they believe were caused by fluoridation of the city's water supply. in most of these cases, the courts have held in favor of cities, finding no or only a tenuous connection between health problems and widespread water fluoridation. to date, no federal appellate court or state court of last resort (i.e., state supreme court) has found water fluoridation to be unlawful. early cases a flurry of cases were heard in numerous state courts across the u.s. in the 1950s during the early years of water fluoridation. state courts consistently held in favor of allowing fluoridation to continue, analogizing fluoridation to mandatory vaccination and the use of other chemicals to clean the public water supply, both of which had a long-standing history of acceptance by courts. in 1952, a federal regulation was adopted that stated in part, "the federal security agency will regard water supplies containing fluorine, within the limitations recommended by the public health service, as not actionable under the federal food, drug, and cosmetic act." the supreme court of oklahoma analogized water fluoridation to mandatory vaccination in a 1954 case. the court noted, "we think the weight of well-reasoned modern precedent sustains the right of municipalities to adopt such reasonable and undiscriminating measures to improve their water supplies as are necessary to protect and improve the public health, even though no epidemic is imminent and no contagious disease or virus is directly involved .... to us it seems ridiculous and of no consequence in considering the public health phase of the case that the substance to be added to the water may be classed as a mineral rather than a drug, antiseptic or germ killer; just as it is of little, if any, consequence whether fluoridation accomplishes its beneficial result to the public health by killing germs in the water, or by hardening the teeth or building up immunity in them to the bacteria that causes caries or tooth decay. if the latter, there