Fluoride Action Network

A History of Water Fluoridation in California: Lessons Learned

Source: Journal of the California Dental Association - Nov 2019 | November 8th, 2019 | By Ernest Newbrun, DMD, PhD

*Original article, with Tables, at https://www.cda.org/Portals/0/journal/journal_112019.pdf


Water fluoridation is the most effective measure in preventing caries. This article examines the history, and lessons learned, of water fluoridation in California tracing referenda and decisions by administrative bodies. Progress was slow until a breakthrough when Assembly Bill 733, the fluoridated drinking water act, became law in 1995, thanks to the courage and persistence of then Assemblymember Jackie Speier (D-Burlingame). More recently, administrative bodies have exerted their authority to direct water agencies to fluoridate, thereby avoiding expensive and divisive referenda.

When Americans think of California, they conjure up images of Hollywood, the Golden Gate Bridge or even Silicon Valley. The most populous state in the U.S., California has an economy ranking fifth in the world,1 raised automobile emission standards earlier than other states and on health issues was one of the leaders in banning smoking in work areas and public places. Yet when it came to community water fluoridation, one of the 10 great public health measures of the 20th century,2 California sadly lagged behind most other states until quite recently. This is the story of the fight for fluoridation in California.

Early History of Water Fluoridation in California

From 1945 to 1947, four independent clinical trials were undertaken in North America to determine if adding fluoride to public water supplies to an optimum level (then 1.00 ppm) would reduce the prevalence and severity of dental caries similarly to naturally occurring fluoride (TABLE 1). These trials were planned to run for 15 years, but after 6.5 years, the caries prevalence in 4- to 6-year-olds residing in test cities was already about half of that in the control nonfluoridated cities. Accordingly, two of the control cities, Muskegon, Mich., and Oak Park, Ill., did not wait for these trials to finish and started fluoridating.3 California was in the vanguard; in the spring of 1951, the San Francisco Board of Supervisors unanimously requested that the water department take steps to fluoridate San Francisco water. The supervisors approved an enabling ordinance and an appropriation of $40,000 of water department funds. In the fall of 1951, a declaration of policy regarding communal water fluoridation (CWF) was put before the voters, who voted to fluoridate the water (56% in favor and 44% opposed). The San Francisco Water District and Antioch in Contra Costa County were the first in California to do so, starting in August 1952. Zachary Stadt, DMD, MPH, the dental health director of Contra Costa County, compared the caries prevalence in Antioch school children before fluoridation in 1952 to 10 years later in 1962 (TABLE 2). The dental findings showed greatly reduced tooth decay — a 55% reduction in the mean number of decayed, extracted and filled deciduous teeth (deft) in 5-year-olds and 84% reduction in the mean number of decayed, missing and filled permanent teeth (DMFT) due to caries in 6-year-olds and 60% to 64% in 8- and 10-year-olds.4

Among the other communities in California that fluoridated in the 1950s were Hayward, Healdsburg, Morgan Hill, Palo Alto, Pleasanton and Vallejo — all in Northern California (TABLE 3).5 In the 1950s and early 1960s, there were 36 referenda in California on CWF, in which 11 communities voted favorably while 25 others rejected fluoridation.6 The reason opponents were more successful in these referenda might have been in part because the health benefits, documented by statistics, were not as emotionally compelling as the opponents’ inaccurate portrayal of fluoride as poison at only 1.0 ppm. Furthermore, the children who would gain the most from this public health measure were not entitled to vote. Another reason was that the main proponents of water fluoridation were health professionals (dentists, physicians and public health workers) who were inexperienced in politics. The general public was mostly indifferent on the issue and politicians preferred not to get involved.

In April 1952, the Sonoma County cities of Cloverdale, Santa Rosa and Healdsburg held referenda on CWF. Cloverdale and Santa Rosa rejected fluoridation (TABLE 4).7 In Santa Rosa, 57% of the voters opposed it and only 43% voted in favor. It was defeated by only 421 votes; the reason, according to one reporter, was “shear apathy” as less than 3,000 of the city’s 9,658 registered voters cast ballots.8 The public utilities board dodged responsibility by merely recommending that it be placed on the ballot, but there were no open hearings. The city council was completely passive on the matter.8 In nearby Healdsburg, voters approved (63% for, 37% against) and the city commenced fluoridation in November 1953.

During the 1960s, 12 water systems serving 516,779 persons were added to the population served by fluoridated water in California (TABLE 5). The largest water system by far was the Contra Costa Water District with a population at that time of 225,000. In the 1960s, California ranked near the bottom (~ 46th) of all states in the percentage (~ 12%) of the population benefiting from community water fluoridation, with only Utah, Hawaii, New Hampshire, New Jersey and Oregon ranked lower. How could this be remedied? One way was to educate the public by starting with future dentists and dental hygienists who would then be able to inform their patients. The public perceives the advice of their dentist or physician as the most trustworthy source of information about fluoridation.9 At the University of California, San Francisco, School of Dentistry, students were taught the physiology, pharmacology and toxicology of fluorides as well as clinical epidemiological evidence of the benefits in terms of caries reduction using a small group seminar format (~ 12–15 students) including a final fluoridation debate that proved very popular. In the process, the students learned about safety issues and the benefits, costs, risks and environmental impact of communal water fluoridation. Some students even volunteered as campaign workers during the East Bay Municipal Utility District (EBMUD) water fluoridation referendum in 1980, a practical learning experience. At the University of California, Los Angeles, School of Dentistry, students heard lectures and were examined on the health issues and benefits of CWF. In the 1975 referendum on CWF, students helped distribute brochures. Students at the University of the Pacific, Arthur A. Dugoni School of Dentistry reviewed an online module on CWF, followed by a two-hour seminar where this and other topics related to community oral health were discussed. At the Ostrow School of Dentistry of USC, the principles of fluoridation were taught using problem-based learning (PBL) in a case, with such cases held in the first two years and cut across all disciplines. At the Loma Linda University School of Dentistry, CWF was incorporated in both the teaching of pediatric dentistry and general dentistry, each devoting about 15 minutes to this topic.

During the 1970s, the biggest fluoridation victory was the EBMUD serving 30 cities in two counties, including Oakland, Berkeley, Richmond and Walnut Creek, with a total combined population of 1,100,000 (80% residing in Alameda County and 20% in Contra Costa County) (TABLE 6). This followed two embarrassing referenda defeats in 1960 and 1964. In 1974, a fluoridation referendum won narrowly, 50.5% to 49.5%,10 and in 1980 voters reapproved fluoridation by 54.9% to 45.1%11 as shown in FIGURE 1. Usually, once a community has been fluoridated, voters are less likely to reject it in a recall referendum or to believe all the dire predictions of the fluoridation opponents.

In the 1970s, in spite of some major successes such as EBMUD and the city of Long Beach in Southern California, the city of Los Angeles was a big disappointment. In 1974, the L.A. City Council adopted a fluoridation ordinance by a 10-4 vote; the ordinance was signed by the acting mayor shortly afterward.12 Subsequently, the L.A. City Council lost courage and reversed its decision, leaving it to the voters to decide. Two prominent state legislators, Art Torres and Richard Alatorre, who had turned against the measure, influenced the city council and the voters. John Yiamouyiannis, PhD, a biochemist, was hired by the National Health Federation in Monrovia to stop fluoridation.13 He succeeded using scare tactics, falsely alleging higher than average cancer rates in fluoridated communities.14,15 The studies cited by Dr. Yiamouyiannis, according to one reviewer, were more like “a propaganda flyer than serious scientific effort.” It took some time to disprove such claims, by which time the referendum was already over.16,17 Opponents of water fluoridation won that referendum handily by 213,573 (56%) votes to 166,549 (44%) votes. Thereby about 9 million people were denied the benefits of communal water fluoridation for another 24 years.

Recent History of Water Fluoridation in California

Dental health experts voiced amazement when San Francisco Supervisor Wendy Nelder suddenly renewed the fight against fluoride in water on Sept. 5, 1984.18 Dentists said the water treatment had saved children’s teeth from millions of cavities and had proven to be inexpensive and safe for more than 30 years. The reaction to her charge that fluoridation of San Francisco’s water — begun in 1952 — might cause AIDS was scathing. In 1981, the Centers for Disease Control and Prevention (CDC) had recognized AIDS as an infectious disease.19 By 1983, a causative retrovirus had been isolated from the lymph node of an AIDS patient by a team of virologists at the Pasteur Institute in Paris. In 1984, a nearly identical virus was isolated by a team led by Robert Gallo, MD, at the National Institutes of Health in Bethesda, Maryland, with evidence that it caused AIDS; this virus was later named human immunodeficiency virus (HIV). CWF opponents, led by Nelder, attempted to pressure the city’s board of supervisors to stop San Francisco’s 34-year-old practice of fluoridating its water supply. Although the local press and radio widely publicized the opponents’ unsubstantiated claims that fluoridation renders people susceptible to AIDS by destroying the body’s defense mechanisms, with rare exception the media were supportive of CWF. Political leaders dismissed Nelder’s call for an investigation into the health effects of water fluoridation; then Mayor Dianne Feinstein denounced Nelder’s charges as “off the wall.” The board voted to continue to support CWF20 based on the city health department’s report on the benefits and safety of fluoridation.21 The safety and dental benefits of CWF were reconfirmed in an updated review of the medical literature by the San Francisco Department of Public Health in 2011.22 Nelder served on the board of supervisors from 1981 to 1991. As top vote-getter in the 1982 election, she became president of the board from 1983 to 1985. During this time, she pushed her antifluoride campaign but could not muster sufficient support from the board to place it on the ballot. Five years later, she tried again but was blocked again. She did not seek reelection in 1990 but ended her political career after unsuccessfully for assessor.23 Her outspoken opposition to CWF possibly contributed to her political demise.

In 1992, only 15.7% of California’s population on public water systems received fluoridated water,5 ranking 48th among states just ahead of Hawaii, Utah and Nevada. By 2014, the percentage climbed to 63.7% and the number of Californians receiving fluoridated water was almost five times higher, increasing from less than 5 million in 1992 to 24.7 million in 2014. The turning point was when the California Legislature and the governor enacted AB 733 in 1995 at the initiative of Assemblymember Jackie Speier (D-Burlingame), “a legislator known for her courage under fire and her penchant for hard-hitting bills,” who pressed on with a statewide fluoridation bill because of the dental needs of children.24 In order to get the bill passed, she enlisted bipartisan support from members of the state Assembly and Senate as well as the influential Speaker of the House Willie Brown as co-authors. The bill underwent further transformation to garner the necessary support of some wavering legislators; the capital costs for the equipment and building had to be funded from nonstate sources. The day-to-day operating expenses could be passed onto the customers who would be saving money on their dental bills. This act required water systems with 10,000 or more service connections to fluoridate once; funding from an outside source was provided. The California Endowment, a private foundation, contributed $15 million25 and First 5 California contributed varying amounts, depending on the county, to fund capital costs to initiate CWF using money obtained through the state cigarette tax.26 The Dental Health Foundation and the California Dental Association (CDA) Foundation were instrumental in distributing these funds. The ongoing expense of CWF is low, ranging from about 50 cents per person per year for communities with more than 20,000 residents to $3 per person per year in communities with 5,000 or fewer residents.27

In 1995, Speier termed out as an assemblymember and her political future was unclear; conventional wisdom would have been to avoid so-called “controversial” issues such as water fluoridation. Speier saw it as a health issue and did not hesitate to persist in promoting passage of this statewide bill; therein lies an important lesson. Clearly it did not hinder her political career; in 1998, she was elected to the California State Senate, and in 2008, following the death of Congressman Tom Lantos, she was  overwhelmingly elected to succeed him as the U.S. representative for California’s 14th Congressional District.

In 1995, Speier termed out as an assemblymember and her political future was unclear; conventional wisdom would have been to avoid so-called “controversial” issues such as water fluoridation. Speier saw it as a health issue and did not hesitate to persist in promoting passage of this statewide bill; therein lies an important lesson. Clearly it did not hinder her political career; in 1998, she was elected to the California State Senate, and in 2008, following the death of Congressman Tom Lantos, she was overwhelmingly elected to succeed him as the U.S. representative for California’s 14th Congressional District.

The city of Los Angeles fluoridated its water supplies in 1999 by action of the city council after several public hearings but without the kind of public outcry from 25 years earlier. However, it has taken longer to fluoridate Los Angeles County, which includes 88 cities, because of the many water suppliers and the vast area covered. According to Maritza Cabezas, DDS, MPH, the county dental director, 58% of L.A. County’s population receive optimally fluoridated water, 5% near optimal, 19% partial and 17% no fluoride.28

In February 2003, the board of the Metropolitan Water District of Southern California (MWD), which supplies water to about 18 million consumers, heard testimony concerning water fluoridation. The board consisted of 55 representatives from various communities and convincing them to move on fluoridation was no small task. Proponents of water fluoridation had a “dream team” of dentists, physicians, public health officials, school teachers and nurses and parents all conveying the message of safety, efficacy and the need for this proven public health measure. The MWD board voted to accept the recommendation, and in September 2003, $5.5 million in grant monies was made available from the California Endowment; as a result, California no longer lagged behind most other states. In November 2007, the MWD started bringing fluoridation systems online at its five massive filtration plants, the largest fluoridation project in the U.S.

In the case of San Diego, both the California attorney general and the city attorney’s office opined that when sufficient funding became available state law would preempt San Diego Municipal Code Section 67.0101 dating back to 1954, which prohibited the city from fluoridation. Accordingly, state law preempts this old city ordinance. In June 2008, the San Diego City Council voted unanimously to accept $3.9 million to fund the city’s fluoridation program. As a result of state law and the availability of funding, the city began fluoridating its public water supply in February 2011. San Diego not only delivers water to its citizens, it also supplies treated water to the cities of Del Mar, Coronado and Imperial Beach. More than 1.36 million people receive fluoridated water treated by San Diego.

Healdsburg has remained fluoridated since 1952 in spite of two attempts by opponents to stop the process by referenda. In 2014, Healdsburg voters again approved fluoridation by a margin of 2:1 (2,184 votes to continue water fluoridation; 1,113 votes to stop water fluoridation). In that referendum, the local Healdsburg Tribune strongly supported continued water fluoridation as did a local dentist, Shawn Widick, DDS. Undeterred by the vote to continue fluoridation in Healdsburg in 2014, another referendum was held in 2016, based on 709 valid signatures gathered by anti-fluoridationists on a proposed ordinance intended to stop fluoridation. The measure was again defeated, this time by 57% in favor of continuing fluoridation in a backwardly worded ballot where a no vote meant continuing fluoridation, which may have confused some voters.29 Although no survey has been undertaken to determine why voters in Healdsburg consistently supported fluoridation, one might speculate that they were more trusting of the medical/dental profession than they were worried about chemical additives.9 Other communities in Sonoma County, such as Sebastopol, Cloverdale and Santa Rosa, lack the benefits of communal water fluoridation. A fluoridation preliminary engineering design report, costing about $113,000, and an environmental impact study on aquatic marine life, costing $66,766, concluded that fluoridation was unlikely to harm federally listed salmonids that occur in local streams. The report was presented to the Fluoridation Advisory Committee (appointed by the Sonoma Department of Health Services) that met for more than two years (2013–2015). This committee recommended overwhelmingly (19 in favor, two opposed) in support of fluoridation.30 Sadly, those recommendations languished without any action by the Sonoma Board of Supervisors, the Sonoma County Water Agency nor the Santa Rosa City Council. The Sonoma County Water Agency supplies drinking water to more than 600,000 consumers in nine cities and water districts in northern Marin County, as well as Cotati, Petaluma, Rohnert Park, Santa Rosa, Sonoma and Windsor in Sonoma County, of which Santa Rosa is the largest customer.

The current tactic of antifluoridationists has been to focus on fluoride not as a carcinogen but as a neurotoxin, claiming that fluoride presents a risk under Section 21 of the Toxic Substances Control Act (TSCA).31 The Fluoridation Action Network, representing fluoridation opponents, has filed a lawsuit in the U.S. District Court, Northern District of California seeking a ban on fluoridation additives.32 A court hearing was expected to take place in San Francisco in August 2019. Challenges to communal water fluoridation based on religious freedom, due process and claims of harm have a long history. The legal validity of fluoridation has been repeatedly tested and affirmed by courts of last resort in the United States.33

Concluding Remarks

It is worth noting that administrative bodies such as the L.A. City Council, the board of the MWD and the San Diego City Council decided to fluoridate (or continue fluoridation as in the case of San Francisco Board of Supervisors) following open hearingsthereby avoiding divisive and expensive  referenda. This should be a guide as to how to proceed in implementing community water fluoridation by the Sonoma County Water Agency in Santa Rosa and the surrounding communities, the last holdouts of major-sized communities in California. In a review of the outcome of decisions regarding CWF throughout the U.S., Easley found a substantial difference between the results of decisions by governing body when compared to results subject to voter referenda. Over a 10-year period from 1980 to 1989, 78% of governing body decisions were in favor of CWF, while only 37% of referenda on CWF were successful.34

Looking at the percentage of Californians served by community water systems receiving fluoridated water35 (FIGURE 2), one sees that for 34 years, between 1961 and 1995, there was little progress in bestowing this proven public health measure to the California public because of apathy, lack of political support and a small but determined opposition. Over those 34 years, the population of California doubled from 15.7 million to 31.7 million, yet those with CWF changed very little, from 12% to 17%. However, 1995 was the year that Speier introduced Assembly Bill 733, after which things improved. Based on the most recent survey (2014), 63.7% of Californians on
community water systems benefited from drinking optimally fluoridated water, slightly below the 74.4% for the nation as a whole.36 California is not in the top 10 states in terms of percentage,37 but it leads in having more people in California receiving fluoridated water than in any other state, almost 25 million. California has come a long way thanks to the efforts of many dedicated public health workers, dentists and a few courageous politicians.

The history of water fluoridation in California is a story of perseverance, strategy and commitment to the oral health of the population. Some of the lessons learned from this history are summarized in TABLE 7. One lesson from the Healdsburg referenda of 1952, 2014 and 2016 is that, though we may win some battles, the dispute over communal water fluoridation never ceases. Historian Donald McNeil13 has described the fight over fluoridation as “America’s longest war,” which is still continuing because the issue is “almost tailor-made for endless controversy.” Some Americans mistrust authority, government and science, and people are prone to resist scientific claims in spite of thorough testing and factual observation when they clash with their intuitive beliefs. Atul Gawande38 points out that even where the knowledge provided by science is overwhelming, people often resist it — and sometimes outright deny it. That is the reason why the fight for communal water fluoridation has continued now for nearly 70 years.

The author is indebted to Howard Pollick, BDS, MPH, for his insightful comments and suggestions concerning this manuscript.


1. Cooper JJ. California Now World’s 5th Largest Economy, Surpassing U.K. Associated Press May 4, 2018.

2. Ten Great Public Health Achievements — United States, 1900–1999. MMWR Morb Mortal Wkly Rep 1999 Apr2;48(12):241–3.

3. Newbrun E. Water fluoridation and dietary fluoride. In: Newbrun E, ed. Fluorides and Dental Caries. 3rd ed. Springfield, Ill.: C.C. Thomas; 1986:12.

4. Stadt ZM, Blum HL, Kent GW, et al. Contra Costa County Fluoridation Report Antioch, California, after 10 years of fluoridation. California’s Health 1964;21:24.

5. Fluoridation Census 1992. U.S. Department of Health and Human Services, CDC. 1993; National Center for Prevention, Services Division of Oral Health, Atlanta.

6. Meuller JE. The politics of fluoridation in seven California cities. West Polit Q 1966 Mar;(1); 19:54–67.

7. Fluoridation in Healdsburg OK’d. The Press Democrat Santa Rosa, Calif., April 9, 1952.

8. Bauers U. Vote against S.R. fluoridation disheartening election result. The Press Democrat Santa Rosa, Calif., April 9, 1952.

9. Arcus-Ting R, Tessler R, Wright J. Misinformation and opposition to fluoridation. Polity (Winter) 1977; 10:281–289.

10. Boriskin JM. The winning of a large fluoridation campaign using minimal manpower and budget. J Calif Dent Assoc 1979 Jun;7(6):53–63.

11. Boriskin JM, Fine JI. Fluoridation Election Victory: A Case Study for Dentistry in Effective Political Action. J Am Dent Assoc 1981 102(4):86–491.

12. Nathan H, Scott S. Fluoridation in California: A new look at a persistent issue. Bull Inst Govt Studies Oct. 1974; vol.15, no. 5.

13. McNeil DR. America’s longest war: The fight over fluoridation, 1950. Wilson Q Summer, 1985;9(3):140–153.

14. Yiamouyiannis JS. Fluoride and Cancer. Nat Health Fed Bull April 1975;21:9.

15. Yiamouyiannis J, Burk D. Congressional Record 191, H7172–7176, July 21, 1975; ibid, H 12731–12734, Dec. 16 1975.

16. Hoover HC, McKay FW, Fraumeni JR. Fluoridated drinking water and the occurrence of cancer. J Natl Cancer Inst 1976 Oct;57(4):757–768.

17. Newbrun E. The safety of water fluoridation. J Am Dent Assoc 1977 94(2):301–304.

18. Perlman D. Fluoride, AIDS experts scoff at Nelder’s idea. San Francisco Chronicle pp. 1, 18. Sept. 6, 1984.

19. Pneumocystis Pneumonia — Los Angeles. MMWR MorbMortal Wkly Rep 1981 Jun 5;30(21):250–252.

20. Löe H. The fluoridation status of U.S. public water supplies. Public Health Rep 1986 Mar–Apr; 101(2):157–162.

21. Werdegar D. San Francisco Department of Health Reply to Board of Supervisors on Questions About Fluoridation. July 26, 1985.

22. Fluoride: Updated Review of the Medical Literature 2000–2005. www.sfdph.org/dph/files/EHSdocs/ehsWaterdocs/Fluoride_Document_Collection.pdf.

23. Supervisor revives fluoride concerns. San Francisco Examiner p. A7, June 6, 2000.

24. Boyd J. Anatomy of a campaign. J Calif Dent Assoc 1997 25(1):29–36.

25. The California Endowment. 20 for 20. www.calendow.org/were-20.

26. First 5 California. www.ccfc.ca.gov/about/about.html.

27. Wisconsin Dental Association. How much does community water fluoridation cost? www.wda.org/wp_super_faq/howmuch-does-community-water-fluoridation-cost.

28. Cabezas M. Water fluoridation status in Los Angeles County cities over a 23-year period, National Oral Health Conference April 29, 2014; Fort Worth, Texas.

29. Healdsburg, California, fluoridation of water supply, Measure T (November 2016). ballotpedia.org/Healdsburg,_California,_Fluoridation_of_Water_Supply,_Measure_T_(November_2016).

30. County of Sonoma. sonomacounty.ca.gov/SearchRes/?q=fluoridation%20advisory%20committee.

31. Connett M. Citizen petition under section 21 of TSCA: Regarding the neurotoxic risks posed by fluoride chemicals in drinking water. www.epa.gov/sites/production/

32. FAN sues EPA to end fluoridation. fluoridealert.org/articles/fan-sues-epa-to-end-fluoridation.

33. Frazier PJ, Newbrun E. Legal, social and economic aspects of fluoridation. In: Newbrun E ed. Fluorides and Dental Caries. 3rd ed. Springfield, Ill.: C.C. Thomas; 1986:117–123.

34. Easley MW. The status of community water fluoridation in the United States. Public Health Rep 1990 Jul–Aug; 105(4):348–353.

35. Centers for Disease Control and Prevention. Populations receiving optimally fluoridated public drinking water — United States, 1992–2006. MMWR Morb Mortal Wkly Rep 2008 Jul 11;57(27):737–41.

36. Centers for Disease Control and Prevention. Community water fluoridation. www.cdc.gov/fluoridation/statistics/2014stats.htm.

37. Pew Charitable Trust. Community Water Fluoridation: the Top 10 and the Bottom 10. www.pewtrusts.org/en/researchand-analysis/data-visualizatio/2014/fluoridation-by-thenumbers.

*Original article, with Tables, at https://www.cda.org/Portals/0/journal/journal_112019.pdf