Welcome, everybody, to another edition of the Filth in America podcast. I'm your host, Brandon Hewlett, infectious disease epidemiologist, an all-around public health enthusiast. Today we're going to talk about a topic that I think a lot of us don't really think about, but definitely know about, a topic that is a routine, everyday kind of experience, a way that we interact both with the public health system and public health history in ways I don't know that we know, but certainly probably just don't think about a whole lot for most of us. Yet it is one that there are passionate people around this particular practice. There are people that have argued that it is everything from a communist conspiracy to mind control, to a conspiracy to increase disease, and others that say, look at this data. We have more data on the safety and the efficacy on this practice than just about anything else that we do. And that topic is the fluoridation of drinking water. Fluoridation of drinking water is very common in the United States. Around 68% of us will have access to fluoridated drinking water on any given day. It's also very common around the world, multiple other countries. It's generally thought of, certainly by the CDC. It's on the list of the 10 most influential and best public health practices ever. And that's a pretty high bar to say of all the different public health things that have ever happened out there, this is one of the top ten most important. However, there are in some parts of the United States vehement opposition groups to the practice. We are really nowhere close to achieving higher levels. We've been in the 60 to 70 percentage area of people having access to community water fluoridation in the United States for quite some time now. It's actually, unfortunately, and depending on how you look at it, going down. That is to say, the per the proportion of folks that have regular access to fluoridated drinking water is actually decreasing in the United States, despite the fact that there is quite a lot of data showing the benefits. And many of us experience those benefits without even thinking about it. So with that, we're going to dive right into the history of water fluoridation. Now, our story, this nice public health story, really starts around 1901. There was a young dental school graduate named Frederick McKay who comes to Colorado, Colorado Springs in particular, and when he gets there, he's really uh surprised at what he finds. He sees that many, many, many of his patients, nearly all of them actually, had a very distinct brown staining on their teeth that was permanent. He couldn't get it off, he couldn't do anything about it, and he had not really seen a whole lot about it. Sometimes he said the teeth were splotched with the color of chocolate candy, yet it wasn't chocolate, it wasn't anything like that. But he had really not seen a whole lot about it. As he looked in the literature of the time, he didn't really find any mention of this brown-stained teeth. So he starts asking folks, hey, what's going on with this thing? What's this particular problem? And there were all kinds of theories in the community. The community had certainly recognized this, but they said, well, it's because people, some people eat too much pork, some people eat inferior or adulterated milk, which at the time in the United States was quite a problem and a growing problem. Other folks said, well, you know, the waters here have a lot of calcium in it, and that's what it is. It's really, really an interesting problem. It comes to be called Colorado brown stain. And a lot of folks really were perplexed at what this was. And so uh Frederick McKay actually starts looking at it and trying to research what's going on with Colorado brown stain. And as he does, he does notice that folks that exhibited this brown staining phenomenon seem to be more resistant to dental caries, cavities. Now, at that time, it was very, very common for people to have a huge number of cavities. Remember, this is an era before most of the oral health interventions that we do today, certainly an era before Florida drinking water, of course, but toothpaste are not available, certainly mouth rinses and a lot of those preventive type things that we do in dental care and personal care were not available. So is this a really, really, really big deal in oral health at the time. Um, and even today, cavities continue to be a problem. And anything like this that decreased the likelihood of cavities, as McKay observed, was of great interest to the dental community. Dentistry had really moved into the modern era at that point, and so folks are very much thinking scientifically. Around the same time, 1901-1902, in Naples, Italy, there was a surgeon named John Eager, who worked for the U.S. Marine Hospital Service, and he largely is doing medical examinations of prospective U.S. immigrants. Now, in this uh capacity, day after day, he observed otherwise healthy men and women whose teeth had a mottled brown stain. Other teeth that he saw had black lines that ran kind of horizontally across them. The Italians, the locals there, had named the conditions dentineri, uh, you know, dark teeth, or dentiscriti, black uh written upon teeth. So black teeth are written upon teeth. And John Eager had never seen anything like it. He asks his superiors, the Marine Hospital Service is kind of set up in a military fashion, so he asks his boss, they don't know. And he publishes some of the first scientific descriptions of these blemises, and he doesn't really have much evidence as to what caused them. Remarkably, without any evidence, without a whole lot of research, and of course independent of McKay, Eager hypothesizes a connection between folks that had these conditions and the local drinking water. Now, uh meanwhile, back in Colorado, as Frederick McKay looks into it, he starts going into the schools. This is an era of public health nursing and some of the school health programs, particularly at that time in Colorado. And so he's able to collaborate with them and get a good overall picture of what's going on. And he finds that about 80%, 80 to 90 percent, depending on what you look at, of the town's school children seem to have this brown stain. And as he expands his investigations, he finds that that staining really wasn't limited to Colorado Springs, which importantly is one of the more wealthy cities at the time. A lot of communities throughout Colorado seemed to have a good number of students that were experiencing this particular issue. And uh rich or poor communities both seem to have folks that were getting this, again, was not seen in other parts. And so Black keeps reaching out to other communities, getting reports, talking to a wide variety of folks. And in 1909, uh renowned dental researcher, Dr. G. V. Black, agrees to come to Colorado and take part in these investigations. Now, G. V. Black is an important person in dental history. He is thought of kind of as the father of modern dentistry. He comes up with a variety of classifications, and he is a fairly well-known dental researcher at the time, as today. Uh, his full name is Green Vardaman Black. Again, I love these names of that era, Green Vardaman Black. And he agrees to work with Black, uh, with uh McKay in these areas and collaborate with him on the mysterious ailment. Now, first, Black really had scoffed at the whole thing. He said, you know, that it's impossible that a disorder like this could go unreported in dental literature. I mean, this is so obvious, and so many kids have it. But he comes west after the Colorado Springs Dental Society also conducts a study really along McKay's lines that shows this there's 80 to 90 percent of the of the city's locally born children have these stains. And when he gets there, he's shocked by how many people have this, and he really gets into it. And he doesn't just do the formal investigation. He actually says that he walks the streets noticing children playing, and he'll glow up to them and talk to them about their game so that he can look at their teeth. And he found it prominent all over the city. So you don't have to search for it. This is really an unusual thing. So McCain and Black investigate this situation for six years or so until 1915. And during that period, they make a couple of important discoveries. They showed that the modeled enamel, as they started referring to it, resulted from developmental imperfections in children's teeth. So that meant that people that lived in Colorado Springs and these other affected areas whose permanent teeth had calcified without developing the stains did not later have their teeth turned brown. It was children and it was during the development. So they were they very were really, really sure that it was young children waiting for their secondary set of teeth to erupt, that uh were having the problem that led to this brown stain. Second, they really were able to quantify that uh children, particularly younger children, uh, that had this situation going on, were very surprisingly and to them inexplicably resistant to decay. They don't know the cause, they don't know what's going on, but they start thinking of theories. And McKay writes about it, although he can't really prove it, and he doesn't do a whole lot of investigations, but he has a theory that there might be an ingredient in the water. I mean, Black was skeptical throughout the whole period. McKay is thinking about it, but again, they can't prove it. They do some laboratory investigations of water, but with the laboratory technology of the time, the water did not seem to have anything unusual in it. And of course, a lot of the tests they're able to do are not really the detailed chemical tests that we might be able to do up to date, or even later that's in the 20th century. So they're really missing a lot. But the water causation concept gets a big boost in 1923. McKay in that year uh goes across the Rocky Mountains to a place called Oakley, Idaho, to meet with some parents who had also noticed these brown stains on their children's teeth. And these parents start telling McKay that the stains began appearing shortly after Oakley built a new water pipeline, a communal water pipeline, to a warm spring that was about five miles outside the town. McKay analyzes the water, doesn't find anything suspicious, but he does advise the town leaders to just abandon this pipeline and use another spring as a water source. Now, McKay's advice was followed, and McKay checks back several years later, and he notices that the younger children of Oakley now are sprouting their healthy secondary teeth without any of this Colorado brown stream, without this modeling that was going on. So it's really interesting to Dr. McKay, and he's he is convinced that there is a water connection in this particular disease state, but he d still doesn't know what's going on. He doesn't know what's wrong with the water. Believe it or not, McKay does take a trip in 1927 to Naples, Italy, and he does see the same thing. He discovers children in one district who no longer showed evidence of this particular disease, and he starts inquiring why are there so many children in Naples that that had this particular issue but don't seem to have it in this one district or Naprous? And it turns out that that particular district, just a few years before uh McKay's visit, had switched their water supply to another source. So in McKay's mind, it's pretty well established now that there is a water connection, but they don't know what it is. Much, much later in the early 30s, McKay and a guy by the name of Grober-Kimpf, Dr. Grober-Kimpf, who is with the public health service, the U.S. Public Health Service, goes to Bauxite, Arkansas, which was a company town owned by the Aluminum Company of America, Alcoa, and they had been brought there to investigate reports of these brown stains in folks presenting to the company clinics and public health service officers in the area. And these two guys find something fairly interesting. It was very prevalent in this town called Bauxite, Bauxite, Arkansas, but did not exist at another time, just five miles away. So McKay looks at the water supply and can't find any clues, but they do publish McCain Kempf, this report of their visit to Bauxite and what they found. And that report reaches the desk of Alcoa's chief chemist, a guy by the name of H. V. Churchill, who was at the company's headquarters back in Pennsylvania. Now, Churchill had been working on a lot of chemical public health interface. He'd worked on claims that aluminum cookware was poisonous. Of course, it's important to the aluminum company of America. And he wanted to look at this particular issue, partially simply because he didn't want another situation where people are thinking the certain minerals were poisonous, certainly in a company town. So he conducts his own tests of the water in bauxite using a new technology, a kind of a spectrographics, photospectrophic analysis, which is a much more sophisticated technology. It's one of the earlier uses of this chemical technology, which was not widely available, certainly wasn't available to McKay. And he actually specifically tasked one of his assistants to assay this. And it takes several days at that time, but there was a fairly surprising result in the water analyses of the water from bauxite. They observed that the town's water supply had very high levels of fluoride. Churchill didn't believe it at first. He actually told his assistant he had contaminated the sample and get another specimen and repeat it, which they did, and they they really can't believe it. And so he writes a letter to McKay demonstrating what he found. Now, fluoride, of course, is a naturally occurring mineral. It does occur in water supplies, depending on where the water's coming from, surface water versus deep wells versus other sources of water all over the planet. Most of the time, the concentrations in terms of parts per million are fairly low or nondetectable. Seawater, generally speaking, has a concentration of about 1.2 to 1.4 parts per million fluoride in it. You do see it range from about 0.2 parts per million, .3 parts per million, all the way up to about 12 parts per million in some parts of the United States and other parts of the of the world. The water in bauxite, where we had all of these mottled teeth, and interestingly, fairly few cavities for folks of that socioeconomic status, was 13.7 parts per million. Extremely, extremely high. And so he definitely, Churchill does, thinks that this is a significant finding and it might explain what's going on. So he writes maybe a five-page letter to McKay. He tells McKay to get water samples from other towns where he has seen this Colorado brown stain. And we really want to find out what role fluorine plays in this matter. So McKay does this and goes all over these various towns in the West where these higher incidence of Colorado brown stain were found, sends that water back to Pennsylvania, back to Churchill, and very, very rapidly, I mean, within months, they find out that the one consistency in all of these water samples are higher levels of fluoride. It did vary what the concentration was, but it's really, really, really high. So it does seem to be that is what is causing this discoloration of uh tooth enamel, which they ultimately publish. But at the time, very few folks really know exactly how and exactly why this is happening. And they don't have kind of the big picture epidemiologic investigation that they wanted. So they're really, really interested and concerned. And along with this, they keep collecting data, both in the public health context in schools and in various dental private practices, of the decreased incidence of cavities in children who are in these areas where the high fluoride fluoride content water is found. And indeed, they find similar things in many of the adults. And they start looking to identify more and more pockets of this and finding more and more areas where we can find this particular thing. Around the same time, all these questions, the relatively new National Institutes of Health had hired its first dental researcher, its dental officer, a guy by the name of Dr. H. Trendley Dean, who ultimately became the head of the dental hygiene unit. Now, when I say the head, at first he's the only one, but they do build a dental hygiene unit, the National Institutes of Health, and his area of expertise rapidly focuses on these preventive dentistry type things. And he gets more and more interested and definitely puts a lot of effort in determining how high fluoride levels could be in drinking water and how much, how common this is, how much fluoride it takes to cause the problem, what the overall prevalence. But they have a problem. They don't have a real practical field method or widely acceptable method to measure fluoride levels. Not to mention, they don't really have a grading scale, a way to look at cavities that might lend itself to this type of analysis. You just kind of have, well, did you have cavities, no cavities? And so he develops a cavity metric. And this particular metric looks not only at the number of cavities, but where they are. Are they missing teeth? Where they're filled teeth at a time. So you can do cross-sectional studies, right? You can look at a point in time and say, well, this person's got so many cavities, so many teeth missing, and so many fillings, and put all that together as an indication of their overall oral health, which allows you to kind of look at a much, much broader swath of children and adults in the United States. He has an assistant really work on this chemical analysis to develop a method to measure fluoride levels consistently down to 0.1 parts per million, which is really, really uh low, really, really hard to do, but he does do this. And with these two things, he sets out to analyze fluoride levels in drinking water across the United States. And by the late 1930s, he had completed quite a lot of surveys across the United States, and he and his staff have made a critical discovery that fluoride levels up to about one part per million. Remember, now that's still 13 times, 14 times less than they found in bauxite. But uh fluoride levels up to one part per million did not cause this brown modeling. And if it did, it was only kind of mild compared to what they had found in other samples of teeth and of people. And he renames this discoloration, this pathology fluorosis. And so that is the name for this particular condition that we use today, right? So now we have pretty good information that the issues are related to drinking water. We have pretty good information that it's related to high levels in fluoride in drinking water. And of course, the research goes on, but uh, you know, history intercedes, right? Not too long after all of those observations are completed. Why we have this little thing called World War II that happens. And Dr. Dean wants to do uh a variety of these health investigations. And there are two things that happen. One, there is with the coming of World War II, this increased emphasis on public health and the health of younger people, because we need folks to go into military service, right? We need a huge number of people. We also need healthy people to work in the factories that are going to produce the war material. So there's a lot of interest, particularly from the government in these public health investigations and understanding. Because as you might imagine, your oral health, your dental health, or in in military terms, your dental readiness, as we call it today, can be an important thing. If you get somebody whose teeth are severely decayed or whatnot, you they may not be well suited to come into military service because you may have to miss time for that. And if you're in an austere environment, right, there may not be a dentist readily available, or if you have significant teeth problems, you also can't potentially eat or do some of the other things you need when you've got this stuff going on. In an austere environment, this is a pretty severe problem. Looking at oral health has long been a part of military fitness and military interest requirements, going all the way back to the Revolution. Certainly, Civil War was a big deal, because you needed to have at least one tooth on the top and the bottom, even at that point to bite open cartridges that you might use. So there was a lot of that. So Dean gets funding to do several epidemiological investigations, including one that is now famous, 21 City study, where he very much establishes that the modeling of the teeth was rare at fluoride levels of one part to a million or below, while they were able to get that preventive effect at that level. And so he publishes that work in 1942. Meanwhile, over in England, of course, they have the Blitz, the bombing campaigns by the Germans on England, particularly the industrial towns, the Capitol, other places are bombed relentlessly by the Germans, and the British are forced for safety reasons to evacuate children from towns to other places. So they went from some of the industrial towns to more rural towns where they might be safe from this bombing that was going on. And with that, really British society and the way it's taking care of its children are different, right? The children are not with their parents. They are guests wherever, and there's new schools set up, and there are new health facilities set up to take care of these children that have been relocated from the cities. Most of this is being done by the government to facilitate this. And he and there is a guy by the name of Robert Weaver, who's a dentist working for the British Ministry of Education. He was aware of the American work and has the flooring contents of the areas that he was looking at analyzing, it proves to be around 1.4 parts per million, which is higher than a lot of the other water supplies naturally occurring. He has a lot of folks that are evacuated from a place called South Shields, an industrial town on the River Tyne in northeast England. And they were evacuated to a lake, to the what's called the Lake District there. And so he has that fluorine content of South Shields analyzed, and it proves to be, like we said, around 1.4, but much higher than his presence in other things. He has North Shields on the other bank of the Tyne analyzed, and there the fluoride content was only about 0.25 parts per million, right? So he exams a thousand children on either side of the Tyne River, and he demonstrates much lower decay rates, both in permanent teeth and deciduous, or the baby teeth, in the South. So he really describes these effects on what they call the primary dentition. So it's really, really clear that things are very closely related and that changing the exposure that young children have as their as their permanent teeth are developing to fluoride seems to be able to head off cavities. So in 1944, there is a pitch to put all of this knowledge into action. And in that year, the City Commission of Grand Rapids, Michigan, after really a long series of discussions with the Public Health Service and other researchers, decides to engage in an experiment where they are going to add fluoride to its public water supply in 1945. So the authorities arrange to collect data on all the children in Grand Rapids and have very detailed analyses of the dental epidemiology and the dental health of the children in the community, as well as the fluoride levels in the water in the community. They also collect data from two other cities. One, Aurora, Illinois, which was relatively close and somewhat similar demographically to Grand Rapids, Michigan, with one big difference. Aurora, Illinois had a naturally high level of fluoride in its drinking water, whereas Grand Rapids, of course, did not. And then they compared to another Michigan city, and this was a very similar city to Grand Rapids, but of course was not going to engage in the fluoridation. So they start looking at water fluoridation. And in 1945, Grand Rapids starts fluoridating its water supply and monitoring that. There was the neighboring town of Muskeon, Michigan, which did not. So they compared both those, and then, of course, Aurora, Illinois, as we said. By 1950, they looked at the interim data. Now the study was supposed to run all the way to 1960 because you could get a long swath, right? These prospective studies, the gold standard for looking at it. We have a population with an intervention, a population without an intervention to compare, and in this case, a third population, right, that that is getting that naturally. And in the 1950 interim data, they were really, really, really surprised at how much change they saw in the children of Grand Rapids, Michigan with respect to their oral health. When they started, some of these children were having between eight and even 16 cavities, depending on how old they were. And in some cases, in some age groups, actually eight-year-olds most significantly had a decrease in the incidence of dental cavities or evidence of dental cavities, right? Fillings and missing teeth, in some cases by two-thirds. It was really, really remarkable over this five-year period. Other age groups saw more or less. Again, younger children didn't see as much because, of course, their permanent teeth hadn't emerged, and older children didn't see as much benefit, but of because, of course, the experiment had started after a lot of the development of their permanent teeth had already happened in their mouths. But as they went, it was so much so that uh city officials in Muskion decided to pull out of the study and start fluoridating that town's water supply. They just didn't think it was ethical to go on, knewing what they knew that, wow, this is such a useful intervention, they couldn't believe it. At that point, many public health authorities, as well as many medical societies, the American Medical Association, the American Dental Association, the American Public Health Association, the new Association of State and Territorial Health Officers, all which still exist today, were convinced. The Surgeon General is convinced and says, really, there's no doubt that many of these children have been spared tremendous pain and suffering and huge numbers of cavities. Overall, it was at least a quarter fewer cavities across the board. Again, it varies from age to age, how much, but it is a huge benefit. And these are very large populations. I think overall there's like 30,000 school children that are involved in the study. Now, the public health service continues to monitor these children, do a lot of things on this particular study, although the control group in the neighboring town doesn't have a control group. The other thing they did was very much analyze the rates of the cavities, the overall cavity incidence and compare it to Aurora, Illinois. And they they found that as time went on, the population of Grand Rapids seemed to have an incidence of cavities that approached and seemed to mirror that of Aurora, Illinois, which had a relatively low prevalence of cavities. So they definitely saw at this point, there's really no question. This is all the societies lined up, the data lines up. We have a prospective trial, which is actually not all that come. You don't always have the opportunity to do those kinds of things. And many towns across the United States start fluoridating their water in the early 1950s. And this is where things kind of change a little bit. All of the authority to fluoridate local water supplies before 1965 resulted from actions of a local entity, a local water board, a local commission, city commission or county commission, or whatever. It was all a local authority with the federal government serving primarily as the research and guidance agency, along with the other medical and public health associations. The 1965 date is important because it was in 1965 when the state of Connecticut actually passes a state-level law requiring fluoridation of any town that had 20,000 people in it or more. But before that time it was all local. They all oppose that bill, but there's some very significant organized opposition. There is an anti-fluoridation society that is formed in Washington, D.C., and then spreads in its chapters around. But there are some vehement public health experts that all line up in support of stopping this bill, right? To oppose the banning bill, not the least of which is a young congressman who's the first person to testify on the congressional bill by the name of Gerald R. Ford, the future vice president, indeed, future president of the United States. And Ford comes before the committee and he says, you know, I'm not a scientist, but I represent part of this community in Michigan that has had this wonderful success, and they are really, really proud of what they were able to do and would really, really oppose any federal measure that would prevent this from happening. They want to keep doing it. And people are very grateful to Congressman Ford for his testimony. And while a lot of the scientific investigations are entered into the record, most of the debate centers around federal authority. Does the federal government have the authority to tell people yes or no? Who's in charge of doing their own things? Does the federal government have the right to intrude on these state or local at that time decisions? Right? Very much a lot of the same discussions about various things that we have today. That bill, of course, is defeated, and fluoridation continues. However, there are several other organizations that continue on in opposition to all of these activities. They tend to start being organized at a federal level, but taking action in communities. After the Federal bill is defeated, there are other bills that come up, but after the federal bill, then there are concerns voiced about the cost to water systems, very costly, right? Isn't fluoride corrosive and won't it destroy the pipes? And of course, the water folks really shut that down. Say, no, we can handle this. It's very simple. The sodium fluoride at that time is what they put in mostly, not so much today. They say we can just adjust the pH of the water, it's not a problem. And then they come up with a variety of other ways to oppose this fluoridation effort that's taking hold across the U.S. And while the number of water systems and the number of people that have access to fluoridated water continues to go up, there is a theory that this mass fluoridation is really the result of a communist plot, and that it's there to put chemicals in the water that will make the American populace passive and will make them more vulnerable. And of course, there's not any truth to this, but there's a lot of folks that buy into this theory, and there's a lot of information. I mean, famously, uh it is even mentioned in the movie Doctor Strangelove, right? General Ripper, the general that's trying to go ahead with all this, says, you know, don't you know about fluoridation? It's the biggest communist conspiracy that there is, right? They're kind of poking fun at this really large-scale opposition, and it shows up all over the country. And there are groups that say this is the new red warfare, and it's more effective than the atomic bomb. And of course, that ultimately over time gets beaten back. But that's one of the early oppositions that goes up, which is I find also interesting because uh, you know, towards the end of the Soviet era, there was openness, and there were some U.S. and Western scientists who were able to analyze the fluoridation practices in the Soviet Union before it all fell apart. And particularly in Moscow and Ludigran, they actually did try to fluoridate their own water, and you know, there were quite a lot of samples that they took trying to do it, and they never could get it quite right. They were putting fluoride in the water, but that, like so many other things operationally in the Soviet system, just didn't work. They weren't able to pull it off, and they tried to get a concentration of about 0.8 uh parts per million, which is very similar to what we use in the United States today. We use 0.7 parts per million as kind of the optimal fluoride level in drinking water today. But uh most of the time the actual fluoride level in their drinking water in Leningrad and Moscow and other places was about 0.3 parts per million. Even they were, they were supposed to, they were ostensibly going for 0.8 parts per million. They just couldn't pull it off. So it's interesting to think that they could pull it off in our country when they can't pull it off in in their own. And it is later that there is quite a lot of additional opposition that tries to be mindful of potential health effects. And a lot of these health effects early on were significantly exaggerated, and you had a quite a lot of misinterpretation of different reports. You know, by 1962, the public health service is recommending the public water supplies team. The public health service finishes the Grand Rapids project and really shows very significant decreases in tooth decay across the board in the areas that it affected. They recommend that public water supplies contain between 0.7 and 1.2 parts per million fluoride, and so that's kind of what's going on at that point going forward. As we said, Connecticut in 1965 passes ultimately 13 states pass various laws, but in most cases it's still relatively low. There is quite a lot of studying of these various phenomena related to fluoride. One other thing, of course, the Food and Drug Administration is there, and one of the quirks of the way the regulatory apparatus works in the United States is that public drinking water is these days is largely regulated by standards set by the EPA, and then various states or locals, depending on how they're structured, try to comply with those standards. But the enforcement is generally state and local activity. And it's more they have some quality standards, right? So the level of floor can't exceed a certain level, but they don't Don't tell you that you have to put it in. They just recommend that. But in all cases, you can't have the amount of fluoride in drink water exceed a certain level. Right now, that is four parts per million because that is the level above which you start seeing what they call skeletal fluorosis, changes in bones throughout the body because of high levels of fluoride. Now, again, this is uh, depending on your water system, at least four times higher, uh, maybe significantly more, maybe five or six times higher than the amount that they consider optimal. And then the FDA actually also has a standard for bottled water. Now, again, we said the regulatory thing is is different. Drinking water is regulated one way. Bottled water uh is in fact specifically regulated by the FDA, not other agencies, not the EPA. And they have two standards that they set for bottled water with no fluoride added. The maximum fluoride level kind of varies, but it will allow up to 2.4 parts per million, depending on the weather conditions on where that product is to be sold. Uh they do that because different areas, weather conditions can affect the storage temperature of the water, which affects how much fluoride can be viable in there. Uh so it does change depending on the weather. For bottled water with added fluoride, they have to make sure that the maximum allowed is 0.7 parts per million, which is the current public health service recommendation for water fluoridation. So there was some opposition saying, well, people can't do this, it's not clear that these various levels look bottled water, not understanding that, well, the FDA said one thing and the other regulator said another thing, and both were complying. And but both of these things were far, far, far lower than anything known to cause any sort of adverse health problem. Now, uh one of the other things that that starts being brought up is a connection between potentially certain forms of cancer, particularly bone cancer, osteosarcoma. This really starts in the late 80s and the early 1990s after a study evaluated by the National Toxicology Program, which was released in 1990. These researchers said that they found what they called equivocal evidence of cancer-causing potential of fluoridated drinking water in animals, rats mostly, particularly male rats. They repeated the study in mice and didn't find it in either female or male mice. But people seized on this, and there were other studies done, and a lot of people started trying to see the National Toxicology Program said there is equivocal evidence, not really understanding that the word equivocal in the NTP's way of using it meant uncertain. So the most compelling evidence that was uncertain level, there's really nothing to worry about in these, and a variety of other types of studies were done, particularly looking at osteosarcoma, which in and of itself is very rare. About 500 osteosarcomas are diagnosed in children or teenagers every year. So it's, you know, given the thousands indeed nowadays, millions and millions of children that are spoken to fluoride in the water, it doesn't really make a whole lot of sense. It's going to be hard, but they definitely looked at these problems in a variety of ways. A lot of groups looked at them, a lot of individuals looked at them. The International Agency for Research on Cancer said fluorides are non-classifiable as to their carcinogenicity because they just don't have any consistent tendency for people in areas with high concentrations of fluorides and water to have higher cancer rates. They just never saw that. And there's really low quality evidence. In 1991, the Public Health Service goes back and issues another report on benefits and risk. They see that the few studies available of any sort of large scale failed to establish an association between fluoride and cancer. They looked at a variety of population-based studies and found really nothing. The National Research Council looks at this. The National Health Service in England looks at it. There's various European committees, European Scientific Committee on Health and Environmental Risks. And the in fact, State of California has its own that as recent as 2011. They have the carcinogen identification committee. They reviewed the evidence and said there was none. So there's a lot of them. And once it is found that really there is absolutely no data to support the idea that fluoridation of drinking water or fluoride exposures within these optimal levels cause cancer. So then the opposition to fluoride, particularly fluoride and drinking water, shifts. And it shifts again to saying, well, the studies are older. We now have more fluoridated products, right? We have fluoridated toothpaste. There are other fluoride. And they said, look, the tooth decay has gone down all over the world, and several communities across Europe, about half of them, some do, some don't, and other countries of the world have also seen this decrease, and they're not fluoridating the drinking water, although some are. So obviously we've got other things to think about. Interestingly, particularly in Europe, there are other ways that fluoridation was given to young children. There's a milk fluoridation program. We don't see that widely in the United States, but we do see it in other countries. The UK in particular did it and saw great effects where they put fluoride in milk rather than water. The certain European communities also would fluoridate salt. That was studied extensively in Switzerland. Spain has it and other things. So some of these places that didn't necessarily fluoridate their water might fluoridate other products to which people were exposed pretty routinely. And so the fluoride levels that these people were exposed to were still within an optimal level. So this, well, they don't do it, and they're still seeing it kind of is a little bit hollow. There is some fluoridation of water supplies in Europe and Australia and other places too. And we talked about in the Soviet era. So this does happen in other places, but there's this opposition that is out there. Then it shifts, and one of the more recent areas of opposition, again, kind of starts with a national toxicology program that talks about potential for reduced IQs or other neurodevelopmental problems in kids exposed to fluoride, which is an interesting take. They cite a variety of studies, including, like we said, an NTP that says this may be a thing that looks at. And there were several studies conducted, mostly in China, but others that showed this particular reduction in IQ. Now we're talking less than one point in some of the studies. And when you dig into the studies, they're really small, they're low quality. There's a little bit of problem with controls because some of these studies are done in areas where we have high natural content of fluoride in coal, and the coal is burned. Air quality standards may not be the same as other places. So the effective exposure to fluoride is way, way, way, way, way high. Again, that's the optimal range that we try to standardize our water supplies to here in the United States. In fact, I looked at several of these studies, and a lot of them start analyzing effects on children when the exposure is at 20 parts per million or 40 parts per million. I mean, if it's 20 parts per million, right? I mean, that's 20 times this one part per million kind of threshold that they discovered uh nearly 100 years ago. And, you know, even more than the optimal fluoride for U.S. water supplies, which is about 0.7. What health organization uses between 0.7 and 1.2, the original public health service recommendation. The U.S., after 2015, we said 0.7, 0.7 parts million, is the optimal fluoridation level. So it's really interesting. They're very low quality. And also one of the observations, whether it's the Cochrane Review or Public Health Service, or all these entities are looking at some of these newer studies, they also said several of the studies had a high risk for bias. They don't have all the data, don't have all the information, so they can't prove definitively, but they note that there is a risk for bias. And when they say bias in these things, they mean statistical bias, right? A systemic way that that data was collected or the population was structured that would lean one way or another consistently in the observations, not like a prejudicial kind of bias. But in the studies that had a high risk of bias because of their study design or the population studied or the way that it was done, so on, is where they saw these neurodevelopmental problems in the study, and there weren't that many of them, but there was one or two that had a low risk of bias. They did not show any of these connections. So the studies are really poorly done, and this has been pointed out. And again, the National Toxicology Report specifically mentions that there is nothing that they saw that definitively shows a link between the fluoride exposure and health at the levels that are common in the United States. However, they do acknowledge that there were studies that said that. Now, they again they point out that those studies were low quality and have high risk for bias and all of this. But that then got seized on, and then there's the anti-fluoridation and the fluoride action network and all these entities that will use that to advocate for the removal of fluoridation. In one large city, Portland, it's actually been a very aggressive and heated debate. There were some opponents who had their houses firebombed as various referenda go forward on whether or not to water to fluoridate the water supply. Currently, their water supply is not fluoridated. These neurotoxic effects are are all over the web. You can Google it and you can see it. And again, a lot of them go back to these very poor studies or to the to the report on it. There's been a 10-year court battle between this fluoride action network, which is nationally active, but I think it's based on the West Coast, that was released in uh November of 2024, where the Fluoride Action Network sued the EPA to force them to look into the fluoride data. EPA had resisted this, saying we've this is basically a solved problem. We've studied this tons, it's a better use of resource not to, right? This is going back and forth for 10 years in the courts. The Fluoride Action Network keeps saying, well, the studies you're looking at are old, and of course, all studies are older than when you look at them. They're all done before they're published, and by the time they're published, you read something that's looking back. So that's kind of an interesting argument. And they they look at this national toxicology program report, which is very intentional now. It's not come out in one report, it's come out in phases, but they are very clear that they don't see anything definitive that shows that there's any risk to the public health from these activities. But nonetheless, the court uh in November 24 said that yes, there were studies that uh indicate that there was a risk, and therefore the EPA must look at it. However, and they specifically write this, there is no indication that there is a risk to the public health. There's no indication that there's actually a problem here. The regulatory world, again, our uh the standards in the United States are set by EPA. The way their rules are written is that if there is a study, they have to look into it. Not they have to look into it after there is a definitive link. And so the Fluorid Action Network, and you see this now. I live in Tennessee, and there's actually a bill before our state legislature in the upcoming session to ban fluoride treatment. Even though we have some of the cities that are the earliest, Milan, Tennessee, a small town in West Tennessee, started fluoridating their water system in uh 1951, Paris, Tennessee, started doing it in 1952. And it's interesting, a lot of the cities, there's some cities north of Boston that are you see a lot of fluoride opposition, these are some of the first cities to do it after the Grand Rapids study. And now that's where you're seeing these oppositions or uh originate from, and it all comes from, I think, some misunderstanding of regulatory speak words to the way these words are used in common language and in people trying to spin these things for their own. Interestingly, there have been some other recent things, so IQs might go down nationally, and it's interesting there's something called the Flynn effect, where we've seen, we think, in the last several decades, the average IQ of children in the United States increasing over the period of time, which coincides very closely with uh the period of time that the proportion of children being exposed to Florida water supplies has been increasing. This peaked out in the early 2000s, as we said, it's been decreasing. Interestingly, the Flint effect has been seen to end, and the average IQs were slightly lower in the last uh ten years than they had been previously. So that certainly doesn't align with any sort of neurodevelopmental or neurodegenerative uh issues with fluoridated water, and we would have seen it with large numbers. But these debates are still out there. I think it's a great story of using these data from starting with heads-up clinicians to the academic and public health community to larger studies to a policy action, but the ongoing, I think, controversies that can surround these kind of issues. And it's a great, great story of that going on. So I hope you've enjoyed this episode. We'll have another one, not too long, here on the Filth of America podcast. Take care of yourselves, everybody.