3 ms·

>The safe levels are built around a model of the amount of water a human being can consume, both directly (drinking tap water) and indirectly (cooking, drinks m

by gojomo 2y ago

>The safe levels are built around a model of the amount of water a human being can consume, both directly (drinking tap water) and indirectly (cooking, drinks made with tap water, etc.). The epidemiological studies suggesting detectable harm at 1.5mg/L are from whatever amounts are actually consumed in affected areas, not some "model" of the max any person could consume. Given the variety of human practices – preferences for packaged drinks, different food-preparation approaches, etc – the same tap levels could easily result in gigantic differences in net consumption among different individuals. If the standard is half the "safe" level, but some people consume 4x or 10x as much tap water, & perhaps even have a higher baseline of non-tap-water flouride consumption, then some percentage N of the population could be developmentally-harmed, even at levels "safe" for "most". How high of an N should we accept for the modest benefit of fewer cavities? Your link shows no public benefits other than less tooth decay, doesn't compare flouridation to other interventions, & doesn't weigh costs versus benefits. If I'm reading its "DMFT Index" ("Decayed, Missing, Filled Teeth [per capita]") values right, it also shows a very modest benefit: a "DMFT" of 0.06 in flouridated areas, and 0.115 in non-flouridated areas. Roughly, instead of one cavity-affected-tooth per 17 kids, there's one cavity-affected-tooth per 9 kids. Yes, we should try to minimize cavities, but what N% of outlier-consumption overflouridated kids should get a 5-IQ-point drop for that marginal benefit? What if we shifted the flouridation expense into reminding kids to brush or use a flouridated rinse? What if we just paid a cash bonus to kids who manage to avoid permanent-tooth cavities through whatever interventions work? (The same funds would go to treatment/amelioration for those who wind up with decay anyway.)

fzeroracer 2y ago
> How high of an N should we accept for the modest benefit of fewer cavities? You do realize dental issues kill people, right? If you are going to be actually honest in your argument, then you should be comparing the # of people that die as a result of poorer health outcomes as a result of dental complications versus the band of people having overexposure to fluoride especially since you immediately jump to the worst possible outcome on your end of the argument.
- gojomo 2y ago
  Yea, all the costs and benefits should be weighed! I suspect a lot more people die over their lifetime from being -5 IQ than cavities. But, let's be sure all the effects are net-tallied – not just an unquantified hand-wavy "saves lives via dental health" with zero consideration to any stupidity or behavioral issues created.
woodruffw 2y ago
First, three procedural points: 1. You're presumably talking about the HHS review in your adjacent comment. Here's the actual monograph[1]. Notably, the review's authors consider it a "medium confidence" finding. In the NTP's taxonomy[2], that makes it a lower impact conclusion than the voluminous findings that show that fluoridation at 1.5mg/dL (much less 0.7mg/dL) has no adverse developmental effects. 2. The monograph is explicit about the limitations of its conclusions. In particular, the monograph explicitly says that it doesn't offer a quantitative account of fluoride-for-lost-IQ-points, and explicitly concludes that its findings do not address fluoridation at levels used in the US or Canada. 3. The monograph is focused on fluoridation at or above 1.5mg/dL, with extensive consideration given to much higher fluoridation levels. As a whole, the monograph doesn't not present the cohesive, "closed case" for a relationship between municipal water fluoridation and developmental risk that you're suggesting exists. At best, it presents a body of evidence showing a moderate correlation between negative developmental effects and natural/dietary fluoride consumption at levels that are 5-10x times the level introduced in the US. > If the standard is half the "safe" level, but some people consume 4x or 10x as much tap water, & perhaps even have a higher baseline of non-tap-water flouride consumption, then some percentage N of the population could developmentally-harmed, even at levels "safe" for "most". First: neither your source (nor any source I'm aware of) shows developmental effects in adults, i.e. a general population sampling. Not even at extremely high naturally occurring fluoride levels. However, even if we reduce to children, neither your source (nor any I'm aware of) shows a multiplicative effect to fluoridated water consumption. In other words: children in areas with 5mg/dL of naturally occurring fluoride appear to have blood levels that consistently correlate with that natural level, regardless of variations in dietary patterns. The parsimonious explanation for this is that fluoride doesn't bioaccumulate in soft tissues and is mostly excreted when not accumulated in teeth and bones, which research supports[3]. The TL;DR for this is that there's no positive evidence (and a lot of negative evidence) for differences in consumption during normal human activity having any effect on blood/urine fluoride levels. Baseline changes result in changes; volume does not. (This ties in with the earlier point: you can definitely increase the amount of fluoride in your system over a point in time by, say, drinking 3 cups of green tea in a row. But children aren't doing that, and their most accessible equivalent - drinking water - is not something that they can chug liters of at a time.) > Roughly, instead of one cavity-affected-tooth per 17 kids, there's one cavity-affected-tooth per 9 kids. I personally wouldn't describe that kind of reduction as modest. On the city scale, that's thousands of dental procedures averted per year. Factored with differences in dental care (e.g. childhood cavities correlating with worse adult dental outcomes), and you have an expensive, easily preventable public health problem. > What if we shifted the flouridation expense into reminding kids to brush or use a flouridated rinse? Brushing reminders and basic dental hygiene are exceedingly well-messaged in developed countries. Despite that the problem remains, as evidenced by studies consistently showing differences between fluoridated and un-fluoridated populations with generally good dental practices[4]. I suppose we could always spend more on educating parents and children on good dental hygiene. But municipal fluoridation is cheap, effective, and most importantly pervasive: it addresses the last X% of the population that can't or won't practice good dental hygiene. [1]: https://ntp.niehs.nih.gov/sites/default/files/2024-08/fluoride_final_508.pdf https://ntp.niehs.nih.gov/sites/default/files/2024-08/fluori... [2]: https://ntp.niehs.nih.gov/sites/default/files/ntp/ohat/pubs/handbookclarificationmarch2019_508.pdf https://ntp.niehs.nih.gov/sites/default/files/ntp/ohat/pubs/... [3]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7261729/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7261729/ [4]: https://onlinelibrary.wiley.com/doi/10.1111/cdoe.12685 https://onlinelibrary.wiley.com/doi/10.1111/cdoe.12685

by gojomo 2y ago

fzeroracer 2y ago

> How high of an N should we accept for the modest benefit of fewer cavities? You do realize dental issues kill people, right? If you are going to be actually honest in your argument, then you should be comparing the # of people that die as a result of poorer health outcomes as a result of dental complications versus the band of people having overexposure to fluoride especially since you immediately jump to the worst possible outcome on your end of the argument.

gojomo 2y ago
Yea, all the costs and benefits should be weighed! I suspect a lot more people die over their lifetime from being -5 IQ than cavities. But, let's be sure all the effects are net-tallied – not just an unquantified hand-wavy "saves lives via dental health" with zero consideration to any stupidity or behavioral issues created.

woodruffw 2y ago

First, three procedural points: 1. You're presumably talking about the HHS review in your adjacent comment. Here's the actual monograph[1]. Notably, the review's authors consider it a "medium confidence" finding. In the NTP's taxonomy[2], that makes it a lower impact conclusion than the voluminous findings that show that fluoridation at 1.5mg/dL (much less 0.7mg/dL) has no adverse developmental effects. 2. The monograph is explicit about the limitations of its conclusions. In particular, the monograph explicitly says that it doesn't offer a quantitative account of fluoride-for-lost-IQ-points, and explicitly concludes that its findings do not address fluoridation at levels used in the US or Canada. 3. The monograph is focused on fluoridation at or above 1.5mg/dL, with extensive consideration given to much higher fluoridation levels. As a whole, the monograph doesn't not present the cohesive, "closed case" for a relationship between municipal water fluoridation and developmental risk that you're suggesting exists. At best, it presents a body of evidence showing a moderate correlation between negative developmental effects and natural/dietary fluoride consumption at levels that are 5-10x times the level introduced in the US. > If the standard is half the "safe" level, but some people consume 4x or 10x as much tap water, & perhaps even have a higher baseline of non-tap-water flouride consumption, then some percentage N of the population could developmentally-harmed, even at levels "safe" for "most". First: neither your source (nor any source I'm aware of) shows developmental effects in adults, i.e. a general population sampling. Not even at extremely high naturally occurring fluoride levels. However, even if we reduce to children, neither your source (nor any I'm aware of) shows a multiplicative effect to fluoridated water consumption. In other words: children in areas with 5mg/dL of naturally occurring fluoride appear to have blood levels that consistently correlate with that natural level, regardless of variations in dietary patterns. The parsimonious explanation for this is that fluoride doesn't bioaccumulate in soft tissues and is mostly excreted when not accumulated in teeth and bones, which research supports[3]. The TL;DR for this is that there's no positive evidence (and a lot of negative evidence) for differences in consumption during normal human activity having any effect on blood/urine fluoride levels. Baseline changes result in changes; volume does not. (This ties in with the earlier point: you can definitely increase the amount of fluoride in your system over a point in time by, say, drinking 3 cups of green tea in a row. But children aren't doing that, and their most accessible equivalent - drinking water - is not something that they can chug liters of at a time.) > Roughly, instead of one cavity-affected-tooth per 17 kids, there's one cavity-affected-tooth per 9 kids. I personally wouldn't describe that kind of reduction as modest. On the city scale, that's thousands of dental procedures averted per year. Factored with differences in dental care (e.g. childhood cavities correlating with worse adult dental outcomes), and you have an expensive, easily preventable public health problem. > What if we shifted the flouridation expense into reminding kids to brush or use a flouridated rinse? Brushing reminders and basic dental hygiene are exceedingly well-messaged in developed countries. Despite that the problem remains, as evidenced by studies consistently showing differences between fluoridated and un-fluoridated populations with generally good dental practices[4]. I suppose we could always spend more on educating parents and children on good dental hygiene. But municipal fluoridation is cheap, effective, and most importantly pervasive: it addresses the last X% of the population that can't or won't practice good dental hygiene. [1]: https://ntp.niehs.nih.gov/sites/default/files/2024-08/fluoride_final_508.pdf https://ntp.niehs.nih.gov/sites/default/files/2024-08/fluori... [2]: https://ntp.niehs.nih.gov/sites/default/files/ntp/ohat/pubs/handbookclarificationmarch2019_508.pdf https://ntp.niehs.nih.gov/sites/default/files/ntp/ohat/pubs/... [3]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7261729/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7261729/ [4]: https://onlinelibrary.wiley.com/doi/10.1111/cdoe.12685 https://onlinelibrary.wiley.com/doi/10.1111/cdoe.12685