The energy use by AI probably is just as, if not more, carbon intensive, but the article never says that. It talks about the energy use of the general data center.
> The carbon intensity of electricity used by data centers was 48% higher than the US average.
In case anyone is wondering why that is, it's because they put data centers in the places with the cheapest electricity. Which, in the US, is in places like Virginia and Ohio, where they burn fossil fuels.
If the people always talking about how cheap solar is want to fix this, find a way to make that cheapness actually make it into the customer's electric bill.
I've always wondered why data centers aren't taking off more in places like Iceland (cheap geothermal) or Quebec (cheap hydro). Both of these places are also pretty cold and one would think this benefits cooling.
There are periodically news articles and such about data centers in Iceland, of course, but I get the impression it's mostly a fad, and the real build-outs are still in Northern Virginia as they've always been.
The typical answer I've seen is that Internet access and low latency matter more than cooling and power, but LLMs seem like they wouldn't care about that. I mean, you're literally interacting with them over text, and there's already plenty of latency - a few extra ms shouldn't matter?
I'd assume construction costs and costs of shipping in equipment also play a role, but Iceland and Canada aren't that far away.
How much bandwidth is there in Iceland? I suspect not much because the population is only 400K. You will need to lay new undersea fiber. And how are you going to build them? The construction alone would take a massive amount of resources and manpower not feasibly available there. And what about the power supply? In data center heavy areas like Virginia, data center power consumption is already 25% of the entire state power consumption, and VA has 22x more people than Iceland. So if you build even 1/5th the number of data centers in just Virginia, that will consume the entire power grid of Iceland. Therefore, in addition to the data centers themselves, you are also going to have to build an entirely new grid and distribution system.
I did already mention both of those: re. bandwidth, I can't imagine LLMs use that much of it? It's just text - absolutely peanuts compared to something like Netflix. That said, of course, there are multimodal models. Construction difficulty is a factor, but at the same time, it's not like Iceland or Quebec/Canada are backwater regions, they're developed countries. Building a warehouse with some wires in it isn't the most complicated thing ever.
As for power, that's what I was referring to with geothermal and hydro - Iceland and Quebec both have famously cheap electricity. The former would need a large increase in capacity, for sure, but Quebec already pumps out a lot of power (and regularly sells it to the Northeastern US).
Not saying it wouldn't be difficult, by any means, but it does seem like all the right incentives are there.
I agree, the effects of fluoride probably aren't in the top 5 things to be concerned about (although perhaps they are from a political perspective, with it becoming such a strong topic of debate for a variety of reasons). But do you assume that getting to n=10,000 is going to show little or no effect (e.g. having a level you define as little effect)? I'm not convinced the NTP data is extremely high quality and can't make much conclusion from it on the effects.
Also, for other commenters: the 2832 children number I believe comes from the supplemental content from the supplemental material for the NTP Fluoride Monograph: https://cdn.jamanetwork.com/ama/content_public/journal/peds/... (this url is very long because of some hashing measure, sorry: if it is no longer accessible, it is the supplemental content for doi:10.1001/jamapediatrics.2024.5542), on page 51 of the PDF. I have a small summary table of data I view relevant here:
The columns are:
* Studies used; Fluoride Exposure; Number of Studies / Number of Observations (number of Children)
* Estimate for slope in linear Model, given as increase in IQ points per mg/L increase (95% CI) (p value)
> But do you assume that getting to n=10,000 is going to show little or no effect (e.g. having a level you define as little effect)?
I don't necessarily assume this, but even if you assume linearity, 0.7 * -0.32 is pretty dang small at baseline. I think if you generate n=10000 showing MLE=-.32 or +.05, few people are going to change their minds. I might, but I don't think it does much to shape the debate.
The issue is that putting fluoride in the water isn't really "treating" the water. It's in essence acting a medication (see my paragraph below for a justification of this), to the benefit of people's teeth. As far as I know, every other chemical added / removed from the water is done for the purpose of the taste of the water, protecting the pipes which serve the water, or disinfecting the water. In this way, it's different from all the other chemicals, and there is also some limited opposition to other chemicals (e.g. debate on the use of UV / chlorine / ozone).
As for a loose argument for why fluoride in water is medicinal: the FDA classifies toothpaste as a cosmetic and also potentially a drug (depending on whether it contains fluoride and the claims the product makes):
> Ingredients that cause a product to be considered a drug because they have a well-known (to the public and industry) therapeutic use. An example is fluoride in toothpaste.
> Some products meet the definitions of both cosmetics and drugs. [...] Among other cosmetic/drug combinations are toothpastes with claims to freshen breath and cleanse the teeth that contain fluoride.
[Both quotes are from https://www.fda.gov/cosmetics/cosmetics-laws-regulations/it-...]
I think the common consensus is that the primary benefit of fluoride is topical, not systemic:
* Initially, fluoride was considered beneficial when given systemically during tooth development, but later research has shown the importance and the advantages of its topical effects in the prevention or treatment of dental caries and tooth decay. [The Fluoride Debate: The Pros and Cons of Fluoridation; Prev Nutr Food Sci, 2018; https://pmc.ncbi.nlm.nih.gov/articles/PMC6195894].
* The actual mechanism of fluoride action is still a subject of debate. A dogma has existed for many decades, that fluoride has to be ingested and acts mainly pre-eruptively. However, recent studies concerning the systemic effect of fluoride supplementation concluded that the caries-preventive effect of fluoride is almost exclusively posteruptive. [Systemic versus topical fluoride; Carries Res, 2004; https://pubmed.ncbi.nlm.nih.gov/15153698/]
* As noted by
Thorrez, your link does not mention topical application vs systemic ingestion. There is a publication from the CDC however stating that the benefit of fluoride is mainly topical:
> Fluoride's caries-preventive properties initially were attributed to changes in enamel during tooth development because of the association between fluoride and cosmetic changes in enamel and a belief that fluoride incorporated into enamel during tooth development would result in a more acid-resistant mineral. However, laboratory and epidemiologic research suggests that fluoride prevents dental caries predominately after eruption of the tooth into the mouth, and its actions primarily are topical for both adults and children (1).
[https://www.cdc.gov/mmwr/preview/mmwrhtml/mm4841a1.htm ; 1999].
This material was covered in depositions for TSCA Fluoride trial in 2018, where Casey Hannan (director of the division of oral health at the CDC) was the examinee for the deposition. A temporary upload of a clip from this deposition may be found at https://0x0.st/8Lom.mp4.
If we take the known harmful level of fluoride as being >1.5mg/L then the NTP monograph itself has some information ():
> areas including central Australia, eastern Brazil, sub-Saharan Africa, the southern Arabian Peninsula, south and east Asia, and western North America (Podgorski and Berg 2022). Regions of the United States where CWS and private wells contain natural fluoride concentrations of more than 1.5 mg/L serve over 2.9 million U.S. residents (Hefferon et al. 2024). The U.S. Geological Survey estimates that 172,000 U.S. residents are served by domestic wells that
exceed EPA’s enforceable standard of 4.0 mg/L fluoride in drinking water, and 522,000 are served by domestic wells that exceed EPA’s non-enforceable standard of 2.0 mg/L fluoride in drinking water (USGS 2020).
[https://ntp.niehs.nih.gov/sites/default/files/2024-08/fluori... Page 2 or Page 22 of the PDF]
Note in the US this is almost all people drinking well water. So if we take the known harmful level at 1.5mg/L, then there are lots of people known to be drinking water above these concentrations. I'm not sure I would say we're necessarily ignoring them, but could argue regulations aren't up to date: the current EPA MCL is 4.0mg/L and secondary MCL is 2.0mg/L.
For more in depth data, we can take the EPA's Review of Fluoride Occurrence for the Fourth Six-Year Review (2024) [https://www.epa.gov/system/files/documents/2024-04/syr4_fluo...]. Page 15 of the PDF shows artificially fluoridated water nowadays has fluoride concentrations between 0.6mg/L and 1.2mg/L. Page 18 shows that ~4.7 million are being served with concentrations of fluoride >1.5mg/L. This is higher than the Hefferon et al figure but it seems this figure is based on data from 2006-2011 (where the population was lower, but also the recommended fluoride concentration was higher, with the max at 1.2mg/L pre-2015). I also am not convinced Hefferon et al has any figures on private wells (although maybe I misread the paper).
Just to note, the words "medium confidence" appear in neither the NTP monograph nor the taxonomy you referenced. They use the term "moderate confidence", which I guess has a similar meaning, but given the scale is from very low to low to moderate to high, I don't think this alleviates any of my concerns.
Do you have a reference for the claim that exposure to fluoride from natural dietary sources is far higher than what occurs from fluoridated water?
An EPA review on fluoride exposure that I found (https://www.epa.gov/sites/default/files/2019-03/documents/fl...) puts most estimates of the "natural" dietary fluoride intake at 0.9mg per day. This is in contrast to the estimated 0.7 * 2 = 1.4mg of fluoride a person will ingest from consuming fluoridated water (with a fair number of water systems fluoridated at levels greater than 0.7mg/L).
Another study I found from the EFSA estimates fluoride intake from non-supplemented food at 0.120mg per day for adults compared to 0.500mg per day from water fluoridated at (1.0mg/L)
(https://efsa.onlinelibrary.wiley.com/doi/epdf/10.2903/j.efsa...). Admittedly, in countries where salt is fluoridated, this will constitute the majority of fluoride ingested (especially given most of them don't fluoridate their water :P). But I don't think anti-fluoride advocates would support this either.
I also don't understand what you mean by the "strong claim" and "weak claim" of the NTP monograph. You seem to have doubts that the claims of the NTP monograph are true, based off of the known mechanisms of fluoride toxicity?
My best guess for why the rational anti-fluoride advocates are so stirred up over water fluoridation is that it is a policy proposed without currently a rigorous scientific backing. Per the recent Cochrane review, there is evidence that fluoridation mildly benefits children's teeth, and a lack of high-quality evidence that fluoridation presently benefits adults teeth. There also isn't good evidence that fluoride consumption isn't harmful at present levels (fluorosis is known to occur, and studies evaluated by the NTP point to neurodevelopmental harms, albeit with the conclusion for higher concentrations of fluoride); nor is there strong evidence that systemic fluoride ingestion has any benefits. They might therefore be angry at a somewhat political policy of forced medication that isn't well backed.
The NTP monograph is a very flawed document, as the review failed to consider a crucial confounder/modifier - iodine/thyroid status. Fluoride toxicity is directly dependent on the individual's thyroid/iodine status. If iodine-deficient, even miniscule amounts of fluoride may affect you. If iodine intake is excessive, then iodine toxicity may be pre-dominant - this has been known since the 1930s.
Are you sure the estimates of the fluoride intake and fluoride consumed respectively are wildly incorrect in light of this? This isn't the best source of information but using data from here (https://www.teausa.com/teausa/images/Tea_Fact_2021.pdf) you can put the estimate at the number of cups of green tea consumed by the average US citizen at 0.1 per day. This is definitely concerning for someone drinking lots of green tea but I don't think it invalidates the statistics. The EPA study also does account for tea consumption, stating in some contexts it forms the highest component of fluoride intake from beverages.
For the second article, this is interesting information and I can see causes for concern in the study (there were multiple hick-ups in the peer review process), and ideally high-quality randomised control trials would form the basis for a conclusion. But what is your opinion on policies of water fluoridation in light of this (I know you are a different commenter than who I was replying to, and don't expect your opinion to be the same)? Is it that people should be focussing on studying its (potentially harmful) effects in light of iodine exposure within regions? The link you posted, written by members of Parents of Fluoride-Poisoned Children, states that:
> As fluoride toxicity is directly related to iodine status - and iodine toxicity to fluoride status -, both mass-supplementation programs require urgent reassessment on a global scale.
and also asks:
> Furthermore, we call for the proper evaluation of the toxicity of fluoride on neurodevelopment based on the extensive body of evidence that addresses the impact on iodine and thyroid hormone metabolism.
They (Andreas Schuld) also state in a later article (https://substack.com/home/post/p-139843513) that:
> We also learned that most of the research linking fluoride to thyroid dysfunction had been actively suppressed by public health agencies worldwide, including the World Health Organization (WHO), the European Scientific Committee on Health and Environmental Risks (SCHER), as well as the U.S. CDC, the Agency for Toxic Substances and Disease Registry (ATSDR), the NTP, and the EPA.
While you are right that it is very rare that a water system will fluoridate their water to levels of 1.5 mg/L, I don't think it's true that all systems fluoridating their water have targets or achieve a level of 0.7mg/L. You can see in the EPA's analysis of their fourth Sixth Year Review (SYR4) (https://www.epa.gov/system/files/documents/2024-04/syr4_fluo...) that there is a large variation in the fluoride concentrations of fluoridated entry points (from 0.6mg/L to 1.2mg/L, with the 0.6mg/L cut-off being artificial).
The NTP monograph doesn't conclude that fluoridation at levels of 0.7mg/L are safe or unsafe, but it is better to be safe than sorry. With some populations receiving fluoridated water at concentrations of 1.2mg/L and an estimated 2% to 7% of the population receiving water fluoridated above this concentration, I think it's reasonable to be concerned in light of the NTP's monograph on fluoride (even if this just means to increase focus on de-fluoridation of water).
As per the NTP:
> The moderate confidence conclusions may also be relevant to people living in optimally fluoridated areas of the United States depending on the extent of their additional exposures to fluoride from sources other than drinking water.
Also just to note, the EPA's secondary maximum contaminant limit (SMCL) is 2.0mg/L. This isn't the federal limit as set forth by the MCL of 4.0mg/L, but notice is still required by the EPA here.
Taking the recent Cochrane report in mind, which shows a small reduction of 0.24 decayed tooth per child in places practicing fluoridation, and fails to find high quality studies on the effects of fluoridation for adults, it is reasonable to question the EPA's limits and the US's policy of fluoridation.
I can't find any strong evidence for the benefits of systemic ingestion of fluoride which makes me ultimately conclude that the policy is an ineffective one of forced medication (in the name of those who can't brush their teeth).
With no evidence of it being a safe policy, I don't know why the CDC and EPA still advocate nowadays for water fluoridation. Although perhaps costly to change, neither do I know why the EPA sets their limits to levels above where known harms (such as dental fluorosis and neurodevelopmental effects) occur. As Judge Edward Chen says:
> In all, there is substantial and scientifically credible evidence establishing that fluoride poses a risk to human health; it is associated with a reduction in the IQ of children and is hazardous at dosages that are far too close to fluoride levels in the drinking water of the United States.
