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> Even if the factor is off by 10, it's already too much chemical exposure. Source, please. Drinking one gallon of water a day is perfectly safe. Drinking 10 i
by burnte 2y ago
> Even if the factor is off by 10, it's already too much chemical exposure.
Source, please. Drinking one gallon of water a day is perfectly safe. Drinking 10 is not. 500 mg of acetaminophen is fine, 5 grams is not. 2 beers is reasonable, 20 is not. Factors of ten are pretty large safety margins.
- margalabargala 2y agoThe thing off by a factor of 10 here was not the level of the chemical, it was the calculation of the recommended safety level. Also, different substances follow different safety curves. A 10x difference in acetaminophen takes you from very safe to very dangerous. A 10x difference in lead takes you from less dangerous to more dangerous; there isn't a "safe" dosage of lead.
- MichaelZuo 2y agoHow do we know for certain that acetamminophen in even a tiny dosage is ‘very safe’? e.g. There could be some effect via a delayed chain reaction process that takes decade to accumulate to be noticeable...
- margalabargala 2y agoCompared to lead? Decades and decades of extensive, high quality research. Low quantities of lead have exactly the long term low-dose exposure effects you describe. They have been identified.
- MichaelZuo 2y agoYes, so how is the same for acetamminophen known to be roughly zero?
- margalabargala 2y agoVia extensive research and double-blind studies. There are thousands of articles showing levels of acetaminophen that do, and do not, cause hepatotoxicity. Here are all of them: https://scholar.google.com/scholar?hl=en&as_sdt=0%2C38&q=acetaminophen https://scholar.google.com/scholar?hl=en&as_sdt=0%2C38&q=ace... This isn't new, here's an article from a half century ago discussing exactly this: https://www.researchgate.net/profile/Barry-Rumack/publication/22020528_Acetaminophen_Poisoning_and_Toxicity/links/0deec526ed7ec38793000000/Acetaminophen-Poisoning-and-Toxicity.pdf https://www.researchgate.net/profile/Barry-Rumack/publicatio...
- MichaelZuo 2y agoHow does this prove there are no delayed effects that take decades to accumulate to be noticeable, that’s it close enough to zero to not worry about?
- margalabargala 2y agoIt doesn't, obviously, since it's not possible to prove a negative. Much like there's nothing that proves that you won't begin to be able to fly if you stand on one leg long enough. If what you've been shown so far is insufficient evidence for you, then I'm afraid you're on your own. I don't need to play the "how about this" moving goalpost game.
- MichaelZuo 2y ago> I don't need to play the "how about this" moving goalpost game. This seems like a non sequitor, Why does your opinion of which ‘games’ allegedly exist, or not, matter? It doesn’t seem possible for your written opinions to ever outweigh any other HN user’s…?
- margalabargala 2y agoDo a lot of things seem like non sequiturs to you?
- dTal 2y agoIndeed, 100% of people who take acetaminophen eventually die.
- cwillu 2y agoHow do you know that exposure to comments by people named “cwillu” does not lead to cancer by some delayed chain reaction that takes decades to become visible?
- MichaelZuo 2y agoI never said that I knew such a thing?
- citrin_ru 2y agoI’m pretty sure take one lead molecule per day would not cause any detectable harm, even 1 additional nanogram likely too. So there a safe dosage of lead it is just hard to determine where the line between safe and unsafe is.
- margalabargala 2y ago"You're pretty sure" isn't unfortunately scientifically admissible evidence. There is no known safe dosage of lead. If you are able to detect lead intake in a person, and are unable to detect harm in that person attributable to that lead, that would be news to the scientific community and you should publish it.
- logifail 2y ago> > I’m pretty sure take one lead molecule per day would not cause any detectable harm [..] even 1 additional nanogram likely too > "You're pretty sure" isn't unfortunately scientifically admissible evidence From those two comments I feel obliged* to point out that one atom of lead - or indeed one atom of any element - is really a very, very, very small quantity... A quick refresh on just how many atoms an element there are in one gram of that element might be in order. > There is no known safe dosage of lead I'd happily ingest a lead atom if you can prepare one for me. Q: Is there a safe known dosage of ionizing radiation? I ask because I'm flying later today... [* full disclosure, Chemistry PhD]
- margalabargala 2y agoYes, I'm familiar with exactly how small an atom is. Identifying a single lead atom, and measuring harm caused by ingesting a single lead atom, are beyond the capability of our tools at the moment. You can form a hypothesis that one atom would cause no harm, I can form one otherwise, but until we're able to quantify that then these are just hypotheses. Among lead levels we are able to detect and measure the quantity of, there's no known safe level. And there very well may be points below which the harm caused, is so small that it's some people consider it an acceptable risk, as with your airplane and radiation example.
- burnte 2y ago> The thing off by a factor of 10 here was not the level of the chemical, it was the calculation of the recommended safety level. Doesn't matter to the point I was making which is that a factor of ten is significant enough that you can't just assume what happens at X level means the same for 1/10th of it or 10x it.