5 ms·
> With increasing evidence that chronic exposure to PM2.5, a neurotoxin, not only damages lungs and hearts but is also associated with dementia, probably not.
by crazygringo 1y ago
> With increasing evidence that chronic exposure to PM2.5, a neurotoxin, not only damages lungs and hearts but is also associated with dementia, probably not.
PM2.5 is not a neurotoxin, that's an absurd thing to say.
It's literally any particles under a certain size. Whether it's a neurotoxin is necessarily going to depend on what the substance is made of.
Whether your PM2.5 exposure is coming from automobiles or wildfires or a factory, the potential outcomes may be different in different areas of the body. Heck, my PM2.5 meter skyrockets whenever I cook anything in a frying pan, because many of the aerosolized oil droplets are PM2.5.
- epistasis 1y agoFrying pan PM2.5 is pollution, and has been linked to increased childhood asthma, on of the easier and more immediate readouts from exposure. Linking dementia to that is a far harder scientific task due to the amounts of exposure and variability over time. Here's one blog post going over some of the evidence linking gas stoves to asthma: https://www.health.harvard.edu/blog/have-a-gas-stove-how-to-reduce-pollution-that-may-harm-health-202209072811 https://www.health.harvard.edu/blog/have-a-gas-stove-how-to-...
- bcrosby95 1y ago[flagged]
- culi 1y ago> Children living in households that use gas stoves for cooking are 42% more likely to have asthma, according to an analysis of observational research. While observational studies can't prove that cooking with gas is the direct cause of asthma, data also show that the higher the nitrogen dioxide level, the more severe the asthma symptoms in children and adults. Nobody is saying frying some eggs is equivalent to sucking the tail pipe of a 50s era car. You're arguing with yourself.
- rvba 1y agoMakes me wonder if cooks, who (in many countries) stand in front of a gas stove for long hours every day have a statistically higher chance of asthma?
- klipt 1y agoEven worse than asthma https://preventcancer.org/article/lung-cancer-asian-american-women/ https://preventcancer.org/article/lung-cancer-asian-american... > Environmental exposures, such as cooking oil fumes and secondhand smoke, have long been identified as risk factors for lung cancer among women in Asia who do not smoke
- bakql 1y agoThose exposures are completely unrelated to the burner used in the kitchen.
- blueflow 1y agoHow is that related to what GP wrote?
- epistasis 1y agoThat poster seemed to be saying that frying pan PM2.5 was not a health risk: > Heck, my PM2.5 meter skyrockets whenever I cook anything in a frying pan, because many of the aerosolized oil droplets are PM2.5. I'm not sure how they determined that PM2.5 is not a neurotoxin, or the full extent of their claims, but frying pans inside are a common cause of minor health problems.
- blueflow 1y agoThe point was that PM2.5 is a measurement of particle size, and that by itself allows no judgement about its toxicity. The same way you cannot argue that things of 5 centimeter diameter are healthy. The toxicity judgement comes from the information what substance has the form of PM2.5, and the journo managed to omit that.
- epistasis 1y ago> The point was that PM2.5 is a measurement of particle size, and that by itself allows no judgement about its toxicity. This does not logically follow at all. The size indicates where it can reach in the lungs, whether cilia can eject it, etc. A 5cm ball shot at the head at high speed is indeed dangerous. We are talking about inhalation of particles causing irritation, and the size is indeed the major factor. Content as well, but frying pan particles filled with carbon chains that have gone through who knows what reactions are indeed of concern. Lots of extremely nasty things are easily accessible from chains of hydrocarbons, from toluene to formaldehyde. > The toxicity judgement comes from the information what substance has the form of PM2.5, and the journo managed to omit that. I believe the journalist is not at fault here in the least. The scientific papers I have seen usually class all PM2.5 together, and perhaps by source. But the size itself is of great concern due to the size allowing easy entry to the body that is not possible for larger sizes.
- 1y ago
- deleted 1y ago[deleted]
- tim333 1y agoGas stoves produce NO2, not PM2.5.
- epistasis 1y agoFrying pans produce PM2.5, gas stove or no. I am talking about PM2.5. What is your point?
- tim333 1y agoYou link to a report about gas stoves not frying pans.
- epistasis 1y agoOH! Thank you for pointing out the error! I seem to have pasted the wrong link, and am not on my computer that I was doing the searching on before... please accept this short book chapter instead, though it is far more dry than the page I remember reading before. https://www.ncbi.nlm.nih.gov/books/NBK385529/ https://www.ncbi.nlm.nih.gov/books/NBK385529/ Apologies!
- tim333 1y agoAh - that makes more sense.
- stephen_g 1y agoThe point is that your link seems to be almost entirely talking about something else (pollutants from burning gas inside, which is primarily NOx)! There is one passing mention of gas stoves producing some extra PM2.5 (which I expect will be different in composition to the PM2.5 produced in the pan) but all of the rest of it seems to be focused on the NOx
- ljf 1y agohttps://www.cieh.org/ehn/environmental-protection/2025/april/which-study-reveals-gas-hobs-are-polluting-indoor-air/ https://www.cieh.org/ehn/environmental-protection/2025/april... Quote: Research shows cooking on domestic gas hobs can cause two of the most harmful air pollutants, NO2 and PM2.5, to exceed WHO guidelines
- culi 1y agoThis is what frustrates me the most about air pollution indexes. They all treat PM2.5 equally regardless of the source. Smoke from a wildfire in an industrial area is NOT the same as smoke from a wildfire in a woodland. Hell, even some pollen fragments can be PM2.5. Formaldehyde and benzene particulate matter should not be treated equally to pollen fragments
- readthenotes1 1y agoPollen fragments are really bad for some of us....
- culi 1y agoOf course! Different bodies have different sensitivities. But we're talking averages here. What's gonna cause the most social harm
- hollerith 1y agoOK, but wood smoke is really bad for you even if the wood is completely natural.
- daedrdev 1y agoyes but smoke from any urban area will have asbestos and numerous other potent toxins
- culi 1y agoSure, but asbestos, lead, formaldehyde, benzene, etc particulate matters are all undoubtedly going to be more harmful than most types of wood smoke. An urban area will have both wood smoke (which is often treated, possibly with methyl bromide) and industrial smoke. Few would deny breathing in campfire smoke is less likely to cause more immediate harm than a fire at a waste site
- oidar 1y agoFormaldehyde and benzene are not particulates, they are VOC’s - a very different kind pollutant.
- embedding-shape 1y ago> PM2.5 is not a neurotoxin, that's an absurd thing to say. Indeed, imagine seeing "... chronic exposure to 5 ML, a chemical poison, not only...". Not sure how they can mistake a measurement for what the particles actually are.
- mrob 1y agoThe "PM" in PM2.5 stands for "particulate matter", so it actually is a noun and not just a unit of measurement.
- embedding-shape 1y agoStill doesn't make sense to claim that "PM2.5" is a neurotoxin, depends entirely on what the specific particles are, not the size of them. What is more dangerous, PM2.5 or PM10? Well, naturally, smaller particles are more harmful to humans usually, but without knowing what the particles are, it's impossible to tell. Just like "5ML is/isn't more dangerous than 10ML", it doesn't really tell us anything.
- notmyjob 1y agoI don’t know. Pm2.5 by definition doesn’t include gasses and as I understand it the issue is that the particulate matter, whatever it happens to be, gets in the bloodstream. Is there any particulate matter of that size that is not neurotoxic once it enters the bloodstream? I don’t know the answer but it seems like a legitimate question.
- blueflow 1y agoAmino acids! I'm sure now some other HN poster will come up with an explanation how Amino Acids are still neurotoxic of some sort.
- tpm 1y agoThat's too easy, glutamate is neurotoxic in high doses.
- blueflow 1y agoWhat about sugar?
- notmyjob 1y agopm2.5 is a metric used in assessing air quality. Amino acid aerosols are not a source of air pollution.
- blueflow 1y agoamino acids droplets are pm2.5. pm2.5 refers to the particle size. See what i wrote in the other thread... https://news.ycombinator.com/item?id=45784538 https://news.ycombinator.com/item?id=45784538
- notmyjob 1y agoPm2.5 is a specific particle size, yes, we do agree on that. Importantly, it is also a common measurement used in assessing air quality. In that context it is typically composed of particles from a set of common sources, like wildfires, industrial sources, automobile pollution, etc…. It is, in the context of air quality monitoring, never composed of amino acids. It seems valid to make claims about pm2.5 and health, even though the claim does not distinguish wildfire pm2.5 from pm2.5 from automobile pollution or other sources. Maybe I misunderstood you to be saying otherwise.
- meowface 1y agoYeah, very silly statement for them to write. I wouldn't be the slightest bit surprised if certain pollutants in that range were proven or will be proven to be causing gradual damage to the brain but that has to be presented properly.
- tzs 1y agoFrom what I've read apparently pretty much all PM2.5 encountered by most people has neurotoxic effects. It looks like there are a couple reasons for this. 1. There are a lot of substances that are neurotoxic. Most things that create PM2.5 pollution will involve some of them. 2. PM2.5 is good at getting to places where the body really doesn't like foreign objects and so the mere presence of PM2.5 particles can trigger responses, such as inflammation, that can cause neurological damage even if the particle itself is made of a normally non-toxic substance.
- asgraham 1y agoI was initially skeptical of this claim because I’d previously learned that to cross the blood-brain barrier particles need to be ~200nm (PM2.5 = 2500nm). However, PM2.5 does seem to be an important category of particles for brain damage: somehow these particles can access the brain [1]. Obviously, yes, it depends on exactly the particle whether it will be “neurotoxic,” but generally “unnatural” particles in the brain are not going to do good things. (I am not an expert in particulates) it seems like things larger than this don’t penetrate the blood-brain barrier, so they can’t be neurotoxic. So PM2.5 is probably at an intersection of large enough to be unhealthy but small enough that the blood brain barrier doesn’t help (probably some evolutionary argument to be made here). [1] https://pmc.ncbi.nlm.nih.gov/articles/PMC9491465/#:~:text=PM2.5%20can%20pass%20through,blood%20vessels%20and%20brain%20nerves. https://pmc.ncbi.nlm.nih.gov/articles/PMC9491465/#:~:text=PM...
- pedalpete 1y agoThe article does suggest the particles travel "from the nose to the brain", but I think that may be a bit of hyperbole. In the studies described, they weren't looking for these particles in the brain. There is potentially a case to be made that the particles result in systemic inflammation, or some other pathway which leads to effects in the brain, rather than a direct action.
- ahaucnx 1y ago100% agree. It is super important to know the composition of the particles. Unfortunately currently only super expensive instruments can measure this in real-time. This is why I believe contextual information will become much more important in future. Detect an indoor short PM2.5 spike around lunch time, probably a cooking event. Detect medium elevated levels outdoor in a city in the morning and late afternoons, probably traffic related smoke. I actually made a small tool to simulate different events that contain a quiz. Give it a try here [1]. [1] https://www.airgradient.com/air-quality-monitoring-toolkit/planning/defining-the-project/#interactive-aq-simulator https://www.airgradient.com/air-quality-monitoring-toolkit/p...
- malfist 1y agoThe quiz hides the chart. Makes it hard to answer
- kccqzy 1y agoEh I'd give the author a bit of a benefit of the doubt. It's probably just sloppy writing for identifying correlation but not causation. PM2.5 particles themselves are not categorically neurotoxins; they just happen to be associated with other neurotoxins, such that high PM2.5 is a good proxy for high neurotoxin pollutants.
- monster_truck 1y agoThere are a lot of things wrong with this. Almost anything under 2.5nm is going to weigh <500 daltons, which will cross the blood brain barrier, allowing it to have neurotoxic effects.
- NedF 1y ago[dead]
- dyauspitr 1y agoThey might intentionally saying that something of that size is problematic.
- BrtByte 1y agoIdeally we'd move toward more source-specific or composition-specific air quality standards but that's a much tougher data and policy problem
- blueflow 1y agoOn second thought, i think this is intentional. If scientists interpolate from well-chosen substances onto all Pm2.5, it should be provable that earths atomosphere is toxic beyond limits and uninhabitable. "We destroyed earth" sells well and would justify further research funding. </tinfoil-hat>
- xnx 1y agoIs this a bit like saying that bullets made from glass are healthier than those made of lead? I thought some of the harm comes from the size of PM2.5 particles alone.