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.
https://www.health.harvard.edu/blog/have-a-gas-stove-how-to-...
> 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.
The toxicity judgement comes from the information what substance has the form of PM2.5, and the journo managed to omit that.
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.
Water and sugar particles, for instance, are almost certainly harmless below some reasonable threshold.
What they do there is up for further study.
Many studies show a high correlation with childhood respiratory defects and living near roads (or even attending school near roads) specifically a road with diesel truck traffic, and a recent study showed a decrease in effects when air filters are installed in the schools. https://pmc.ncbi.nlm.nih.gov/articles/PMC6949366/
They said that the category "small particles" is not equal to the category "neurotoxic".
Much like how "Walks on Two Legs" is not "Men", there may be some overlap in the categories, but the first does not reliably indicate the second. (Or vice-versa.)
https://www.ncbi.nlm.nih.gov/books/NBK385529/
Apologies!
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
I just asked ChatGPT: when using a fry pan, does the smoke contain formaldehyde and benzene?
> Cooking at very high temperatures (over 450°F or 232°C), especially with oils or fats, could theoretically contribute to benzene formation.
"could easily"? Hardly.
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.
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.
I'm sure now some other HN poster will come up with an explanation how Amino Acids are still neurotoxic of some sort.
See what i wrote in the other thread... https://news.ycombinator.com/item?id=45784538
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.
[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC9491465/#:~:text=PM...
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.
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/p...
</tinfoil-hat>
I thought some of the harm comes from the size of PM2.5 particles alone.
Not a very powerful effect.
And yet the US largely bans healthier, denser living by law. Density grows out of less dense areas, and those less dense areas nearly all have strict density caps preventing density, as well as road infrastructure designed to never allow density. And the dense areas of the country, which already show healthier lives for people and longer lifespans, have similarly tight caps on building more density
All this is to say that we have made a political choice as a society and are now reaping what we have sown. However we can choose something better for the future.
Our choices are not the result of a free market, but one highly constrained by land use restrictions.
This is seen very clearly in housing prices. Dense living is hugely undersupplied, and therefore very expensive.
I want to be in the heart of a bustling city where I can walk to everything and do something different every night. That's not possible in suburbia.
They'd probably rather live in a single family home in NYC.
They have to choose between contradictory desires: single family home over condo, but NYC over suburbs or rural.
2/3 of home buyers have single family detached as their preferred housing, so more people want to live in that type of housing than currently do so.
Much of the rest of what is said here contra your viewpoint is also readily observable common knowledge.
Here's a quote:
> To be clear: Climate change is a very important problem. It needs to be solved, along with other problems like malaria and malnutrition. Every tenth of a degree of heating that we prevent is hugely beneficial because a stable climate makes it easier to improve people’s lives.
Reducing sprawl is plainly a good strategy to reduce transportation and infrastructure needs, and preserve wildlife.
Glad to see different people want different things in life.
Not everyone wants to live in the country or the suburbs. I wouldn't live there if you paid me.
Noise in cities is mostly from cars, as is the dirt and death and destruction. Which is why I advocate so hard for allowing low car lifestyles and building, something that is largely banned in the US.
The only reason there would be madness, filth and ugliness in a rural area is if you left it there, because you are the only one living on your property.
Obviously, you have to sometimes go out into a hub of activity to get groceries or whatnot, but the onus is on you to provide evidence that those hubs are epicenters of madness and filth in a rural area, but not the urban area.
Your argument makes 0 sense without any evidence.
This makes me think you don't actually live in a rural area. It's not like you're pioneering, no connection to the rest of society. There's still school for the kids, church, stores, and yes, even neighbors.
Plus, most humans find having a social life to be one of the greatest joys in life.
I find it fascinating that you think it's acceptable to call cities centers of madness, filth, and ugliness, but think it's completely unacceptable to think that of rural areas. Have you actually lived in a city? Or are you just basing it off of perceptions you get from media?
Use of sulfur by farmers causes asthma: https://pmc.ncbi.nlm.nih.gov/articles/PMC5783654/
Stockyards smell awful.
My childhood friend's grandfather owned a silage plant. Ever smelled silage?
The local pig farm has created the worst smell I've ever directly experienced, and it's been a problem since the 90s.
These are just a few examples of filth and ugliness. As for madness, meth use and inattentive, drunk, or road-raging pickup truck drives with provide you that.
There's too much "trad life" larping on Instagram these days, and one of the many many parts of the experience that viewers miss is smell.
There was noise from constant tractors running around (for both cereal agriculture and cattle farming), even more noise from the nearby gigantic steel building company. People constantly driving around for any reason with stinky noisy vehicles (often poorly maintained). You would get bad smells from the cattle farmer muckspreading or the porc farmer cleaning out. Sometimes you would actually need to stay inside because the nearby cereal farmer thought it was a good idea to spray pesticide with a helicopter.
And that's before even talking about the "nature" part, like a swan chasing you because for some reason he thought you were a threat when you were just passing by, a random confused board wondering if he should charge you or just go about his life, gigantic carnivore fish that will bite you if you are not careful (silurid fish, they caught one over 2m in the river next to my house). You can add the random stray dog (or just common farmer dog) that may not be that friendly and agressive bulls that may catch you by surprise if you unknowingly walked on their territory (to take a shortcut or whatever).
I have learned the hard way that nature is a bitch and rather nasty most of the time. We built society/civilisation because otherwise we wouldn't fare very well alone or in small groups. And the parts of nature we exploit for civilisation are not better than cities, in fact they are often much nastier (you get the nature default, plus the crap humans put on top).
I think people who have some sort of fetish for nature are low IQ or weird excitement with unnecessary risks. My experience living with/around the people there taught me that indeed, most of them are quite dumb and that's probably the reason they are here.
There are plenty of small developments (e.g. 100-150 houses with 2-3 acre plots with some basic amenities like road clearing) that are far away from anything you describe.
The beautiful areas are breathtaking if you can afford to live there.
I experienced both. I grew up in a beautiful pastoral landscape with prosperous dairy operations and a mix of tourism and small business. Small scale dairy farming is dead, and that death caused a chain reaction. My old home is a rural ghetto at this point. Distribution centers are the big thing that was supposed to save the day, but they have high turnover and generate truck traffic and other issues.
It’s nice we get the choice though, and I do like to visit it still. I could just never return to such isolation and poor services.
And on that front, prices in dense areas are way way above suburban areas. Even if you subtract the lawn. People will pay far far more per sqft for a home in a dense urban area without a lawn! Which indicates that dense living is far undersupplied.
Not coincidentally, we don't have to ban suburban living, we only ban dense living. Literally anybody could buy an apartment building, tear it down and build a single family home, but how often do you ever see that happen? But you can't go the other direction, by law.
One more thing to consider - no U.S. city has “excellent” infrastructure so it’s difficult to know what the demand would be like if that kind of city existed in the US. NYC doesn’t count, the subway is good by US standards but it’s junk compared to asia standards. Slow, loud, disgusting, lots of delays and maintenance on weekends.
For example how much would a nice apartment in manhattan be worth if i could easily hop on a bullet train and be in the Hamptons on Long Island within 50 minutes? Or in Mystic Connecticut within 45 minutes?? Suddenly commuting from the suburbs daily, so i can relax in nature on the weekends loses its appeal. Just one example.
With that said it’s good the market offers different housing “products” based on personal preference or life-stage (young, kids, older, etc)
This is easily disproven by the state of the real estate market and relative value of said urban condos to suburban sfh
You'd be correct if you referred to some people, but acknowledged that for plenty of people, a detached home with a yard is the last thing they want. Lawn care and home maintenance, no thanks. Let me just pay a fee for my share of building maintenance, please.
Price in the full cost of that sprawl and it becomes less desirable.
How bizarre you think you can talk for literally everyone in existence.
Absolutely untrue. My own desires are quite the opposite of what you describe. Besides which, tiny downtown places can often be more expensive than considerably larger ones in the suburbs.
What differences in behavior do we see between city and rural?
Suburbs have more cars per capita, more driving in general, more asphalt,[0] more time commuting/being on the streets to reach common destinations, more exposure to smoke from fires, and sometimes even more exposure to pollutants and pesticides from farming (especially if they have golf courses. Golf courses use about 5x more pesticides than farmland per acre). Suburbs also have more suicides per capita than cities
[0] https://www.sciencedirect.com/science/article/abs/pii/S03043...
My mom used to work in public health research, and one example that was hard to quantify was suspected cancer clusters around roads that were oiled gravel, where the oil was contaminated with industrial waste products. Basically, people who were outside in the summer near a road seemed to get lung cancer at higher rates due to road dust.
Issue was there just weren’t enough people or documentation of the supply chain to really prove it. They were able to stop the process of “donating” waste products to the highway departments.
In an urban environment, it’s easy. There are probably 500,000 people living along busy commercial corridors in NYC where you can reliably measure stuff like exposure to diesel particles or whatever.
https://news.ycombinator.com/item?id=45157897 (129 comments)
https://news.ycombinator.com/item?id=44846164 (124 comments)
There are reviews online that also take into account long-term cost (including the price of the filters themselves and how often they need to be replaced).
https://chillphysicsenjoyer.substack.com/p/measuring-my-diy-...
I built one (< $50) and I'm pretty happy with the results. As someone with a life long sensitivity to air quality, the air definitely feels cleaner.
The blog is persuasive and provides a full air quality analysis. It's cheap and effective, a potent combination.
mackeye•3mo ago