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.
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.)
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.
I'm sure now some other HN poster will come up with an explanation how Amino Acids are still neurotoxic of some sort.
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...
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.
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.
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?
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.
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.
What differences in behavior do we see between city and rural?
I grew up in “nature” (aka a forest that emerged from not working farmland iykyk) and every ride to school, the grocery store, a friend’s house, or heaven forbid medical care or a restaurant visit involved 30-45 minutes of driving. That sucks.
and some of us prefer not sitting in cars, trucks, or tractors all day.
The horror! :-)
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...
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).
mackeye•4h ago