I want to pull two quotes from the article.<p>> “Our findings emphasise that exercise remains beneficial even in polluted environments,” lead researcher Professor Po-Wen Ku said in a statement. [...] “We don’t want to discourage people from exercising outdoors,” said Co-author Professor Paola Zaninotto.<p>The health effects of exercise outdoors are combined from two effects:<p>- Positive effects due to exercise. These start out strong but level off after a while.<p>- Negative effects due to pollution. These increase almost linearly with time spent outside.<p>One might ask, is there an amount of daily exercise at which the negative effects overpower the positive ones? Yes, in a handful of cities around the world, after a few hours of exercise, the pollution makes additional outdoors exercise actually harmful.<p>But almost everywhere a marginal minute of exercise provides a positive effect on health regardless of time already spent exercising, and there is nowhere in the world where something like an hour of exercise a day is a net negative. Get out there. Pick an active means of commuting (cycling, running, walking, skiing, rollerblading, skateboarding, unicycling) and don't worry so much about pollution unless you live in one of those single-digit cities which I forget where they are, but probably concentrated in Asia.<p>(I feel bad about typing this out without linking to the source. I'm looking for it in my notes!)
I remember an interview with the producthead of Google Earth (the desktop client), she said when photographing all the streets, the cars also checked for air pollution:
She mentioned a capital in Europe, where the amount of particles under certain sizes differed by 10x from one crossing to the next.
The measurement may very well be accurate but statements like that should set off massive red flags and not be taken at face value. A factor of ten difference for something that just kinda diffuses through the air doesn't "just exist". You don't get gradients like that "naturally" for the most part. It's the result of something. Maybe there's a source something is upwind of and something else is downwind of. Maybe there's conditions causing it to concentrate. Or it varies 10x day to day, but on an average basis it equals out. Etc. Etc.
If you have ever been to a city that has banned fossil fuels then you can absolutely tell the difference, to most of the overpopulated European cities that I have visited. It’s astonishing how peaceful and comfortable it is to run or even stroll when every breath is just 100% refreshing; you feel 10 pounds lighter. Meanwhile the blackened filter of our home HVAC needs replacement again… and allergies.
Which cities are you referring to? Some cities have policies that discourage gas and diesel cars, and plans to outlaw them by 2030, but I'm not aware of any that have banned them outright yet.
Sadly, fossil fuel (pollution) has been marketed as a masculine culture thing now. In the free (=individualistic) West, I expect it to stick around for at least another 50 years.
Maybe you mean this, but does "fossil fuel" really mean Diesel engines? Those were very awful to breathe around and were widespread in European cities as we all know.
I wish more people paid attention to air quality. I'm a delivery driver and air quality has a noticeable effect on my energy levels throughout the day and also my mood. Slightly rainy days are probably my favorite days to work because no one is outside digging up roads and kicking up tire dust with leaf blowers and the rain seems to clean the air a bit.
Before people freak out about their morning run, I’m very hard pressed to find 25 PM2.5 on this map of the US. (Note these numbers are AQI, you have to zoom into the bad AQI numbers and look at their PM2.5). Albeit it’s a Saturday morning, not rush hour.<p>China and India look rough though.<p><a href="https://www.iqair.com/us/air-quality-map" rel="nofollow">https://www.iqair.com/us/air-quality-map</a>
Please note that air quality in an area varies dramatically over time. You are looking at a current snapshot with maps like that. The map linked below has his more historical data and I can see several _weeks_ this past year in my area (which currently has very good air quality) where the PM 2.5 weekly average exceeded 25ug/m^3.<p><a href="https://map.purpleair.com/air-quality-raw-pm25" rel="nofollow">https://map.purpleair.com/air-quality-raw-pm25</a><p>Localized phenomena like a neighbor starting a fire, up to the activity of nearby factories and power plants, up to national and global phenomena like wildfires and weather patterns, all have dramatic effects. Looking at an air quality map once and determining that you don’t have to think about air quality because you’re in the US is a mistake.<p>Exercise outdoors is a wonderful thing, obviously, but there are some days, even in the US, where you might think twice or even consider shifting your exercise to a different (less-polluted) time of the day.
Cities have mostly only gotten cleaner with time. This is way, way, way down the list of things that I'm worried about killing me.
And all the while, nothing is done to get old 2-stroke mopeds of the road in Europe. It’s such a low hanging fruit to get those hyper polluters out of cities but in an individualistic society, personal cult status seems more important than common health.
If only you could see it. In the big cities the air quality has improved, however, I am not sure if it really has, or if we are now just burning hydrocarbons more efficiently so that the particle sizes have become invisible.<p>Put it this way, although cars are allegedly better than they were, fuel consumption hasn't dropped considerably. The cars are more numerous than ever, and, although there are EVs, there are still more ICE cars than there were in the good old days when petrol came with lead in it.<p>I am not sure that most people in urban areas even know what good air tastes and smells like. I take a canal path through lush countryside, far from any cars for most of the way. This canal has an aqueduct (or is it a viaduct?) over a motorway and the contrast is incredible. You go from basically smelling flowers to air pollution and back to clean air again quite quickly, so the filth is totally noticeable. Note the cars on the motorway are going at speed, so they should be working efficiently (until a few decades ago 56 mph was what engines were optimised for regarding efficiency in the UK).<p>If just living in a major city then you don't get this instant switch from bad to good air. So you just don't notice it. If you could see the filth, you would prefer a swimming pool that was pissed in, it is that toxic.<p>If you do have to live in a city, my top tip is to find out if there are any meteorologists in town. If there are, buy a house next to where they are living. Anecdotal, however, I used to work with meteorologists and they would always live to the West of the city centre, to get cleaner air than those living in the east of the city, or further downwind.<p>Again anecdotal, however, due to the canal and motorway experience described above, in post-industrial countries such as the UK, it is definitely the vehicles rather than any other source. Given the choice of microparticles that just get in your blood or clumps of big particles that you can eventually cough up and spit out, I would much prefer the latter. My hunch is that the legislation to improve vehicle emissions has optimised the exhaust for nanoparticles. Please prove me wrong!
Sure thing, here's a report from the Greater London Authority tracking the history of air quality in the city since the "Great Smog" event 1952, which caused an estimated 4000 deaths.<p><a href="https://www.london.gov.uk/programmes-strategies/environment-and-climate-change/environment-and-climate-change-publications/70-years-great-london-smog" rel="nofollow">https://www.london.gov.uk/programmes-strategies/environment-...</a><p>The main takeaway is that yes, urban air quality (including fine particulate matter) has improved massively over time, but most of it had little to do with road traffic, as for decades it wasn't a significant contributor to the overall mix. The important change was the move away from burning solid fuels like coal for household heating and in power stations within cities, to using gas and electricity with larger, out-of-town power stations.<p>As other sources have declined, road traffic has indeed become the largest contribution to urban air pollution, but even here there has been progress. Fine particulate emissions have continued to decline as car manufacturers have adapted to more stringent regulation (cheating scandals notwithstanding). A bigger problem now is higher non-exhaust emissions caused by larger and heavier vehicles. This is something else that will need to be solved via regulation. Other policies like Low Traffic Neighbourhoods can also help to restrict the worst pollution to major roads and away from where most people live.<p>Urban air quality is never going to be as good as that in the countryside, but it's not true to believe that no progress has been made, and that it's simply been a switch in the type of pollution.
For urban areas the risk of air pollution is another reason for cities to have congestion pricing to support public transportation.
> I am not sure that most people in urban areas even know what good air tastes and smells like.<p>I run air filters in my apartment throughout winter months, which tend to be the worst in terms of air quality here.<p>When I go outside in the morning I can really smell the stuff in the air, for a brief moment, until I get used to it. But you definitely notice the difference!
> Anecdotal, however, I used to work with meteorologists and they would always live to the West of the city centre, to get cleaner air than those living in the east of the city, or further downwind.<p>The industrial-revolution era mill owners were very aware of this too. Posh area of Manchester is to the south (westerly winds;) Leeds to the north (mix of northerly and westerly winds I believe).<p>Also, anecdotally, smaller towns and villages can have poor air quality too due to log burners. They're an absolute pain. You can tell when an area has become gentrified when shiny new chimneys start popping up or a log burner shop opens up!
Exhaust fumes were easy to optimize.<p>Lots of particles cars emit are from tires and break pads. I think someone was measuring that but I don’t have sources but most likely I read that somewhere in the comments of HN.
air pollution, light pollution, noise pollution, toxins and poisons, random falsehoods in your mind<p>facts that read as curse to be found on an amuelet dug up in some near(ish) future iteration of whatever the,, it is,, that we are doing right now
It sounds terrible . What will happend in the future?! The research doesn't differentiate between seasons , and every one knows how polluted the air is in the winter when everyone is heating their home and apartament.
In the future electric cars and heat pumps will improve the situation.
One more reason to look to an electrically heated future. Where I live the air becomes unpleasant in winter as some neighbours heat their homes by burning what i can only assume are old tires and horse carcasses.
I remember as a kid visiting the home of a relative who had an old oven for wood/coal heating, even though the primary heating was now a gas (natural gas not gasoline) heater.<p>The old oven remained though, and was used as a self-emptying trash can. When it filled up, a fire was lit to empty it. I don't remember what the sorting rules were (I assume "does it burn well and not smell up the apartment <i>too</i> badly when lighting it") and how common plastic packaging was back then, but I'm sure that the emissions coming out from the chimney were not a concern.
I look at the PM2.5 data for my city every day, and at this point (Nov) in the winter season, the only acceptable time to exercise is between 2PM-4PM after vertical mixing kicked in. Outside that duration, particulates are elevated after morning rush our, after evening rush hour, or during overnight inversion trapping evening rush hour + wood burning smoke until the next morning rush hour.<p>This is one the main reasons why I would prefer working remote, it is hard to utilize this time well (for exercise) if you are in the office.<p>At least with PM you can wear a mask, although I am still searching for the best one that works during intense exercise.<p>Also wanted to point out
"Trump EPA moves to abandon rule that sets tough standards for deadly soot pollution"<p><a href="https://apnews.com/article/epa-soot-air-pollution-trump-zeldin-deregulation-d7df5b24a159284e96b12958a840c3d8" rel="nofollow">https://apnews.com/article/epa-soot-air-pollution-trump-zeld...</a>
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