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NO2 is a very hazardous air pollutant which doesn’t get a ton of attention. The main sources are combustion engines and gas stoves. Asthma looks to be mostly ca

NO2 is a very hazardous air pollutant which doesn’t get a ton of attention. The main sources are combustion engines and gas stoves. Asthma looks to be mostly caused by gas stoves. I’ve got a sensor that can detect no2 and it noticeably spikes when using gas. Switched to induction after that.

enquirewithin 2mo ago
I’ve often wondered about this. Does the area immediately above where the gas stove was have an exhaust fan that vents to atmosphere? I would have assumed a properly specced exhaust fan would capture and remove combustion products from a gas stove?
- Gigachad 2mo ago
  I’ve never once been in a property that had an exhaust fan sufficient. I’ve had the exhaust on full blast and the spike on the air quality sensor on another floor of the house is rapid and massive. I suspect a sufficient ventilation would require something more like a lab fume hood that can pull a negative pressure on the area around the stove. And from what I have seen, a good number of exhaust fans are straight up fake and just ventilate back in to the room rather than ducted outside.
  - flir 2mo ago
    > And from what I have seen, a good number of exhaust fans are straight up fake and just ventilate back in to the room rather than ducted outside. Culinary Cargo Cult.
  - throwway120385 2mo ago
    There's a filter in it you're supposed to change regularly when they're in that configuration.
    - deleted 2mo ago
      [deleted]
    - Gigachad 2mo ago
      They contain a feels good filter to make you think something is happening. But to actually filter the pollution you'd need a activated carbon filter for the n02 and a hepa filter for the smoke. Which none of them contain and would clog rapidly. It's massively easier to just not create the no2 by replacing gas with induction, and to vent the smoke outside rather than trying to trap it in a filter. I think the introduction of cheap consumer air quality sensors like from IKEA will start to make this problem a lot more visible to people.
- rcxdude 2mo ago
  Can you smell what's being cooked on the gas stove? If so, the combustion products from the stove are also reaching your nose.
  - enquirewithin 2mo ago
    That’s a good point, and obvious now you point it out. On the other hand, when water turns into steam at standard atmospheric pressure, it expands in volume by about 1,700 times. Whereas the gas in your stove is already a vapour, mostly methane, turning in to mostly water vapour and carbon dioxide. So the expansion ratio isn’t going to be anywhere near as high as that. I’d say you’re still right. Still, I wonder to what extent an exhaust fan does help. If the exhaust fan can vent x cubic feet per minute and the room is y cubic feet in volume then it takes z minutes to full ventilate the room, etc etc.
- inigyou 2mo ago
  Air molecules move randomly at over 300 meters per second (not coincidentally close to the speed of sound).
  - enquirewithin 2mo ago
    That’s a hyper local measurement, and temperature dependant. You’d sure notice if the air in your kitchen was swooshing around at 671 miles per hour.
    - inigyou 2mo ago
      It squeezes me with approximately the weight of an elephant sitting on my chest. But humans are adapted to this and don't notice. It helps that the insides of my lungs are being squeezed outwards by the same force. Otherwise I surely couldn't breathe.
      - enquirewithin 2mo ago
        > It squeezes me with approximately the weight of an elephant sitting on my chest Nope. > It helps that the insides of my lungs are being squeezed outwards by the same force. So you agree your first statement is incorrect. I’m glad we sorted that out.
        inigyou 2mo ago
        I am indeed wrong. Air pressure is about 100kPa, which is to say 100 kilonewtons per square meter, which is about the weight of 10 kilokilograms or tonnes per square meter, and the surface area of a human is about a square meter, so the air pressure force acting on a human is about 10 tonnes, and an elephant weighs about 5 tonnes, so it's actually the weight of two elephants. So I am a bit wrong, but you are very wrong.
lompad 2mo ago
>Asthma looks to be mostly caused by gas stoves. Do you have a source for that? Because as far as I can see, asthma isn't _that_ less common in countries where gas stoves are barely used, such as germany. Still has like 60-70% of the asthma cases the US has. There's also a ton of other pollutants the US hasn't yet forbidden, but the EU has, which could also explain a lot of the difference in rates. Don't get me wrong, it's certainly a good idea to get rid of gas stoves. I just think it's a bit much to declare them the primary cause of asthma.
- agos 2mo ago
  Germany has a ton of NO2 for other reasons, for example diesel motors
  - AlecSchueler 2mo ago
    > N02 is a very hazardous air pollutant which doesn’t get a ton of attention. The main sources are combustion engines and gas stoves. Asthma looks to be mostly caused by gas stoves That makes sense but the unverified claim is that gas stoves are the main contributors to asthma.
- d2323 2mo ago
  This was in the news last month and might be referring to the same source 'Replacing gas stove can help asthmatics as much as some drugs, US experts find' https://www.theguardian.com/environment/2026/jul/24/replacing-gas-stove-can-help-asthmatics-as-much-as-some-drugs-us-experts-find https://www.theguardian.com/environment/2026/jul/24/replacin...
tim333 2mo ago
I suffered a bit from NO2 living near Oxford Street which got mentions such as "London’s Oxford Street is world’s worst place for toxic NO2 pollutant" https://www.cityam.com/londons-oxford-street-worlds-worst-place-toxic-no2-pollutant/ https://www.cityam.com/londons-oxford-street-worlds-worst-pl... It's better now with more EVs and low pollution vehicles and the street should be pedestrianised from October.

enquirewithin 2mo ago

I’ve often wondered about this. Does the area immediately above where the gas stove was have an exhaust fan that vents to atmosphere? I would have assumed a properly specced exhaust fan would capture and remove combustion products from a gas stove?

Gigachad 2mo ago
I’ve never once been in a property that had an exhaust fan sufficient. I’ve had the exhaust on full blast and the spike on the air quality sensor on another floor of the house is rapid and massive. I suspect a sufficient ventilation would require something more like a lab fume hood that can pull a negative pressure on the area around the stove. And from what I have seen, a good number of exhaust fans are straight up fake and just ventilate back in to the room rather than ducted outside.
- flir 2mo ago
  > And from what I have seen, a good number of exhaust fans are straight up fake and just ventilate back in to the room rather than ducted outside. Culinary Cargo Cult.
- throwway120385 2mo ago
  There's a filter in it you're supposed to change regularly when they're in that configuration.
  - deleted 2mo ago
    [deleted]
  - Gigachad 2mo ago
    They contain a feels good filter to make you think something is happening. But to actually filter the pollution you'd need a activated carbon filter for the n02 and a hepa filter for the smoke. Which none of them contain and would clog rapidly. It's massively easier to just not create the no2 by replacing gas with induction, and to vent the smoke outside rather than trying to trap it in a filter. I think the introduction of cheap consumer air quality sensors like from IKEA will start to make this problem a lot more visible to people.
rcxdude 2mo ago
Can you smell what's being cooked on the gas stove? If so, the combustion products from the stove are also reaching your nose.
- enquirewithin 2mo ago
  That’s a good point, and obvious now you point it out. On the other hand, when water turns into steam at standard atmospheric pressure, it expands in volume by about 1,700 times. Whereas the gas in your stove is already a vapour, mostly methane, turning in to mostly water vapour and carbon dioxide. So the expansion ratio isn’t going to be anywhere near as high as that. I’d say you’re still right. Still, I wonder to what extent an exhaust fan does help. If the exhaust fan can vent x cubic feet per minute and the room is y cubic feet in volume then it takes z minutes to full ventilate the room, etc etc.
inigyou 2mo ago
Air molecules move randomly at over 300 meters per second (not coincidentally close to the speed of sound).
- enquirewithin 2mo ago
  That’s a hyper local measurement, and temperature dependant. You’d sure notice if the air in your kitchen was swooshing around at 671 miles per hour.
  - inigyou 2mo ago
    It squeezes me with approximately the weight of an elephant sitting on my chest. But humans are adapted to this and don't notice. It helps that the insides of my lungs are being squeezed outwards by the same force. Otherwise I surely couldn't breathe.
    - enquirewithin 2mo ago
      > It squeezes me with approximately the weight of an elephant sitting on my chest Nope. > It helps that the insides of my lungs are being squeezed outwards by the same force. So you agree your first statement is incorrect. I’m glad we sorted that out.
      - inigyou 2mo ago
        I am indeed wrong. Air pressure is about 100kPa, which is to say 100 kilonewtons per square meter, which is about the weight of 10 kilokilograms or tonnes per square meter, and the surface area of a human is about a square meter, so the air pressure force acting on a human is about 10 tonnes, and an elephant weighs about 5 tonnes, so it's actually the weight of two elephants. So I am a bit wrong, but you are very wrong.

lompad 2mo ago

>Asthma looks to be mostly caused by gas stoves. Do you have a source for that? Because as far as I can see, asthma isn't _that_ less common in countries where gas stoves are barely used, such as germany. Still has like 60-70% of the asthma cases the US has. There's also a ton of other pollutants the US hasn't yet forbidden, but the EU has, which could also explain a lot of the difference in rates. Don't get me wrong, it's certainly a good idea to get rid of gas stoves. I just think it's a bit much to declare them the primary cause of asthma.

agos 2mo ago
Germany has a ton of NO2 for other reasons, for example diesel motors
- AlecSchueler 2mo ago
  > N02 is a very hazardous air pollutant which doesn’t get a ton of attention. The main sources are combustion engines and gas stoves. Asthma looks to be mostly caused by gas stoves That makes sense but the unverified claim is that gas stoves are the main contributors to asthma.
d2323 2mo ago
This was in the news last month and might be referring to the same source 'Replacing gas stove can help asthmatics as much as some drugs, US experts find' https://www.theguardian.com/environment/2026/jul/24/replacing-gas-stove-can-help-asthmatics-as-much-as-some-drugs-us-experts-find https://www.theguardian.com/environment/2026/jul/24/replacin...

tim333 2mo ago

I suffered a bit from NO2 living near Oxford Street which got mentions such as "London’s Oxford Street is world’s worst place for toxic NO2 pollutant" https://www.cityam.com/londons-oxford-street-worlds-worst-place-toxic-no2-pollutant/ https://www.cityam.com/londons-oxford-street-worlds-worst-pl... It's better now with more EVs and low pollution vehicles and the street should be pedestrianised from October.