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I’m in New York right now and I’m seeing a lot of news / government warnings to stay indoors due to the wildfire smoke.

For example: Stay indoors, mask up: Staying safe as ‘hazardous' smoke levels choke NYC area

I don’t have an air purifier in my home. So is my indoor air actually safer? How is the air getting filtered?

Laurel
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Elliot Gorokhovsky
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  • This can use some details about what it means by reducing wildfire smoke – Joe W Jun 09 '23 at 12:40
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    @JoeW There's a huge wildfire going on in Canada for the past week or so. The smoke has drifted down to northeastern US, and it's causing terrible air quality along the eastern seaboard. – Barmar Jun 09 '23 at 15:00
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    @Barmar I understand that but the question just asked if staying indoors reduced wildfire smoke and I was asking for more details about what was being asked as that didn't make any sense to me. A question should include details from the claim so that people don't need to read third party sources to understand what is being asked. As the question has been edited it makes a little more sense as to what the claim is as it isn't reducing wildfire smoke but protecting you from it. – Joe W Jun 09 '23 at 16:20
  • It does have a link to the specific advisory about this instance. – Barmar Jun 09 '23 at 16:21
  • @JoeW I agree -- this question has no claim. It should be in maybe Physics. For decades people have been asked to stay indoors on bad air days (most often smog in CA) and this is no different. It's not controversial. And it's easily Googled. – Owen Reynolds Jun 09 '23 at 21:14
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    @Barmar I know that but as I said people should not have to visit a third party site to understand the question. – Joe W Jun 09 '23 at 23:18
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    Your carpet, sofa, curtains, clothing, walls etc. adsorb the smog particles (very effectively) so you don't breathe them in any more, and you get rid of them with the next run of the washing machine, or next spring cleaning. – Karl Jun 11 '23 at 21:14
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    If you have central HVAC in your home, you have an air filter/purifier, at least a primitive one. – R.. GitHub STOP HELPING ICE Jun 11 '23 at 22:11

1 Answers1

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Yes, for some time.

Your home acts as gas-reservoir for a time.

International Energy Agency’s information centre on energy efficient ventilation. writes

Summary
Evacuation of people from their homes and workplacesis a standard response to the hazards created by the release of toxic gas. However by staying indoors a person can take advantage of the clean air stored within the house volume, as well as the damping the house provides for sudden changes in outdoor toxic gas concentration. The relation between indoor and outdoor concentration is explored in this study, where it is shown that in most cases the risk of exposure to high concentration levels is substantially reduced by remaining indoors during the entire period of toxic gas release. Ratios of indoor to outdoor concentration are presented for typical rates of air infiltration and outdoor concentration variation

In prolonged cases your house air will run out and effect is diminished.

Your building shields your partly from fine-particles and smoke

EPA on Wildfires and Indoor Air Quality

When wildfires create smoky conditions, there are things you can do, indoors and out, to reduce your family's exposure to smoke.

However, they also suggest taking action by using portable filters:

Have a supply of N95 respirators and learn how to use them.
Indoor Air Filtration

Tl;dr: it's safer for a time, but you or your building management needs to take action. In any case, it's better then outdoors.

pinegulf
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    To add to this, staying indoors would be less effective when toxic gasses persist over long periods of time, but most cases aren't predicted to fall into this category (and when they do, an evacuation is likely to be ordered). And even if it does persist over long periods of time, a house with closed windows and doors may still block some of the gasses. – NotThatGuy Jun 09 '23 at 11:12
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    @NotThatGuy it's further complicated by being a mixture of gases and particulate matter. The latter can be filtered (to some extent) with readily-available materials, the former can't. The first (IEA) quote, discussing gases, is relevant, but perhaps less so than it seems, given that in the context of this question particulates are the bigger threat. – Chris H Jun 09 '23 at 13:09
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    Also, not for nothing, but people who are staying inside are definitionally *not* driving around in their cars (or riding in taxis, this being New York), and thus adding exhaust to the already polluted air. Reduced auto traffic doesn't make the air quality any *better* (in terms of wildfire smoke), but it does help to stop making it *worse*. – Darrel Hoffman Jun 09 '23 at 13:40
  • @DarrelHoffman Wildfires produce a smoke problem. Exhaust pollution is irrelevant here. Reducing the number of cars on the roads does nothing to protect humans from the effects of wildfires. – Therac Jun 09 '23 at 17:22
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    @Therac I'm saying, in a cumulative sense, wildfire smoke + auto exhaust has to be at least *slightly* worse than just the smoke. Now if everyone in NYC drove EV's, it wouldn't make a difference, but we're not there yet. You have an A + B = C situation. If you want to reduce C but you can't do anything about A, your only option is to reduce B instead. – Darrel Hoffman Jun 09 '23 at 18:15
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    @DarrelHoffman Being shot at + drinking water from lead piping is also slightly worse than just being shot at. But does it make a ban on lead piping a viable way to address gang violence? – Therac Jun 09 '23 at 18:19
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    The difference is that those are entirely unrelated, and there's no common protection from both bullets and lead in the water. In the case of exhaust and smoke, staying indoors, using air purifiers, wearing masks, etc. all of the same measures help for both things. And reducing exhaust will reduce (even if only by a small degree) the collective strain on air purifiers, allowing them to work more effectively against other pollutants such as smoke. – Darrel Hoffman Jun 09 '23 at 18:26
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    @DarrelHoffman It is the lead in both the bullets and the water which damages you (albeit in different ways) – Henry Jun 09 '23 at 18:32
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    @DarrelHoffman EVs aren't particulate-free either (extra tyre wear from such heavy vehicles) - so even they would make a difference - still a small one though. – Chris H Jun 09 '23 at 20:57
  • "Settling velocity. A particle in stationary air will settle under the action of gravity and reach a terminal velocity quite rapidly." https://www.sciencedirect.com/topics/physics-and-astronomy/settling-velocity "Particles from smoke tend to be very small (with diameters of 2.5 micrometers and smaller)." https://ww2.arb.ca.gov/protecting-yourself-wildfire-smoke – Mazura Jun 10 '23 at 02:10
  • "Particles with radii between 0.1 and 1.0 micrometers (a micrometer is one-millionth of a meter) can stay aloft for 20 or more days. Larger dust particles with radii between five and 10 micrometers usually fall out of the sky within 24 hours." https://www.nesdis.noaa.gov/news/the-dirt-atmospheric-dust – Mazura Jun 10 '23 at 02:10
  • It's like when the power's out you don't stand there in front of the fridge like usual. W/e it is, somewhere between 20h or 20d, it will settle, but not if you keep opening the door of your hermetically sealed house. ... Which if it is, close the outside fresh air intake on the *duct work* of your furnace.( *Not* the exhaust or the combustion air intake which are usually the two PVC pipes) – Mazura Jun 10 '23 at 02:15
  • *Furnace Fresh Air Intake?* https://diy.stackexchange.com/a/263901/23295 – Mazura Jun 10 '23 at 02:26
  • While a sealed house will prevent much of the particulates from entering, there's also the factor that most modern houses are heated (and cooled) by a forced-air furnace. These have fans and filters that will clean some of the particulates from the air. [What is a Merv rating for furnace and air filters?](https://www.furnacefilterscanada.com/what-is-merv-rating/) shows that the better quality filters will handle smoke. – Ray Butterworth Jun 11 '23 at 02:50
  • @DarrelHoffman: And wildfires also correlate with climate change, and thus with automobile traffic, among others. – Eric Duminil Jun 12 '23 at 06:57
  • I think this would be better served in Chat. How does one do this moving? – pinegulf Jun 12 '23 at 09:37