I picked up a CO2 monitor a while ago myself, and the biggest surprise was having it on in the morning in our bedroom with the doors closed. It was easily over 1000ppm IIRC.
Ever since then I've made sure to set my AC system to run the "house fan" for 15 minutes or so every hour at night just to circulate the air in the house, and while the numbers went down significantly, anecdotally I swear that I wake up easier in the mornings now.
Another surprising place that really high CO2 concentrations show up? The inside of full face motorcycle helmets when at a stop. IIRC they quickly reach as high as 20,000ppm! There is also some speculation that full-face motorcycle helmets that stay closed in an accident are more dangerous in some ways, as the high CO2 concentrations in the helmet can be really dangerous to an unconscious person's brain function.
Exhaled breath is about 3.8% or 38000ppm so (20000) that's really high! I'm not too surprised since the turnover rate through a few small holes with a relatively large volume is bad. Reducing the facial volume would help a lot as each breath would expel more CO2 as a fractional percentage.
It seems that any sort of face covering or even significant exercise could raise your ambient CO2 level well above 1000ppm.
I'm a bit surprised that levels 38-60x below our exhalation % (and it's not lack of O2, because you use up less than 10%/breath) has such a significant effect. The one thing that may drive it is that the efficiency of lung ab/desorption goes roughly as the square of concentration so a 2% change in CO2 concentration might be enough to have an effect on O2 and blood pH.
Really interesting article... all the numbers are completely believable, but seem really high based on the conference room effects at 0.1% They even refer to a person without a helmet in still air as being at 2000ppm, which is comparable to the worst tested "school house" data.
I'd argue that if there is an effect here it isn't the O2 concentration since a 1% change in atmospheric pressure happens at about 275ft. That's a pretty small hill!
A 1000ppm change in 02 partial pressure happens in about 30C temperature change. Really, if this is a real effect it better be actually due to some effect of C02 concentration.
> "house fan" for 15 minutes or so every hour at night just to circulate the air in the house,
Depending on your climate, this could significantly raise the humidity in your house. Reason is that moisture from the AC coil are wet after the AC turns off. Typically drips off into the pan until next time AC cycles.
If you run the fan you will then evaporate into the air circulating some of the moisture just removed.
I live in florida, so I'm well accustomed to the humidity! But thanks for the tip, I actually hadn't thought about that.
Part of my home automation system is humidity sensors as well, and while they do spike over 65% sometimes (probably when we have the windows open), they stay around 55% to 60% for the past 30 days. Since I'm only running that fan cycle at night, when the AC tends not to run or not run as much, I'm guessing that helps mitigate the effects of that.
Doesn't that heavily depend on the design of the AC system? I know nothing here, so this is heavily a question.
I ask because I have a heat pump for cooling/heating, but the furnace is the blower. I thought when the fan ran, it pulled from the outdoor intake which is in a very different location from the actual heat pump coils.
that moisture came from inside the house. When it drips, it usually drains outside the home. Perhaps it just pedantic, but it won't raise humidity, but it may lower less.
Helmets? That's interesting; I tend to open the visor a bit when at a stop, it gets really warm in there really fast. I know you shouldn't try to take off a helmet in case of an accident, but is opening the visor at least okay?
> I know you shouldn't try to take off a helmet in case of an accident,
At least here in Germany this advice is considered outdated and people in (mandatory for driving) first aid courses get taught a simple technique to remove a helmet safely (ideally with two people).
Reason being is that with the helmet on it is harder to monitor breathing and impossible / very difficult to do CPR, and the helmet will also interfere with the stable side position.
It’s interesting to see how differently first aid is taught across countries. Eg the last training I did in the US (California), I was surprised by two things that I had not encountered when I was trained in France:
- a big concern around pathogens - always have gloves with you and put them on when administering first aid especially if the person is bleeding; use a mouth dam for mouth to mouth and if you don’t have one don’t do mouth to mouth, just chest compressions, etc
- training first aid responders around what to do when a person needing medical attention tells them not to help because they don’t have health insurance (this point was repeated numerous times by the EMT training us, saying it was routine for them to have to deal with it)
Can you expand on your second point, if you have a moment?
I knew someone (in California) who crashed his bicycle on a curb in front of a number of people. He picked himself up and had a bloody but minor wound on his arm. But overall he was unharmed, just some surface bleeding.
"Of course" multiple people called 911, and an ambulance arrived in short order. He had insurance, but he wasn't interested in getting in an ambulance, he wanted to look after his bike while wrapping up his light wound, and then treating it later.
I'm told the exchange was awkward to say the least.
Interesting. I'm an American, and once sustained a bloody but minor scrape of my knee when playing basketball in China. I went to the campus clinic/dispensary to obtain some bandages, since I couldn't find any that were the right size at the nearby convenience store; there, the staff practically tried to admit me, telling me that I had sustained a very serious injury and that I needed to take it seriously and start a course of antibiotics. After an awkward conversation concerning my refusal to take antibiotics without (what I deemed to be) sufficient cause (being mindful and wary of the resistance risks of an unnecessary course), and their belief that I was being disrespectful of their medical expertise, I left with a bottle of antibiotic pills that I never took. My knee was as good as new in a week or so.
Point being, medical cultures can differ quite a lot, even from locality to locality, and the differences can be seen even in the handling of minor scrapes.
Correct me if I'm wrong: I think that a wound that is bleeding is a wound that's, at least in part, being protected from infection by 'internal positive pressure'.
My grandpa taught me that; to let wounds bleed freely for a while, if possible, to reduce the chance of infection.
The most surprising things I was taught when taking classes in Germany (which went beyond the mandatory classes you have to take to get a driver's license) are the following. Well, not really surprising once you think about it...
- Mouth-to-nose is usually better than mouth-to-mouth, at least when there is no obstructions (like bleeding, broken nose, snot, etc).
- If you're doing chest compressions, expect a high probability of breaking a few ribs. Don't stop, as it is highly unlikely the ribs will break "inwards" and puncture a lung, and a broken rib is still better than being dead.
- Remove all clothing from the chest area you're working during CPR. Yes, that includes bras, specifically. The reason being that any clothes will hurt your hands/rip your gloves (if you have some)/shave the skin off your hand especially when you have to do CPR for 15mins. Bras in particular often have wires etc in them that will hurt your hands even worse. As one of the EMTs training us put it: "Don't be shy, no time for false modesty, it may cost a life."
- Don't forget to breath when giving mouth-to-*. Also, don't forget to actually lift your head when you breath. Else you will just breath in the spent air again that you and the person you're helping just exhaled. Given that CPR is very physically taxing, according to the EMTs it is quite common for people giving the CPR to faint themselves if they breath incorrectly.
- It is more important to call for help than to do CPR. Always call first, if you're alone. And stay on the phone until you're being told you can get off the line. Apparently a lot of people either do not call, or call, scream some stuff into the phone, then hang up to administer help, often forgetting to tell crucial details like their location because it is such a high stress situation.
- Defibrillators do not actually restart hearts that stopped beating. They essentially stop the heart in order to reboot it in hopes it will restart with a proper pace/rhythm.
It's not usually taught, I think, because if you dony have a knife (which is what professional rescuers will use if they need to do this), removing clothes tends to add delay and also involve moving the subject, both of which are strongly contraindicated in most circumstances where a lay rescuers needs to use CPR in the first place.
The man has a pretty good explanation in that case, iff there was a good reason to administer CPR. So what would it cost the rescuer, exactly? Unless you start undressing every unconscious woman you encounter, even if they seem to have no other problems...
People have been sued for injuries caused while performing CPR, so I could certainly imagine someone being sued for undressing a person (without their consent, obviously) to perform CPR.
You can sue anyone for just about anything. But it doesn't seem like a very winnable case to me. Maybe in some crazy jurisdictions. Many places have 'good Samaritan' laws that protect people who are not medical professionals when they cause injuries during a good faith attempt to safe someone's life. I would assume injuries to someone's modesty are included...
At the end of the day, would you rather let a woman in need of CPR die because you are afraid of maybe getting sued, with an even smaller chance of a conviction?
There's also the court of public opinion to consider, in which actual legal standing is irrelevant. Small comfort if you successfully rebuff a suit but lose your reputation in the process.
In Germany not performing what we call "lebensrettende Sofortmaßnahmen" (stable side position, clearing airways, CPR) is (at least technically) criminally liable to § 323c StGB. I shall also point out that first responders have some legal protections and insurance.
Do you have a link for that? Every time I look into one of these/similar stories it is a shitty insurance company either heavily encouraging or basically forcing the suit if the person wants to be covered for their injuries at all.
This should not happen. Another rule is that you must not to put yourself on top of the victim or walk crossing over the body of other people. Is disrespectful and can be dangerous also. You have to sidestep it and approach from one of the sides.
I understand how social rules about touching other people can differ in different cultures, but a side position looks clearly different to a "riding" position to me in this sense.
People feel often ashamed, can feel humiliated, violated, happy, sad, or anything their want, but they have to understand that CPR means that 1) you life is at risk and 2) some stranger(s) will put their mouth in yours and their hands near your breasts for some time. Period of time that can last for many minutes or even hours. Often longer than the duration of most violations. There is often a legal obligation to do it for some people. To pass and quit the area is not an option.
Sorry but there is no time to find a young sexually acceptable partner for you to happily wake up in her/his arms and upload your booze adventure to instagram, forever-happy style. Deal with it. There is nothing sexually arousing in the experience for the rescuers about your vomit taste or about your body leaking different kinds of fluids over yourself. Not even remotely.
If the person is able to tell you that they have no insurance, this by itself means they're able to talk reasonably, this means they are conscious and can breathe and so (absent heavy ongoing bleeding e.g. from a gunshot wound) they aren't dying right now - so urgent emergency healthcare isn't really required.
If they can move on their own, then they can get to the clinic of their choice themselves if and when they choose to; if they can't (which can be caused by anything from a sprained ankle to a fractured hip) then they still may prefer to be delivered to the hospital by family&friends or a taxi instead of paying thousands for an ambulance delivery.
good point about using that as an assessment of the persons state of being. they still could be bleeding however which needs to be stopped unless it's just surface scratches, or have broken bones that need temporary stabilizing.
it seems other than for the first point the question only becomes relevant after any relevant first-aid actions are completed.
i have been in a situation where a guy fell out of his wheelchair. he wasn't injured, he just could not get back into his wheelchair and he was to heavy for any of us to help him without us risking to drop him in the process which might have then actually risked an injury. he looked like the kind of person who might not have had insurance. though he didn't make any statement about that and no-one even considered that to be an issue. we saw no choice but to call 911, which sent an ambulance with people who could help (and they knew him too).
i wonder now how we would have reacted if he had told us that he has no insurance. we might have been looking for alternative help with an outcome that could have been good or bad.
with that in mind i'd think other than for the reasons you mentioned the statement should be ignored.
Yeah ever since I read that, I crack the visor or open it when i'm sitting still.
And for opening the visor in accidents, I'm no expert but I believe it would be safe to do if you can do it without moving their head. IIRC the reason you don't want to take off the helmet is because you could strain their neck doing so. If you could move the visor without moving their head, it probably won't hurt, but at the same time I'm not sure if I'd worry about that in this kind of situation (having seen a motorcycle accident, the amount of co2 that person is breathing is, to me anyway, far down the list behind "call 911" and "make sure they don't get run over again").
I think the findings were more to try and get the helmet manufacturers to design systems which let more air in during an accident or when stopped.
[1] has the study I remember reading about, and it turns out that according to their abstract, opening the visor at a stop has little effect on average! So maybe my behaviour of cracking the visor isn't doing much...
Moving an unconscious person's head or neck can cause paralysis (if they have a spinal injury). Don't do it without training. In a city it's almost surely best just to wait for the EMTs.
Unless it is terribly cold, I always run a small crack at low speeds. My helmet has a notch that is just a half inch of crack. At high speeds the vents pull air through. It is funny because I never thought about CO2, just that it is too freaking hot.
I used to ride with a just-a-bit opened visor because it was so hot in the city, with all the traffic and all, (and the beard didn't help the air flow) so I ended with eye infection because of the dust ingress. So I just bought one with better vents (and audio). Worth every $ even though I had to patch the audio circuitry a bit.
Yeah I always open my visor when I'm stopped/riding slowly for longer than I can comfortably hold my breath. Depending on the temperature outside, if I don't open my visor it will fog up real fast.
I monitored the CO2 in my bedroom every second for three months and I found results similar to you. If I was sitting right next to the sensor in the evening it would go up to about 1900 ppm. Cracking open the window for an hour or so eventually brought things down to the 500ppm range.
What was interesting is how fast the ppm increases when someone enters the room. I would plot the data and see a blip on the graph when I entered. It was within seconds of entering.
I noticed the same when I am sitting near the sensor. I'm thinking though that it is partially due to me essentially breathing onto the sensor and the sensor dynamics having an averaging function so that I'm not sure what the sensor reports and what I breathe in are the same. Repositioning the sensor so it wasn't in the "line of sight" of my breath changed the readings significantly.
Your post has made me consider getting a C02 monitor, will something as simple as this 20 buck Chinese version suffice? https://www.newegg.com/Product/Product.aspx?Item=9SIADJN8NP4...
Seems a useful thing to have. Separately it is very stressful being on stage at conferences that are stuffy with no fresh air, hot stage lights and probably very low oxygen. I had a friend who did press ups before going on stage to energize herself as the tech conference chair and raise the energy level of the sleepy audience - she got really out of breath!
I can't see that link (it says the product ID is invalid), but I know that measuring CO2 is actually pretty hard and requires some somewhat expensive stuff, but measuring things like O2 is easy (i believe, i'm going from memory here).
So most cheap CO2 monitors are actually just oxygen monitors that aren't actually measuring the CO2 levels but are measuring the drop in O2 levels and extrapolating from there.
I don't know if that matters for what you might want to use them for, but it's something to be aware of.
I don't have mine any more, I actually borrowed it from a friend and it was a fairly expensive one (like in the $200 range) that he was using for some other stuff.
IIRC the thing to be aware of is that a monitor that actually measures CO2 is going to cost several hundred dollars. The cheap ones don't measure CO2, but some kind of VOC as a proxy. So depending on the source of the CO2, they can be more or less accurate.
Something to research. I'm not an expert, just someone who recently did some shopping for CO2 monitors for my home.
I didn't. Part of my requirements are that I can tie the device into my home automation. After doing a lot of digging and not finding something I wanted, I shelved the idea of adding CO2 sensors to my house for now. Decided instead to just assume CO2 was high, and I'm having a whole-house HRV installed in a few months.
I wonder what the number is for people who wear respirators for dust/fumes. There's the paper masks people are most familiar with and the charcoal canisters for working with chemicals. Since it's sealed off would it be even higher than a motorcycle helmet?
There’s probably all kinds of confounding factors here, but on high pollution days (code purple air quality) when I’m bicycling I need to take my N95 mask off every few minutes for “fresh air.”
> I picked up a CO2 monitor a while ago myself, and the biggest surprise was having it on in the morning in our bedroom with the doors closed. It was easily over 1000ppm IIRC.
I did quite a lot of research trying to find the best CO2 sensor that would also do humidity/temperature. CaDi by nuwave* is what I settled on. An Irish company. I've been using it for a week now and it is working great! Things that surprised me: the difference it makes if I leave all the internal doors open in the apartment, not just the bedroom door. That even leaving one window open just a crack will help with ventilation. And of course how quickly a room with couple of people in it can go above 3000ppm CO2.
I always sleep with the window open, because the fresh air feels nice.
In evolutionary terms, you could speculate that the nice feeling of fresh air could be an instinctual response directing the organism to seek higher quality air.
It's a greenhouse CO2 monitor, which is the most common kind. I've heard that they're not as accurate as CO2 monitors that are designed for humans, but those tend to be much more expensive.
As a full face helmet proponent and user (since I started riding motorcycles in India), your comment really makes sense.
This is something I used to do almost on instinct,usually at lower speeds (because the helmet had a sort of an intake and a vent that worked well at higher speeds).
Ever since then I've made sure to set my AC system to run the "house fan" for 15 minutes or so every hour at night just to circulate the air in the house, and while the numbers went down significantly, anecdotally I swear that I wake up easier in the mornings now.
Another surprising place that really high CO2 concentrations show up? The inside of full face motorcycle helmets when at a stop. IIRC they quickly reach as high as 20,000ppm! There is also some speculation that full-face motorcycle helmets that stay closed in an accident are more dangerous in some ways, as the high CO2 concentrations in the helmet can be really dangerous to an unconscious person's brain function.