Hacker News Reader

Comment by rahuldottech | Hacker News Reader

This really bothers me. I live in a VERY polluted place, and unfortunately moving away won't be an option for me for at least half a decade. What can I do to minimise the health effects of such an atmosphere? I'm planning on getting an indoor air filter for my home.

View on HN

Buy a cheap PM detector (There are a few on Amazon using the Plantower sensor that are ~$50.) Buy any HEPA air filter for your home. Buy the best cabin air filter you can for your car (Bosch makes HEPA filters for some cars), and try to get your office to install something, or just buy one for your desk.

The hard math of it is that no matter what you do, you aren't going to be able to reduce your exposure by more than 75% or so, because you have to go outside sometimes, so going super high end on filtration makes essentially no difference in terms of total exposure.

> The hard math of it is that no matter what you do, you aren't going to be able to reduce your exposure by more than 75% or so, because you have to go outside sometimes, so going super high end on filtration makes essentially no difference in terms of total exposure.

Couldn't you get a mask for outdoor use?

https://www.guidingtech.com/62349/whats-difference-n95-n99-p...

You can. However a mask on your face is not comfortable and so in practice I doubt you would wear it unless there was great need.

I wore a mask all day Saturday while working on the insulation in my attic. I can report it was easier to breathe at the end of the day than times I've been in there without a mask. (fiber glass is not easy on the lungs - though there may be some other factor not related to the mask involved). However I also had red marks across the back of my head where the bands were digging in. It was also more tiring to breathe wearing the mask all day.

Sure, but what about when you eat? What about when you're exercising? My point is that caring much about filtration efficiency quickly stops mattering after you've done the obvious things, because there are simply going to be times where you're not breathing filtered air, and those will very quickly become your main source of exposure.

This also means that if you feel like you need to get a mask, you should probably get the most comfortable, least restrictive one, even with a worse rating because (say) 90% filtration all the time is better than 99% filtration 80% of the time (if the discomfort causes you to take it off 20% of the time)

I think it's more like 99% on particularly bad days, because where I live over 100 ug/m3 is common during the fire season (which is apparently now November to April)

But if you live in places where the particulates are normally low then yeah, cutting from 50 to 5 is hard.

As an aside, I recently bought a car that has a cabin air filter, a first for me. I am genuinely surprised at how much of a difference it makes, especially on air quality alert days. (I live in the Bay Area, which isn't too bad, but we've had plenty of Spare the Air alerts this year.)

Is the Plantower sensor a very precise one? I'd like to buy an air monitor, but of course there's no way (at least for me) to know which ones are precise and which aren't.

If you care about accuracy, my understanding is that the Purpleair is your best choice. I don't care about absolute accuracy, although it seems to agree within 10% or so with nearby putpleairs.

The main reason for a monitor is just to make sure your filtration is working and sized appropriately. Take it outside, take a reading, take it inside, see if it's a lot lower. I don't see a need to spend a lot for this or install something that connects to my wifi and needs to be updated etc.

Starts with monitoring. Awair or laseregg are good quality monitors. Then you can assess how well filters work.

I think there are masks you can use outside too. You can also check which times of day/days are worst. And which streets. You can carry the laseregg around for local measures.

PurpleAir also makes an indoor air quality sensor that measures particulate matter: https://www2.purpleair.com/products/purpleair-pa-i-indoor

Not sure how it compares with Awair or laseregg.

I have no affiliation with PurpleAir, but they are pretty popular in Utah.

Just google brands and find that they may be not so accurate or may be calibrated for some specific region of China

https://smartairfilters.com/en/blog/how-accurate-are-common-...

So may be better solution are local laboratories with calibrated equipment

Masks are tricky.

Most "light" masks are for huge particles and can't defend against most of dangerous chemicals

Military and science masks are working good against some chemicals and do not protect from another. Except solutions with O2 tanks on your back

I'm not sure what _VERY_ polluted means, but you might consider taking up more physical activity. On GCN youtube cycling channel they argued (including interviews with some health professionals) that even if you live in a city with considerable pollution, the positive effects of commuting on a bicycle outweigh the negative effects of air pollution. They were primarily talking about Britain-scale pollution of course. The principle might change if transfered to a more extreme environment. Something to look into.

My hunch is OP lives in an Indian metro. I absolutely do not recommend commuting on a bike or exposing self to outdoor air in any way during a commute in an Indian metro.

Any physical exertion that makes you breathe harder will cause you to take in more pollution, worsening the effects. Even if exercise helps to offset the damage, your best bet in a polluted place would be to do it inside.

It's about the balance of positive and negative effects. There's always some kind of pollution and there's always some kind of benefit from exercise. The benefit from commuting on a bicycle is considerable. Question is how does the effect of pollution compare. If air quality is better indoors and you can do it indoors, great, but for many people commuting is one of the few opportunities to be physically active.

There's been studies done specifically on people cycling to work, and IIRC the conclusion was that the overall QALY result was significantly positive. But that does depend on your baseline - for someone who is fit and active anyway the marginal gain might be small, but for the average person the 10+ QALYS you get from being active vastly outweigh the combined (run over + pollution + injury) cost.

https://eos.org/articles/novel-air-pollution-study-gauges-in... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2920084/

I'm assuming Delhi?

Not much you can do except get out. I've already started moving out for the first 2-3 weeks of November and working from a city like Panjim

Its not difficult, firstly buy a monitor which tracks CO2, PM2.5, VOC:

https://www.aliexpress.com/item/32887570197.html?spm=a2g0s.9...

Tracking CO2 is very useful for internal spaces.

And an Air purifier: https://www.amazon.com/Purifier-Display-Formaldehyde-Sterili...

Why is the first step to monitor it, not 'get a HEPA filter & fan / purifier'?

Monitoring seems like it's interesting to do if you want to, but if you already know it's an issue, just start addressing it?

Yeah, I'm confused by all the comments saying this too, especially since those detectors are yet another nontrivial expense.

If you know you're in a polluted environment, why would you need instrumentation before taking action? To me it's like getting blood work done before you err on the side of exercising.

If you're closing up your house to avoid outside air pollution, you will spike your CO2 levels.

You need to keep enough ventilation going to ensure you don't exceed 800ppm CO2.

You also need to monitor the PM2.5 levels to ensure your air purifier is working.

An air quality monitoring device is an essential piece of equipment for anyone.

> You also need to monitor the PM2.5 levels to ensure your air purifier is working.

But if you don't have an air purifier, and you're concerned about air quality, surely you want to get one before you start worrying about whether or not it's working?

Or both at the same time, sure, my only point is that if there's already concern I don't see the point in monitoring before or without mitigating.

Do you live in Beijing?

We got an expensive swedish air purifier but it still sucked hard (noisy, made the air smell very stale). You might be able to mitigate some of the effects, but not all of them. And if young kids are involved (or you are expecting), screw the career, move.

Did you get an IQAir? I bought the GCmultiGas and I get the kind of stale air, I think it is just hyper sanitized or something. That filter cleared up my sinus issues in like two days.

It’s called BlueAir I think? That life is behind me now. I love living in china, but the air pollution is a deal breaker.

https://www.consumerreports.org/cro/news/2011/07/why-not-a-d...

Find one that can filter nano particles.

https://www.bbc.com/future/article/20191113-the-toxic-killer...

That's brutal! We're poisoning ourselves.

Essentially all air filters filter nano particles.

https://smartairfilters.com/en/blog/can-hepa-filters-capture...

That's specific to HEPA filters. Most air filters are not as capable as HEPA filters.

Read the rest of the article. The cheap furnace filter filters nanoparticles too, just not as well. Both larger and smaller particles are pretty easy to filter. It's the ones around 0.3um that are the toughest to filter.

Reply on news.ycombinator.com