Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

The Weight of Numbers: Air Pollution and PM2.5

undark.org

Post reply on HN
Print view View original

31–40 of 68 posts

Re: The Weight of Numbers: Air Pollution and PM2.5

#31

Post by mturmon »

jonathankoren wrote: post #19
mikeyouse wrote: post #15

Does anyone have a sense of where the damage is done regarding PM? I live in SF and our apartment is a block away from a busy road and a gas station, both of which concern me. Not to mention the wild fires of late depositing ash all over our yard.. Also, being a SF apartment, there isn't A/C so we leave the windows open on hot days. Is there data around whether an active air filter running in a closed room before we…

Purpleair.com has a map of of sensors that update in near real time you can look at.

That is a cool site. I had not known there was such an extensive sensor network out there.

One thing to remember about the kind of location the parent comment wrote about: particulates are very local. Trace gases like O3 or CH4 can have very sharp spatial gradients - e.g., near highways, major streets, or dairy farms. You can observe sharp decreases from emission levels to background levels within 10s of meters. And PM2.5 mixes even more poorly than these trace gases, meaning PM2.5 shows sharper gradients.

So, if you live in a built-up area and you really want to find out about PM2.5 due to your open window, or on your patio or backyard, you may need a very close-by measurement.

You will still observe correlations between health outcomes and mean PM2.5 within, say, one 1km^2 monitoring footprint versus an adjacent footprint. So the background level is definitely telling you something.

Re: The Weight of Numbers: Air Pollution and PM2.5

#32

Post by sundvor »

clumsysmurf wrote: post #11

Its probably worse that it looks "Researchers from Queen Mary University of London have found that people exposed to air pollution levels well within UK guidelines have changes in the structure of the heart, similar to those seen in the early stages of heart failure." https://www.sciencedaily.com/releases/2018/08/180803103315.h...

That's interesting.

We're looking at moving our son to a new school that's right at the corner of two major artery roads in Melbourne, with some 17 000 vehicles passing daily (just on one of them) according to VicRoads. The building doesn't appear to have a HVAC/filtration system. Playground is behind the building, but still has significant back traffic and is inside of 100-300 metres from the main roads.

I'm saying that the fumes from the cars and trucks could likely have long term health impact, but struggling to convince wife of this - she says if it was that dangerous, then why wouldn't someone have done something about it? I must clearly be paranoid.. ?

Personally, even though the small school appears otherwise excellent, I'm loath to expose him to these fumes.

I seem to have acquired an ability to taste them whilst on my bicycle commute, and will don a Respro mask when riding the streets with the most backed up traffic.

Re: The Weight of Numbers: Air Pollution and PM2.5

#33

Post by whatever1 »

mikeyouse wrote: post #15

Does anyone have a sense of where the damage is done regarding PM? I live in SF and our apartment is a block away from a busy road and a gas station, both of which concern me. Not to mention the wild fires of late depositing ash all over our yard.. Also, being a SF apartment, there isn't A/C so we leave the windows open on hot days. Is there data around whether an active air filter running in a closed room before we…

PM2.5 are mostly secondary organic aerosols, meaning particles that form after the reaction of other emissions. Unfortunately these can occur even with chemicals that have traveled for days and then they react with local emissions. So if you live in a forest which emitts a load of pinene and other organics and due to microclimate you receive NOX etc from a city not that nearby, boom you get very high PM2.5.

Re: The Weight of Numbers: Air Pollution and PM2.5

#34

Post by clumsysmurf »

sundvor wrote: post #32
clumsysmurf wrote: post #11

Its probably worse that it looks "Researchers from Queen Mary University of London have found that people exposed to air pollution levels well within UK guidelines have changes in the structure of the heart, similar to those seen in the early stages of heart failure." https://www.sciencedaily.com/releases/2018/08/180803103315.h...

That's interesting. We're looking at moving our son to a new school that's right at the corner of two major artery roads in Melbourne, with some 17 000 vehicles passing daily (just on one of them) according to VicRoads. The building doesn't appear to have a HVAC/filtration system. Playground is behind the building, but still has significant back traffic and is inside of 100-300 metres from the main roads. I'm saying…

You have a legitimate concern, I've seen a few studies over the years measure VOCs as a function of distance from busy roads. Here is a very recent one:

https://www.sciencedaily.com/releases/2015/04/150421105344.h...

https://futurism.com/an-app-can-identify-highly-polluted-are...

Re: The Weight of Numbers: Air Pollution and PM2.5

#35

Post by sundvor »

clumsysmurf wrote: post #34
sundvor wrote: post #32

Earlier quoted context omitted.

That's interesting. We're looking at moving our son to a new school that's right at the corner of two major artery roads in Melbourne, with some 17 000 vehicles passing daily (just on one of them) according to VicRoads. The building doesn't appear to have a HVAC/filtration system. Playground is behind the building, but still has significant back traffic and is inside of 100-300 metres from the main roads. I'm saying…

You have a legitimate concern, I've seen a few studies over the years measure VOCs as a function of distance from busy roads. Here is a very recent one: https://www.sciencedaily.com/releases/2015/04/150421105344.h... https://futurism.com/an-app-can-identify-highly-polluted-are...

Thanks, greatly appreciate that. This helps fuel (no pun intended) my belief that Australia is just ignorant of such things, and that this - in addition to the fact that it's very uncomfortable data - may be why we don't "hear about it" so as to speak.

Re: The Weight of Numbers: Air Pollution and PM2.5

#36

Post by infinite8s »

cyrildorsaz wrote: post #16
mikeyouse wrote: post #15

Does anyone have a sense of where the damage is done regarding PM? I live in SF and our apartment is a block away from a busy road and a gas station, both of which concern me. Not to mention the wild fires of late depositing ash all over our yard.. Also, being a SF apartment, there isn't A/C so we leave the windows open on hot days. Is there data around whether an active air filter running in a closed room before we…

I bought a AirMega last year. It always runs on "quiet mode" and the PM2.5 is below 5 all the time in my 900sqf apartment. http://airmega.com

Does it work well for a multiroom apartment?

Re: The Weight of Numbers: Air Pollution and PM2.5

#38

Post by gh02t »

gascan wrote: post #9
gh02t wrote: post #3

I recently built a sensor for particulate matter (using the Plantower PMS7003, a laser-based sensor) and it's interesting to look at the effects of every day tasks. Cooking for instance causes a huge spike in PM1.0/2.5/10.0 levels, but so do more mundane tasks like vacuuming or spraying aerosols. I'd like to add a sensor for CO2, but it's a bit more complicated. A lot of the easy to use sensors marketed for the purpo…

Cooking with gas or electricity? I've heard before that cooking with gas causes significantly more indoor air quality problems, but I'm curious what your observations are.

Cooking with gas doesn't release much particulate matter, but it does release volatile organic compounds. Most of it seems to be from the food itself; if you can smell it then there's stuff in the air. Any cooking involving oil seems to be the worst offender.

Re: The Weight of Numbers: Air Pollution and PM2.5

#39

Post by gh02t »

clumsysmurf wrote: post #13
gh02t wrote: post #3

I recently built a sensor for particulate matter (using the Plantower PMS7003, a laser-based sensor) and it's interesting to look at the effects of every day tasks. Cooking for instance causes a huge spike in PM1.0/2.5/10.0 levels, but so do more mundane tasks like vacuuming or spraying aerosols. I'd like to add a sensor for CO2, but it's a bit more complicated. A lot of the easy to use sensors marketed for the purpo…

Are there any schematics / plans for your project? I honestly don't trust Phoenix's sensor data (many times it says things are OK - AQI is green - but just looking around you can tell its not).

I don't have any personally, but the Plantower sensors are pretty straightforward. They just use standard UART serial, you can use an Arduino or even a simple USB-to-serial adapter, the only catch is that it must use 3.3V power and logic. Their datasheet describes how to wire them up and talk to them and you can also find plenty of code examples online.

The PMS7003 is a very accurate laser based sensor with forced airflow, I trust it. Sharp also makes a much cheaper analog sensor based on IR, but I didn't get very reliable measurements from it.

Edit: here you go https://learn.adafruit.com/pm25-air-quality-sensor/overview . Is for the PMS5003 but that's basically the same sensor.

Re: The Weight of Numbers: Air Pollution and PM2.5

#40

Post by oh_sigh »

sonofblah wrote: post #17
oh_sigh wrote: post #14

Earlier quoted context omitted.

I have this one and it works quite well: https://www.amazon.com/gp/product/B071RF6B2Y I compared it with a friends much more expensive device, and the results were within 5% of each other.

None on Amazon appear to have overall high ratings. There's probably opportunity in the space for someone who can create an effective, reasonably-priced model.

Agreed. I was concerned about ordering mine based on the reviews, but after looking at a lot of reviews, it is because people didn't read the manual(or, couldn't understand it's Chinglish). The actual product itself works well though, and the readings were within a few percent of my friends Fluke 985(~$5k particle counter - because he is a HVAC professional).
Post reply on HN