Updated WHO global air quality guidelines | Hacker News Reader

Updated WHO global air quality guidelines

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167 pointsmalingo53 comments

It took me a few minutes to figure out how to read the Executive Summary (Table 0.1, page xvii).

The AQG number is the main recommendation, and refers to the concentration in micrograms per cubic meter (ug/m^3). So the report says the world should aim for 5 ug/m^3 or less of PM 2.5 annually, and 15 ug/m^3 or less PM 10 annually.

The interim targets are meant to be realistic goals to set along the way, so anywhere with worse than 75 ug/m^3 PM 2.5 on a daily basis might aim for that goal first.

I had to check how the concentrations compare to various AQI (Air Quality Index) reports, like my iPhone weather app. 5 ug/m^3 of PM 2.5 is an AQI of 21. Currently an AQI of 0-50 is considered “good”, so maybe down the road the scale will be adjusted based on these new recommendations.

https://www.airnow.gov/aqi/aqi-calculator-concentration/

Curious to see what the previous recommendations were, the 2005 report has the same first 3 interim targets for PM 2.5 and PM 10. The current report’s 4th interim target is set to the AQG (final recommendation) level from the previous report, and the new AQG level is now lower than the previous one. This is because there is now stronger statistical evidence of health damage occurring at levels above the new recommendation, the data has shown we needed a new lower threshold.

> So the report says the world should aim for 5 ug/m^3 or less of PM 2.5 annually, and 15 ug/m^3 or less PM 10 annually.

Looks like a decent guideline, but it’s important to keep in mind that there appears[0] to be no safe level of particulates.

[0] https://en.wikipedia.org/wiki/Particulates

I wonder if there's a difference in harm caused between human-generated particulates vs particulates from, say, a forest. I assume at some point as air quality improves, natural pollen, bacteria, etc, would become a significant factor in simplified PM-based AQI, and my question is, is that still a problem?

Certain types of fine particulates are certainly more harmful than even forest fire smoke. For example asbestos, brake dust, leaded gasoline in dust, etc.

But the vast majority would probably be roughly the same.

Something like aerosolized salt from a humidifier using tap water is essentially harmless. But it still counts as PM2.5

>So the report says the world should aim for 5 ug/m^3 or less of PM 2.5 annually, and 15 ug/m^3 or less PM 10 annually.

what does "annually" mean in this context? That your time-weighted expousure should be less than 5 ug/m^3, or that it should be always under 5 ug/m^3?

The former; it means the average exposure over the year. The latter “always under” guideline is also included as a separate item: they recommend that your 99th percentile maximum daily exposure stay less than 15 ug/m^3 for PM 2.5, and less than 45 ug/m^3 for PM 10. 99th percentile means they recommend this level 99% of the time, and assume/allow for several days per year of exposure to higher concentrations.

There are recommendations for other specific pollutants too, I left those out, but the table includes recommendations for O3, NO2, SO2, and CO. There’s a 2nd table on the next page with recommended maximum exposures for those last 3 in terms of 1-hour and other timeframes smaller than 24 hours.

I never truly appreciated how valuable good air is until I moved to Asia and experienced weeks at a time living in air with AQIs over 100 and namely high PM2.5 levels.

The physical effects of spending even an hour outside are immediately apparent and scary when I contemplate what this would probably do to my health if I rack up years of exposure. It's even scarier to think about children who are exposed to this air from birth and grow up inhaling it every time they walk to school, go outside to play, etc.

Same here. I live in Nairobi. The air quality here isn't all that good, but I acquired a newfound appreciation for it when I visited Gurgaon in India a few years ago. When I first landed, I actually mistook the dense smog for clouds. I came pretty close to passing out once while waiting for a taxi on the street. I was basically in air-conditioned rooms the entire time I was there, save for a short trip to Delhi, which felt noticeably better.

I've been equally surprised when visiting other cities with cleaner air than my own. It might be one of the things that pushes me to uproot my life here and try make a home someplace else.

Ever felt that stingy feeling when you were outside on a bad air day (aqi 200+), like when having a hoarse or raspy voice, as if you just breathed a whiff of glass powder?

That's how it can feel.

It's a pretty common occurrence around here to lose your voice completely for a couple of days after spending an hour or two outside in winter smog. Still, almost nobody cares about air quality. I spent many years in this society and still don't understand such behavior.

Situations like these are where wearing outdoor N95 masks should be normalized for peoples health.

That happened to me when I visited Mumbai. After two days I couldn’t take it anymore and had to leave. It’s hard to believe people live under these conditions their whole lives.

People have statistically calculated the loss of years to be lived due to monthly exposure to such conditions.

This, combined with the currency controls that China implements are, for example, an interesting manifestation of how the Chinese people literally sacrifice their lives and purchasing power to improve their economy, become globally competitive, and make their ‘leaders’ wealthy. The average person there does not know that they are doing this, but the leadership has this option in a totalitarian government that other states do not.

They are following the path of the West. We also sacrificed the health and lives of workers for a long time so capitalists could make more money. Any kind of consciousness and willingness to reduce pollution is a pretty new phenomenon. And we are still OK with people living in old buildings with lead paint and lead piping although we know how harmful that is.

China's environmental track record stinks to high heaven (literally) and there's no doubt the country's leadership has been and is sacrificing public health for economic growth the same way the US did during industrialization. But the situation in Asia isn't as simple as China.

I live in Taiwan. While there's no doubt that some (and at times perhaps a lot) of the air pollution in Taiwan blows over from China, there are plenty of domestic sources of air pollution. Taichung has the fourth largest coal-fired power plant in the world, and the area between Taichung and Kaohsiung is home to many factories and industrial sources of pollution. Scooter usage is very high as well.

Taiwan is a democracy, getting closer to developed than developing, and a lot of younger people care about the environment. But without manufacturing and the pollution that comes with it, Taiwan doesn't have an economy.

Malaysia has a lot of air pollution. Some is industrial, but a lot comes from fires in Indonesia. A similar situation exists in Thailand. The northern part of the country, including Chiang Mai, has horrible seasonal pollution from agricultural fires in Myanmar and Laos. And of course many parts of India are infamous for pollution.

The bottom line is that Asia is the world's factory and home to many natural resources that have severe environmental consequences when exploited. Asian countries want to develop and the only realistic paths to economic growth are paved with pollution.

Living here has made it clear to me that for all of the talk about reshoring manufacturing in the US, it isn't going to happen, not just for economic reasons, but because there's no way Americans will be willing to sacrifice the clean(er) air and water they have today.

Pollution in Asia is a big problem but the West, because of its consumption that drives industrial activity in Asia, is reasonably as much a cause of the problem as the people in Asia are.

I think sometime in the future people will look at the way we are accepting pollution these days in the same way we are looking back at how people openly worked with mercury in the past.

It’s kind of of insane that we know about the harm done by pollution but shrug it off because doing something would be too expensive.

Any recommendations for air qulity sensors?

Quite like this idea, as (I assume) it also makes data available to others: https://airly.org

Not a recommendation, but this is a thing - "ESP8266 Adds WiFi Logging To IKEA’s $12 Air Quality Sensor" https://hackaday.com/2021/07/24/esp8266-adds-wifi-logging-to...

Tried to buy a LaserEgg recently. It’s presumably less reliable than AirVisual, but also is a bit cheaper. Acts like a desktop accessory. Can’t comment on its performance, the customs of the country I’m in now have determined that air quality monitoring equipment cannot be imported for personal use.

Also, took note of a recent article[0] by Jeff Geerling. It’s relying on AirGradient’s sensor.

[0] https://news.ycombinator.com/item?id=28457135

If you're willing to get your hands dirty, ESP32 + PMS5003. I wrote my own (crappy) firmware, most users prefer this ↓

https://github.com/esphome/esphome

I can confirm, that way is really easy. Here's my config:

https://www.pastery.net/yxbssn/

I have an Awair Element, https://uk.getawair.com/products/element, and it suits my needs just fine.

I also like the Awair Element. Enough that I bought two.

If you just want a sensor that will give your computer raw data that you can then further process, a pretty simple approach is a Sensirion SPS30. Sparkfun has them [1].

You can hook it to a USB port via a serial/USB adaptor, such as this FTDI cable from Sparkfun [2].

The male pins on the cable from the SPS30 will plug right into the female sockets on the FTDI cable.

There's sample code provided that easily builds on Unix and Unix-like systems (you'll just need to change one line to tell it the device name of the serial port). That code will poll the sensor and give regular readings, and also (assuming you keep it running long enough) do the periodic cleaning cycle of the sensor.

The SPS30 also has an I2C interface, although it is not as capable as the UART interface (it only provides mass concentration data, not number concentration data).

Sparkfun also caries a similar sensor from Honeywell [3], but I don't see any links to sample code or drivers, and the datasheet they link to does not have a lot of detail on the protocol.

Note: Sparkfun has several FTDI cables. The one I've linked to has 5 V power, 3.3 V signals. They also have one that is 5 V power and signals. The SPS30 is 5 V power 3.3 V signals, but is 5 V tolerant on the signals so the 5 V power and signals FTDI cable should also work without frying the SPS30.

Going the other way, in general, a 3.3 V serial device can send to a 5 V serial device with no problem unless the cable is really long because the lowest voltage the 3.3 V will output for a high output is still above the lowest voltage the 5 V side accepts as a high. So the 3.3 V SPS30 signal should also work with the 5 V FTDI cable.

But I recommend the 5 V power 3.3 V signal cable in general. You can use it with both 3.3 V and 5 V signal systems with no problem. With the 5 V signal cable you have to be careful to not use it with 3.3 V systems unless they are 5 V tolerant. An example of a 3.3 V system that is not tolerant is Raspberry Pi.

[1] https://www.sparkfun.com/products/15103

[2] https://www.sparkfun.com/products/9717

[3] https://www.sparkfun.com/products/14959

Most of my early life I lived in luxurious ~5 - 25 AQI. I live in pretty much the same area (California) and seems like during the summer we are going to suffer through varying levels between 80 and 500 AQI. It's a good time to get into the air cleaning industry (hepa, etc...)

How does this compare to current EU guidelines?

Air quality in Europe is already in a sorrid state

Wait till people fire up the coal in their homes like they do every winter.

I feel almost alone when I complain about this stuff. Coal + old clunkers = fantastic. There is no escape unless ones moves far away from all humans

Most countries in Europe have banned burning coal at home for decades. For heating burning wood is a major source of pollution. Other reasons are cars and the relatively high population density.

Enforcement is pretty lax though, plenty of folks in the suburbs burning coal and logs on their ‘trendy’ open fires.

The particulate output of these pales in comparison to the coal plants though. Reminds me of when China clamped down on street vendors who used open fires while ignoring the steel plants down the road.

Tonnes of release doesnt tell the whole story though. Domestic burners are closer to the ground and other humans. Coal power stations have stacks to shoot the emissions higher in the atmosphere.

In developed countries it just seems like a backward step when people can afford something better than fashion driven legacy technology.

Exactly, and even in china I imagine the coal plants have at least a basic filtration system, not to mention European coal plants. Which of course no home fireplace has.

It really depends. I am not located in China, but our problems are pretty similar in nature. We have a lot of smaller, I am not sure what they're called, boiler houses? One to two-storey pipes with zero emission control, piping out black smoke 24/7 for most of the year.

Coal plants in Europe are much cleaner than they used to be (still we should work on shutting them down).

Nowadays emissions from traffic, industry in general and heating all are in the same order of magnitude: https://ec.europa.eu/jrc/en/news/air-quality-atlas-europe-ma...

There’s an old dude upwind from our house who still heats his home with coal.. probably the last in our village of 4000 people which has had mains gas since the 1990s.

It’s choking outside in the winter, just from this one fire. I’m thinking about offering to put in a heat pump for him and pick up his electricity bill, it’s that bad.

Imagine what it was like when everyone used to heat with it !

You don't have to imagine it, just look at Balkan capitals that are falling behind.

Sarajevo: https://duckduckgo.com/?q=sarajevo+winter+smog&t=ffab&iar=im...

Skopje: https://duckduckgo.com/?q=skoplje+winter+smog&t=ffab&iar=ima...

Keep in mind that both of these are in the valley surrounded by hills and mountains, forcing the smog to stay for days during colder weather with no rain or snow to disperse it.

On top of that, there's a report published this month that estimates about 19k deaths across Europe in the past three years because of coal-powered power plants in the WB6 area: https://www.euronews.com/2021/09/07/western-balkan-power-pla...

Not bad by European measures, though still pretty light compared to many regions of Asia (speaking from rich experience, sadly)

https://aqicn.org/city/bosnia-herzegovina/sarajevo/us-embass...

https://aqicn.org/city/macedonia/centar/

(Scroll and look for "Air quality historical data")

Hey, at least you have only one such neighbor. Imagine how bad it is with a few thousand of them, burning sulfur-rich coal 10-11 months a year with a few plastic bottles and car tires thrown in for good measure. Wait, I don't have to imagine it, just take a look outside.

Highly recommend the Crown episode ‘The Fog’ that goes into how bad it once was in London.

The Australian Wildfires of 2020 were a wakeup call to me for both how important this is to happy living and how shared our atmosphere is.

I spent that entire period watching windy.com particulate maps and forcasts trying to time when I rode into work, for weeks on end it wasn't smart to do so, and those fires were in another state to me entirely, thousands of KM away.

I feek for those who live in countries where polution is nearly as bad year round as those fires were during their peak.

The Netherlands, a slow-mover in most environmental aspects, has a pact to try to meet the former guidelines in 2030. Compliance with the new WHO guidelines will outlive me, at least if no technical magic bullit outside of governements hands shows up. I’m quite positive on liquid H + electrify everything but the rate of change is far, far to slow.

Luckily we have our "greenest cabinet ever" in power at the moment, headed by the self proclaimed "vroom vroom party". I'm sure everything will turn out fine.... /s

”Blue” hydrogen is currently produced from natural gas and is worse for the environment than coal.

When looking at air quality in Europe, the west coast of Ireland is the best place to live.

Is this because the wind is usually coming from the Atlantic ocean, so basically all the pollution there is blown towards continental Europe, and there is no polluter to the west of them (only sea)?

That would make sense but I would also wager that the wind blowing over the water acts as a bit of a filter. As wind contacts the water, some of the pollutants would be absorbed by the ocean and taken out of the air cleaning it. Just a theory.

I don't think that's a major factor, the wind is mostly high above the water. Being far from polluting sources is the key for Ireland. Specifically, their western coast gets fresh air from thousands of miles of ocean, though admittedly there's a little bit of shipping and boating there. Compare to here on East Coast US, the wind comes from the continent, any fire out west/northwest leads to smog and haze here.

In part, yes. Given it is a low emission region, areas of Ireland such as Mace Head typically don't have air quality issues from local sources. The predominant wind direction is blowing in area west->east across the atlantic, which means they're exposed to 'baseline' levels of ozone, which is both produced and destroyed over the ocean as well as in part transported from North America. With regards to particulate matter, the only real downside is that sea salt aerosol is in higher abundance there.

Thanks for posting! This is a good reference to correctly implement and document APIs for Open-Meteo [0].

I soon want to integrate CAMS data from the Copernicus Project to offer Air Quality APIs for non-commercial use applications.

[0] https://open-meteo.com/

How does it compare to older guidelines

Wonder how Singapore fares ...

Scroll down for historical data: https://aqicn.org/city/singapore/central/

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