Wednesday, September 16, 2020

Since this is the era of big data, lets compare our plight with those from far and wide

There are claims that we've been exposed to the worst air in the world. True? Fair comparison? Let's investigate that without belittling the terrible air quality conditions we've all had to endure for at least a week now.  

Here's a map of global air quality right now. It uses all available measurements worldwide and uses machine learning methods for spatially interpolation. US west coast is in baaad shape. Worst ranked cities right now are all in our neck of the woods. 


But to do a proper apples-to-apples comparison, we should compare our air during our "bad" season with the "bad" seasons in other places, not our bad against their better times. So lets leverage data from the US State Department's (DoS) air quality monitors around the world. These are easily obtained from one place and have a pretty good quality control regime. 

I've pooled PM2.5 data from the ten highest embassies which recorded data for at least two years anywhere between 2012- 2019. These are: New Delhi & Kolkata (India), Dhaka (Bangladesh), Ulaanbaatar (Mongolia), Kampala (Uganda), Kathmandu (Nepal), Jakarta (Indonesia), Chengdu & Shenyang (China), and Manama (Bahrain). You can see more details about their air quality here. "Normal" conditions were defined as the range between monthly lower and upper quartiles, since the median passes right in the middle of it. This is also known as the interquartile range, or IQR.

The above figure shows how air quality in Seattle, Spokane, Vancouver, Omak and Yakima have varied from 1 Jan- 15 Sept 2020, against the backdrop of IQRs at ten embassies. As can be seen, the overseas cities experience terribly compromised air quality primarily in the winter months. Right now is their "better" season. Even though we spiked right to the top of the AQI chart this week, bear in mind that:

  • All these overseas locations see concentrations that are higher than their own IQRs 25% of the time. Or put another way, they record even higher concentrations for 3 months of the year.
  • Our air will not remain this bad for several months. Most WA sites have experienced some improvement already and we're still on track to clear out in the Friday- Saturday timeframe. 
  • In spite of our wintertime temperature inversions and woodsmoke concerns, we're still in far better shape at that time of year.

Moral of the story: yes its bad here now. Many others have it worse for much longer. Folks who live in these environments and our diplomats serving there can offer us some coping tips. 

40 comments:

  1. Thanks so much for your efforts in this rough time. You've really helped us set expectations and understand what's going on here.

    Two questions for you. Firstly, what advice would you give folks in "sensitive groups" whose living spaces are getting unbearably hot and stuffy after days of having windows closed and no A/C? Is excess CO2 buildup a concern? I needed to get a nearby hotel room to escape the heat in my low-airflow apartment, but I know that's neither the most economical, safest, or best long-term way to resolve this issue. Any recommendations?

    Secondly -- when you say "we're still on track to clear out in the Friday-Saturday timeframe", what does that look like in terms of AQI breakpoints in many areas? Are we talking down to, like, low "Unhealthy", or "Unhealthy for Sensitive Groups" by Saturday? Better/worse? (I'm located in Redmond, if you're able to provide a localized approximate forecast.)

    Thanks again for your time and efforts in this area!

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    1. Hi h2g2, Sometimes there are no great options. One suggestion I thought was good: if you can get a filter or clean vacuum cleaner bag cut to the size of a window in your house, you could open the window and place the filter so that it covers the entire opening. Tape the filter all around the open window frame and makie sure there is a good taped seal all the way around. Excess CO2 can make you drowsy and give you a headache. Turning on bathroom ventilation fans or hood fans over the oven can help vent the air to the outside.

      We are still on track to see gradual improvement through Friday and cleaner air by Saturday.

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    2. A 20x20x1 Merv 13 filter and a 20 inch box fan will clean your air up. Order them to your door online. Co2 buildup in your home is absurdity, no it is not a concern. Even if all of your windows and doors are closed 365, transference is a thing and you're not going to avoid it without spending millions to renovate your apt/house.

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    3. Hi Matthew, Generally speaking you're correct and most homes have enough natural ventilation where CO2 will not be a problem. A number of factors can cause CO2 to reach levels that may cause adverse symptoms. Poor ventilation in small apartments can cause CO2 conc to exceed 1000 ppm. If a small apartment has several occupants, this may cause higher levels of CO2. If the home is using wood heating and is poorly ventilated, it can also be a problem. https://ohsonline.com/Articles/2016/04/01/Carbon-Dioxide-Detection-and-Indoor-Air-Quality-Control.aspx

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  2. i never knew Mongolia was so bad. very interesting!

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    1. Yes, they burn dried sheep dung to cook and heat with, and also they have a natural valley which traps in the smoke during cold winter months in an inversion.

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    2. Having been in Ulaanbaatar, it is a beautiful area but most heating includes coal especially in the Ger neighborhoods on the outskirts. Also and more importantly there is a very large coal fired power plant, the smoke from which stays in the large valley unless a strong wind is blowing. The residents are friendly and do the best they can in this modern city surrounded by a diminishing nomadic lifestyle countrywide.

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  3. Looks like aqi numbers are moving up again in Vancouver Wa and Camas Wa—now in the 400s. Are we still reasonably expecting some relief by Saturday?

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    1. Yes, still on track despite the recent uptick. Wind shift has placed you directly downwind of OR fires, but another windshift is coming that will tap into clean marine air.

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  4. Just fascinating. Thank you so much.

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  5. I live in Omak and the air quality hasn't been this bad in a long time. I hope this will clear out over the weekend and the wind shifts southeast. I think if we had a high pressure system across Washington it would help because it goes in a clockwise motion as to where a low pressure system goes counterclockwise and brings the smoke north. Thanks for the information (High 5)

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  6. I've been monitoring air quality for a few years now using purpleair.com and I have seen the high numbers in other parts of the world. However, I've never seen "off the scale" numbers like what I've seen during these wildfires. For example, west of portland on the oregon coast there were numbers that were 700 plus! the scale appears to stop at 500. Can you explain that please? Thanks for this informative site.

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    1. Yes there have been "off the scale" values in other places too (New Delhi, for instance has several values well in excess of that). While the Hazardous scale maxes out at 500, EPA has some guidance on what to do above that (see https://cfpub.epa.gov/airnow/index.cfm?action=aqibasics.pmhilevels). The algorithm just continues to calculate an AQI and report it, but the strong advice is to limit your exposure immediately.

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  7. Lived in Korea for 4 years. Battled the bad air quality the entire time. I consider myself to be lucky because I'm prepared for this from my time living there. So many people are obvious to the dangers of air pollution, especially PM2.5. I've seen people running outside today, and having their kids play outside. It's a bit frustrating because I feel like they aren't taking things seriously.....or don't know that they should

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    1. I think, honestly, it's lack of education and communication. This phenomenon is so new (relatively) that the govt doesn't really have a plan to keep people from hurting themselves accidentally. In the past week I've seen my neighbor mow his lawn with no PPE (and a gas mower) as well as a bouncy house kids party. I think people just don't understand.

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  8. Thank you very much for your point about perspective. I've been lucky enough to travel a bit to Asia (Hanoi, Bangkok) and sub-Saharan Africa (Kampala, Nairobi). Polluted cities are a lot like my home town Los Angeles in the 60s, where you frequently took a deep breath at your own peril. One of the reasons I've lived in Seattle for 40 yr is air quality. For a decent sized city it's pretty good. Except now! And don't forget pacific NW's water quality, which seems unmatched to me.

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  9. Former aid worker here. In northern India around November, air pollution often maxes out at 999 ppm, which is apparently the highest these particular sensors can reach so who knows how high it is really. Delhi on a good day looks like most of Washington now. China used to have really high numbers too although I don't know if they are still that bad. You can occasionally see similar numbers in Nepal, Pakistan, Turkey, and a few other countries. Also when the rainforests in Indonesia are on fire, you sometimes get numbers in that region like we have now. (I get my numbers from aqicn.org which has a lot of US embassy data, so I assume it's fairly accurate.)

    I can say from experience that it's a real problem! And it depresses me that my wife and I decided to move back to Spokane to raise kids where the air is clean, and now here we are.

    Also, I saw something the other day saying our numbers during this latest stretch are comparable to what LA went through in the 70s. If that's true, it's good news in that we've had this before and got through it, bad news in that we apparently have to go through it again. (Also, it seems like cleaning up auto exhaust is easier than solving global warming.)

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  10. Is the bad air in the amazon due to fires as well?

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    1. They are certainly a factor. See the satellite hotspot detects: https://go.nasa.gov/35MbZLi

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  11. Ranil, a week ago I had no idea you existed, and today you are my favorite blogger! Keep up the great work.

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  12. Why have we gotten almost no wind? Where I am we regularly receive wind, especially in the evening. With this smoke it has been eerily calm.

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    1. Temperature inversion has been keeping the lower levels of the atmosphere very calm. Moderate winds are blowing higher up but not able to mix down.

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    2. Ah. Thank you for the reply. Always fascinating to me how weather works.

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  13. This is interesting data. Thank you!

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  14. How's it looking for the Tri Cities area Thursday, Friday ?

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    1. Please see the forecast map at https://enviwa.ecology.wa.gov/home/text/421#Forecast

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  15. Really interesting article! Thank you!

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  16. Very cool graph! Thank you for giving us some context.

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  17. I'm noticing a strange discrepancy between the Air Now map and the Washington Dept of Ecology map for the same 2.5 PMI readings from apparently the same sensors. For example just now (9 am Thursday) the Air Now map shows 181 reading from Tacoma 36th st while the WA DOE reading at the same time from the same location is 251 for the same 2.5 PM. What is causing this difference?

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    1. Hi Dwight, Your question is timely. Please see my blog post this morning for a complete explanation.

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  18. Interesting spike in the Seattle AQI in late June (if I am reading the x-axis correctly). If it were a little later I would think it might be related to 4th of July fireworks. I wonder if this is related to a specific event or some kind of anomaly?

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    1. There was a fire in the International District on June 26th, pretty much right across I-5 from the monitor.

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    2. Fire was on June 25 early morning: https://fireline.seattle.gov/2020/06/26/2-alarm-fire-in-the-chinatown-international-district/

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  19. Thanks very much for your excellent reporting and commentary. Having been assigned or TDY to many of the posts listed, though long ago, I recall that the solution was to stay inside and use masks, air filters, and humidifiers. In Shenyang, local custom was to wear bee keeper-style hats and face covering scarfs, since coal ash and those portions of the Gobi Desert making a break for the border also caused eye problems. It is interesting that Chiang Mai, Thailand, was not on the list. The March-May rice stubble burning, plus the enterprising foragers who start forest fires to stimulate the growth of valuable mushrooms, can make life unpleasant. It was an annual ritual for the Consulate to send out an "Air quality not better this year." cable. As to AQI figures: When the Embassy in a capital which must not be named began posting its readings on the Internet, it sparked vehement charges that the numbers were American lies and propaganda. The official numbers were apparently produced using the old East German method that predicted every May Day would be sunny and just great for the scheduled parade.

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  20. I would advise people to construct box fan filters with MERV 13 or higher MERV ratings during this air quality event. It'll cost one 30 bucks. Buy the five pack of filters and it'll be even cheaper when the filter needs changing. Used by NGO's all the time in places like Mongolia with consistently poor air quality

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  21. Thank you for your report and putting air pollution in the USA in perspective. I have been living in Kathmandu for the past 9 years. Air pollution is a fact of life and deaths here. Outside burning of agricultural residues and garbage are huge contributors to the bad air here. We are used to wearing masks outside and operate an air purifier in our bedroom. Sadly this brown air drifts up to the Himalayan glaciers, increasing melting and endangering the lives of mountain people. ICIMOD has excellent regional information for those with more interest in mountains. I will soon return to Washington - I thought we might have many green days instead of red. It will improve in Washington but improvements in our Himalayan region will take years and loss of thousands of glaciers.

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  22. in the 70's 80's and LIKELY FOREVER, Western Washington State weather systems always came through the Gulf of Alaska. They warmed on the way I guess? Point being, they always had a slow,counter-clockwise twirl, slowly making a counter-clockwise arch. NOW, OUR NEW WEATHER IS A DIRECT BLAST, (from North, or South) NO TWIRL, NO ARCH, Just a hard turn to the East. The (TV news)satellite motion views look more like dragon-breath, consistently blasting. Debating is pointless, we NEED TO ADAPT to our NEW WEATHER. Fires and floods.

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    1. It seems like you're referring to the jet stream or upper level winds. What is experienced at the surface is the result of the complex interactions of this steering flow with terrain, forests, water bodies, urban areas etc. And all the emissions it picks up en route, plus chemical reactions that take place in the process.

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