Too many apples-to-oranges comparisons with Beijing
"Our air is worse than Beijing"
"This is the worst air quality in the world"
Some variant of these claims have been repeated in the past few days. Are they true? Lets make an apples-to-apples comparison and find out.
If we compare conditions across the world right now, then WA probably has the ignoble distinction of being one of the most polluted places. Here's the global AQ map as of 1PM PDT:
Colors are AQI colors (see legend in plot below). South and east Asia are seeing a lot of reds and maroons, which means a lot of people are exposed to Unhealthy or worse air at this point in time. Washington is in the same abyss, air quality wise. Not good.
Now lets see how air quality at a few WA sites compare with normal patterns seen in Beijing and New Delhi year round. Data from those cities are were obtained from air quality monitors at the respective US Embassies, which routinely record very high PM2.5 concentrations. I've defined "normal" 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 and Omak have varied from 1 Jan- 20 August 2018, against the backdrop of monthly IQRs in Beijing and Delhi. As can be seen, the latter cities experience terribly compromised air quality primarily in the winter months. And its MUCH worse than what we experience, even during wildfire season. Even though Omak spiked right to the top of Delhi's IQR a few days ago, bear in mind that:
In spite of our wintertime temperature inversions and woodsmoke concerns, we're still in far better shape at that time of year.
So stacking the relatively "clean" season in Beijing/ Delhi against our "dirtiest" season is not a proper comparison.
Nevertheless, wildfire smoke- even of relatively short duration- still affects the health of a lot of people. This blog, even the article just below, contains a lot of resources on steps that can be taken to minimize its harmful effects.
"This is the worst air quality in the world"
Some variant of these claims have been repeated in the past few days. Are they true? Lets make an apples-to-apples comparison and find out.
If we compare conditions across the world right now, then WA probably has the ignoble distinction of being one of the most polluted places. Here's the global AQ map as of 1PM PDT:
Colors are AQI colors (see legend in plot below). South and east Asia are seeing a lot of reds and maroons, which means a lot of people are exposed to Unhealthy or worse air at this point in time. Washington is in the same abyss, air quality wise. Not good.
Now lets see how air quality at a few WA sites compare with normal patterns seen in Beijing and New Delhi year round. Data from those cities are were obtained from air quality monitors at the respective US Embassies, which routinely record very high PM2.5 concentrations. I've defined "normal" 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.
- Delhi's concentrations are higher than it's own IQRs 25% of the time. Or put another way, Delhi records concentrations higher than Omak's spike, for 3 months of the year.
- Omak's air is unlikely to remain "Hazardous" for several months.
In spite of our wintertime temperature inversions and woodsmoke concerns, we're still in far better shape at that time of year.
So stacking the relatively "clean" season in Beijing/ Delhi against our "dirtiest" season is not a proper comparison.
Nevertheless, wildfire smoke- even of relatively short duration- still affects the health of a lot of people. This blog, even the article just below, contains a lot of resources on steps that can be taken to minimize its harmful effects.
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