Here’s a map that Donald Trump tweeted out on Monday afternoon, which claims that the U.S. of A has the best air quality in the world. There is a problem with the map, however: It does not show that the U.S. has the best air quality in the world. It does, however, show that the U.S. does not have very many dust storms. America: not a lot of dust storms!
In the fine print, the map that Trump tweeted notes it is a visual representation of “annual average concentrations of ambient (outdoor) fine particulate matter.” This includes common pollutants like smog and smoke from places burning coal, natural gas, etc, but also includes... dirt. And sand.
Per the WHO report:
Air pollution does not exclusively originate from human activity and can be greatly influenced by dust storms, particularly in areas close to deserts. This is partially illustrated in Figure 2, which shows modelled annual average PM2.5 concentrations by area (rural/urban); and shows that rural areas in Africa and Eastern Mediterranean regions have higher concentrations than urban ones.
Let’s go back to the map. Here it is again:
Wow, those huge pink and purple splotches across Africa, the Persian Gulf, and India sure look like places that are mostly... desert. Specifically sandy desert with lots of sand... particles. Truly wild.
Where you see the worst levels on the map are densely populated urban centers in hot, arid climates. Much of China’s major population centers also show up in the deep purple section. Nobody would argue that the United States’ air quality is worse, on the whole, than China’s.
Here’s another claim that the map makes: “91 percent of population (none in U.S.) are exposed to air pollution concentrations above WHO suggested level.”
This is not, unfortunately, what the actual data says. From the report:
Based the modelled data, 91% of the world population are exposed to PM2.5 air pollution concentrations that are above the annual mean WHO air quality guideline levels of 10 μg/m3 (Figure 4). Apart from the high income region of the Americas, all regions – both high‐income and low‐and middle income – have less than 26% of the population living in places in compliance with the WHO AQG.
What that’s saying is that the Americas are doing pretty well—more than 26 percent of our population lives in areas that are in compliance of the WHO’s guideline levels. That’s great! But some parts of the U.S. are, unfortunately, absolutely exposed to air quality pollution concentrations worse than an annual mean of 10 μg/m3. If you go on this interactive WHO map and zoom in, you see little yellow areas all over the states. Take the Central Valley of California, for example: Hanford, a small city south of Fresno with a population of 55,547, has a Mean PM2.5 (µg/m3) of 16 (this is data from 2016).
So... that is not correct. It is highly possible that this is just another pretty graphic that staffers put on Trump’s desk with vague information.
Here’s another map, which is less fun for the U.S.: deaths attributable to ambient air pollution, where we’re in the 20,000-44,999 range.
Anyway, according to the actual data, Finland has the best air quality in the world. The U.S. is pretty good, on average, but not the best. Sorry.