Where in the world is the air pollution worst? It’s not clear, pun intended.
Earlier this week, the World Health Organization released a report analyzing air pollution levels in nearly 1100 cities in 91 countries. The analysis was based on air particulate levels between 2003 and 2010.
There were plenty of news stories based on this report citing cities in Iran, Pakistan, India and Mongolia as having the worst air pollution. Forbes reported that the Iranian city of Ahvaz was the worst.
The Guardian did this breakout of the data on its wonderful DataBlog, which has the sub-headline “Facts are Sacred.”
Local aside: I didn’t see the specs on tree-hugging Seattle, but here’s one from my old Seattle PI buddy Scott Sunde citing studies showing how the poor neighborhoods seem to have crappier air. And here are some earlier reports from Grist and Crosscut (the latter written by former PI colleague Robert McClure, now at Investigate West) about our own air quality problems.
But after the initial findings from WHO were reported, questions started drifting in like the fog does, on little cat’s feet … What? Okay, enough with the puns and metaphors.
A city in New Zealand was ranked as just as bad as Tokyo, an error which was later cleared up by WHO. Taiwan noted it was left out entirely, which might have been a good thing. The Wall Street Journal noted Beijing, despite its obvious crisis in air quality, was ranked as having pretty good air compared to many other cities. As the Journal says:
Beijing ranked just below Lagos, Nigeria, in the WHO’s assessment, which relies on official country data. But the Chinese government’s proclivity for fudging numbers as well as its lack of available measurements for what are known as “fine” pollutant particles may be contributing to its lower ranking.
That’s often the problem with many of these broad-based reports, and not just for WHO. Most of the data come from governments, which don’t always provide the most accurate (or honest) assessments of their problems.