Environmental scientist and activist James Conca, writing in Forbes, reports on a study by an organization called Eco Experts that these are the world’s 10 most polluted cities:

I knew the instant I saw Paris and Los Angeles as numbers 9 and 10 that there must be something terribly wrong with the methodology of whatever “study” lay behind these “findings.” When I went to the source, I found this and instantly knew what was wrong:

There are two big problems here: (1) limiting the study to 48 cities worldwide, and (2) considering only air and light and noise “pollution.”

Take #2 first. I daresay if you asked the vast majority of people what comes to mind when you say “pollution,” they’d think of smog (air pollution) and filthy rivers and lakes and beaches (water pollution) and filthy dumps and streets (solid waste pollution) long before they’d think of “light” and “noise.” Excluding water and solid waste pollution would give a pass to many of the world’s most squalid cities because (among other reasons) their electric supplies often are interrupted, leaving them without light and much of the sound that’s considered “noise pollution.”

But #1 is the far bigger problem, and it’s so elementary it’s astounding that Eco Experts would dare float their “study” before a watching world, and that Conca would report it without objection.

According to the UN, in 2016 there were 512 cities in the world with at least 1 million inhabitants; there were another 551 with 500,000–<1 million inhabitants, and who-knows-how-many (but surely many more than of the other two sizes combined) cities with under 500,000 inhabitants.

Let’s be charitable to Eco Experts and figure they picked their 48 out of only the 1,063 cities with 500,000 or more inhabitants. That means its sample size was 48/1,063 = 4.5% of the available pool. How did Eco Experts determine which 48 cities it would include in its sample? Might it have been to ensure that some cities in highly developed countries would make the list of 10 worst so as not to give the appearance that developed-world cities tend to be cleaner than developing-world cities? That wouldn’t fit too well with the politically correct standard of cultural relativism.

Here’s the UN’s map showing the locations of the 512 cities with at least 1 million inhabitants in 2016 (and projected for 2030):

I’ve been in most of North America’s cities of 1 million or more inhabitants, and I’ve been in a fair number of Europe’s, and I can’t think of a single one whose air (let alone water or solid waste) pollution levels would come anywhere near those of any of the African and Asian cities I’ve been in. (I’m not so sure about light and noise “pollution,” because, not generally thinking of light and noise as pollution, I’ve not taken careful notice of them. It’s not difficult, though, to imagine why richer cities might be brighter and possibly even noisier. Something about constant, reliable electricity?) But there are far more of these big cities in Africa and Asia (not to mention Latin America and the Middle East) than in North America and Europe.

Here’s the UN’s list of cities of 10 million or more inhabitants as of 2016:

Can anyone who’s ever traveled to Paris or Los Angeles (the only two from developed countries other than Moscow [and it’s increasingly difficult to think of Russia as a developed country in any respect other than its nuclear arsenal] to make Eco Experts’ top-10 polluted list) and also to Mumbai, Mexico City, Dhaka, Karachi, Kolkata, Chongqing, Lagos, Manila, Rio de Janeiro, Kinshasa, Tianjin, Shenzhen, Jakarta, Bangalore, Chennai, or Lima (16 out of the 31 cities of 10 million or more) possibly think that any one of those is less polluted than Paris or Los Angeles? (About the only “pollution” on which Paris or Los Angeles might be worse on most days is “light pollution,” since so many of those other cities have highly unstable electric grids and so suffer frequent brownouts and blackouts.)

And that’s just to look at the 31 cities with 10 million or more inhabitants; it’s not even to consider the 481 other cities of 1 million or more, or the 551 with 500,000–<1,000,000.

Or how about we just look at the 28 cities each of which houses 40% or more of its nation’s entire population?

Anybody want to bet that San Juan (yes, even San Juan, which is technically in part of the United States), Ulaanbaatar, Panama City, Brazzaville, Monrovia, Kabul, Luanda, Dakar, Phnum Penh, Ouagadougou, Beirut, Muqdisho, Baku, Abidjan, Conakry, and N’Djamena (that’s 15) are all cleaner than Los Angeles or Paris?

A study taking a large enough random sample from the world’s cities of, say, half a million or more inhabitants to yield a statistically significant result, and including water and solid waste pollution along with air and, okay, noise, and light, would certainly have yielded a very different top ten, and probably the most important variable controlling the pollution score would be the level of economic development. As Jack Hollander argued so persuasively in his 2004 book, The Real Environmental Crisis: Why Poverty, Not Affluence, Is the Environment’s Number One Enemy.

My bet is that such a study would find not a single city of over half a million in highly developed countries among the world’s 10 most polluted—and probably none even among the 100 most.

This “study” doesn’t even pass the smell test. (Pun intended.) It’s a classic case of an absurdly biased sample, and the only real question is why.

P.S.: Here’s what Conca says about himself in his Forbes author bio : “I have been a scientist in the field of the earth and environmental sciences for 33 years, specializing in geologic disposal of nuclear waste, energy-related research, planetary surface processes, radiobiology and shielding for space colonies, subsurface transport and environmental clean-up of heavy metals. I am a Trustee of the Herbert M. Parker Foundation, Adjunct at WSU, an Affiliate Scientist at LANL and consult on strategic planning for the DOE, EPA/State environmental agencies, and industry including companies that own nuclear, hydro, wind farms, large solar arrays, coal and gas plants. I also consult for EPA/State environmental agencies and industry on clean-up of heavy metals from soil and water. For over 25 years I have been a member of Sierra Club, Greenpeace, the NRDC, the Environmental Defense Fund and many others, as well as professional societies including the America Nuclear Society, the American Chemical Society, the Geological Society of America and the American Association of Petroleum Geologists.” Hmmm. And he still didn’t call out Eco Experts for their obviously fallacious “study.”