In a recent Spacing article, called Pollution and the fall and rise of urbanism, Dylan Reid argues that one of the reasons why urbanism declined in the 20th century was because of industrial pollution. (There are, of course, other contributing factors beyond just pollution.)

This article is the first time I have come across a study supporting the widely held belief that pollution and prevailing windows are the reasons for why the east sides of many former industrial cities are poorer than the west sides. Here is more on that from the article:

People recognized and understood that pollution had an impact on them, and they tried to avoid it if they could afford to do so. Have you noticed, for example, how in so many cities (Toronto included), the east side is poorer than the west side? It’s because the prevailing winds in Europe and North America are west to east, and they blow pollution to the east side. A fascinating study by economists Stephan Heblich, Alex Trew and Yanos Zylbergerg quantified this effect, identifying how 19th century pollution was dispersed eastwards and showing that the most polluted areas were also the poorest. 

What the authors discovered is that not only did pollution cause a geographic sorting based on wealth, but that there’s also a certain degree of persistence to it. This makes sense if you think about it. Pollution in our cities has waned significantly and yet here we are still remarking and talking about east vs. west.

It goes to show you just how long lasting the impacts of our city building decisions can be.