How Pittsburgh Cleaned Its Air After the War

by | Aug 5, 2026 | Cities, History

At a time when cities are routinely affected by wildfire smoke not of their making, let’s take a look at how America’s onetime steel capital took deliberate actions to clear the severe air pollution largely caused by its leading industry.
 
Pittsburgh passed a smoke control ordinance in 1941 modeled after a St Louis law from 1940, but implementation was delayed until 1947 due to World War II.  The key was switching from coal to natural gas in a city that sits on the largest coal seam in the eastern US.  But, how to get the gas to coal country?
 
During the War from 1942-44, the Big Inch and Little Big Inch oil pipelines were built from Texas to New Jersey via Pittsburgh to fuel northeastern industry mobilized for the war effort.  This meant not having to ship the oil by tankers susceptible to attack in the open ocean.  
 
After the War, the pipelines were converted to handle natural gas. Pittsburgh today has one of the highest proportion of natural gas usage of any city in the country. 
 
Meet Bob Pease, former head of Pittsburgh’s Urban Redevelopment Authority and later the Allegheny Conference, as he describes the awful air pollution he encountered when moving to the Steel City in the late 1940s:
Even before Pittsburgh’s steel mills were working 24/7 during World War II, civic leadership was concerned about the thick smoke permeating the skies.  Lights were often turned on during daylight hours and office workers brought extra white shirts to work so they could change after lunch because their collars were covered in soot when they returned from their meals.
 
Clearing the air was one of four pillars propelling Pittsburgh to the forefront of American cities seeking to remake themselves following World War II.  The other three were flood control, cleaner water and urban redevelopment.
 
The lights are on midday along downtown Pittsburgh’s Liberty Avenue in 1940 below:
Pedestrians, a scooter rider, and a dog walker on the Atlanta Beltline urban trail, with Ponce City Market and converted brick warehouses lining the path.

It wasn’t Covid – three women wore masks while shopping in downtown Pittsburgh to help publicize a new smoke control ordinance taking effect in late 1947:

How Pittsburgh Cleaned Its Air After the War

An ode to Pittsburgh’s smoky skies:

Map of the Atlanta Beltline urban trail, a 22-mile loop circling the central city and connecting 45 neighborhoods, parks, and landmarks, with the trail and rail routes, MARTA lines, and interstates marked.

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This post is adapted from our biweekly newsletter. Read the original newsletter.

Read our previous post: How Charlotte Used Culture for Urban Revitalization.