Pittsburgh Cleans Its Air

In the nineteen forties, Pittsburgh kept its downtown streetlights on during the day. Not for decoration, but because the air was dark enough that people could not see clearly in daylight. Photographs from the period show men in business suits walking through what looks like dusk at ten in the morning. The smoke came from the steel mills, from the coke ovens along the river valleys, and from the coal that heated virtually every building in the city.

The Smoke Control Ordinance, passed in nineteen forty-one, was the city's attempt to stop this, and Mayor David Lawrence began enforcing it in nineteen forty-six, working with business leaders and civic groups across party lines to end the burning of untreated coal in the city limits. It was not a simple political achievement. The railroad companies, the utilities, and the mining interests all had reasons to resist. Lawrence made the calculation that Pittsburgh's image, and its commercial future, required clean air more than it required cheap smoke.

The results were dramatic. Within a few years, the city had switched to natural gas heating and diesel locomotives had replaced steam on the railroads. By nineteen fifty-four, smoke pollution in downtown Pittsburgh had declined by ninety percent. People who had lived there their entire lives later described the change as revelatory. They could see the hills across the rivers for the first time.

The Pittsburgh Renaissance, as civic leaders called this period, went beyond air. A new sewage treatment plant was built. The first two expressways were constructed. The Golden Triangle at the Point was cleared of aging warehouses and turned into Point State Park. Pittsburgh used the leverage of postwar prosperity and New Deal-era civic partnership to remake itself physically.

The clean air campaign that began in Pittsburgh contributed to the national movement that produced the federal Clean Air Act of nineteen sixty-three. The city that had made the problem also helped make the solution.