By Jonny Lupsha, Wondrium Staff Writer
The World Health Organization has updated its air quality guidelines. Previous standards for clean, breathable air are no longer sufficient, the U.N. health agency said. The coal era of industrialization caused major air pollution.

Among many other topics, climate change and pollution have come up repeatedly at the United Nations General Assembly. Amidst the discussion, the World Health Organization (WHO)—a U.N. agency specializing in international health—released its updated recommendations for air quality standards that sustain healthy, breathable air for life on Earth. Of the six major air pollutants, the WHO said that 90% of people on Earth live in an area with at least one serious pollutant.
Air pollution itself isn’t a brand-new phenomenon, but when did things become so bad? In his video series The Industrial Revolution, Dr. Patrick N. Allitt, Cahoon Family Professor of American History at Emory University, pointed towards the coal-powered Industrial Revolution for answers.
Lethal Smoke Inversion Event of 1948
“The first coal-driven era of industrialization was filthy,” Dr. Allitt said. “For more than a century, British and American industrial cities were coated in soot. Within a decade of completion, even the grandest buildings in the industrial cities all over the world were black: the sky over Manchester, Sheffield, Pittsburgh, Cleveland, Dusseldorf, and Liege was often smoky, sometimes yellowish with sulfur compounds.”
According to Dr. Allitt, this led to high incidences of asthma, shortness of breath, and stinging eyes. On occasion, the big industrial cities of the Western world were even deadly. Donora, Pennsylvania, a suburb of Pittsburgh, was one of the most highly polluted cities in America in the early and mid-20th century. The extent of its pollution is difficult to imagine today.
“It was the site of wire and zinc factories, and it produced toxic smoke that prevented any vegetation from growing on the nearby hillsides,” he said. “In 1948, a smoke inversion episode at Donora killed 20 people and injured hundreds more with lung ailments.”
The largest local employer was United States Steel, who denied any responsibility, but the incident was so severe that it contributed to some of the earliest discussions about pollution regulation in local and state government in the area. Previously, air pollution had been considered a simple annoyance.
London Fog
In December 1952, a fog set in in London that made the Donora incident pale in comparison.
“The fog in London had been famous ever since Sherlock Holmes’s day, memorably described in some of Arthur Conan Doyle’s stories about Sherlock Holmes,” Dr. Allitt said. “This is the thick, yellowish-black ‘pea soup’ fog where nothing would be visible for more than a few yards ahead. Sometimes the fog got so bad that all transportation would come to a standstill, even the ambulances.”
It was, he said, composed of soot and sulfur dioxide from factories and power stations combined with automobile fumes. However, in December 1952, the unthinkable happened. According to Dr. Allitt, over a period of five days, the wind dropped and the fog intensified so badly that it killed between 8,000 and 12,000 people, injuring 100,000 more.
Fortunately, the tragedy served as a wake-up call to the British government.
“The 1952 incident was severe enough to lead to passage of Britain’s Clean Air Act of 1956, and eventually to the establishment of a parliamentary ban on the use of coal inside London,” Dr. Allitt said. “The result is that it no longer has these notorious fogs. The last one was in the early 1960s, before the legislation had fully taken effect.”
Carbon emissions regulations are always a hot political topic and the debate continues this week at the U.N. General Assembly.