After the smog cleared out of the Mon valley that deadly October 1948, after Dr. William Rongaus’s pleas for people to leave town went unheeded, after nearly 6,000 area residents had been sickened and 20 people had perished during the smog or in the immediate aftermath, a 25-person team from the nation’s Public Health Service (PHS) arrived in Donora to “find out precisely what caused the deaths and to establish ways and means of preventing future tragedies of this kind.”

Under the direction of James G. Townsend, MD, head of the PHS’s Division of Industrial Health, the team of doctors, nurses, veterinarians, medical technicians, chemists, engineers, statisticians, sanitarians, housing inspectors, and weather technicians surveyed the land and air and interviewed survivors, town officials, area physicians, officials of the steel and zinc mills, and many others. They conducted two autopsies and took air samples from a variety of locations over a period of many days. The final report, called “Air Pollution in Donora, PA: Epidemiology of the Unusual Smog Episode of October 1948: Preliminary Report,” consisted of 173 pages of data, maps, charts, tables, and graphs.

In the end, the report blamed a combination of factors for the tragedy, including the unusual weather pattern, the overall health of the victims, and maybe, conceivably, perhaps, not outside the realm of possibility one or a combination of toxins emitted by the many smokestacks pouring forth out of Donora’s mills. Those smokestacks released soot, particulate matter, carbon monoxide, sulfur dioxide, sulfuric acid, and a host of carcinogenic metals. US Steel, which owned the mills, was never overtly blamed in the report, an omission widely considered by historians to have been almost solely a political decision.

Politics likewise played a role in the Great Smog of London, when a temperature inversion in early December 1952 bottled up all the soot, particulate matter, and other toxins escaping untold numbers of coal-burning factories and coal-fired chimneys in the city, causing a catastrophe that led to the death of 12,000 people.

Much of the coal being used by Londoners at the time was called “nutty slack,” a brown dust with bits of coal. Nutty slack generated little heat while emitting highly contaminated smoke, but it was the cheapest, most widely available fuel for city-dwellers. Black coal was still being rationed, a leftover from WWII.

Coal was used in Donora as well, but it was of a finer grade than nutty slack, and so gave off less toxic fumes. In addition many homes in Donora used natural gas for heating, not coal. In any case, both tragedies involved a prolonged temperature inversion followed by political maneuvering at its worst.

Kate Winkler Dawson writes in her book, Death in the Air: The True Story of a Serial Killer, the Great London Smog, and the Strangling of a City, “Coal, it turned out, was one of the few thriving international industries remaining in postwar Britain—more than 250 million tons were mined domestically every year; it was a key export for the country at a time when national budgets were tight. More than seven hundred thousand workers were employed in British coal mines. Politicians weren’t ignorant of the environmental concerns of burning huge quantities of coal every year, but their hands seemed tied.”

London’s politicians reacted at first with denial that nutty slack was at fault, preferring instead to blame the weather. Minister of Housing Harold Macmillan kept insisting that simple, common fog couldn’t possibly have been the culprit. “So far as I know,” he sarcastically intoned during a meeting in the House of Commons, “no inter-departmental committee has investigated the weather conditions which cause fog; I believe they are generally well understood.”

To which his primary opponent, Norman Dodds, who worked tirelessly to prompt an investigation of the smog, replied with trademark bluntness, “Is consideration being given or will it be given to initiating a much more thorough investigation, on the lines of that conducted by the American government in 1948? Has the right honorable gentleman seen the report?”

Dodds wielded the PHS report like a broadsword, swinging at whichever Minister of Parliament stood in his way. At one point he read a portion of the PHS report to his colleagues in Parliament, and then exclaimed, “America usually does things in a bigger way than we do, but I wonder what they are thinking about 6,000 [the initial estimate] English people dying in Greater London alone.” Macmillan’s response was to slowly, over a period of months, form a committee to investigate. Ah, the politics of delay.

Like Macmillan and his cronies, Donora mill officials maintained a rigorous denial of fault, though perhaps not as contemptuously as Macmillan. They insisted that smoke coming from their mills was blameless or at least a minor inconvenience. The deaths were caused, read a statement from American Steel & Wire Co., a subsidiary of US Steel, by “an unprecedentedly heavy fog which blanketed the borough for five consecutive days.” The mills had been operating safely for nearly 50 years, how could they possibly be at fault?

To this day US Steel has not admitted fault in the Donora disaster, and most likely it never will. As for the London disaster, Macmillan remained truculent about the whole affair. His political ambitions weren’t damaged much by it. He became Britain’s Prime Minister in 1956 and resigned in 1963, a victim of the Profumo scandal.

Just as the Donora Death Fog prompted the nation’s first clean air act, the Air Pollution Control Act of 1955, so too did London’s Great Smog prompt the first clean air act in Britain, the Clean Air Act of 1956. Since that time air pollution levels in the US and UK have fallen dramatically.

Why it so often takes a tragedy to get politicians moving is beyond me. Just politics as usual, I guess.