Donora’s disaster of 1948 leaves no mark on earth itself
No chemical spike in sediment analysis
In the fall of 1948, a three-day weather inversion trapped emissions from U.S. Steel’s Zinc Works in Donora, creating a poisonous industrial cloud that smothered the town, killing 20 residents, sickening more than 6,000, and elevating the death rate in the Monongahela River valley community for months afterward.
The Donora Smog, as it is now known, is one of the world's worst environmental disasters, but it does not register in a new forensic analysis of sediment dredged from the bottom of nearby Markle Lake by University of Pittsburgh researchers.
The researchers went looking for chemical markers of the Donora tragedy, expecting a black band of deadly sediment or a sudden spike in the chemical composition of the lake’s muddy historical record. Instead, they found sediment layers that tell a longer, more complex, story of human industry and industrial pollution in Western Pennsylvania.
The inversion, an event that looms large in Donora’s human memory, does not register in the lake bed’s historical log.
“It’s not that surprising,” said Daniel Bain, a professor at the University of Pittsburgh who advised the graduate students leading the research. “It was a three-day event and it only produced a teeny-tiny amount of sediment, if it even got in there.”
But the sediment record speaks volumes about the region’s industrial legacy. Researchers found highly elevated arsenic concentrations in the oldest and deepest muds, deposits from colonial tanneries that lined the lake shores and dumped their pollution into the water.
“These legacy activities, they’re relatively harder to nail down because they existed at a period when maps weren’t as great,” said Robert Rossi, the first author on the paper and now a researcher at Temple University.
“You might not have known that, say, Jethro down the street had a leather tannery and he was dumping arsenic in the lake in his backyard.”
On a rare map of the area from 1867, a tannery and a paper mill sit side by side along the shore of the lake named for the Markle family, which owned much of the lakefront. The paper mill, which the Markles opened in the early 1800s, was eventually forced to close in the late 1870s because the water it used from a lake feeder stream became too polluted from tannery discharges and acid mine drainage from coal mining and coke production to use in the making of white paper.
“One irony is that the mining of coal and making of coke so polluted Sewickley Creek that it made the production of high-quality paper in that area impossible,” wrote Glenn Markle, one of the descendants of the Markles of Markle Lake. “They were one of, if not the, dominant paper producers west of the Alleghany Mountains.”
But Donora does show up in the mud, said Mr. Bain, although not as the scientists initially thought. In 1915, the Donora Zinc Works factory opened and the levels of zinc in the sediment skyrocketed and remained elevated well past the Donora smog event in 1948. Mr. Bain said the zinc levels remained high because industrial activity in the area did not actually decrease.
The zinc mill in Donora, 37 river miles south of Pittsburgh, finally closed in 1957. But in 1952 the Duquesne Light Co. opened its Elrama coal-fired power plant, a major, long-term source of air pollution until its closure in 2012.
“We thought that once Donora closed, we’d start to recover a more normal amount of metal that’s coming into that lake,” Mr. Bain said. “It didn’t happen, and we think it’s probably because of the opening of Elrama.”
The Donora event remains a large part of the environmental consciousness of the region. Donora itself has sought to commemorate it by adopting the motto “The birthplace of clean air,” a reference to the tragedy’s role in passage of the 1970 federal Clean Air Act.
“When I was little, I pictured old Pittsburgh as hell, hell with the lid off,” said Mr. Rossi, who grew up in Pittsburgh across the river from where his grandfather worked in the Jones & Laughlin Steel Corp. mill on the South Side. “I remember hearing a lot of stories about how smoky everything was from the mills — my grandma had white metal on the furniture and you had to clean them every day.”
He laughed. “That’s a typical growing up in Pittsburgh story.”
Today, despite cleanerlooking air, the Pittsburgh region is ranked as the eighth-worst for year-round particle pollution on the American Lung Association’s 2017 “State of the Air” report.
Although city workers no longer need to change their shirts after lunch because of soot in the air, the study’s scientists worry about repeating patterns of careless industrial pollution.
“What happens with that highly salty water from fracking when it touches this legacy contamination that we don't really think about?” Mr. Bain said. “The fracking waste stream is just another instance in a long line of cases where we generated a lot of waste and we don’t knowwhat to do with it.
“If we could get ahead of these things,” he said, “maybe we could do this whole human thing a little more effectively and efficiently.”