Ambient air measurements for the carcinogen formaldehyde in the Schiller Park area during 2017 registered many times higher than a risk assessment threshold in the Integrated Risk Information System (IRIS), the standard used by the U.S. Environmental Protection Agency (EPA). What does air quality expert and author Rich Trzupek think about that? Not much.
“IRIS is an extremely conservative assessment that should be used in the same kind of way insurers use actuarial tables when pricing an insurance policy,” Trzupek told the DuPage Policy Journal. “It’s a tool to help identify the sum total of relative risks, not a way to nail down any one absolute risk.”
Levels of what the EPA considers another hazardous pollutant, ethylene oxide (EO), near the Sterigenics plant in Willowbrook were far more in line with the risk standards under IRIS than formaldehyde and other carcinogens monitored in Schiller Park and the greater Chicago area. Most air samples tested for EO in November in Willowbrook, in fact, showed no traces of the compound at all. (Measurements from samples taken in May by the EPA, the reporting of which caused the initial panic in the area, were discovered to be flawed.)
But the news reports, especially those by the Chicago Tribune’s Michael Hawthorne, that began when the May EO measurements became public have filled residents with an unfounded fear by greatly exaggerating the threat, Trzupek said.
“Using the IRIS approach to scare people about EO emissions is reprehensible,” he said. “It’s nothing more than a cherry-picking exercise with zero context. A scary story can be told about any chemical if you know where to find the numbers, and the story is taken out of context.”
November's air samples show no levels of EO in Willowbrook residential areas, near parks or near schools. Two locations adjacent to the Willowbrook plant had variable levels of the compound. But those monitors are also close to Route 83 and Interstate 55, near where Sterigenics uses ethylene oxide to sterilize medical equipment, pharmaceutical drugs and food. Motor vehicle exhaust is a source of EO.
“As the EPA states, ‘It’s premature to draw conclusions from the data. EPA plans to continue monitoring in the Willowbrook area for three months and will continue to post data as it becomes available,’” Sterigenics noted in a statement.
Trzupek says keeping risk in perspective is key when weighing the dangers from hazardous compounds, or from any potential hazard. According to the most recent study published by the Centers for Disease Control, the risk of accidental poisoning deaths in the United States is 181 deaths per million. For unintentional falls, it’s 107 deaths per million.
“A reasonable person looks at those stats and says, ‘I should be careful about how I store my prescriptions and exercise caution when using a ladder,’” Trzupek said. “A reasonable person does not say ‘I’m never going to take prescription drugs or use a ladder, because then I will die.’”
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