Can we agree on this? If authorities know of chemical emissions that can cause cancer — even if they don’t know yet how great the risk is — they ought to let the public know right away.

Three chemical plants in the suburbs have been emitting significant amounts of ethylene oxide gas, which has been linked to breast cancer and lymphomas. But state and federal authorities took their time, in each case, in letting the public know.

Although the U.S. EPA reclassified ethylene oxide gas in 2016 from “probably carcinogenic” to “carcinogenic” — and found it is 50 times to 60 times more dangerous than previously thought — a debate remains as to what level of emissions threatens the health of people who live nearby.

What is not debatable is the right of residents to be told.

EDITORIAL

Emissions at the Sterigenics plant in Willowbrook have been the subject of protests for months. And now we know, thanks to a Chicago Tribune report last week, that two other plants — one in Gurnee and another in Waukegan — also have been sending ethylene oxide into the air that thousands of people breathe.

In the case of Sterigenics, a branch of the federal Centers for Disease Control and Prevention learned last May that the plant was emitting ethylene oxide, which it had been doing since the 1980s, and might be responsible for an unexplained “chronic” health risk. But the public wasn’t told until July.

Now it turns out federal authorities also knew Vantage Specialty Chemicals in Gurnee and a Medline Industries facility in Waukegan were emitting significant amounts of ethylene oxide, which is used to sterilize various devices and equipment, often for medical use. In both cases, the government kept the information under its hat.

The companies are legally operating with permits. But Illinois Attorney General Lisa Madigan’s office calls existing safeguards “alarmingly inadequate.”

Environmentalists have complained for years that the Illinois Environmental Protection Agency moves too slowly against environmental threats. In September, Madigan’s office complained that the IEPA refused to release Sterigenics’ emissions reports from 1996 to 2008.

Elected officials from Sens. Dick Durbin and Tammy Duckworth on down are demanding answers, which can’t come soon enough.

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