A proposed change in the state’s cleanup of dioxins drew fire last week from Attorney General Jennifer Granholm.

The Michigan Department of Environmental Quality, as part of its work to update its criteria for cleanup, proposed an increase to its standard for acceptable contamination from 90 parts per trillion to 150 parts per trillion.

According to Granholm, there is no evidence to support such an increase.

“Generally, scientific information suggests that we should be going for a tightening, not a loosening in standards,” said Genna Gent, spokeswoman for the Attorney General’s office.

Granholm cited an analysis from the Michigan Department of Community Health that suggested a 12 parts per trillion standard.

But DEQ spokeswoman Geralyn Lasher said that number wasn’t supported by any real data and was only a reaction to a U.S. Environmental Protection Agency investigation to determine a dioxin toxicity criterion.

“It wasn’t a formal report, it was very much speculation,” she said. “It was a look at if the latest numbers that the EPA had come up were implemented,