A professor who has studied petroleum coke and the oil industry for more than a decade says the piles of petroleum coke stored on the bank of the Detroit River "is not a hazardous substance."

Jan Ciborowski of the Great Lakes Institute for Environmental Research at the University of Windsor said pet coke poses no bigger threat than piles of aggregate currently stored on the Canadian side of the river on Windsor's west end.

Petroleum coke is a by-product of oil refining.

"This coke is a fine dust and behaves like any other fine dust. When it's windy, it blows and causes dust problems. It's the same concerns on both sides of the border," he said.

Ciborowski's colleague, Chris Weisener says the piles of petroleum coke stored just east of the Ambassador Bridge would need to be analyzed to determine if they pose any real health or environmental risks.

If the piles are strictly comprised of the oil refinery by-product petroleum coke, Weisener says they would be 95 per cent carbon and five per cent sulphur.

"With maybe trace amounts of metal," said the prof, who specializes in geomicrobiology and geochemistry. "You'd have to do a chemical analysis to determine contaminants."

Weisener said carbon is used in water filtration, for example.

"There are some benefits to this material," he said. "But whether or not that material is like that, it's tough to say without analysis."

Ciborowski said if clean water were run through pet coke, it would pick up "trace metals."

"The same thing happens with soil. It doesn’t leach metals any more than anything else," Ciborowski said of pet coke. "It's relatively non-toxic."

Detroit Bulk Storage is piling the pet coke along the bank of the Detroit River. Pet coke is resold for producing asphalt or to be used as an alternative to coal. The crude oil by-product is currently classified as non-toxic.

"What they need to do is provide data on the composition of the material, at least to assure the public of its nature," Weisener said.

Weisener said there is not much information about pet coke available, so its effects are not conclusively known.

"Part of the issue is that there hasn't been conclusive research database collected, yet," he said.

Ciborowski, has done some research on pet coke.

Ciborowski 's team in 2007 found pet coke is a stabilization agent that could be good for the environment, "under very controlled circumstances."

The Michigan Department of Environmental Quality conducted tests near the pet coke piles last week.

"From the air perspective, as long as it's not being burned, the only concern would be fugitive dust," said Chris Ethridge, of the MDEQ.

Ethridge "wouldn't want to say either way," if he's concerned by the pet coke.

According to Health Canada, "the impact of a fugitive dust source on air pollution depends on the quantity and drift potential of the dust particles injected into the atmosphere. Fugitive dust contains both the large and fine particulate matters."

The piles had people in Windsor protesting on the weekend. The pet coke also concerns at least one U.S. politician.

"I am very concerned," Congressman John Conyers wrote in a statement. "We must ensure that not only is the river protected, but also the people in the community as well. It is important that we meet with relevant stakeholders."