Athabasca River low in heavy metals from oilsands: U of A study
Study tested water from 12 sites along Athatbasca River near Fort McMurray
New research suggests that heavy metals released from the oilsands aren't finding their way into nearby rivers.
"If you buy bottled water in a glass bottle, you'll find five or 10 times more lead in that water than you would in the Athabasca River," Bill Shotyk of the University of Alberta said Friday.
Shotyk was releasing preliminary results from the university's new $4.7-million lab that is capable of measuring water contaminants to parts per quadrillion. He and his colleagues used that equipment to analyze water taken in October from 12 sites on the Athabasca River from just upstream of Fort McMurray to 125 kilometres downstream.
They found that the amount of heavy metal contamination dissolved in the water is vanishingly small – less than that found in remote rivers in wilderness parks.
"The lead values in the Athabasca River are much lower than the Nipissing River in (Ontario's) Algonquin Park," he said.
Shotyk didn't measure major contaminants such as mercury and hydrocarbons, which have both been shown to be entering the environment from oilsands mines.
His results have not yet been peer-reviewed or published. But they promise to complicate the understanding of the environmental impact of the oilsands industry.
Study focused on dissolved contaminants
Previous studies from both university and government scientists have shown significant levels of heavy metals in the river and the regional snowpack. Those found increasing circles of concentration with the bull's-eye centred on oilsands developments.
Shotyk said the reason his results are different is that he focused exclusively on contaminants actually dissolved in the water. Other studies have included heavy metals found on particles suspended in the water as well.
"Those metals are in those mineral particles," Shotyk said.
"I would guess what we're measuring dissolved in the water is dwarfed by what the river's moving naturally as sediments. But the part that we're measuring – the dissolved part – that's the part that's relevant to the aquatic organisms."
'Dissolved metals are not the whole story'
David Schindler, a University of Alberta ecologist who did some of the first work measuring heavy metal emissions from the oilsands, said Shotyk's study in fact confirms his findings.
"It is no surprise that most of what is in the river is particulate," he wrote in an email.
His team found the same thing when they analyzed the snowpack from the river surface.
"We analyzed both (for) dissolved and particulates, and most of the contaminants were in the particulate fraction. Most of the dissolved fractions were below limits of detection, which were very low."
But he disputes Shotyk's contention that heavy metals in sediments don't find their way into plants and animals. Metals can contaminate sediment layers where organisms lay their eggs and hatch larvae, he said.
"Dissolved metals are not the whole story."
Shotyk acknowledges that how contaminants move between sediments and living organisms are an active subject of study.
"That's what I will be evaluating for the next 10 years. But there's no question that heavy metals dissolved in the river are really low."
More results from his lab are forthcoming, Shotyk promised. A colleague is conducting an analysis similar to the one done for heavy metals, but on polycyclic aromatic hydrocarbons, a cancer-causing toxin that has already been shown to be leaching into groundwater and evaporating into the air from oilsands tailings ponds.
"We're putting together the pieces of the puzzle," he said.