No small feat

No small feat

The University of Ottawa’s Jack Cornett studies tiny traces of rare atoms to unlock mysteries of environmental health
September 30, 2014

Jack Cornett is very clear about what drew him to the University of Ottawa two years ago from his position as director general of the Atlantic Naval Research Laboratory in Halifax. It was the accelerator mass spectrometer (AMS).

“Imagine standing in a desert where you can see a kilometre in each direction,” explains the professor of geology. “There are probably tonnes of grains of sand. And then imagine detecting the presence of just one of those grains of sand. That’s how powerful the accelerator mass spectrometer will be.”

Also called an “atom buster,” the spectrometer is as big, at about 25 metres long, as it is powerful. Cornett, who holds the Canada Research Chair in Radiochemistry and Environmental Health, will use this leading-edge equipment housed in the Advanced Research Complex to detect and measure tiny amounts of radioactive atoms in very small samples.

While the technology sounds like something out of a sci-fi novel, it will be used by Cornett to solve a variety of very familiar, real-world problems such as osteoporosis, radiation exposure and environmental contaminants.

Take, for example, the concern over organic contamination around Alberta’s Athabasca oil sands. The spectrometer will allow the AMS team of researchers to determine whether that contamination comes from mining the oil sands or from natural processes like forest fires or the erosion and combustion of coal deposits.

The researchers will start by detecting and measuring very tiny amounts of the rare carbon-14 radioisotope in soil and sediment samples from the affected area.

“Carbon-14 is very rare, but it is found in trace amounts of about 1 per trillion in the atmosphere,” says Cornett. “So if contamination is from a source that has been in contact with the atmosphere in the recent past, the spectrometer will be able to detect carbon-14 in the sample. However, carbon-14 decays over thousands of years, so if the contamination is from the oil sands, which is a very ancient source of carbon, there will be no more carbon-14 there — it will have all decayed.”

Along with uncovering extremely small amounts of radioisotopes, the spectrometer eliminates interference by background isotopes and speeds up results. “We’ll be able to get an accurate measurement in about five minutes,” explains Cornett. “In the past, it could take a week or so.”

On the biomedical front, the geologist will use the equipment to advance the diagnosis and treatment of osteoporosis, which affects as many as 15 percent of Canadians.

“You can give a patient a tiny amount of the rare isotope calcium-41, which is not found naturally in the skeleton, and it will be absorbed by the bones and label them for life,” he says. “We can test if the patient is losing bone mass and at what rate because, as bone loss occurs, the calcium-41 levels in a patient’s urine rises and we can look at the efficacy of treatment.”

Calcium-41 is radioactive, but the dose is so low that it is safe to give to a patient and most radiation detectors can’t trace it. The AMS, however, is about a million times more sensitive so, as bone breaks down, even a minute amount of calcium-41 in urine can be easily detected.

The AMS will also help researchers monitor permafrost melt rates, trace pollutants in well water to figure out their source and measure radiation exposure. But that’s not all. The atom buster will even be used to unravel mysteries of the universe.

“We’ll be able to measure radioisotopes that have yet to be identified, that help us determine the origin of the cosmos,” says Cornett. “For example, we will be able to look at lead-205, which is a signature of supernovas. This was inconceivable before. The AMS has totally revolutionized the measurement of rare atoms and isotopes.” For Cornett and his fellow researchers in the Earth sciences, it’s a revolution that opens up a boundless world of possibilities.

This story originally appeared in the summer 2014 issue of Research Perspectives, a publication of the University of Ottawa.

MAIN IMAGE: Jack Cornett will use the University of Ottawa’s accelerator mass spectrometer to measure tiny amounts of radioactive atoms in very small samples for applications in health and the environment. Credit: Peter Thornton, uOttawa