Greg Evans spends his days tracking smog - one particle at a time.
A professor of Chemical Engineering and Applied Chemistry, Evans is director of a new U of T research group devoted to fighting airborne pollution - the Southern Ontario Centre for Atmospheric Aerosol Research (SOCAAR).
Over the next five to 10 years, Evans and other SOCAAR researchers will investigate the origins of certain types of particles in smog and how these particles transform in the environment. The results will help in understanding the health impact of particles and in the development of more effective pollution regulations.
"What we are doing is trying to determine where the particles are coming from, both in terms of geography and sources - whether it's cars, diesel trucks, or industrial plants. And we're trying to find out what causes the number of particles in the air to fluctuate so much," says Evans.
"SOCAAR will also try to figure out whether the particles we are breathing are different from the ones we were breathing a couple of hours ago, or the ones we'll be breathing tomorrow."
It is not where Evans expected to be. Back in high school, playing bass and keyboards in a band had more appeal than chemistry. His father, Don, was a philosophy professor at U of T, but Evans was interested in the other family tradition - music. He quit university to record an album and it was only when the band's fortunes later faltered that he returned to chemical engineering at U of T.
Two summers of research work, looking at the environmental impact of coal and occupational exposure of steel workers, and he was hooked.
The instrument that most defines Evans now is a Laser Ablation Mass Spectrometer (LAMS). Graduate student Phillip Tan proposed the project in the 1990s, but it took years to build and a tough six months in 2000 to get it to work (a period the department chairman referred to as the "Silence of the LAMS," Evans recalls).
The LAMS has redeemed itself since then with some spectacular detective work, in one case tracking particles that came to College Street in Toronto from a sandstorm in the Sahara - after a detour to Mexico.
It did this by producing chemical 'fingerprints' of the composition of particles in air drawn from College Street. The LAMS accelerates the particles in the air, almost to the speed of a bullet, and uses a high-powered laser to break the particles into fragments. A mass spectrometer is used to record the chemical composition - or fingerprint.
A $3-million award to SOCAAR from the Canada Foundation for Innovation, the Ontario Innovation Trust and other partners will enable researchers to take the next major step with a unique combination of technology, says Evans.
In addition to using the LAMS to look at individual particles, SOCAAR will have a portable LAMS to measure particles in many locations across southern Ontario.
Chemistry professor John Abbott will study the chemical transformation of particles and Frances Silverman, of the Department of Medicine, will look at the health effects.
"At the moment, the health impact is regulated strictly in terms of total mass of particles," says Evans. "If we can find out which ones may be having more serious health effects, we can try to regulate those."