Atmospheric Measurement Techniques (2015,v8, p2881-2912; doi:10.5194/amtd-8-2881-2015 / by J.M. Wang, et al.
“We found it was a large amount of transport trucks, but a good proportion was just cars – a mixture of both,” Wang said. “We suspect they were older vehicles.”
The researchers took real-time measurements of the exhaust of about 100,000 cars driving past air-sampling probes on one of Toronto’s busiest roads. The study was borne out of concern that vehicle fleet emissions spread farther than previously known. In addition to total particulates and carbon monoxide, the researchers found that a quarter of cars measured produced over 76 percent of pollutants like benzene, toluene, and other known carcinogens.
Besides driving an older vehicle (anything older than seven years), Wang said driving behavior could also have a huge impact on pollution. “Cruising at normal speeds is better than heavy braking and heavy acceleration,” he said. “Stop-and-go traffic can increase emissions for vehicles.”..