A study by scientists at the University of Toronto in Canada, confirmed that the majority of cars pollutants, comes from a very small number of vehicles.
According to the study of the University of Toronto, just 25 percent of cars and trucks they measured, produced 95 percent of the total particulates and 93 percent of the carbon monoxide.
Based on carbon dioxide measurements, over 100 000 vehicle-related plumes were automatically identified and fuel-based emission factors for nitrogen oxides; carbon monoxide; particle number, black carbon; benzene, toluene, ethylbenzene, and xylenes (BTEX); and methanol were determined for each plume.
Greg Evans, a University of Toronto chemical engineer, one of the study’s authors, explains:
“As we looked at the exhaust coming out of individual vehicles, we saw so many variations. How you drive, hard acceleration, age of the vehicle, how the car is maintained–these are things we can influence that can all have an effect on pollution.”