Getting stuck in heavy traffic is a nightmare for many motorists and the exhaust emissions are not good for the air.
Now, a new study from the University of Toronto Scarborough suggests that road traffic also contributes to water pollution.
The study, published in the journal Environmental Research Letters, found that chemicals used in vehicle fluids, tires and paints were higher in streams near heavy traffic.
“Traffic is an important source of a surprisingly wide range of organic pollutants to urban surfaces and subsequently to nearby watercourses,” the study said.
Water samples were collected during three rainfall events between 2014 and 2018 from the Mimico Creek (which runs through Brampton, Mississauga and Toronto) and Little Rouge Creek (which runs through the Whitchurch-Stouffville, Markham and Scarborough) watershed.
The study found that levels of pollutants were higher in the densely populated Mimico Creek area, which is surrounded by more traffic compared to Little Rouge Creek, which “drains a largely rural landscape.”
These pollutants move from road surfaces to nearby streams when it rains or while attached to road dust, the study said.
Researchers say that this runoff of rainwater contributes to the degradation of streams that drain urban land, known as the “urban flow syndrome.”
They say that while a shift to electric vehicles will reduce road emissions, their study shows that many of the pollutants that enter urban streams come from non-exhaust sources such as lubricants, de-icing fluids, tires and car paint. They propose mitigating measures such as regular street sweeping to remove road dust, the development of wear-resistant tires and the immediate repair of leaky vehicles as a few ways to improve urban water quality.