A City of Toronto study has found high levels of cancer-causing toxins in the air around a major highway interchange in South Etobicoke.

On Wednesday, the city’s Environment & Energy Office released its second report on air quality, this time in the community where the Gardiner Expressway, the QEW and Highway 427 meet.

Like South Riverdale — the subject of the first study and the area where the DVP and the Gardiner meet — certain chemicals were found above provincial or national standards.

“One of the most concerning things is to know that there are cancer-causing chemicals in our air that people in South Etobicoke are breathing and this is actually related to an increased risk of cancer for the community,” said Heather Marshall of the Toronto Environmental Alliance.

City staff found increased amounts of nitrogen oxides, benzene, benzo(a)pyrene and two types of particulates — which increase the risk of everything from heart, lung and breathing problems to cancer.

The authors said most of the chemicals are from vehicle emissions, although furnaces, boilers and industrial manufacturing contribute as well. Some of the pollution comes from other parts of southern Ontario and the U.S.

“We need to make sure the cars are moving well,” Marshall said. “But we also have to give people options so that they can leave their car at home … The TTC has to be the go-to transport option for people. We need to make sure they can get out of their cars and into the TTC and that means expanding transit and it also means improving TTC service and keeping the rates, the fares, low so people can afford it.

“Is the City of Toronto doing enough? I don’t think so.”

Chemicals that exceed provincial or national standards

Five of 30 air pollutants were studied by the City of Toronto and found to exceed the Ambient Air Quality Criterion developed by the Ontario environment ministry.

The five substances are nitrogen oxides, benzene, benzo(a)pyrene, particulate matter PM10 and particulate matter PM2.5, and come from car emissions. Residential boilers and furnaces as well as some local industry also produce nitrogen oxides and particulate matter.

Nitrogen oxides are common air pollutants that contribute to smog. Both nitrogen oxide and smog are linked to cardiovascular and respiratory illnesses and death.

Benzene is a carcinogenic solvent derived from coal tar and petroleum and is used to make many products.

Benzo(a)pyrene is a carcinogenic hydrocarbon commonly produced by burning wood, car exhaust fumes and coal tar.

Particulate matter PM10 is tiny airborne particles of between 2.5 and 10 micrometers in size from wood burning stoves, smoke from factories and road dust.

Particulate matter PM2.5 is another kind of air pollution which is smaller than 2.5 micrometers and are from driving autos, burning plants and smelting.

South Etobicoke air quality study

Impact of air quality on health in South Etobicoke