A recent study conducted by McGill University over 15 years revealed that the decline in air quality in Toronto and Montreal is responsible for the deaths of 1,100 people annually.

The study, which was released last Monday, reported that ultrafine particles are capable of entering the bloodstream when inhaled due to their small size, which may contribute to heart and lung diseases, as well as certain types of cancer.

The researchers stated that there has been an increase of up to 17.4% in respiratory deaths associated with unstable ultrafine particles, along with a 9.4% rise in coronary artery disease.

The scope of the research spans from 2001 to 2016, covering large areas of the two cities inhabited by millions of people, using ground-level measurements, aerial images, and land use information.