Despite various improvements implemented over the years, the air quality within Toronto's subway system still fails to meet international standards, according to a recent study conducted by a group of chemical engineering students at the University of Toronto. Professor Greg Evans, a key member of the research team, noted that their interest in subway air quality has spanned over a decade. Specifically focusing on Line 2, he pointed out that air quality levels have remained stagnant and are considered subpar compared to numerous subway systems globally.
The students involved in the study undertook extensive research by riding the full length of Line 2, spending approximately two hours per trip to collect air samples. Their findings indicated a concerning presence of various airborne particles, including trace metals such as copper, chromium, and zinc. Although Health Canada has not established a formal threshold for health impacts regarding these pollutants, it does recommend maintaining the levels of particulate matter in indoor environments as low as possible.
Platforms Experience Elevated Toxicity Levels
While the Toronto Transit Commission (TTC) trains are equipped with filtration systems that do help in reducing exposure to airborne particles, the study highlighted that air quality deteriorates significantly on the platforms. According to Isaac Lo, one of the researchers, pollutant concentrations on the platforms are about two to three times higher than those found on trains. Despite the alarming findings, the researchers noted that the sample size of the study was relatively small, and they found no immediate cause for concern for the average commuter.
However, prolonged exposure to poor air quality could pose health risks for individuals who spend extended periods of time on the subway. Joyce Wu, a pulmonary function technologist, suggested that vulnerable individuals may want to consider wearing masks while commuting on the subway to mitigate potential health risks. Additionally, the concerns are magnified for TTC employees, who are exposed to these particulates for much longer durations on a daily basis.
Marvin Alfred, the President of the Amalgamated Transit Union Local 113, underscored the importance of ensuring a safe environment for both workers and commuters. He expressed concerns that previous efforts to address air quality have not adequately addressed the risks associated with the subway environment. In response to the study’s findings, the TTC emphasized that safety remains its top priority. The commission stated that numerous tests and studies conducted have deemed the air quality within the subway system to be safe and showing signs of improvement. They further stated that air quality in the Toronto subway is comparable to that of other transit systems across North America.
Looking ahead, the TTC has received approval to purchase new trains specifically for Line 2. Professor Evans noted that newer braking systems introduced on Line 1 have contributed to a reduction in airborne pollutants and expressed optimism that similar advancements will soon be implemented for Line 2.
