Over five dozen schools in Toronto exceeded federal guidelines for lead in drinking water during the 2023-24 school year, provincial testing data shows.
Federal government guidelines consider drinking water safe if its lead content is five parts per billion or less. The Province of Ontario has more lenient rules, which allow up to 10 parts per billion.
Samples taken from Toronto District School Board and Toronto Catholic District School Board schools during the last school year found 66 of the city’s schools exceeded the federal threshold.
Twenty-one also tested over the provincial limit of 10 parts per billion.
MAP: Dark grey indicates Toronto schools with test results over 10 ppb, and light grey indicates test results over 5 ppb. Click on a point for details.
"There's no level of lead exposure that isn't linked to negative health outcomes, but it's particularly dangerous for children and youth," explained Julie Mutis, a community outreach worker at the Canadian Environmental Law Association, which wrote a report on the data.
"When we're talking about children in a very important stage of development in their brains, it can impact your cognitive development. We see outcomes like a decrease in IQ, difficulties with attention and focus, behavioural issues, and things such as delays in fine motor skills."
Zion Heights Middle School, located on Leslie Street near Finch Avenue East, had eight water tests exceeding federal and provincial standards during the last school year, the highest number in the city and the second highest in the province.
Lead was used in plumbing systems until the 1970s, and in solder until the 1990s. That means even relatively new school buildings can suffer from the drinking water issue.
The provincial government has spent nearly two decades trying to eliminate lead from drinking water in schools and childcare facilities, the CELA’s report notes, yet the problem still persists.
Replacing parts of plumbing systems or installing filters is the best way to ensure drinking water isn’t dangerous to students, according to Mutis.
However, she said schools that haven’t received those expensive upgrades will often flush their water systems in the morning to get rid of the water that had been sitting overnight in the pipes.
"There's sort of this reliance on flushing,” she told TorontoToday. “In the morning — if you know a tap has lead components to it — flushing it for a certain amount of time as prescribed by your local public health unit, and then considering it good to go for the rest of the day.”
“That is not really best practice any more."
In the late 1990s, there was a noticeable fall in social ills like teen pregnancy and violent crime in the United States, which has been linked to the phasing out of lead in gasoline around twenty years prior. Similar correlations were found in other industrialized countries.
The CELA is urging the Ontario government to mandate more thorough testing. Currently, schools that test below the provincial lead contamination threshold can skip some annual tests.
The group also wants mandatory parental notification when students are exposed to high levels of lead in their school’s drinking water.
"The focus is that the lead should come out," Mutis stressed.
