For nearly four years, researchers have been using data collected from wastewater samples to determine when and where COVID infections were rising in the province. Now, Ontario is shutting down its COVID wastewater testing program. The province says they don’t need to continue testing because the federal government does the same thing. But critics disagree and say we could be losing vital information about the spread of viruses in the future.

Ivan Semeniuk is the Globe’s science reporter. He’s on the show to talk about what we can learn from wastewater testing, how it’s been used in other regions, and why experts are worried about Ontario shutting down this system.

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