Guest: Kieran Leavitt, Toronto Star politics reporter

For decades, adding fluoride to the water supply of many Canadians towns and cities has been standard public health protocol. Fluoridation has proven to slow tooth decay, and the practice has widespread support among doctors and dentists, including the World Health Organization, Health Canada and the Canadian Association of Public Health Dentistry. But there remains a vocal opposition against fluoride in Canada's water supply, borne out of distrust of government and science. The City of Calgary has recently voted on whether to restore fluoride in their tap water, the latest in a long, fraught history over the chemical compound. Alberta-based journalist Kieran Leavitt joins "This Matters" to chat about how a widely-supported public health measure has become a battleground of politics.