A London, Ont., plumber is warning people not to flush used syringes down toilets or kick them into catch basins, saying that while it seems safer than leaving them in the street, they can present a danger to those who work with the city's plumbing. The opioid crisis has been a simmering problem for at least a decade in the city, with recent figures putting the number of deaths from apparent overdoses at an average of eight a month since the pandemic.