A Canadian scientist involved in a recent World Health Organization (WHO) study that called malathion "probably carcinogenic" says Winnipeggers have little to fear, even though the city uses the insecticide in its mosquito nuisance fogging program.

"What most people are exposed to is very, very low levels of the agent for short periods of time," said John McLaughlin, chief science officer and senior scientist for Public Health Ontario.

"We do not expect there would be health effects from that."

McLaughlin was part of a group of experts assembled by the International Agency for Research on Cancer (IARC), a WHO agency.

As one of two Canadian scientists on the team, he is considered a leader in Canadian cancer research.

McLaughlin said the experts were tasked with evaluating five insecticides and herbicides, including malathion.

The group looked at the most recent published literature on pesticides and herbicides to determine if there was any link to cancer in humans.

"The evidence that we were reviewing in this report was primarily based on people using malathion in workplace settings, where they would be using it on a regular basis. They might be using it at high levels and they would be using it for a long period of time," he explained.

McLaughlin said people who work with malathion are required to take precautions anyway, such as wearing protective clothing or masks.

Still, he said it's up to governments and regulators to decide whether they want to continue using malathion.

"I think that's prudent and that's worth doing, but it doesn't seriously change our understanding of how to either work with this agent or to control mosquitoes," he said.