City should test more homes for lead in water, expert says
City of Winnipeg offers free testing to 200 out of potential 23,000 homes with lead pipes
An expert in toxicology and water quality says the number of homes where the City of Winnipeg is testing for lead in the water is too small to get an accurate picture of the potential risk to residents.
On Wednesday, the city sent out a letter to approximately 23,000 homes in Winnipeg that may have lead pipes, with the goal of finding 200 volunteers to undergo testing. They reached that goal in less than a day.
"Testing only 200, this is a little bit problematic," said Eva Pip, a retired University of Winnipeg biology professor who specialized in water quality issues and a clean water advocate.
Pip told Ismaila Alfa, host of CBC Manitoba's afternoon radio show Up to Speed, that similar tests were done in the 1980s and the differences between adjacent houses could be "like night and day."
"You can have very high levels in one house and the one beside it have levels within the acceptable concentration," Pip said. "So you really want to test as wide a range as you can in order to get a better picture."
Lead is a neurotoxin that can affect the brain and nervous system. It's especially dangerous for children, who absorb lead at a higher rate than adults, and can lead to cognitive development problems and low IQ.
It can take 10 years for half of the lead absorbed in bone to be excreted from the body, Pip said.
"So this is not something that you ingested and it's gone the next day," she said.
The Manitoba government ordered the city to test the water after the federal government cut the maximum amount of acceptable lead in drinking water in half, down to 0.005 milligrams per litre.
The vast majority of lead in water comes from service pipes that connect a house to the municipal water supply, said Graham Gagnon, director of the Centre for Water Resources at Dalhousie University.
"There might be other … lead components, whether it's through solder or brass, but there's not necessarily lead pipe within the home," he said on CBC Manitoba's morning radio show, Information Radio.
Many cities, including Winnipeg, add a chemical called orthophosphate to the water to prevent lead leaching from the pipes into the water. The effectiveness of the chemical can be reduced if the home is farther back from the street, which means the water has to travel a farther distance through the lead pipes, Gagnon said.
The city said the tests are merely a precaution and the water is safe to drink.
While the city regularly tests for water contaminants such as E. coli and chlorine, homeowners usually have to take the initiative on testing for lead, which can be expensive, Pip said.
Residents who want to test their water but weren't among the 200 households receiving the free tests from the city can take a water sample to one of several private testing laboratories.
With files from Cory Funk and Ismaila Alfa