How concerned should Winnipeggers be about lead in the soil? 3 takeaways from the lead contamination report
Risk is generally low, but some findings from the provincially commissioned report raise concerns
Children in three Winnipeg neighbourhoods are expected to have blood lead levels above what is considered safe, according to a report released this week about the amount of lead in soil throughout Winnipeg.
However, the independent review — commissioned by the provincial government and completed by the health and environmental consulting company Intrinsik — also found that lead levels are generally decreasing, and have been for decades.
Given that consuming lead can cause serious health issues — especially in young children — there is an understandable concern over the report's findings.
But before jumping to conclusions about how much lead is really in the city's soil, here are a few of the key messages from the report worth noting.
How serious is the soil contamination?
The risk is low, according to the report and Manitoba health officials, but 10 areas of the city were identified in the report as points of "potential concern."
That's because samples from those areas contained lead concentrations above 140 parts per million — the residential soil quality benchmark.
Those areas include parts of neighbourhoods like Centennial, Daniel McIntyre, Glenelm/Chalmers, North Point Douglas, the River and Osborne area, St. Boniface, Wolseley, and much of the West End, including Sargent Park, Weston and Minto.
Manitoba has conducted studies on lead contamination in the soil periodically over the past 40 years, and lead concentrations have decreased over that period, according to the report, which was released Wednesday.
"The main sources of lead emissions in Winnipeg are no longer present," the report said, noting that emissions from leaded fuel in vehicles and airplanes, and from facilities like lead smelters and scrap yards are no longer in the air.
It adds, however, that recent samples were taken from a greater soil depth than in the past — meaning the results cannot be directly compared.
"Higher concentrations of lead may be found in soils closer to the surface, and people are more likely to come into contact with these soils."
As well, most samples have historically been taken from public boulevards, schools and playgrounds. The only study to test private property was one conducted in St. Boniface in 2017 by the University of Manitoba, the report said.
"As a result, lead concentrations in some of these areas may not be well understood. It is also possible that other neighbourhoods not included in these studies may have soil lead concentrations at levels of potential concern," it said.
The airport is one of those areas, says Shirley Thompson, an associate professor at the U of M's Natural Resources Institute.
The report, citing previous studies, says children living within a one-kilometre radius of the airport show elevated blood lead levels.
"[The fact] that there are no [soil] samples within that area should be rectified — and that's not one of the recommendations," Thompson said.
To get to the heart of the issue, however, a better survey must be conducted, says Bruce Lanphear, a professor at Simon Fraser University in B.C. who has researched early childhood exposures to environmental neurotoxins, including lead.
"Find out particularly the hotspots. When you take the average, it minimizes the problem in certain communities, in certain homes," Lanphear said in an interview with CBC's Information Radio.
"You want to do a much better assessment. Then you want to prioritize, based upon those levels."
Are Winnipeggers affected by lead?
The report warned that children from three different neighbourhoods have unsafe blood lead levels. But data about blood lead levels in Winnipeg — or Manitoba in general — isn't something we actually have.
Except for Quebec, blood lead testing is not required anywhere in Canada, nor do public health officials or family doctors have to track or share information about blood lead samples with other medical professionals, according to the report.
To make their conclusions, the report's authors predicted blood lead levels based on the lead contamination in a neighbourhood's soil, air, food, dust and water.
The average predicted blood lead levels for the 10 neighbourhoods identified as areas of concern were "higher than what has been reported for Canadian children," the report said.
Children from North Point Douglas, Weston and Daniel McIntyre were predicted to have blood lead levels above two micrograms per decilitre — the level of concern.
"That's pretty typical for children who live in a community that has lead in the water, the soil, the paint on older houses," said Lanphear, adding that children affected by lead from multiple sources are the ones most at risk — and that tends to happen in older or impoverished areas.
Specifically, Lanphear said children living in an impoverished area might be exposed to not only lead in soil and water, but also to more air pollution and possibly pesticides.
North Point Douglas, Weston, Daniel McIntyre and Centennial were highlighted as such areas in the report. Historically, areas like Point Douglas and Weston in particular were zoned for heavy industry — meaning there may have been more lead in those areas because of industries like manufacturing and rail.
The Intrinsik report suggests that Manitoba track blood lead tests for children seven years old or younger.
Children in that age range have developing nervous systems, making them most susceptible to the non-reversible effects of lead contamination, which can impact behaviour, intelligence and the ability to learn.
Lanphear notes that the effects of lead contamination are very subtle until later in life.
"The manifestations are from the chronic low-level exposure to lead over a child's early life, and then you'll start to see that there are some kids who have just a little more problems learning, or a little bit more acting-out type behaviours — ADHD-type behaviours," he said.
Monitoring blood samples would not only allow people to act on the lead issue, but it would help identify how a person may be consuming lead based on where they live, said the U of M's Thompson.
"We know [lead] is in the soil; we don't know how much of that is getting into children," she said. Testing, she said, would "tell us not just what's available, but what actually occurs … and what risk this poses."
The report focused on the effects of lead on children, but lead contamination can have long-term health consequences for adults, such as high blood pressure, heart disease, and kidney and reproductive system problems.
Anyone who is concerned about potential lead contamination can request a simple blood test from any physician, Lanphear says.
How can we be proactive about contamination?
Being educated about lead exposure, practising good hygiene — such as washing your hands after being outside — and controlling the amount of dust around the house can help, the report says.
It adds, however, that even those steps "may have a limited to no effect" on blood lead levels in children.
Kids are often more exposed to soil in places like schoolyards or playgrounds, and young children may also eat soil, said Thompson.
Eighteen of 22 soil samples collected by researchers from Weston Elementary School had high traces of lead.
Given that, children should avoid contact with soil with high levels of lead, the report suggests.
Previous studies that have looked into getting rid of contaminated soil altogether were designed too differently to accurately measure how effective that approach is, the report said.
There was a concerning note in the report regarding protection, however.
Given the current understanding of lead toxicity, it's clear that old methods for evaluating lead exposure — and what levels were considered safe — were not effective in protecting people.
But some of today's safety benchmarks are based on old data, the report said.
"The Canadian residential soil quality guideline is based on pre-2000 science," it said.
"Comparing soil concentrations to this guideline [140 parts per million] may not provide an adequate level of protection for young children."
With files from Sarah Petz and Information Radio