GUELPH, Ont. – It began almost two decades ago as a discussion topic for agricultural researchers who were curious about a natural soil toxin that was threatening to disrupt Canadian durum exports.
It ended with research solutions that have become a template for researchers in Asia.
“When we would get together in a working group of scientists from government and universities, we were interested in the fact that durum wheat tended to accumulate cadmium from the soil and at the time, it was a problem,” said Beverley Hale, associate dean of research and innovation at the Ontario Agriculture College.
Read Also
Agriculture ministers agree to AgriStability changes
federal government proposed several months ago to increase the compensation rate from 80 to 90 per cent and double the maximum payment from $3 million to $6 million
“But it was really under the radar at the time, even though durum had levels that exceeded international acceptable standards and we were having some export shipments turned back because of elevated levels.”
Cadmium is a metal that can cause kidney dysfunction and brittle bones if significant levels are stored in the kidneys.
Plant breeders and other researchers got to work and developed new durum varieties that do not absorb cadmium into the grain.
“We really have resolved the durum issue since then with new varieties,” said Cynthia Grant, a soil management and fertility scientist at Agriculture Canada’s research centre in Brandon and one of the members of the working group that included Hale.
“It was a very successful program. In fact, it is a bit of a poster child worldwide for how to deal with cadmium accumulation in plants.”
Grant worked on agronomic and soil research while researchers from Swift Current and Winnipeg led the breeding effort.
As well, the international standard for acceptable cadmium levels was doubled, which helped Canada stay under the tolerance level.
However, cadmium accumulation is still an issue for some crops and food.
Hale said researchers, including Canadians, are now working to develop soybean varieties that do not take cadmium from the soil into the plant. It is a significant issue in Asia and major soybean-producing countries where elevated cadmium levels are a problem.
She said tests have also shown that cattle can store cadmium through the feed they eat, and ground beef from older animals can have elevated levels.
Potatoes can also have elevated levels.
“A lot of producer groups don’t want to talk about this or see it become a public issue because people aren’t dying every day and they don’t want public panic over a safety issue,” she said.
“It is a lower level risk, but I think there are enough smoking guns out there about the dangers of elevated levels in humans to say it is an issue. We should work in a sensible and calm way to minimize it in the diet.”
Hale said farmers should take the issue seriously.
“The most important thing farmers can do is pick varieties that are low accumulators.”
She said farmers should also consider having their soil tested for cadmium.
Grant said several prairie crops, including flax and sunflowers, can contain higher cadmium levels, but human consumption is in low enough quantities that health-damaging accumulations are unlikely.
However, she said scientists continue to monitor cadmium levels in prairie soil and noted that farm management practices can contribute to the problem.
Some phosphorus fertilizers have elevated levels and can increase cadmium levels in the soil.
“We monitor to make sure we are not adding to the problem.”
