OTTAWA, Ontario — Now that the Canadian government has approved Dow AgroSciences’ new corn and soybean traits, anti-biotechnology groups are crying foul on a system they say is a treadmill and bound to fail.

Last month Canadian authorities approved Dow’s Enlist corn and soybean traits, which were designed to be resistant to the company’s herbicide 2,4-D. Enlist corn and soybeans are also stacked to be resistant to the herbicides glyphosate and glufosinate.

“It’s significant that the approval happened,” said Lucy Sharratt, coordinator of the Ontario-based group Canadian Biotechnology Action Network (CBAN). “It shouldn’t have happened. We know what the consequences of the use of 2,4-D-tolerant crops will be and there’s a human health cost to this expanded use of 2,4-D.

“We think the introduction of 2,4-D-tolerant crops is an admission of failure. As predicted, weeds have become tolerant to glyphosate.”

Dow anticipates launching the Enlist weed control system in corn in Canada and the United States for the 2013 growing season, although it is still going through the regulatory process in the United States. Launch of the Enlist system for soybeans is anticipated in both countries for the 2015 growing season once regulatory approvals are granted.

“We’re hopeful that the American government won’t approve the 2,4-D-tolerant crops,” Sharratt said. “It may be a slim hope, but ... The burden of this pesticide is being placed on farmers. It’s unacceptable. The corporate solution to this problem is more pesticide-tolerant crops, but we don’t think it is a solution.”

She said what happened with glyphosate-tolerant crops will also happen with crops tolerant to 2,4-D.

“Any weed control measure that you use repeatedly, will bust,” said Gary Hamlin, a spokesman for Dow AgroSciences. “Even plowing. You can’t keep doing the same thing season after season after season. The intention is not to replace glyphosate. The idea is to return it to its historical level.”

Hamlin went on to say if the Enlist system were meant to replace glyphosate, then the same problem of weed resistance would occur, as CBAN states. But he said Enlist is meant to complement the Roundup system, not replace it.

In a statement it released last week about Canada’s approval of Enlist, CBAN quoted cancer researcher Meg Sears. “This century’s epidemiological research of 2,4-D formulations continues to show elevated risks of cancers, particularly non-Hodgkin’s lymphoma,” Sears is quoted as saying.

Sears published a paper in 2006 that questions whether 2,4-D is safe. Called Pesticide Assessment: Protecting Public Health on The Home Turf, she and co-authors state “multiple deficiencies in the 2,4-D PACR (proposed acceptability for continuing registration) illustrate systemic problems with pesticide regulation in Canada. The 2,4-D assessment is contrary to the ... Declaration of Helsinki, and does not approach standards for ethics, rigor or transparency in medical research.

“Canada needs a stronger regulator of toxic chemicals, with the competence and will to protect Canadians’ health. (The) 2,4-D ‘safety’ claims should be publicly withdrawn by the PMRA and Health Canada. The 2,4-D PACR should be grounds for federal bureaucratic, legislative and regulatory changes,” they wrote.

The CBAN statement also said Norway, Denmark and Sweden have banned 2,4-D. Hamlin said 2,4-D is registered for use in Sweden and Denmark and that the U.S. Environmental Protection Agency has extensively evaluated the health issues surrounding 2,4-D and doesn’t think the chemistry can cause any form of cancer.

“That stuff has been evaluated for decades,” he said.