Herbicide that’s 'possibly carcinogenic to humans' used in Jasper park

Over the past decade, herbicides have been banned in dozens of jurisdictions across Canada, including the Municipality of Jasper, yet they are still being used to combat invasive plant species in Jasper National Park. Last week, red and white signs popped up near Wyne Road in the west end of town, just before the railroad overpass, warning passersby of pesticide use. The signs were posted by Kinder Morgan’s Trans Mountain, which conducts an annual weed control and vegetation management program along its pipeline in the park. The program is part of a commitment between Trans Mountain and Parks Canada, following the expansion of the Anchor Loop pipeline project in 2008. The 158-km twinned pipeline parallels Highway 16 from Hinton to Hargreaves, B.C., cutting through JNP on the way. “Keeping our facilities and pipeline rights-of-way clear of problem weeds and other obstructions is necessary for public safety and fire control and in the case of Jasper National Park, is part of our commitment following the completion of the Anchor Loop Project to ensure that invasive plants are managed in the park,” stated Ali Hounsell, a spokesperson for Trans Mountain, in an emailed statement. According to the company, it uses three herbicides along Wyne Road, including Clearview Herbicide, MCPA and the controversial herbicide, 2,4-D. The weed killer, 2,4-dichlorophenoxyacetic acid, commonly referred to as 2,4-D, is one of the most widely used herbicides in the world and is banned for lawn care in every province east of Manitoba as part of a wider ban on cosmetic lawn care products. In June, the World Health Organization’s (WHO) International Agency for Research on Cancer (IARC) reviewed the latest scientific literature and classified 2,4-D as “possibly carcinogenic to humans.” This is a step below the more conclusive category “probably carcinogenic,” but two steps above the “probably not carcinogenic” category. The Canadian Cancer Society was less direct, but discourages the use of herbicides for cosmetic use. “As a health organization, we have evaluated current research on pesticides and acknowledge that there is potential for them to be cancer causing (although more research is needed),” stated Paula Trotter, a communications coordinator for the Canadian Cancer Society, in an emailed statement. “The environment is critically important to our health, and if pesticides are necessary to protect the environment, then that benefit would have to be weighed against the health risks of exposure.” In 2008, Health Canada re-evaluated 2,4-D and concluded the herbicide meets the country’s health and safety standards and is acceptable for continued use in Canada. At the time, Health Canada said its findings were consistent with WHO, as well as the Organisation for Economic Co-operation and Development (OECD). “Health Canada’s conclusions indicated that the continued use of 2,4-D for both agricultural and residential use does not pose a health concern when used according to label direction,” said André Gagnon, a media relations officer for Health Canada. “This conclusion is not changed by the recent WHO (IARC) hazard classification, as pesticides are registered for use in Canada only if the level of exposure to Canadians does not cause any harmful effects, including cancer.” Trans Mountain pointed to Health Canada as justification for its use. “Trans Mountain uses low-residual herbicides that have been approved and rigorously tested by Health Canada, and Health Canada continues to support 2,4-D as a safe and effective tool for controlling weeds,” it stated in an email.

For at least two Jasperites, the use of herbicides in the park is a serious concern. “It’s been six years that they’ve been doing this out here,” said Lynda Knight, who placed her own sign next to the one left by Trans Mountain. Her sign, handwritten on blue poster board, warned people about the dangers of herbicides. “It doesn’t work,” she said during an interview. “The daisies come back every year.” She said she would prefer Parks Canada let the invasive species grow rather than using chemicals to try and stop them. “I believe in evolution and it didn’t stop when Charles Darwin said it happened, it keeps on going, and I think if these plants are thriving here and growing here there’s probably a reason for it. I believe in the intelligence of the planet more so than ours.” For Gord Ruddy, a long-time birder, he said he was disappointed Parks allows Trans Mountain to use herbicides in the park and said his main concern is the impact the chemicals have on birds. “Right now is just the absolutely worst time to spray, because juvenile birds are leaving the nest and it’s deadly to birds,” he said. “It doesn’t really matter whether you think the jury is still out or not, the scientific evidence is very clear that those kinds of chemicals are really nasty to birds.” Trans Mountain said it takes measures to minimize the risk to human health and the environment and follows municipal bylaws that require the company to post warnings 72 hours before it spot sprays. The signs are left for an additional 72 hours once the spraying is complete. According to the company, the herbicide targets up to eight plant species along Wyne Road, including oxeye daisy, Dalmatian toad flax, common mullein, tufted vetch, yellow clematis, Canada thistle, yellow toadflax, hawkweed species and mustard species (tall hedge and dog mustard). “When an invasive species is let loose into areas, especially as something as fragile as the mountain ecosystem, they can take completely over and ruin your biodiversity,” said Don Hare, program coordinator for Alberta Invasive Species Council. “There are a number of things you can do, but certainly herbicides can be the most cost effective and least labour intensive,” he said, explaining pulling weeds often causes them to spread even more. Hare said herbicides are effective because they get into the root system of the plant and can be used to selectively target specific plant species. He also explained infrastructure projects, such as pipelines, create new vectors for invasive species, allowing them to spread easier. “We always encourage early detection and rapid eradication,” said Hare. “It’s so important to get ahold of these things before they establish. The cost is infinitesimal compared to trying to handle a bigger situation,” he said, explaining the mountain pine beetle could have been stopped had people reacted quicker. In 2010, the Municipality of Jasper passed a bylaw that banned the use of herbicides on any land the municipality is responsible for. The bylaw does not stop people from privately using herbicides on their own property, but the town advocates people use less intensive techniques, such as dethatching or aerating their lawn. The two-page bylaw also recognizes Parks’ authority and environmental mandate, allowing Parks to use herbicides on municipal lands as long as it meets a strict set of criteria. That criteria includes using herbicide only if it targets non-native species posing a significant risk to the park ecosystem. It also allows for it when there is no alternative way to control the invasive species, however the herbicide has to be effective and registered in Canada, and the necessary permits have to be obtained. The bylaw also stipulates Parks must minimize the potential environmental risks by using the lowest effective toxicity, the smallest effective amounts, and the most conservative methods when applying it. Parks Canada uses several methods to control invasive species including mechanical, biological and chemical techniques.

"Parks Canada’s surveys have found that certain populations of the most aggressive non-native plants and invasive species have shown little to no reduction in population size when using methods other than herbicide, such as intensive manual picking, mechanical whipping and re-seeding of disturbances," said Greg Fenton, the superintendent for Jasper National Park in an emailed statement.

"Herbicide use was introduced in order to control these species that are aggressive, difficult to control, and pose a substantial ecological threat to the park."

He said Parks Canada uses herbicides less than five per cent of the time and currently uses the "steam and flame" method to decrease the use of herbicides. The steam and flame method uses steam kill the plant.

This story was updated with comment from Parks Canada.  

Paul Clarke [email protected]