An insider’s look into the city’s pesticide arsenal

The City of Regina’s pest-control chief thinks of pesticides, herbicides and insecticides as “tools in a tool box.”

His department has just released detailed information on the pestcontrol tools it uses most often, in response to a recent freedom of information request from concerned residents associated with the Saskatchewan Network for Alternatives to Pesticides (SNAP).

The data — which cover 13 years ending in 2017 — shows a recent uptick in the use of some toxic chemicals, including a powerful rodent poison. But they also point to a sustained downturn in the amount of weed-fighting chemicals sprayed on city-run green spaces.

Russell Eirich, Regina’s manager of forestry, pest control and horticulture, said his department is getting “creative.” In its fight against insects, the city has made extensive use of biological agents that unleash bacteria with no apparent danger to humans. One, known as Vectobac, is now by far the most widely used weapon in the city’s arsenal.

“We try to look for the least toxic options first,” Eirich said.

He said all the products his crews use are approved by Health Canada. But some are considered toxic or potential causes of cancer.

Over the past eight years, Eirich’s department has cut back on herbicides like glyphosate and 2,4 D. The World Health Organization’s International Agency for Research on Cancer has deemed them “probable” or “possible” carcinogens.

In 2017, crews sprayed about 14 kilograms worth of 2,4 D, an active ingredient in products like Killex and Trillion that control broadleaf weeds.

The city previously used far more 2,4 D, with totals exceeding 200 kilograms prior to 2010. That’s about when council pressed for a herbicide-reduction strategy, which has cut down average annual usage by about two thirds.

Eirich said his department has shifted to a more targeted strategy. Crews survey parks and count the number of weeds in an area, and only spray if they exceed a certain threshold.

“We’re not going out there and spraying everywhere for no reason,” he said. “We try to use those products responsibly.”

The data points to a similar trend in the use of glyphosate, which is found in Monsanto’s Roundup and Dow’s Vantage products. Since the herbicide reduction strategy came into effect, crews have used 173 kilograms per year on average. That’s less than one quarter the annual average over the six years previous.

Last year, about 100 kilograms were needed. Eirich said 2017 was an especially slim year for herbicides, since many parks did not meet the threshold for spraying either agent.

Paule Hjertaas, a spokesperson for SNAP, said she’s noticed the difference. She said she suffers from a chemical sensitivity and believes that pesticides are connected with health problems she first struggled with about 30 years ago. That’s prompted her to stay away from affected parks — but the recent changes have given her renewed freedom.

“The city parks I’ve been able to use, and that’s been very nice for me,” she said.

“I view that as a positive trend. I just think we could go further.”

Eirich said he said he expects to see an uptick in herbicide use when this year’s numbers come in, as conditions favourable to weeds are hitting much of the city ’s green space.

And not all herbicides have seen recent drops. Last year, the city used more of a product Eirich calls “one of our strongest remedies.” Overdrive — which contains the toxic chemical dicamba — is part of the city’s fight against an invasive plant known as Leafy Spurge. The city used 22.5 kilograms in 2017, more than during any year in the data.

Eirich explained that the city is obligated to fight Leafy Spurge by the provincial government. He said the department has been testing non-toxic options, including releasing beetles that may be effective in combating the plant.

But he stressed that his department has few options if it wants to control weeds, an issue that prompts frequent complaints from residents.

“Our choices are very limited in terms of effective products,” he said.

Eirich also acknowledged that the city made greater use of one of its more powerful poisons last year: Rozol, a product used to eradicate Richardson’s ground squirrels. The surge came after two years of decline for the troublesome creatures, which are commonly called gophers and can dig holes in sports fields.

“All of a sudden we saw the gophers make a roaring comeback,” Eirich said.

The city used 122 kilograms of Rozol last year. It was part of a springtime anti-gopher blitz, and preceded the use of a safer chemical that suffocates the animals. All told, crews treated 12,000 gopher holesin2017.

Eirich expects to see even higher numbers when 2018 data comes in, likely in the neighbourhood of 18,000 holes.

In past media coverage, some have expressed concern that pets or other animals could fall victim to the poison. The chemical is an anticoagulant that causes death by internal hemorrhaging, and animals often take hours to succumb to its effects.

Some worry they might be eaten if they wander out of their holes and die.

But Eirich said his staff are out every day for two weeks following the treatment to monitor the holes they’ve poisoned. He said they push the Rozol in deep, where pets can’t get to it, and stay on the lookout for danger.

“If the gophers kick out the bait we’re putting it back,” he said. “If the gopher is sick or dead outside of the hole we pick it up.”

All told, they recovered 218 dead gophers last year. Eirich said there has not been any “collateral damage,” meaning there were no reports of harm to pets or humans.

Eirich said the city’s “numberone program” is its mosquito-fighting campaign. That shows in the numbers. The city used more than 10,000 kilograms of Vectobac last year, far more than any other product.

Vectobac contains a naturally occurring bacteria that targets mosquito larvae. The city actually used less than usual last year, owing to dry conditions with little of the standing water preferred by biting insects.

“It’s considered very, very safe,” said Eirich.

The city attacks other insects using other biological agents that act in similar ways. That includes Dipel, the main weapon in the efforts to fight cankerworm infestations.

But Hjertaas said she still has concerns about some other insecticides in the city’s tool box, particularly chemicals used to kill wasps. she said there are always alternatives, like ensuring that garbage cans are properly covered.

“The best is to find a nest and suck it up with a vacuum,” she said.

Eirich said negotiating so many competing demands can prove difficult. His department is often subject to criticism from opposing and apparently irreconcilable sides — those who complain about poor landscaping and others who worry about the possible effects of chemical agents.

“It’s not an easy path,” he said. “We’re really trying to balance the needs of the community.”

The city parks I’ve been able to use, and that’s been very nice forme.i view that as a positive trend. I just think we could go further.