'We are being lied to': Edmonton doctor alarmed at pesticide use in local lakes

Guinevere Park can be seen in this Google Street View photo from July, 2022. (J.D. Davies/Google Street View)

A whistleblower who played a key role raising the alarm of the health risks posed by the oilsands has a new concern — this time in his own backyard.

Dr. John O’Connor is campaigning with fellow concerned citizens against the use of the insecticide rotenone to rid Edmonton waters of invasive goldfish that have been breeding in a number of lakes in Edmonton subdivisions.

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O’Connor worked as a physician for Indigenous communities downstream of the oilsands and drew public attention to what he noted was a high prevalence of unusual cancers.

"The risks to human health are well known, yet we are being lied to!" O’Connor said in an email about rotenone and the messaging behind its use in his neighbourhood.

Rotenone, the main component of the insecticide noxfish, is a World Health Organization class II toxin linked to Parkinson’s disease and developmental neurotoxicity. Sales of rotenone have been banned in the United Kingdom since 2009.

EPCOR, Edmonton’s utility company, notified residents in May 2024 that it would be using the insecticide in West Edmonton’s Lake Guinevere, O’Connor said.

In a statement to Canada’s National Observer, EPCOR said it needs to prevent the spread of invasive species to the North Saskatchewan River, or they could overwhelm native species and destroy ecosystems.

There are two options for successful removal of invasive goldfish: rotenone or draining and maintaining a dry storm pond for a winter season, Ryan Fournier, press secretary to Rebecca Shulz, Minister of the Environment and Protected Areas for the province, told Canada’s National Observer in a statement.

"Rotenone is the least disruptive and most successful eradication method," Fournier added.

Goldfish and koi are invasive species that have been introduced to a number of Lethbridge ponds. (Photo: City of Lethbridge)In flyers, EPCOR has told residents that rotenone is not harmful to humans, but to expect to see workers in hazmat suits on the day of application. EPCOR also advised residents to pull back their belongings from the lake and noted odours would be present.

That’s when the red flags were raised for O’Connor. He and other concerned residents dug into the research and found that exposure to the pesticide carried dangers to health.

When the group disputed EPCOR’s claims that the insecticide was harmless, the utility’s response was that it did not want to alarm residents, O’Connor said.

O’Connor and others began doorknocking to speak about the flyer and set up a table on the lake’s trail to inform local residents about the risks of rotenone and gather signatures on a petition against its use. Within a couple of days, the petition had 300 signees and counting.

"People were angry and enraged… people were not told [of the risks]," he said.

Beyond the lake, EPCOR has plans to use the insecticide in man-made stormwater ponds.

In a statement to Canada’s National Observer, EPCOR said it is mandated by Alberta Environment and Protected Areas (AEPA) to eradicate invasive species from stormwater management facilities.

The utility maintains that the best way to eradicate goldfish is through chemical treatment using rotenone, and that the chemical "does not affect wildlife, humans or pets when applied as directed."

The chemical breaks down naturally in water with no long-term adverse effects, and is also diluted and generally applied below the surface of water to reduce risks to surrounding areas and individuals, the utility explained.

However, O’Connor says his advocacy group feels "betrayed, saddened and angry at the utter lack of transparency," he said in an email to Canada’s National Observer.

In the most recent flyer to residents, distributed Tuesday, the same claims regarding the pesticide’s "harmlessness" were repeated to residents, O’Connor said.

O’Connor pointed to more than 300 more ponds around Edmonton that will be potentially targeted for rotenone application — with many residents unknowingly exposed.