Pigeon poop removed from Saskatoon bridge was a health hazard, says U of S prof

The 600 tonnes of pigeon poop recently removed from one of Saskatoon's bridges and the way it was cleaned up were a threat to human health, says a University of Saskatchewan professor.

Earlier this week, the City of Saskatoon gave an update on renovation work being done on the Sid Buckwold Bridge.

Part of that work included workers euthanizing 2,300 pigeons and then scooping up about 600 tonnes of pigeon droppings at a cost of $800,000. By weight, that's the equivalent of 100 African elephants.

The bridge's load capacity — including both "live loads" (people and cars) and "dead loads" (the weight of the bridge, including the poop packed into its cavities) — was at its limit, putting the bridge at risk of failure, the city said. 

But U of S biology researcher and professor Susan Kaminskyj said such droppings are a biohazard and pose a real health risk to humans.

Kaminskyj, who runs the fungal cell biology and microscopy labs at the U of S, said breathing in the tiny fungal spores from pigeon poop can make you sick or worse.

If you are a healthy person, breathing in the spores would likely cause cold-like symptoms.

"It's like having a three- or four-week cold and then you get better," Kaminskyj told Saskatoon Morning's Jennifer Quesnel. "If you're unlucky, it kills you."

There are antifungal medications you can take, but they are not very effective, Kaminskyj said.

The city said workers used electric Rototillers to loosen up the feces, then used shovels or hammer drills with spade bits.

Allan Construction then collected the dry pigeon poop from the cavities with a vacuum truck and took the material to the landfill.

At the landfill, the feces was placed in a separate area from the regular waste and covered with earthen fill. 

Kaminskyj said using jackhammers to remove some of the droppings was a mistake because that would release spores that can get in your lungs from up to 10 metres away.

"They're making about as much dust as you can possibly make.

"Fungal spores are really, really, really tiny. They are small fractions of millimetres."

But Todd Grabowski, the city's acting engineering manager, major projects and preservation, said in a note that workers involved in the removal of the poop wore appropriate personal protective equipment that included body suits, gloves, respirators with a particulate filter and air monitor.

Besides the health risk, Kaminskyj said the city could have repurposed the pigeon poop.

Historically, bird poop was a rich source of plant fertilizer, especially for nitrates and phosphates. "Guano is the best organic fertilizer. What happened here was that they threw it away," she said.

"They also said it can't be composted. Well you don't compost fertilizer, you use it."

The city did offer the feces to other parties for fertilizer, but "those parties were not interested unless the fecal material was hauled at taxpayers' expense."

Grabowski said the fecal material is a mixture of pigeon feces, straw and garbage that required "processing and handling that would have significantly increased the project cost."

The city has now erected wire and fencing in the places where the pigeons made their mark to prevent them from roosting there.

The city is also looking at other methods such as using a falcon or using sounds to deter pigeons from the bridge.