Carbon monoxide levels at the Charles Gorman Arena were nearly triple the Health Canada guidelines on Sunday. (Google Street View)

The City of Saint John is investigating after elevated levels of carbon monoxide at the Charles Gorman Arena over the weekend made some people sick.

A user called the arena on Sunday afternoon, saying he and several teammates who were in the arena on Saturday night had experienced flu-like symptoms, according to a statement issued by the City on Wednesday afternoon.

The arena attendant used a hand-held device to test the air quality and detected carbon monoxide levels of up to 67 parts per million (ppm), the statement says.

Health Canada's residential indoor air quality guidelines call for a "short-term limit" of 25 ppm, based on a one-hour average, while the long-term exposure limit is 10 ppm, based on a 24-hour average, according to the website.

The attendant immediately evacuated the building, notified management and the city's safety officer, officials said.

Programming was cancelled for the rest of the day while the building was ventilated.

Exposure can be 'serious'

Levels returned to normal, but the source of emissions of the colourless and odourless gas has still not been positively identified, they said.

The natural gas-fired boilers were checked on Monday and no leaks or malfunctions were detected, according to the statement.

The ice resurfacer was also pulled from service and tested, but the results were "within industry standards."

Meanwhile, staff at other arenas in the city have been monitoring carbon monoxide levels and checking resurfacer emissions, city officials said.

When carbon monoxide is inhaled, it reduces the ability of blood to carry oxygen, according to the Health Canada website.

"The effects of exposure to CO can be very serious," it states.

Low levels can cause symptoms such as headaches, tiredness, shortness of breath and impaired motor functions.

High levels over a long period of time can cause dizziness, chest pain, tiredness, poor vision and difficulty thinking.

Exposure to very high levels can cause convulsions, coma and even death, the website states.

It is a common byproduct of the burning of propane, natural gas, gasoline, oil, coal and wood.