01/14/2019 14:55 EST | Updated 01/14/2019 22:01 EST

Montreal School Ecole des Decouvreurs Evacuated Following Reports Of Nausea, Dizziness

Carbon monoxide poisoning is suspected.

Graham Hughes/CP
Ecole des Decouvreurs elementary school is shown in the Montreal borough of Lasalle on Jan. 14, 2019.

MONTREAL — Carbon monoxide levels in the hallways of a Montreal elementary school where 43 people fell ill Monday and required hospital treatment were as much as five times the level that usually triggers an evacuation, a fire official said.

"At 35 (parts per million) of carbon monoxide in the air, we evacuate a building,'' Eric Martel, an operations chief with the Montreal fire department, told The Canadian Press. Inside the Ecole des Decouvreurs in the city's LaSalle neighbourhood, firefighters detected up to 175 parts per million in the hallways — and 900 in the furnace room

Martel said a defective heating system was to blame for the gas, which left dozens of students and staff feeling nausea and dizziness. Some were vomiting, and an emergency room physician said nine children lost consciousness at the school.

Graham Hughes/CP
A Gas/Metro van is shown outside Ecole des Decouvreurs on Jan. 14, 2019.

On Monday afternoon, the Montreal Children's Hospital reported that 10 patients who received the most serious exposure — including the nine who lost consciousness — had been transferred to another area hospital to receive hyperbaric oxygen therapy. The treatment involves breathing pure oxygen in a pressurized room.

"The good news is all of these patients are in stable condition .... These are precautionary measures, and we expect that they will be released healthy very shortly,'' Dr. Robert Barnes, the hospital's associate director of professional services, said.

In addition to the 10 transferred for hyperbaric therapy, one child was being kept overnight at the Montreal Children's Hospital for oxygen therapy and observation.

The hospital had declared a code orange, which is used for an emergency situation with multiple victims, at around 12:30 p.m. Between 15 and 20 people, including one adult, were initially reported to have been affected, but then a second wave reported symptoms.

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