Hundreds of schools across Ontario have reported cases of carbon monoxide poisoning, but the levels of the substance is believed to be “extremely low.” Officials across the province have directed students and staff to remain indoors, and the Canada Post has closed many mail facilities.
About 600 schools have so far reported exposure to the gas, and three dozen have reported with 10 or more cases. Of those, 256 reported 6 or more people inside, while 141 reported just one.
Cathy Bennett, an Ottawa nurse with the Canadian Association of Nurses in Residence, called the numbers “very shocking,” and said those showing symptoms “should be looked at as a potential poisoning and have their symptoms looked at.”
Still, she said the patients should be treated with water and nitrite tablets if symptoms of nausea and vomiting continue. Once cleared, they can be sent home.
Carbon monoxide poisoning can quickly lead to hospitalization, but levels of CO are very low. In an average dwelling, for example, an individual is most likely to suffer without incident. In this instance, the amount of carbon monoxide is thought to be less than 1 part per million.
In a comfortable, clean home, the average concentration of CO is 1 ppm, and in the ventilation system of a home of any size, CO levels are also usually very low.
During flu season, however, levels of CO in the air may spike, but should be screened before people begin to experience symptoms. A quick test using a CO-test mask or the CO-Paleter can produce a reading of about 1 ppm.
There are four major sources of CO: furnace or furnace-related chimney flues, gas appliances, gasoline vehicles, and gas fired space heaters, said Mr. Reid.
Factors such as cracks in your home, gaps in your attic, large appliances sitting against wall joints, and excessive heating temperatures can all create conditions for CO. Flue gases from gas fired devices — such as furnaces and air conditioners — will vent off into the atmosphere, with the CO trapped on the outside of the furnace.
There is no standard carbon monoxide alarm in Canada, which is why it is important to have several. In Ontario, the Safe Growing, Safe Living and Breathing standards have the same four temperatures for carbon monoxide levels, but some builders may be trying to make their homes more energy efficient by lowering the thermostat.
“The first thing you want to do is look at the insulation, because you don’t know if it’s sealed properly,” said Mr. Reid.
Experts recommend alternating air intakes throughout the day to ensure a constant flow of air into your home.