Are newer stoves less polluting? Your gas and induction questions

Recently, we wrote about researchers ditching their gas stoves after measuring the high levels of dangerous indoor air pollution they produce.

Some scientists and chefs, concerned about the health and environmental impacts of gas stoves, are switching to electromagnetic induction stoves or even portable induction burners and touting some additional benefits.

These stories prompted some questions from readers. What about gas fireplaces or furnaces? Or propane stoves? Are newer gas stoves less polluting? Are induction stoves safe for those with pacemakers?

Here are the answers to some of those questions.

Dave Rose of Innisfil, Ont., asked if the nitrogen oxides — contaminants linked to negative health impacts such as asthma — are naturally found in small amounts in the gas or come from burning it.

The answer is that they're produced during burning, when nitrogen and oxygen in the air react with each other due to the heat from the burning gas. 

Meanwhile, carbon monoxide is produced by incomplete combustion of the gas.

Eric Lebel, research scientist at PSE Healthy Energy in California and lead author of a recent study on pollution from gas stoves, said his team is starting to look at natural gas composition in different cities, including Toronto and Vancouver.

While it's mostly methane, he said, "there could be other pollutants in the gas as well." Those could include volatile organic compounds and sulphur compounds used to make natural gas — which is normally odourless — smelly and therefore detectable when there are leaks.

WATCH | Why gas stoves are bad for the climate — and you:

Of course, some pollutants are generated from heating cooking ingredients such as oil and fat (and any food you burn) regardless of what kind of stove you use, so turning on the hood fan is a good idea.

While our stories dealt with natural gas stoves, Peter Gosse of St. John's, N.L., has a different kind of gas stove, and wrote in to ask how it compares.

University of Saskatchewan professor Tara Kahan, who has studied pollution from stoves, said high levels of nitrogen oxides are also emitted during cooking with propane stoves, so the health impacts would be expected to be similar: "From an air quality perspective, it's not an obvious improvement over methane."

Lebel said the pollution from cooking with propane is something his team is "actively studying."