Australia’s federal government looks like it’s digging its heels in on gas but be warned, cooking with it is bad for your health. And while rangehoods can help, not all of them were created equal. In fact, the best ones are so loud people don’t turn them on.
Australia is on course for a gas-fired economic recovery, with renewed talk of putting in a $6 billion gas pipeline from one end of the country to the other. The fossil fuel’s credentials as a “transition fuel” have been contested loudly but there’s another downside to gas that gets far less airtime – cooking with the stuff is bad for your health, especially children.
Gas might be favoured by top chefs but there’s an overwhelming body of evidence that’s been gathered in the past 20 years to suggest that it puts our respiratory health at risk – something that’s pretty top of mind at the moment.
In fact, a recent study on the health effects of cooking with gas out of California opened with a reminder that air pollution and susceptibility to COVID-9 are linked.
“New evidence suggests that a small increase in long-term exposure to fine particulate matter (PM2.5) leads to a large increase in the COVID-19 death rate; this further establishes the substantial value in protecting the population from the respiratory vulnerability caused by widespread air pollution,” the study by UCLA Fielding School of Public Health stated.
The impact of gas on air quality has received scant attention considering how many people cook with gas around the world, with around 38 per cent of Australian homes fitted out with a gas cooking appliance.
A 2018 study led by University of Queensland researcher Luke Knibbs found that around 12 per cent of childhood asthma around the country can be contributed to gas cooking.
While this might not sound like many, as the researchers point out: “the proportion of the population exposed is relatively large, so that the contribution to the population asthma burden is considerable.” (Note that the study also included the contribution of household mould to childhood asthma).
In the US, the situation looks worse. A comprehensive literature review of two decades worth of research on this topic by the Rocky Mountain Institute, Mothers Out Front, Physicians for Social Responsibility, and the Sierra Club shows that living in a home with a gas cooking increases the risk of a child having asthma by 42 per cent.
How bad can it really be?
Childhood asthma is not the only adverse health effect we need to worry about.
Formaldehyde, carbon monoxide and nitrogen dioxide (NO2) are among a nasty cocktail of offending particles and gases emitted by gas cooktops that can cause adverse health effects. Homes with gas stoves found to have NO2 concentrations 50 – 400 per cent higher than homes with electric stoves.
According to research from organisations such as the Rocky Mountain Institute, exposure to NO2 only a little higher than outdoor concentrations can exacerbate symptoms of asthma in adults.
Beyond asthma, gas cooktops are linked to other respiratory conditions – everything from an uncomfortable wheeze to something more serious such as chronic obstructive pulmonary disease.
Elevated NO2 levels have also been linked to other conditions such as cardiovascular problems, diabetes, cancer, reproductive issues and brain development in children.
Extraction devices can help but relying on them is dangerous
Rangehoods that extract the problem particles out of the air can be effective, but these devices vary in quality and subsequent effectiveness. The best on the market vent the polluted air outdoors and can capture particles and gases with greater than 75 per cent efficiency.
From there, there’s a steep decline to lower performance devices with less extraction power or devices that simply recirculate air. At this lower end of the spectrum, as little as 15 per cent of pollutants are captured.
Good rangehoods work. According to Dr Knibbs from UQ, high-efficiency range-hoods could reduce the amount of childhood asthma associated with gas stoves from 12 per cent to just three per cent.
While a powerful rangehood that vents outside can be enough to offset most of the harmful effects of gas cooktops, these are typically super noisy.
As a result, people with the top-of-the-range ventilation equipment are likely to be among the significant cohort who don’t habitually turn them on. A survey of Melburnians found that 44 per cent of people in the city did not use them regularly.
It’s also unclear how many homes in Australia are kitted out with rangehoods that are effective, and regulation in this space appears patchy. According to Building Connection, the National Construction Code does not explicitly mention rangehood ducting or the ventilation of kitchens in the air quality section. There are some requirements, thankfully, for those living in combined living/sleeping area and large commercial kitchens (The Fifth Estate welcomes further information on this – editorial@thefifthestate.com.au).
While proper ventilation indeed helps, RMI research concluded that “we cannot rely on current exhaust ventilation practices alone to protect families from unsafe levels of gas stove pollution”.
In addition, energy efficiency upgrades to stop air escaping and seal the build envelope can inadvertently exacerbate the impacts of gas stovetops.
What can be done
The RMI report proposes a series of recommendations to improve what it describes as a “significant and solvable health problem in plain view” in the US, with the switch to electric cooktops the ideal long-term solution.
“The health case for transitioning to all-electric cooking has been slowly mounting for more than 40 years but policymakers must urgently address air pollution now,” said Brady Seals, senior associate at Rocky Mountain Institute and report author.
Other suggestions are directed at regulation, such as rules forcing manufactures to produce appliances that are safe.
If you’re an individual worried about health effects but can’t afford to switch to an electric cooktop, there are ways to mitigate the problem.
Always open the windows and turn on the exhaust hood during cooking. Other options are installing a low-level carbon monoxide detector, or using a plug-in induction cooktop.
Living in a share house with no heating, we used to leave the oven on and open all the time as our only means of keeping warm. We had no idea of the risks. The cat used to sit on the open oven door as well. Lots of people in rental housing use appliances in ways they are not intended for as a result of not having adequate and affordable heating/cooling etc.
No standards for rental properties either (add it to the list). I live in an old rental apartment in Sydney with a gas stove and oven, and there is no rangehood at all. There’s a window I suppose, and plenty of draught gaps in the door, window frame, floor…
I live in Parkes NSW and I was the first to have an induction cook top. After cooking every day for the last 14 years, I have found it extremely hard to cook on anything else, the induction cook top has step less control when cooking, it is quicker than electric element stove tops and quicker than gas. Once you have mastered cooking on an induction cook top you wouldn’t cook on any thing else. You will use 40% less energy to get the same result cooking on anything else.
Of course eventually hydrogen might be a worthwhile replacement. Its exhaust is water.
Whilst Morocco is ahead of the ball game, in respect of using ‘de-salination and hydro electricity’ Australia which is a far larger country than Morocco continues to procrastinate, even though its scientist have been working for years on the use of ‘de-salination plants coupled together to produce electricity’…but perhaps recent Morrison government think tanks…overseen by the very industry that is exposing so many to major health problems…view clean energy as not the way to go…for their bottom company profits…and they after all donate to the major political parties.
https://www.researchgate.net/publication/294422790_Renewable_hydropower_generation_as_a_co-benefit_of_balanced_urban_water_portfolio_management_and_flood_risk_mitigation
Specifically, the study provides evidence that Sydney’s interdependent goals of deferring capital intensive flood storage works, maintaining water security, better utilising existing desalination and hydropower assets, and increasing renewable energy generation can be achieved through applying systems thinking to a complex citywide water planning problem. The work also makes a valuable contribution to the energy-water nexus literature at the under-explored city-scale.
Other ‘top chefs’ such as Neil Perry, Tetsuya & at the Veu du Monde all exclusively use induction cooking.
Induction is also the preferred cooking method for top chefs in the UK.
Gas has an outdated reputation.
If asthma increases greatly due to gas cooking why does Victoria not have a larger asthma rate than other states. We appear to sit in the middle with significantly more households with indoor gas appliances?