Too many cooks spoil the AIR: Cooking overtakes vehicle exhausts as London's biggest source of harmful air pollution, study finds

When it comes to sources of air pollution in London, cars and construction might be the first things that spring to mind.But a new study has revealed a more unexpected culprit behind some of the city's highest emissions: cooking.Scientists from the UK Centre for Ecology & Hydrology measured emissions of ultrafine particles that are known to penetrate the bloodstream, lungs, and organs – posing a risk to human health.Their results revealed that cooking produced more direct emissions than vehicle exhausts, with emissions significantly higher during mealtimes.'Most people smell cooking but never consider it as a pollutant, yet cooking can release large amounts of fine particulate matter into the atmosphere,' said Dr Ben Langford, lead author of the study.'Over recent decades we have dramatically reduced emissions from road transport, but we have paid far less attention to emissions from commercial kitchens and food preparation.'Our results suggest this is an area where further improvements in air quality could be achieved relatively quickly through better filtration of kitchen fumes.' When it comes to sources of air pollution in London, cars and construction might be the first things that spring to mind. But a new study has revealed a more unexpected culprit behind some of the city's highest emissions: cooking (stock image) Scientists from the UK Centre for Ecology & Hydrology measured emissions of ultrafine particles that are known to penetrate the bloodstream, lungs, and organs – posing a risk to human health. Their results revealed that cooking produced more direct emissions than vehicle exhausts –with emissions significantly higher during mealtimesFor the study, the team analysed the sources of air pollution in both London and Beijing.In London, measurements were taken from the atmospheric observatory at the top of the BT Tower – a 623ft–tall building in the heart of the city.The researchers focused on particulate matter measuring less than one micrometer – one–thousandth of a millimetre.Worryingly, because of their small size, these particles are known to penetrate deep into the lungs and bloodstream, increasing the risk of respiratory issues.The measurements revealed that in both cities, emissions were significantly higher during mealtimes.In London, cooking accounted for a whopping 83 per cent of midday emissions, and 87 per cent of early evening emissions.In contrast, traffic exhausts accounted for less than 10 per cent.Before you panic that your home cooking is contributing to air pollution, the researchers say that commercial kitchens are largely to blame.Writing in their study, published in npj climate and atmospheric science, they explained: 'Our measurements reveal that a substantial fraction of non–refractory primary PM1 emissions from developed urban centres originates from cooking, likely dominated by cooking oil emissions from shallow and deep frying in commercial settings.'According to the researchers, these 'surprising' findings demonstrate the success of transport emission regulations and the shift towards electric vehicles in London.Dr Eiko Nemitz, co–author of the study, said: 'Air quality policies targeting vehicle exhaust emissions have been highly effective.'As a result, cooking emissions are now a surprisingly important and poorly regulated part of the urban pollution mix.'Despite their importance, cooking emissions have only recently been added to the London Atmospheric Emissions Inventory.That means it's impossible to make direct historical comparisons.However, the researchers highlight that fine particulate matter emitted by vehicle exhausts in the UK fell by 94 per cent between 1996 and 2024. Six common air pollutants identified that harm your health and the environment According to the Environmental Protection Agency, there are six major pollutants which can impact on human health and well–being. EPA calls these pollutants 'criteria' air pollutants because it regulates them by developing human health–based and environmentally–based criteria for setting permissible levels. Particulate matter: Particulate matter is the term for a mixture of solid particles and liquid droplets found in the air.These particles come in many sizes and shapes and can be made up of hundreds of different chemicals.Some are emitted directly from a source, such as construction sites, unpaved roads, fields, smokestacks or fires.Fine particles (2.5 parts per million)are the main cause of reduced visibility (haze) in parts of the United States, including many of our treasured national parks and wilderness areas. Carbon monoxide: Breathing air with a high concentration of CO reduces the amount of oxygen that can be transported in the blood stream to critical organs like the heart and brain.At very high levels, which are possible indoors or in other enclosed environments, CO can cause dizziness, confusion, unconsciousness and death. Nitrogen dioxide: Nitrogen dioxide primarily gets in the air from the burning of fuel. NOIt forms from emissions from cars, trucks and buses, power plants, and off–road equipment.Breathing air with a high concentration of NO can irritate airways in the human respiratory system. Such exposures over short periods can aggravate respiratory diseases, particularly asthma, leading to respiratory symptoms (such as coughing, wheezing or difficulty breathing). Sulfur dioxide: The largest source of Sulfur dioxide in the atmosphere is the burning of fossil fuels by power plants and other industrial facilities.Short–term exposures to SO can harm the human respiratory system and make breathing difficult. Children, the elderly, and those who suffer from asthma are particularly sensitive to effects of SO.Ground–level ozone: The ozone layer in the lower area of the lower portion of the stratosphere, approximately 12 to 19 miles above the surface of the planet (20 to 30 km). Although ozone protects us against UV radiation, when it is found at ground level it can cause health problems for vulnerable people who suffer from lung diseases such as asthma. It is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC) – that are found in exhaust fumes – in the presence of sunlight.Lead: Major sources of lead in the air are ore and metals processing and piston–engine aircraft operating on leaded aviation fuel. Other sources are waste incinerators, utilities, and lead–acid battery manufacturers. The highest air concentrations of lead are usually found near lead smelters. Depending on the level of exposure, lead can adversely affect the nervous system, kidney function, immune system, reproductive and developmental systems and the cardiovascular system.Infants and young children are especially sensitive to even low levels of lead, which may contribute to behavioural problems, learning deficits and lowered IQ.