Welcome to our Healthy Homes & Workplaces 10-part series. In these stories, we delve deep into the science and engineering behind our machines to reveal our Dyson top tips, tricks and recommendations for keeping your home and workplace clean and healthy though lockdowns and beyond. Find out more on Instagram through #DysonHealthyHome.
Cooking up a storm: the impact of cooking on air quality
As the festive season looms, many choose to spend more time cooking. But what impact does it have on our indoor air quality?
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From appliances, to the methods we use and the food that we cook, the kitchen can be an indoor pollution hotspot. Whether you’re cooking up a festive feast or baking for family and friends, preparing food can release a unique mix of pollutants into the air. Kitchen concentrations of ultrafine particles can often be 10 to 40 times higher after cooking and in some cities, it’s estimated that cooking contributes to 62 per cent of total PM2.5 pollution in homes.
“As the days get colder and people spend more time indoors, it’s important to be aware of sources of pollutants within the home and how we can mitigate our exposure," says Dyson Air Quality engineer Sam Taylor. "Cooking appliances, methods of cooking and the type of food used can all have an impact on this.”
Cooking appliances
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The combustion process emits ultrafine particles, which include oil droplets, steam from the water used to cook, ingredients and condensed organic compounds. Research has found that Nitrogen dioxide (NO2) levels are consistently higher in homes that cook with gas rather than electric stoves. It also indicated that levels were greater when cooking for longer periods of time. Electric stoves may not produce as much air pollution as their gas-powered counterparts, but particulate matter can be emitted from the food being cooked on the stove, regardless of the fuel.
Ovens are also pollution offenders, particularly self-cleaning variations, according to the 2001 California Air Resources Board study. As food waste is burned away, potentially harmful concentrations of particulate matter, NO2, carbon monoxide and formaldehyde are released into the kitchen air.
Ensuring that kitchen appliances such as ovens or stoves are fully vented, and are installed, used and maintained correctly can help to minimise this exposure. Furthermore, opening the window while you cook if the air outdoors is clean enough or using mechanical ventilation like a purifying fan can assist by filtering out pollutants.
Cooking method
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The way that food is cooked can affect air pollution inside the kitchen. Oil-based cooking, such as grilling and frying food is generally more polluting then water-based cooking like boiling or steaming, as it generates more fine particles.
Odours released from browning food - like grilling steaks or toasting bread - might smell appealing, but the compounds released during the cooking process that cause these smells, are actally a source of gas pollution.
An investigation in Sydney using Dyson’s air quality backpack found that personal exposure to NO2 and PM2.5 levels increased while grilling food outdoors on a BBQ. Simple measures such as opting for water-based cooking where possible and minimising higher-polluting cooking methods can help minimise personal exposure.
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When it comes to creating ambience, warmer light helps to signal to the brain that it is time to relax. Daylight tracking technology within the Dyson Lightcycle Morph light supports the body clock by providing the right light for the right time of day, as well as being flexible – from task lighting for a specific workspace, to ambient mode, mimicking candlelight without the straining flicker.
Food type
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The type of food and cooking temperature also impact the amount of pollution released. Higher emissions are observed at higher temperatures, while ingredients with higher fat content have been found to give off more pollution.
The oil type used in cooking can affect pollutant levels and in general, oils with higher smoke temperature produce lower levels of particulate matter. Research indicates that olive oil is one of the worst offenders, releasing the highest concertation of particulate matter.
“Understanding indoor air pollution is the first step in empowering people to make educated choices in the kitchen to help reduce air pollution exposure," says Dyson Head Chef, Joe Croan. "Simple changes in routines such as the type and quantity of oil you use when cooking can have a positive impact in the kitchen.”
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With people spending even more time indoors as they prepare for a lockdown winter, our Dyson specialists share their top tips on how to keep a healthy home over the long, cold winter.
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With autumn already here and the clocks going back at 02:00 on Sunday 25th October, the change in daylight hours can affect our sleep patterns. We often look forward to an extra hour of sleep but evidence suggests we do not actually benefit from it.
Footnotes
Wan, M-P, Wu, C-L. Sze To, G-N, Chuan, T-C, Chao C.YH, 2011. Ultrafine particles and PM2.5 generated from cooking in homes. Atmospheric Environment 42(40)9018-9040.
Chao, C.Y. Cheng, EC. 2020. Source apportionment of indoor PM2.5 and PM10 in homes. Indoor and Built Environment 11, 27-37.
Chao, C.Y. Cheng, EC. 2020. Source apportionment of indoor PM2.5 and PM10 in homes. Indoor and Built Environment 11, 27-37.
Abdullahi KL, Delgado-Saborit JM, Harrison RM (2013). Emissions and indoor concentrations of particulate matter and its specific chemical components from cooking: A review. Atmospheric Environment, 71: 260–294.
