Is Cooking Making Your Indoor Air Unsafe?

There is nothing better than a home cooked meal, especially during the holidays. But as we all gather around the kitchen, should we be worried about what we are breathing in besides delicious aromas? The World Health Organization warns that 2.1 billion people (1 in 3) worldwide use cooking methods that may be putting their health at risk. Household air pollution exposure can cause stroke, cardiovascular disease, lung cancer and irritate your lungs causing severe asthma and COPD symptoms. This may be due to a variety of factors including the fuel being used, the type of stove, the preparation method, the ventilation and even the ingredients. Below we discuss what may be causing air pollution problem as you cook and simple fixes you can make to protect your indoor air quality.

Pollutants Found in Your Kitchen

The emission of particulate matter (PM) into the air is a byproduct of any kind of cooking, but certain types of cooking release more particles than others. The danger to your health occurs when these tiny particles get inhaled deep into your lungs, causing irritation and corrosion of the alveolar wall (the air sacs where oxygen is exchanged into the blood stream) which affects your lung function.

Another danger of many types of cooking is the production of volatile organic compounds (VOCs), like carbon monoxide (CO) and nitrogen oxide, among others. For instance, formaldehyde, a dangerous carcinogen, is often a byproduct of broiling or overcooking food.

Carbon monoxide (CO) is a highly toxic gas that is invisible to the naked eye, odorless, tasteless and non-irritating. While cooking with electric ovens does not produce much CO, gas ovens – especially older ones – are more likely to create CO due to the combustion. Without proper ventilation, CO can build up indoors, and at high levels, cause severe poisoning symptoms including headache, dizziness, weakness, upset stomach, vomiting, chest pain and confusion. If left untreated, because it prevents your body from receiving oxygen, breathing in large amounts of CO can cause unconsciousness and even death.

Similarly, though nitrogen oxide (NO_x) can find its way into your home regardless of cooking method, it is most found in high concentrations when using gas. Exposure to high levels of NO_x can lead to chronic lung disease like bronchitis, cause severe asthma symptoms, and negatively impact lung functions and cause respiratory illnesses in vulnerable individuals, like young children.

How does cooking create indoor air pollution?

There are many cooking factors that can produce the pollutants described above. First, the type of appliance you use to cook can directly affect what is released into the air. Studies have shown that combustion stoves, like those that use gas, release much more harmful particles than electric stoves. In fact, gas stoves that are not properly ventilated outdoors are one of the biggest sources of particulate matter. Using an electric stove does not eliminate the problem however, so ventilation is always important to minimize indoor air pollution.

The way you prepare your food can also influence the level of pollutants in your kitchen. In general, the temperature and time of cooking directly correlate with the amount of particulate matter that is released into the air. Frying and deep-frying release high amounts of PM and other harmful pollutants. This type of cooking is more dangerous because it involves heating ingredients in oil or fat to extremely high temperatures. Grilling or browning meat are other high conductors of particulate matter. This makes boiling or steaming safer options and suggests that simply changing the method you use to cook can matter.

Lastly, the food itself that is being prepared can affect the particles released into the air. Meat dishes emit more particles than vegetables, especially when frying. The fat content of the meat also matters, with high fat meat slabs product significantly more particular matter than lean meat. The use of different oils and spices release products into the air that not only affect the amount particulate matter in the air but can also react with other things in the room and worsen the air quality.

5 Steps to Minimize Cooking Pollutants at Home

1. Switch to an electric or convection stove. Cooking on a gas stove creates significantly higher PM emissions than electric ones. Gas ovens are also more likely to have carbon monoxide and gas leaks that may be deadly.
2. Properly ventilate your kitchen. When cooking, use an extractor fan or a range hood to remove airborne pollutants from your home. Both fans and hoods should ventilate to the outdoors and should be used every time the burners or oven are on. If you don’t have either of these appliances, just opening the window can help clear pollutants from your home and protect your family from short- and long-term health effects from cooking activities.
3. Grill and barbecue outdoors. Cooking at high temperatures can produce more pollutants, so, if possible, move these activities outdoors.
4. Have protections in place to monitor pollution. Besides a smoke detector, which should be standard in every kitchen, installing a carbon monoxide detector on every level of your home can warn you and your family if something is in the air that you can’t see. Place carbon monoxide detectors at least 15 feet from gas stoves. All-in-one indoor air quality monitoring devices are also available to help monitor pollutants like humidity, particulate matter and volatile organic compounds.
5. Pay attention and be strategic while cooking. Cooking on a back burner, which is better ventilated because it is right under the hood or fan and covering your pots and pans whenever possible will keep pollutants from accumulating in the air. Being careful to watch your food and not overcook or burn can prevent harmful VOCs from being released into the air. Also be sure that all cooking surfaces are clean of debris to prevent burning.

Learn more about how to decrease air pollutants at home.