As both concerned individuals and national governments continue making efforts to reduce their own carbon emissions and ease global climate change, the term ‘pollution’ has become a common household word. But what many people do not know is that their own household could be worse off than the air outside of it, harboring many common outdoor pollutants at even higher levels. And their own daily eating habits could be a major source.
While this news is often shocking, it should not come as much of a surprise. We are all familiar with common outdoor sources of greenhouse gases: gasoline-powered cars, passenger airplanes and wildfires, just to name a few. What do all of these things have in common? Each one gets its energy through the combustion of fossil fuels. Now take a look inside your own home. Where do you burn fossil fuels indoors? In the kitchen, of course.
Lean, healthy grilled meats. Decadent cookies and layered cakes. Even a simple piece of toast. The things you cook every day are a major contributor to your home’s indoor air quality, and the different sources used to cook them produce varying levels of volatile organic compounds (VOCs) and particulate matter that can have a serious impact on your health and wellbeing when they are chronically respirated. In the midst of a pandemic when we are spending even more time indoors than usual, this could become a real problem in many homes. But by staying educated and taking action to reduce or destroy your own emissions, you can create a safer, healthier home environment with less indoor air pollution.
Cooking sources, methods and their contributions to indoor air quality
The fact of the matter is, if you cook food inside your home, you are, by default, releasing harmful pollutants into your air. But the type and amount of emissions released depends largely upon your source for cooking.
Gas ovens and cooktops
Just like outside pollution sources, it is the indoor cooking methods that rely on the direct combustion of fossil fuels – most commonly natural gas – that tend to be the biggest offenders in terms of harmful particles released. From roasting, baking and broiling inside a gas oven to frying, sautéing and even boiling water over a flame, cooking through direct combustion of natural gas produces a larger variety and a higher quantity of harmful particles than non-combustion cooking methods like electric ovens and microwaves.
Electric ovens and cooktops
If you have an electric or induction range, you may be on track toward a less polluted home, but you are certainly not out of the woods. While electric ovens and cooktops do not rely on direct combustion, they, like all cooking methods, still produce a variety of harmful particles. Usually, this is at a lesser degree than with a natural gas oven or stove, but particular cases of electric cooking like stir-frying or frying tortillas could potentially produce even higher amounts of particulate matter. In the case of self-cleaning ovens, which rely on extreme temperatures to burn away caked-on debris, both the electric and gas varieties have been found to release high levels of pollutants.
Whether on an electric or gas burner, frying and deep frying release a high amount of harmful emissions into your indoor air. This cooking method requires the oil to be heated to a high temperature, and hot oil emits compounds called polycyclic aromatic hydrocarbons (PAHs), which can be harmful to your eye and respiratory health.
Indoor pollutants released by cooking and their potential health effects
How you cook and what you cook are the prime driving factors for the type and concentration of harmful particles that end up suspended within your indoor air, and each type of particle can have a unique impact on your health.
Nitrogen dioxide (NO2)
A common outdoor pollutant, nitrogen dioxide (NO2) can find its way into homes regardless of their cooking methods, but it has been observed at notably higher concentrations in homes that cook with gas combustion. One study estimated that cooking with gas adds 25–33% to the week-averaged indoor NO2 concentrations during summer and 35–39% in winter.
Health effects: NO2 is an irritant of the respiratory system, and can affect the mucosa of the eyes, nose and throat. Chronic high-level exposure can lead to bronchitis, while chronic low-level exposure can exacerbate asthma, negatively impact lung function for susceptible individuals, and increase young children’s risk of respiratory infections.
Carbon monoxide (CO)
Carbon monoxide (CO) is colloquially known as the “silent killer,” and for good reason – it is a highly toxic gas that is invisible to the naked eye, odorless, tasteless, and non-irritating. And although it is virtually undetectable by human senses, CO monitors are only required by law in 27 U.S. states, leaving many households susceptible to its harmful, and sometimes lethal, effects. While normal cooking with electric ovens does not produce much CO, gas ovens – especially older ones – are susceptible due to the combustion.
Health effects: CO can build up indoors, and at high levels, can kill. Common symptoms of CO poisoning often resemble an onset of the flu, including headache, dizziness, weakness, upset stomach, vomiting, chest pain, and confusion. Because it prevents your body from receiving oxygen, breathing in large amounts of CO without intervention causes unconsciousness followed by death.
Often found within a variety of building materials and furniture inside modern homes, formaldehyde is a carcinogenic organic compound that can also be produced and emitted into your home’s air through cooking, after which it can be inhaled and cause a range of health effects.
Health effects: Formaldehyde is carcinogenic. High-level exposure has been linked to certain types of cancer. There may be a link between formaldehyde exposure and cancers of the nasopharynx, nasal sinuses, and blood (leukemia), although not all studies have confirmed this.
The label of particulate matter (PM) covers a broad range of pollutants of varying microscopic sizes, measured in microns. Gas stoves that are not vented properly are one of the biggest sources of particulate matter indoors. Particles include sulfates, nitrates, ammonia, sodium chloride, and water. Studies have shown that inhalation of particulate can have a negative impact on your health.
Health effects: Particulate matter is so small that it can enter your bloodstream when inhaled. Its most devastating impacts are on the cardiovascular, cerebrovascular, and respiratory systems. Exposure can cause heart disease, lung cancer, and death.
Minimizing pollutants and their sources for better indoor air quality
Do not take your chef’s hat off just yet. While some indoor air pollution is virtually inevitable, there are multiple measures you can take to reduce your emissions and maintain a cleaner, healthier indoor air quality.
Switch from gas to electric cooking
While cooking with electric can still release pollutants, it generally emits a much smaller quantity. Electric ovens and ranges have come a long way, with a variety of cooking features that elevate them far beyond the classic red-hot coils you may be familiar with. If you are still not sold on traditional electricity-heated burners, consider exploring induction technology, which uses a magnetic field to indirectly heat metal cookware. This gives you complete control over your cooking temperature without the surface of the range ever getting hot, so it is easy to clean and less likely to cause accidental burns.
Utilize proper ventilation in your kitchen
With proper ventilation in place, pollutants released through cooking are quickly transferred out of your home. Methods include range hoods and microwave vents with a direct path to the outdoors. Range hoods tend to ventilate the back of the range more efficiently, so try to cook on the back burners when possible. If you do not have a range hood or mechanical venting system, open multiple windows while cooking to encourage polluted air to flow out of your home.
Implement an air purification system
Even if you do not cook, outdoor pollutants can infiltrate your home and negatively impact your indoor air quality. Utilizing modern air purification technology in your home can only be beneficial. Some purifiers can remove gases and odors while capturing up to 99.97% of pollutants as small as 0.3 microns. Dyson’s latest air purifier technology is engineered to destroy formaldehyde, a common pollutant released by cooking, and provides real time data on your indoor air quality.
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