Claim: The radiation from Bluetooth earbuds, such as AirPods, causes brain cancer. Rating: About this rating False

For years, rumors have spread that the radiation from Bluetooth-operated, wireless earbuds such as AirPods can “fry” or “cook” our brains — in other words, that they can cause brain cancer:

This is because the idea of radiation is often associated with heat and cancer, as is the case for sunlight.

These claims have appeared on various social media platforms including Reddit, Facebook (here too) and Instagram. Some of these posts appeared on the pages of serious-sounding groups, such as the Environmental Health Trust. Others reshared compelling videos:

Rumors that wireless devices can “cook” or “fry” one’s brain burgeoned in 2015, when a group of more than 200 researchers signed an appeal to protect humans against “non-ionizing electromagnetic fields” (EMF). Their open letter mentioned, without citing, “numerous recent scientific publications” that allegedly suggested EMF might cause cancer and other harmful effects on cognition and the reproductive system, as well as in animals and plants. They called for authorities to create better guidelines and enforce stricter standards. As we reported in 2019, that open letter never mentions AirPods specifically, for a simple reason: In 2015, they did not exist.

The research has yet to find proof they’re cancer-causing, or even a correlation between Bluetooth earbuds and poor health, as of the time of this writing.

What Is EMF Radiation?

EMF radiation has two sources: some of it is man-made, but it also occurs naturally. There are two types: non-ionizing radiation and ionizing radiation. Research has shown that the latter type — which is high-frequency and high-energy — can cause cellular damage as well as cancer, which is what we fear when we hear the word “radiation.” This category includes ultraviolets (which come from sunlight), X-rays and therapeutic radiation, such as what medicine uses to treat certain types of cancers. “Ionizing” means that this kind of radiation can remove negatively-charged electrons from atoms, a process that turns atoms into positively-charged — and therefore reactive — “cations.”

Below the visible spectrum, we find non-ionizing radiation, low-frequency waves. Non-ionizing radiation has low frequency waves and low energy. This group includes radiation emitted by microwaves, mobile phones and Wi-Fi, but also television and radio. This is also where Bluetooth radiation falls, around 2.4 gigahertz — somewhere between mobile phones and microwaves. The National Cancer Institute published a helpful chart:

(National Cancer Institute)

What one study found, however, is that Bluetooth headphones and earphones emit far less radiation than mobile phones — one-tenth to one-four hundredth as much, the study said.

What the Research Shows

While ethical concerns make it difficult to experiment with the effects of non-ionizing EMF on human health, researchers across the world have done large-cohort observational studies, which has allowed a scientific consensus to emerge. This research focused on cellular phones, which we will use as a benchmark for the effects of Bluetooth given that the phones emit more radiation in the same frequency range than wireless earbuds and headphones.

Between 2001 and 2006, Danish scientists looked at the incidence of cancer in a cohort of 420,095 people who’d begun to use mobile phones between 1982 and 1995. They found that the number of cancers in that cohort was not higher than in other groups and concluded, with a very high level of certainty, that the devices did not cause cancer.

In 2021, scientists across 14 countries recruited 899 children and young adults between the ages of 10 and 24 who had developed brain cancer, and 1,910 children and young adults in the same age bracket to act as controls. “Overall,” they wrote, “our study provides no evidence of a causal association between wireless phone use and brain tumours in young people.”

More recently in 2022, a “Million Women Study” in the United Kingdom focused specifically on brain cancer among women. The team of scientists recruited 776,156 women between 1996 and 2001 and checked in again with them in 2011 to see how many had developed brain cancer. There, too, they found cellphone use did not increase the incidence of brain cancer.

Meanwhile in 2020, the Institute of Electrical and Electronics Engineers’ publication IEEE Access published a study that concluded that EMF were harmful to human health. In the years since, the IEEE retracted the study. “The article should not be used for research or citation because of errors found in the analysis reported in this article, resulting in inaccurate results and conclusions,” the retraction note read.

We have reported on the danger of radiation for other devices before, including microwaves and CFL lightbulbs.

You may have heard rumors that Bluetooth headphones can cause cancer. This not only includes popular wireless headphone brands like Bose and Beat but also wireless earphones like Apple AirPods and bone-conduction headphones like Shoxx.

The idea is that devices like these emit a form of energy known as radiofrequency radiation (RFR) that can damage the DNA of brain cells over time and lead to brain cancer. To date, the evidence supporting these claims is weak.

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Evidence of a Threat

In 2015, several studies suggested that long-term exposure to electromagnetic radiation (EMR) from cell phones, cell phone towers, WiFi, and even wireless baby monitors could increase the risk of brain tumors, cognitive impairment, male infertility, testicular cancer, and other long-term health concerns.

The studies prompted more than 200 scientists from around the world to petition the World Health Organization (WHO) and United Nations (UN) to impose stricter regulation of EMR.

The controversy surrounding Bluetooth was brought to the fore in 2019 in tandem with the growing popularity of AirPods and other wireless headsets. The focus was placed on a particular type of EMR known as radiofrequency radiation (RFR) that is emitted at a lower bandwidth to enable wireless communication.

In a 2019 study published in the Frontiers of Public Health, researchers from Canada, Sweden, and the United States advised that consumers should be warned of the potential threat even though the “epidemiological evidence does not suggest increased brain tumor risk.”

Why Researchers Were Concerned

Electromagnetic radiation comes from both natural and man-made sources and can take many different forms. The strength of the radiation falls within a spectrum, known as the electromagnetic spectrum, that ranges from low-frequency to high-frequency.

Comparatively:

High-frequency EMR, also known as ionizing radiation , consists of electromagnetic waves that are strong enough to remove electrons from atoms. Examples include X-rays, gamma rays, and nuclear radiation.

, consists of electromagnetic waves that are strong enough to remove electrons from atoms. Examples include X-rays, gamma rays, and nuclear radiation. Low-frequency EMR, also known as non-ionizing radiation, does not emit enough energy to remove electrons from atoms. Examples include radio waves, microwaves, infrared radiation, visible light, and ultraviolet (UV) light.

Of the two, ionizing radiation has a greater potential to break the structure of DNA in cells, triggering mutations that can lead to cancer.

In the brain, excessive exposure to ionizing radiation can lead to the formation of a tumor called a meningioma. While most meningiomas are benign (non-cancerous), some can transform into a fast-growing cancerous tumor known as an anaplastic meningioma.

Although the risk of this is low with non-ionizing radiation, it shouldn’t suggest that non-ionizing radiation is inherently “non-cancerous.” Excessive exposure to UV radiation from the sun (which falls in the middle of the EMR spectrum) is known to cause changes to the skin, leading to skin cancer.

Some experts expressed concern that RFR may have the same adverse effect on the brain given the high use of cell phones by consumers. The concerns were thought to be greatest among children who have thinner skulls and whose brains absorb as much as 10 times the RFR dose as adults.

What the Current Research Says

Research into the risk of cancer with Bluetooth headphones has been ongoing since the introduction of the devices back in 2004. To date, there is little evidence that the devices are linked to any form of cancer or any other medical condition, including infertility.

To start, RFR lies near the farthest end of the low-frequency wave spectrum, generating even less energy than microwaves or visible light. As such, their potential to cause DNA damage—or, in turn, cancer—is low to nil.

According to the National Cancer Institute (NCI), cell phones emit RFR in the range of 0.7 to 80 gigahertz (GHz), falling well below the frequency that can cause cancer. A 2019 study from California further concluded that the amount of RFR released by Bluetooth devices is between 10 and 400 times lower than the amount released by cell phones.

By comparison, X-rays emit frequencies ranging from 30 petahertz to 30 exahertz. That is roughly 1 million to 1 billion times the frequency emitted by cell phones.

The NCI further reports that since cell phones were first released, there has been no increase in brain cancers in the United States, Australia, or Europe, including in kids.

Even so, some public health authorities are reluctant to give the “all-clear” sign.

While the Centers for Disease Control (CDC), U.S. Food and Drug Administration (FDA), and Federal Communications Commission (FCC) all say that there is no evidence of cancer from cell phone use, the International Agency for Research on Cancer (IARC) still classifies RFR from wireless devices as a potentially carcinogenic (cancer-causing).

Summary

There is currently no evidence that low-frequency radiation released by Bluetooth headphones causes cancer or any other disease. The amount of radiation released falls well below the threshold by which electromagnetic radiation can cause DNA damage that leads to cancer.

Although the CDC, FDA, FCC, and other authorities have concluded that these wireless devices pose no risk to your physical health, the International Agency for Research on Cancer (IARC) still classifies them as potentially cancer-causing.

The microwave is a marvel of modern technology—food can go from ice cold to blazing hot in seconds. But there are a handful of things that should never be put in a microwave. Certain foods, beverages, and containers can burn, melt, or explode if nuked for less than a minute. Some may even turn toxic.

A few of these things are fairly common, and you may have even heated one in the microwave this morning. Just because something bad hasn’t happened doesn’t mean it won’t. Protect yourself and others by keeping these foods away from the hot box, and learn how to safely heat them up instead.

Foods to Never Put in the Microwave

Several foods don’t react well to ultra-fast heating. Some have compounds that can become irritating, and others might explode due to a build-up of pressure.

Chili Peppers

Red hot, orange, or green peppers contain a compound called capsaicin that gives them their kick. When chili peppers are heated, especially the ultra-hot varieties, the capsaicin vaporizes into the microwave’s enclosed air. Opening the microwave door exposes you to fumes that can irritate and burn your lungs, throat, eyes, and nose.

How to heat: Roast, sauté, or grill peppers instead of putting them in the microwave.

Hard Boiled Eggs

You’re tired of cold eggs for your mid-day snack, so you pop one into the microwave for 15 seconds. All seems well until you cut into the egg and it explodes—all over your office, your computer, and you.

Whether in the shell or peeled, hard boiled eggs heated in the microwave release steam. The steam cannot escape the whites, so pressure builds. When you cut (or worse, bite) into the egg, the steam is released instantly. The resulting explosion may burn you.

How to heat: Slice a hard boiled egg into fourths before you heat it in the microwave. If you have a few minutes, pop it into a cup of hot water, and let it sit for 3 to 5 minutes.

Leftover Potatoes

Don’t worry, you can still speed-cook your spuds in the microwave. But if you decide to reheat them later, take steps to keep them from becoming dangerous: Always move cooked potatoes that won’t be eaten into the fridge as quickly as possible.

Potatoes often house Clostridium botulinum, the botulism bacteria. When they’re cooked and not immediately stored in the fridge, spores of the bacteria can multiply. Microwaving the potatoes won’t kill the bacteria either, so your second-day potatoes could cause an upset stomach.

How to heat: Reheat in the oven, but don’t bake potatoes in an aluminum foil jacket. According to research, the tin catches moisture and accelerates spore growth in the warm, moist environment. For a crispier potato skin—and for the sake of your tummy—bake potatoes without the foil jacket.

Grapes

Don’t top your oatmeal with a handful of grapes and slide the whole dish in the microwave. Grapes become superheated, and the sugary pulp quickly turns into molten plasma. They could explode in the microwave, while you’re stirring, or even when you take a bite, sending ultra-hot fruit flying.

How to heat: If you want to heat grapes, consider roasting them in the oven for a few minutes. They also heat quickly in a skillet on a medium-high stove eye.

Processed Meats

Bacon, hot dogs, lunch meat, and sausages should be cooked on the stove or in the oven, not in the microwave. Heating these processed meat products leads to the formation of cholesterol oxidation products (COPs). COPs have been linked to coronary heart disease. Research suggests COPs may also be linked to inflammation, plaque buildup in the arteries, and more health conditions.

How to heat: One study found that grilling also increased the amount of COPs in the meats, so baking in the oven or sautéing may be the safest options.

Tomato Sauce

Heating tomato sauces in the microwave often ends in splatters. The heat and steam produced by the sauce have a difficult time escaping through the thick sauce or around pieces of ingredients. The steam builds up until it’s powerful enough to burst through—and onto the microwave walls. In some cases, the sauce can even explode when you stir it, which could lead to burns and certainly stained clothes.

How to heat: Heat any sauces in a small pan on the stove. This will allow even heating, and you can stir easily to prevent steam buildup.

Beverages to Avoid Putting in the Microwave

Most liquids should do fine in a microwave, so long as you don’t overheat them (which can be dangerous). Here are a couple of liquids where you should take extra care—or avoid the microwave altogether.

Mug of Water

It’s much faster to heat water for tea in your microwave than to wait on a kettle to boil, but the time savings could cost you dearly. Water that is heated by itself in a microwave can quickly become superheated. While you might not see any bubbles, they can quickly form when you add a tea bag, spoon, or even just move the water. In rare cases, it might even explode.

How to heat: Let a kettle do the work. If you don’t have a stove eye readily available, consider an electric option.

Baby Formula or Breast Milk

Microwaving any liquid can cause hot spots due to uneven heating. This is especially dangerous for babies, who could burn their mouths on hot milk, even if the bottle feels warm to the touch. Also, some studies suggest that microwaving baby formula or breast milk can degrade some important nutrients.

How to heat: Use a bottle warmer or place the bottle in a bowl of warm water for more even, safer heating.

Containers That Should Not Be Microwaved

Some containers contain chemicals that can leech into food when heated in the microwave, and others with metal can spark and cause a fire. Always place food on a microwave-safe glass plate or container instead. Cover with a paper towel and microwave as normal.

Styrofoam

Food-safe foam is a type of plastic that can release harmful chemicals into your food and into the air when heated. Foam is also not heat stable when shot through with microwaves. It might melt or warp.

Takeout Containers With Metal Handles

The handled carry-out containers have metal, which could spark, causing a fire. And here’s your critical reminder: Never put metal of any kind in the microwave. Even vintage dishes with a gold gilt on the edges can spark and cause a fire.

Plastic Containers

Some plastic is safer than others when it comes to heating. As a rule of thumb, double-check any plastic container before you zap it—it should say “microwave safe.” In theory, this label tells you whether or not you’ll risk exposure to chemicals if the container is heated. When in doubt, switch to microwave-safe glass containers.

Why You Should Never Microwave Nothing

Never start an empty microwave oven. Without food or a container to absorb the microwaves, the beams are bounced back to the magnetron. This could damage the machine and may even start a fire. Double-check that you’ve put food in the microwave before you press start.

A microwave oven is a staple in many households. It’s such a convenient little contraption to heat up food and drinks quickly and effectively.

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But some people worry about their safety.

What’s the truth? Are microwaves bad for you? Do they cause cancer? Can you microwave plastic? Why did your parents always yell at you for standing in front of the microwave?

We talked with registered dietitian Paige Welsh, RD, LD, to separate fact from fiction, so you can microwave with confidence.

Do microwaves cause cancer?

Microwaves use radiation to cook food. And that can sound awfully scary.

“When you look up how microwaves work, you’re going to see the term ‘radiation.’ People hear that, and instantly, it sounds scary. They’re taken aback by that term,” Welsh acknowledges. “But what a lot of people don’t realize is there are different types of radiation that carry different risks with them.”

Microwaves use non-ionizing radiation to heat up food. That’s the same kind of radiation found in cell phones, TVs, light bulbs and other common household items.

Ionizing radiation is the kind that’s more often associated with a slightly increased risk for cancer. That’s used in things like X-rays and CT scans.

Ionizing radiation can change atoms. It does this by removing an electron, which can create unstable ions. With enough exposure, those ionized atoms can cause cell damage and, potentially, cancer. (Though it takes A LOT of radiation to cause cancer. So, it’s not typically a worry for most people who need the occasional X-ray or CT scan.)

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Non-ionizing radiation, as used in microwaves, doesn’t change molecular makeup.

The National Cancer Institute says that most types of non-ionizing radiation haven’t been found to cause cancer. And the American Cancer Society says, “When microwave ovens are used according to instructions, there is no evidence that they pose a health risk.”

Safe microwave use

Even without the worries about cancer, microwave use can pose some other safety hazards that deserve your consideration.

Welsh shares some tips for safe microwaving.

Don’t use a damaged microwave

Part of what makes microwaves safe appliances for heating up your food is that they’re heavily regulated. The U.S. Food and Drug Administration (FDA) has regulated microwave manufacturers since the 1970s.

“There are very specific standards that determine how much leakage is allowed to come out of the microwave,” Welsh shares. “What is allowed is significantly below any level that would cause any type of damage.”

But there’s a catch.

Those standards are based on well-functioning machines that are in tip-top shape. And any damage to your microwave can compromise its safety.

Damage can allow some of that non-ionizing radiation to escape. And high amounts of non-ionizing radiation can cause burns and damage your eyes.

Don’t use a microwave if it’s:

Dented.

Cracked.

Peeling.

Damaged by fire.

Not latching properly.

Not functioning fully. (For example, if it’s taking longer than expected to heat your food.)

“Damage can cause leakage. And while it would take a very high amount of exposure for you to notice any negative impacts, it’s not worth taking any risks,” Welsh warns.

No need to peek

You probably heard warnings about staying away from a microwave when it’s in use. The reason goes back to the fear of radiation leaking from the machine.

But if your microwave is in good shape, the risk should be very minimal. (Remember those thorough regulation standards.)

“If you have a well-functioning microwave, you shouldn’t be at risk. But standing away is an extra step you can take to further ensure your safety,” Welsh advises.

Standing farther from the machine can decrease your potential for exposure because any teeny bit of radiation that comes out of the microwave mixes with the air around it, essentially diluting it.

Be careful with plastic

When choosing containers to microwave your food in, some plastics should be avoided. Typically, if your plastic bowls, plates and containers say they’re microwave-safe, they’re good to go. Otherwise, keep them out of the microwave.

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“Plastic wrap and plastic containers that aren’t microwave-safe can melt into your food, and we don’t want to be eating bits of plastic,” Welsh cautions.

But some people will tell you that all plastic containers should be avoided in the microwave because they can potentially leak harmful molecules into your food.

Welsh’s take? “We do know that those plastics degrade faster if they’re not approved for the microwave, but it’s not clear exactly what impact that has on our health. We need more research to know for sure.”

If you’re concerned about the potential effects of microwaved plastic, there’s no harm in avoiding it and opting instead for microwave-safe materials, like glass or ceramic.

Don’t microwave metal

The risk of metal containers, silverware and aluminum foil in the microwave is well-documented by social media pranksters. Namely: sparks and fire.

And while a microwave fire is a clear danger on its own, it’s not only the initial flame that’s cause for concern.

“Microwaves use a specific type of metal plate to help prevent radiation leakage,” Welsh explains. “When you put metal in the microwave and it sparks, it can compromise the integrity of that metal plate that keeps us safe.”

Follow food safety guidelines

When you reheat that casserole or soup in the microwave, it’s more than a matter of heating food to make it more palatable. What’s also important is making sure your food is thoroughly heated to kill off bacteria.

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“We want to make sure our leftovers are getting up to a properly high temperature,” Welsh shares. “After our food is initially cooked, there’s always a risk of it becoming contaminated. So, you want to make sure your microwaved food is hot enough to be safe.”

The magic temperature? 165 degrees Fahrenheit (74 degrees Celsius).

Pro tip: Microwaves heat food from the outside in. So, your food is likely to be warmer on the outside than on the inside. Cut your leftovers into smaller pieces to help ensure they heat up consistently. Stir your soup before testing the temperature to make sure it’s thoroughly heated.

Consider nutritional value

When it comes to things like steaming veggies, it turns out that microwaves can be highly efficient and effective.

“When you boil vegetables, you can lose some of the nutrients because the water steals some of the vitamins and minerals,” Welsh points out. “But in the microwave, you don’t have that problem. Microwaves can help to preserve nutrients in our food more than a lot of other cooking methods.”

And consider the timing. If you roast veggies in the oven, that’s more time in high heat, which breaks down some nutrients in your food. In the microwave, those nutrients aren’t affected as much because they don’t cook nearly as long.

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On the other hand, many other microwaveable foods aren’t the nutritional powerhouses your body deserves. While not the fault of the microwave itself, microwaveable meals typically aren’t whole foods. And they’re notoriously high in sodium. So, be thoughtful that you’re not relying on packaged microwavable foods as a staple in your diet.

Bottom line?

Microwaves aren’t inherently bad for you. But using them safely is important. So, use your microwave properly to best enjoy its convenience and other benefits.