Electric and magnetic fields occur naturally and also come from human-made sources. Scientists and oversight agencies generally agree that low-frequency EMFs pose little danger to human health.
Most of us are used to the electronic conveniences of modern life. But few of us are aware of the possible health risks presented by the gadgets that make our world work.
Our power lines, cellphones, microwaves, Wi-Fi routers, computers, and other appliances send out a stream of invisible energy waves. Electric and magnetic fields (EMFs) are produced anywhere electricity is used, including at home and in the workplace.
Some experts are concerned about potential health effects from these fields. But should we be worried?
While most researchers don’t believe most EMFs are dangerous, there are still some scientists who question the safety of EMF exposure. Many say there hasn’t been enough research into understanding whether EMFs are safe. Let’s take a closer look.
Since the beginning of the universe, the sun has sent out waves that create EMFs, or radiation. At the same time the sun sends out EMFs, we can see its energy radiating out. This is visible light.
At the turn of the 20th century, electric power lines and indoor lighting spread across the world. Scientists realized that the power lines supplying all that energy to the world’s population were sending off EMFs, just like the sun does naturally.
Over the years, scientists learned that many of the emerging electrical appliances also create EMFs. As the medical world advanced, much of its diagnostic and treatment equipment, like imaging devices for X-rays and CT scans, were also found to make EMFs.
Today, 90 percent of the world’s population has access to electricity and uses electrical appliances. That means lots of electricity and EMFs are created around the world.
But even with all those waves, scientists generally don’t think EMFs are a health concern.
Radiation exists across what’s called the electromagnetic spectrum. This radiation ranges from very high-energy (called high-frequency) on one end of the spectrum, to very low-energy (or low-frequency) on the other end.
Examples of high-energy radiation include:
- gamma rays
- some higher-energy ultraviolet (UV) rays
This is ionizing radiation, meaning this energy can affect cells on the atomic level by removing an electron from an atom, or “ionizing” it. Ionizing radiation can damage the body’s DNA and cells, which may contribute to genetic mutations and cancer.
On the other end of the spectrum is extremely low-frequency (ELF) radiation. This is a type of non-ionizing radiation. It can move atoms around in the body or make them vibrate, but most researchers agree that it isn’t enough to damage DNA or cells.
In between ELF radiation and high-energy radiation on the spectrum are other types of non-ionizing radiation, like:
- radiofrequency (RF) radiation
- visible light
Electric and magnetic fields join as one field in most forms of radiation. The result is called an electromagnetic field (EMF).
But the electric and magnetic fields in ELF radiation can act independently. So we use the terms “magnetic field” and “electric field” to refer to these two different fields in ELF radiation.
In summary, here are the two types of EMFs that you might be exposed to:
- High-frequency EMFs. This is the ionizing type of radiation. Scientific literature agrees that large exposures can
damage DNA or cells. Medical devices like X-ray imaging machines and CT scans produce low levels of this type of radiation. Other sources include gamma radiation from radioactive elements and UV radiation from either tanning beds or the sun.
- Low- to mid-frequency EMFs. This is the non-ionizing type of radiation. It’s mild and thought to be harmless to people. Household appliances like microwave ovens, cellphones, hair dryers, and washing machines, as well as power lines and MRIs, produce this type of radiation. This category of EMFs includes extremely low frequency EMFs (ELF-EMFs) and radiofrequency EMFs (RF-EMFs).
Non-ionizing EMFs come from both natural and human-made sources. The earth’s magnetic field is an example of a natural EMF. Human-made EMFs are classified into two types, both generated by non-ionizing radiation:
- Extremely low-frequency EMFs (ELF-EMFs). This non-ionizing radiation field can be generated by a variety of sources, including power lines, electrical wiring, and personal appliances like electric shavers, hair dryers, and electric blankets.
- Radiofrequency radiation. This non-ionizing radiation field is emitted from wireless devices, like cell phones, smart meters, tablets, and laptop computers. It’s also generated by radio and television signals, radar, satellite stations, and MRI machines.
EMF exposure intensity decreases as you increase your distance from the object that’s sending out waves. Some common sources of EMFs that emit varying levels of radiation include the following:
- microwave ovens
- smart meters
- wireless (Wi-Fi) routers
- Bluetooth devices
- power lines
- MRI machines
- ultraviolet light (UV) radiation. UV radiation comes naturally from the sun, and from man-made sources like tanning beds, phototherapy, and welding torches
- X-rays and gamma rays. This type of radiation comes from both natural and human-made sources. Natural sources include radon gas, the earth’s radioactive elements, and cosmic rays that hit the earth from beyond the solar system. Human-made sources include medical X-rays and CT scans and cancer treatment.
There’s disagreement in scientific literature over whether EMFs pose a danger to human health and, if so, how much.
The International Agency for Research on Cancer (IARC) has classified non-ionizing EMFs in the radiofrequency range as Group 2B, a possible human carcinogen. These fields are produced by electronic products like cellphones, smart devices, and tablets.
IARC operates under the World Health Organization (WHO). It convenes working groups of scientists from around the world regularly to evaluate the cancer risks presented to humans by environmental and lifestyle factors.
The current IARC evaluation from 2011 pointed to a possible link between RF radiation and cancer in people, particularly glioma, a malignant type of brain cancer.
This conclusion means that there could be some risk. The report emphasized that the link between cellphone use and cancer risk needs to be carefully monitored by the scientific community. It said more research was needed into long-term, heavy use of mobile phones.
Some researchers feel there’s already enough evidence of harm from long-term, low-level exposure to non-ionizing radiation that the IARC should upgrade the classification to a Group 1, a known carcinogen.
Researchers began substantial research into the potential link between cellphones and cancer in 2000 in what would become the
The researchers followed cancer rates and cellphone use in more than 5,000 people in 13 countries. They found a loose connection between the highest rate of exposure and glioma.
The gliomas were more often found on the same side of the head that people used to speak on the phone.
Even so, the researchers said that the connection wasn’t strong enough to conclude that cellphone use caused cancer.
In a smaller, more recent study, researchers analyzed data over almost 2 decades and found that people exposed to high levels of extremely low-level frequency magnetic fields (ELF-EMFs) over a long duration showed an increased risk of acute myeloid leukemia (AML), a type of leukemia in adults.
European scientists also uncovered a possible link between EMF and leukemia in children. In a literature review of previous studies, they suggested that between 1.5 to 5 percent of childhood leukemia can be attributed to ELF-EMFs.
But they noted that the result was inconclusive because monitoring of EMF was lacking. They recommended more research and better monitoring.
In one study, researchers found that an electromagnetic pulse (EMP), or a short burst of electromagnetic energy, can affect nerve activity in rats.
They suggested that long-term EMP exposure could be harmful to cognitive ability and may induce pathology similar to that of Alzheimer’s disease. They added that more research is needed.
Also, tentative research suggests that the body’s tissues and its nervous system may be affected by the heat generated by RF-EMFs. A
Most researchers said further studies are needed.
Possible symptoms related to EMFs in the studies included:
- memory loss
- loss of concentration
- sleep disturbance
EMF exposure levels are monitored and enforced at the global, national, and local levels in a varied patchwork of procedures by multiple organizations, depending on where you live.
The electric industry in the United Kingdom maintains a database where you can see the widely varied exposure limits and enforcement measures in countries around the world.
Internationally, the primary guidance on radiofrequency EMFs comes from the International Commission on Non-Ionizing Radiation Protection (ICNIRP). It bases its guidelines on its evaluation over many years of peer-reviewed scientific literature concerning health effects from RF EMF exposure.
ICNIRP is a non-governmental organization recognized by the
In 2020, WHO updated its international ICNIRP Guidelines for limiting exposure to larger RF electromagnetic fields ranging from 100 KHz (kilohertz) to 300 GH (gigahertz).
The ICNERP guidelines currently specify that people at work shouldn’t be exposed to current electric densities in the body’s head, neck and trunk of greater than 10 mA m-2 (the “basic restriction”).
A lower limit of 2 mA m-2 is given for the general population to account for children and people who may be more sensitive.
The expression 10 mA m-2 represents a measurement of electric current density. It translates as “10 milliamperes per meter squared.”
A milliampere is one 1/1000th of an ampere. It’s the level above which electric and magnetic fields have
In the United States, there are no federal restrictions on overall EMF exposure, but a few states have issued their own restrictions. Also, a variety of federal governmental agencies have responsibility for managing EMF exposure from certain products and technologies.
The Environmental Protection Agency (EPA) coordinates EMF exposure recommendations in the United States. It generally relies on the ICNERP Guidelines.
In its EMF Guidelines, the EPA points out that the ICNERP EMF exposure limits protect people from “well-known biological and health effects of exposure to high EMF levels.”
But the EPA takes a difference stance on low levels of EMF radiation. The EPA states in its EMF Guidelines that it neither recommends nor imposes limits on low-level EMFs because there’s no scientific evidence that low levels of electromagnetic radiation damage human health.
To support its statement regarding the relative safety of low-level EMF radiation, the EPA issued its
In the United States, a variety of governmental agencies have specific responsibilities for managing EMF exposure from various technologies, facilities, and products. Local governments sometimes impose their own controls and regulations. Here are some examples of federal controls:
- Electronic devices. Standards for all electronic devices emitting non-ionizing or ionizing radiation are set by the
U.S. Food and Drug Administration (FDA).
- Cell phones. The Federal Communications Commission (FCC) sets exposure limits on electromagnetic radiation from both cell phones and cell phone towers. The FCC rules and guidelines are based on standards developed by the Institute of Electrical and Electronics Engineers (IEEE) and the National Council on Radiation Protection and Measurements (NCRP), plus input from other governmental agencies.
- Smart meters. The FCC sets exposure limits for radiation emitted from smart meters, those boxes on sides of houses and businesses that use a cellular transmitter to track power consumption.
- Power lines. Currently, there are no federal restrictions on EMFs from power lines in either residential or occupational settings.
- Medical use. Many medical devices and procedures use ionizing radiation to diagnose and treat conditions and disease. Some examples include X-rays, CT scans, and radiation therapy. Various regulatory agencies share responsibility for the safety of these procedures and devices, including the Centers for Disease Prevention and Control (CDC), the FDA, the EPA, and the U.S. Nuclear Regulatory Commission (NRC).
- Nuclear power. Several regulatory agencies share responsibility for regulating nuclear power and coordinating disaster response, including the EPA, the Federal Emergency Management Agency (FEMA), and the NRC.
- Imported products. The U.S. Customs and Border Protection (CBP) screens imported goods to be sure they’re free of harmful substances.
- Workplace. Exposure to EMF in workplaces is governed by legislation and enforced by the Health and Safety Authority (HSA).
Electric fields are produced by voltage, and magnetic fields are produced by electric current. Electric fields are measured in V/m (volts per meter). Magnetic fields are measured in µT (microteslas). Both electric and magnetic fields vary in strengths at different times and locations.
Electric fields vary because of differences in the amount of voltage used by various devices. The higher the voltage supplied to a device, the stronger the electric field will be. An electric field exists even when there’s no current flowing.
Magnetic fields are produced by the flow of electric current and therefore vary depending on the strength and amount of the current being used. The more electric current a device uses, the stronger the magnetic field will be.
It might be surprising to learn just how varied magnetic field levels are around products. The strength of a magnetic field may not depend on how large or powerful the device is. Also, the strength of the magnetic field may vary a lot even among similar products.
For example, some hair dryers have a very strong field, while others produce hardly any EMF. It all depends on the product design. Also, exposure levels vary considerably depending on the distance you are from the device and how long you’re exposed.
Because of these variances, it’s difficult to say with accuracy what the EMF is for products. But both ICNERP and
Read on to learn about some of the most common EMF fields you may encounter in daily living.
The strongest electric fields that we encounter in daily life are beneath high-voltage transmission lines.
Transformers reduce this high voltage before it goes into your home or business. Also, the walls of your home act as a shield to some degree. Directly beneath the power lines is where the field is strongest.
Both fields (electric and magnetic) drop off significantly with distance. The further your home is from high-voltage power lines, the weaker the field. In homes not located near power lines, the background magnetic field may be relatively light.
Televisions and computer screens
Computer screens and television sets work similarly, producing both electric and magnetic fields at various frequencies. Screens with liquid crystal displays (LCDs) don’t produce significant electric and magnetic fields.
For this reason, modern TVs, which generally use LCD, LED, or plasma screens, emit only small amounts of radiation. But it’s enough that you should keep children from getting too close. Watching from a couch several feet away is thought to pose little danger.
The FCC requires that all wireless communications devices sold in the United States meet minimum guidelines for safe human exposure to radiofrequency (RF) energy.
For wireless devices that operate at 6 GHz or less and are designed for use near or against the body (cellphones, tablets, and other portable devices), FCC has set exposure limits in terms of Specific Absorption Rate (SAR).
This is a measure of the rate at which the body absorbs RF energy. The FCC limit is 1.6 watts per kilogram (W/kg).
All wireless devices sold in the United States are certified by the FCC that they don’t exceed FCC exposure limits. The FCC incorporates a safety margin in these limits. If the FCC learns that a device doesn’t perform according to its disclosure, the FCC can withdraw its approval.
To find the SAR value for your phone or one you intend to buy, go to the FCC ID Search database and enter your phone’s FCC ID number. You’ll usually find the number somewhere on either the case or the device. You may have to remove the battery to find the number.
Microwaves are used to detect speeding cars, send television communications, raise bread, and even cook potato chips! But most of us use microwave energy the most in microwave ovens.
Microwave ovens are considered to be safe if you use them correctly. People have experienced burns and other injuries from microwave radiation and superheating, but mostly from misuse.
Microwave ovens operate at very high power levels, but they have shields to reduce leakage of radiation outside the oven to almost nothing.
Microwave ovens also must have safety features to prevent the generation of microwaves if the door is open. FDA tests ovens in its lab to make sure its standards are met. All ovens sold in the United States must have a label stating that they meet the safety standard.
EMFs in your home
Every electrical appliance in your home emits EMFs. Still, according to the ICNIRP guidelines, most people’s exposure to EMF in daily life is very low. Much of your EMF exposure in your home probably comes from the wires carrying electrical current.
You also get short-term high exposures when you are near electrical appliances like refrigerators, microwaves, and washing machines. The EMF radiation drops off sharply as you move away from these appliances.
You can check EMF levels in your home with an EMF meter. These handheld devices can be purchased online. But be aware that most can’t measure EMFs of very high frequencies, and their accuracy is generally low, so their efficacy is limited.
You can also call your local power company to schedule an on-site reading.
Remember that ELF fields vary by location. If you hold your meter to the right of a clothes dryer, for example, you might get a zero reading. A foot to the left, the reading might be higher. So be sure to test in different locations around the electrical appliance, and within your house.
Also, check readings at various points on your walls since much of your home’s electrical current is transported via wires that run through the walls. If you find a reading is highest near your bed, for example, consider moving it to a different part of the room where the reading is lower.
Possible human health effects from exposure to EMFs hasn’t yet been determined with precision and accuracy. Research in the coming years may better inform us.
Some studies point to various symptoms coming from EMF exposure, but researchers generally say more study is needed. Many of the studies use animal or cell models, which are unreliable if applied to human health.
Also, some of these symptoms have been attributed to a condition called electromagnetic hypersensitivity (EHS), where people relate various non-specific symptoms to EMF exposure.
The medical field hasn’t substantiated EHS, although people do experience symptoms that are sometimes distressing and even disabling.
No credible research currently links EHS symptoms to EMF exposure, and EHS isn’t considered to be a medical diagnosis. The medical field advises that further research is needed.
Still, some research gives tentative support to EMF symptomatology. Here are symptoms that some studies have suggested:
- sleep disturbances, including insomnia
- depression and depressive symptoms
- tiredness and fatigue
- dysesthesia (a painful, often itchy sensation)
- lack of concentration
- changes in memory
- loss of appetite and weight loss
- restlessness and anxiety
- skin burning and tingling
The actions you can take to reduce your EMF exposure depends on the type of radiation you’re concerned about. Read on to learn what steps you can take.
Low- to mid-frequency EMFs
Remember that this category of EMFs includes extremely low frequency EMFs (ELF-EMFs) and radiofrequency EMFs (RF-EMFs). This type of radiation is produced by any electric device.
These devices range from refrigerators and vacuum cleaners to televisions and computer monitors (when they’re turned on).
The EMF strength around appliances diminishes rapidly with distance. At 1 foot, the magnetic fields surrounding most household appliances are more than
- Don’t sit or linger near appliances. One of the best ways to avoid EMF exposure in your home is to keep your distance from appliances. You need to get up close to turn on the television, open the fridge or microwave, and load the washing machine. Just keep these close encounters short, and don’t sit next to appliances — or allow your kids to.
- Put your phone down. Especially when you aren’t using the phone, place it away from you. At night when you sleep, put it in another room.
- Use the speaker function or earbuds with your phone. This will reduce RF exposure to your head. Earpieces do generate and emit fields, but not nearly as much as your phone. Using earpieces or speakerphone, you can greatly reduce exposure to your head.
- Don’t carry your phone in a pocket. Try to carry your phone in a bag or briefcase when you’re out.
- Unplug occasionally from electronic devices and electricity. Take a day off from electronics, or even several days. Your body will thank you!
Remember, this is the type of radiation that’s potentially dangerous to your health. High levels of high-frequency EMFs
To reduce high-level exposure and associated risks, try these tips:
- Limit X-rays. Only receive X-rays that are medically necessary.
- Limit your time in the sun. You need some sun for your health, just not too much. Also, avoid sun during the middle of the day when the rays are strongest.
- Limit time in tanning beds. If you must have that quick summer tan, just limit your time under the lights.
If you want to calculate your effective dose of ionizing radiation per year, you can try using the EPA’s Dose Calculator. It carries a warning from the EPA that ionizing radiation is the type of EMF that’s dangerous because it can potentially harm body tissues and DNA.
EMFs occur naturally and also come from human-made sources. Scientists and regulatory agencies generally agree that low-frequency EMFs pose little danger to human health.
But some researchers offer preliminary evidence that some danger may exist for long-term use, specifically to the nervous system and brain cognitive function.
Exposure to large levels of high-frequency EMFs is known to damage human DNA and cells. But it’s very unlikely that you’ll be exposed to levels high enough to endanger your health in your daily life. Exposure comes mostly in small amounts.
The best approach is to be aware that EMFs exist and be smart about your exposure. This is a developing field of research that will undoubtedly expand as our use of wireless devices and labor-saving machines increases. Keep an eye on the news for developing research.