California officially issued guidelines advising of mobile phone dangers, warning of increased risk of brain cancer and other health problems, and that children’s developing brains could be at greater risk: it-s-official-california-issues-caution-cell-phone-use
The biggest source of RF exposure for most people is using a mobile phone next to the head. You can reduce RF exposure a lot by using the phone's speaker and holding the phone farther away from your head, or using wired headphones say neuro-oncologists & public heath experts. The city council in Berkeley California passed a law that requires retailers to tell consumers how far away their phone should be held. news.cnet.com/cell-phone-radiation-self-defense-guide
France and Israel have banned WiFi in kindergartens. The European Union recommends wired Internet rather than wireless in schools. France also banned WiFi routers in nursery and daycare centers, and restricted elementary school WiFi to only when in use for education. The American Academy of Environmental Medicine (AAEM) states in an open letter to school superintendents, “There is a consistent, emerging science that shows people, especially children who are more vulnerable due to developing brains and thinner skulls, are being affected by the increasing exposure to wireless radiation.”
In 2021 a New Hampshire report outlined health risks of cell phone towers in residential neighborhoods.
Scientific American reported a study of mobile phone exposure and cancer in rats: www.scientificamerican.com/article/major-cell-phone-radiation-study-reignites-cancer-questions/ According to Dr. Joel Moskowitz (UC/Berkeley), "The study's results reinforce the need for more stringent regulation of radiofrequency radiation and better disclosure of the health risks associated with wireless technologies."
Dr. Martha Herbert, a Harvard Pediatrician, wrote in this letter to Montgomery County Schools "there are thousands of papers...that document adverse health and neurological impacts of EMF/RFR"..."Radiofrequency electromagnetic radiation from wifi and cell towers can exert a disorganizing effect on the ability to learn and remember, and can also be destabilizing to immune and metabolic function"..."Powerful industrial entities have a vested interest in leading the public to believe that EMF/RFR, which we cannot see, taste or touch, is harmless, but this is not true". The American Academy of Pediatrics in 2013 requested a review of EMF radiation emissions from technology devices, citing impact on children.
In 2015 the Ashland School District in Massachusetts reduced wireless radiation exposure to children: http://issuu.com/localtownpages/docs/2015_8_ashland/15?e=2040944/14450006 and other schools also reported problems: https://www.mirror.co.uk/news/uk-news/school-wifi-networks-could-put-12602188
In 2011 the World Health Organization classified cell phones (and other wireless devices) as a possible carcinogen due to RF emissions. In 2013 Dr. Anthony Miller from University of Toronto School of Public Health recommended that based on new research, radio frequency (RF) exposure should be reclassified as a probable carcinogen.
RF exposure may be also affecting birds, bees, and other animals: http://www.newsweek.com/migratory-birds-bee-navigation-5g-technology-electromagnetic-radiation-934830
How much RF exposure is unhealthy for long periods of time? There are varying opinions from experts. A cautious level of 10uW/m2 peak for sleeping areas is recommended by Baubiologie and by EuropaEM group of universities for most types of RF signals. A group of German doctors recommended exposure below 10 uW/m2 average. Detrimental health effects are documented for example on neurotransmitters of residents near mobile phone towers in Rimbach Germany, even at low RF exposure levels below 60 uW/m2 peak (see the last 8 paragraphs of www.ncbi.nlm.nih.gov/pmc/articles/PMC5920374/ ). For RF exposure measured in V/m in areas where people spend a lot of time like bedrooms see color-coded chart at https://www.emfields-solutions.com/products/ac2-acousticom-2.asp For more info on EMFs also see www.powerwatch.org.uk/
What are "EMFs”? EMFs are “Electromagnetic Fields”.
What is frequency in Hz, kHz, MHz, or GHz? Frequency in Hz is how many oscillations or waves per second: kHz is a thousand per second, MHz is a million per second, and GHz is a billion per second. So 1000 Hz = 1 kHz, 1000 kHz = 1 MHz, 1000 MHz = 1 GHz. Higher frequency is not necessarily worse than lower frequency, higher frequency is not the same as higher RF exposure.
What is RF? RF means “Radio Frequency”. Physically, RF EMFs are electric and magnetic fields oscillating faster than 3 kHz and usually moving together as waves. RF frequencies are from 3 kHz to 300 GHz, and are transmitted by mobile phones, cell towers, Wi-Fi routers, Bluetooth, microwave and other RF antennas. RF EMFs is the topic of this web page.
What is frequency in Hz, kHz, MHz, or GHz? Frequency in Hz is how many oscillations or waves per second: kHz is a thousand per second, MHz is a million per second, and GHz is a billion per second. So 1000 Hz = 1 kHz, 1000 kHz = 1 MHz, 1000 MHz = 1 GHz. Higher frequency is not necessarily worse than lower frequency, higher frequency is not the same as higher RF exposure.
What is RF? RF means “Radio Frequency”. Physically, RF EMFs are electric and magnetic fields oscillating faster than 3 kHz and usually moving together as waves. RF frequencies are from 3 kHz to 300 GHz, and are transmitted by mobile phones, cell towers, Wi-Fi routers, Bluetooth, microwave and other RF antennas. RF EMFs is the topic of this web page.
For lower frequency types of EMFs see AC Magnetic Fields in Homes.
What are government safety standards for RF exposure? Different countries have different standards, and it also depends on the frequency and length of time of exposure.
In USA the limit for RF power exposure of the public (averaged over 30 minutes) is:
2 W/m^2 (=2 million uW/m^2) at frequencies of 100 MHz to 400 MHz
2 to 10 W/m^2 (=2 million to 10 million uW/m^2) at frequencies of 400 MHz to 2000 MHz
10 W/m^2 (=10 million uW/m^2) at frequencies of 2000 MHz to 5000 MHz.
Some countries have lower legal limits, for example in Italy, Switzerland, Poland, and China it is 0.1 W/m^2 (100,000 uW/m^2) at 1800 MHz.
Many studies have found adverse health effects at RF exposure levels far below these government standards (see above paragraphs). Our RF meters can measure much lower exposure levels.
You can view the full US government standard https://ieeexplore.ieee.org/document/1626482 or here http://emfguide.itu.int/pdfs/C95.1-2005.pdf Table 9 on page 25 shows the legal limit for RF exposure of the general public. Different regulations apply to mobile phone use next to your head, but all the US standards are based on heating of human tissue by the RF. However, enforcement of these laws is very lax: microwavenews.com/news-center/cell-phone-carriers-fcc-cozy.
What is your RF exposure while using a mobile phone next to your head? A mobile phone held against the ear is estimated to produce average power of about 10 W/m2 (=10 million uW/m2) on the area of your head near the phone antenna, and about 1 W/m2 (=1 million uW/m2) inside your cranium near the phone. The V/m is estimated around 150 V/m on the outside and 50 V/m on the inside of the head. The RF meter measures less than this because it is designed to be accurate at a distance of 1 foot or more from the transmitting antenna.
For a child their head is smaller and their brain still developing, so this very high exposure is of even more concern. James McNamee with Health Canada in October of 2011 issued a cautionary warning stating "Children are more sensitive to a variety of agents than adults as their brains and immune systems are still developing, so you can't say the risk would be equal for a small adult as for a child." (Globe and Mail 2011). Mobile phones are required to be tested for SAR which measures how much RF power is absorbed in the head as heat, but it does not consider other possible effects besides heating, and also the government assumes adult users will not use their phones for longer than 30 minutes per day, and children for even less time.
Can the RF meters measure WiFi and Bluetooth? Yes. Distance reduces RF exposure, so you could place the WiFi router away from bedrooms and other locations where people spend a lot of time, and turn off WiFi routers at night especially if they are close to a bedroom. Different WiFi devices emit differing amounts of RF power. WiFi routers that need to cover a wider area like schools often radiate at higher power, and should be placed farther away from where children sit. Bluetooth radiates lower power than WiFi but is sometimes worn very close to the head. This article is from Consumer Reports: https://www.consumerreports.org/radiation/do-i-need-to-worry-about-radiation-from-wifi-and-bluetooth-devices/ This video shows RF measurements near a WiFI router or modem: www.youtube.com/watch?v=ICA19oKPi5I
How to reduce WiFi RF exposure in my home: Here are some ideas: move the WiFi router to a more distant location in your house away from your desk, living and sleeping areas. Use wired Ethernet from the router to some of your devices. Turn off the router at night. Put it on a timer to automatically shut off every night. Put a piece of aluminum foil about a foot or so from the router between the router and living/sleeping areas since metal blocks RF which mostly travels in straight lines from the router. Other metal objects can also block some RF. To block RF from entering through a larger area like a wall you can use conductive paint, conductive shielding fabrics, aluminum foil, metal screen or mesh (with holes preferably 1/4" = 6 mm or smaller). Note some routers let you "turn off WiFi signal", but they may still keep radiating the RF carrier which would not reduce the RF.
Where are cell towers and other antennas located? www.antennasearch.com shows locations and frequencies of many antennas in USA.
A cell phone tower is near our house: A study in Rimbach Germany found adverse health effects living near a mobile phone tower, even at low RF exposure levels below 60 uW/m2 (see last 8 paragraphs of www.ncbi.nlm.nih.gov/pmc/articles/PMC5920374/ ). A study recommends that no-one live within 300 meters (1/5 mile) of a phone tower. Other studies have also report ill-health effects living close to phone towers: www.powerwatch.org.uk, and www.mast-victims.org/ RF exposure depends on the distance from the tower, your height compared to the tower antenna (being closer to the antenna height is worse), the number of carriers, operators, and antennas using that tower, the power transmitted by each antenna, antenna patterns, frequencies, type of walls and roof material in your building, metal objects in your vicinity, etc. You can measure the RF exposure using the RF meter and compare it with other locations.
What are 5G frequencies? 5G can use low-band, mid-band (microwave), or high-band (millimeter-wave) RF frequencies:
Low-band 5G uses similar frequencies to 4G: 600–900 MHz, and has coverage area similar to 4G towers.
Mid-band 5G uses microwaves of 2.3–6 GHz, with each cell tower providing service up to several kilometers radius. Mid-band 5G is the most widely deployed and is installed in many metropolitan areas since 2020.
High-band 5G are frequencies of 24–48 GHz & higher, and will require many small cells with transmitters closer together and closer to residences. Due to the higher cost of high-band 5G, plans are to deploy it mostly in dense urban environments. This is likely to increase the public's already high level of RF exposure in urban areas. High-band 5G frequencies can be blocked or reduced by some walls and window materials.
Can our RF meter measure 5G? Yes. Some of our RF meters measure 5G frequency bands up to 6 or 8 GHz which includes the low-band and mid-band 5G, and our mmWave meter can measure the high-band 5G (which is at 24-47 GHz and is found mostly in dense urban environments.
Can the RF meters measure RF exposure from cell phone towers, TV and radio broadcast towers? Our RF meters can measure cell phone towers, and TV towers for TV station 7 and up (that's VHF-Hi and UHF), but will not measure TV towers for stations 2-6 nor radio broadcast towers (AM or FM), since those use frequencies below the frequency range measured by these RF meters. Two-way radios and other RF antennas can be measured if they transmit between 200 MHz to 8000 MHz frequency.
There is a TV or radio tower near my house, what is our RF exposure? Exposure from a TV tower was about 10,000 uW/m2 at 1/2 mile (800 meters) from the tower. Some studies have found health problems for residents near TV and radio towers:
http://dorontal.net/NIR_refs/TV_towers_Sydney.pdf and www.powerwatch.org.uk Sometimes a Faraday cage might be needed to block AM or FM radio towers or VHF TV towers, since those frequencies are under 300 MHz (so the wavelength is long). However for frequencies higher than 300 MHz you can usually shield just some of the walls & ceiling to block probably 75% to 99% of the RF, since higher frequencies are easier to shield.
If I want to reduce RF exposure from a nearby tower or antenna, what can I do? Cell phone towers and antennas use frequencies above 850 MHz (those wavelengths are small), so you can just shield the sides of the house facing the tower (assuming most of the RF is coming from that one direction). Metal will shield like a reflector antenna, the RF is reflected by the shield (if the shield is at least several wavelengths wide). So there is an RF ‘shadow’ behind the shield. A small amount of RF ‘bends’ around the edges of the shield, so the shadow does fill in the farther back you go behind the shield or reflector, so you’d want to block as large an area as you can facing the tower. It does help a little to block side walls too, and the ceiling (especially if the transmitter is higher than your ceiling). You can make a small test shield with cardboard about 4 feet square covered on one side with aluminum cooking foil. Then test the RF using your RF meter about a foot or two behind the shield. This will find out if the RF is coming from mostly one direction. If you don’t get a big reduction about a foot or two behind the shield then the RF is coming from a different direction, or multiple directions, or the frequency might be too low so the wavelength is too wide compared to the shield.
Aluminum siding will block most of the RF radiation from coming through walls. RF waves travel mainly in straight lines from the source and are blocked by metal, so you actually only need the aluminum siding on the sides of the house facing the tower. If aluminum siding is not used, then for interior walls, conductive paint is available which will block RF, or conductive shielding fabrics can be used for curtains, drapes, or wall coverings (fabrics can be sewn). Aluminum mosquito screens will block RF and can be used for windows facing a tower. Aluminum Venetian blinds (with vertical blinds) in front of windows will block some RF. In attic areas you could staple chicken-wire mesh to block rays from the tower entering through the roof or ceiling. Aluminum foil also blocks RF. These all work due to the high frequency of RF. The shielding is mainly needed on the side(s) facing the tower or antenna; the RF can still go around these shields but is much reduced in strength. Usually your mobile phone will still work inside the house after shielding because the phone doesn’t actually need much RF signal power to work. Although there may be cases where you need to take the phone outside to get a signal.
There is an antenna on my building or nearby building: First, find out what type of antenna and what its used for: some antennas are for receiving only (like TV antennas on houses, satellite TV, and some satellite internet antennas), those would not transmit anything so they would not cause any RF exposure nor show anything on the RF meter. See if the building address is found at www.antennasearch.com which gives some information about many transmitting antennas in the USA. Ask the owner of the building or antenna what type of antenna it is. If it is a cell phone antenna then see the above FAQ about antenna towers near your house. Antenna beams usually direct more power horizontally than downwards, so its possible to have more exposure on an upper floor of a nearby building than on a lower floor in the same building as a rooftop antenna.
Could there be a cell phone antenna on the wall of my building? Sometimes a cell phone company has been allowed by the landlord to place an antenna on the outside wall of an apartment or office building, which exposes the occupants in the nearest rooms to high RF fields. These antennas may be as small as a shoe-box and painted the color of the exterior of the building to blend in. These antennas can be located using the RF meter, since the fields get stronger as you approach the antenna.
RF exposure in cities: Oncologists measured high RF radiation in public areas of central Stockholm in 2017. The average RF power was 5,494 µW/m2, based on more than 12 hours of measurements. www.ncbi.nlm.nih.gov/pubmed/30675237 Most of this RF was from mobile phone towers. Environmental RF radiation levels on city streets are expected to increase over the next few years with the introduction of 5G.
Can the RF meter measure Smart Meters? Yes. Smart meters may transmit RF pulses every few seconds or some transmit much less often. Each pulse is generally at a very low level of RF, so to see them you may need to turn off other nearby RF sources like Wi-Fi and mobile phones.
Can the RF meter measure Dirty Power or "Dirty Electricity" (DE)? Not most DE frequencies, since those are mostly below the frequency range of the RF meter.
Can the RF meter measure TV or radio sets in my home? TV and radio sets used in homes are receive-only and do not transmit, so there should not be any RF coming from them or their antenna. Two-way radios can be measured if they transmit between 150 MHz to 8000 MHz frequency.
Can the RF meter measure Ham Radio antenna transmissions? Not most ham radio transmissions, since they are usually below the 200 MHz frequency which is the lowest frequency measured by these RF meters.
What does the RF meter measure? The RF Meters measure Radio Frequency Electromagnetic Fields (RF-EMF). These RF meters measure the RF power in uW/m2 to show how much RF people are exposed to, at frequencies from 200 MHz to 8 GHz. These RF meters do not display the frequency. An RF meter does not measure static or low-frequency fields from magnets, the earth's magnetic field, power lines, nor home wiring, for those you would use a different meter: see AC Gaussmeters at top of page.
Our RF meters have excellent sensitivity (they can measure weak RF signals), wide frequency range (200-8000 MHz), very good accuracy, and are easy to use. For best accuracy hold the RF meter at least 1 foot (12 inches or 30 cm) or more away from the antenna or device that you are measuring, and rotate the RF meter to maximize the measured RF signal. For information on 60 Hz EMFs see: www.magneticsciences.com/EMF-health/
Explain Average RF power. The Safe and Sound Pro II RF meter measure the RF field many times per second and continuously averages those measurements to show the average RF power in µW/m² (often written uW/m2), it means microWatts per meter square. The µ or u stands for "micro" which in scientific notation means 1 millionth.
Another widely used unit is "milliWatts per meter square" (mW/m2), so 1 mW/m2 = 1000 uW/m2
Another widely used unit is "Watts per meter square" (W/m2), so 1 W/m2 = 1 million uW/m2
Other standard scientific prefixes are sometimes used, for example: 1 mW/sq.cm = 10 W/m2 = 10 million uW/m2, and 1 nW/cm2 = 10 uW/m2.
The Safe and Sound Pro II measures from 0.005 to 3,180,000 µW/m² (Linear response from 0.1 to 1,000,000 µW/m²).
There is no easy way to convert between peak V/m and average uW/m2 RF power for modern digital RF signals (like mobile phones & phone towers, or WiFi) because those modern signals are transmitted in pulses (not "CW"), so online converters for CW would not give correct answers. So we recommend using an RF meter like the Safe and Sound Pro II which can correctly average the RF power using numerous samples. Most other RF meters (if they display RF power) use a simple formula which assumes continuous wave (CW) RF power based off the peak of the field, which vastly overestimates the average RF power of most modern digital RF signals transmitted in digital bursts.
Is there an easy way to reduce RF exposure? For a mobile phone you can use wired headphones or put it on speaker so the phone is not next to your head. For a WiFi router you can locate it away from where you spend a lot of time. You can use RF Meters to measure RF exposure in areas you spend a lot of time: if it is below 10 uW/m2 or 0.05 V/m most of the time, and you don't live near any TV or radio towers or in dense urban environments, then you should have low RF exposure.
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