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RF Exposure from Mobile Phones, Towers, WiFi, and other RF

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 holding the phone farther away from your head and using wired headphones or the phone's speaker 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   TV News reports cell phone hazards (video)  
 
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 May 2016 the NIH reported links between mobile phone RF exposure and cancer in male rats. 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."   The study was reported in Scientific American:   www.scientificamerican.com/article/major-cell-phone-radiation-study-reignites-cancer-questions/        http://microwavenews.com/  
 
In 2013 Dr. Martha Herbert, a Harvard Pediatrician, wrote in this letter that "thousands of papers...document adverse health and neurological impacts of EMF / RFR."  Also in 2013 the American Academy of Pediatrics requested a review of EMF radiation emissions from technology devices, citing impact on children.
 
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. 
 
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 have also reported problems:  https://www.mirror.co.uk/news/uk-news/school-wifi-networks-could-put-12602188 
 
Dr. Lennart Hardell, oncology professor at University of Orebro in Sweden, found that people who begin using cell phones before age 20 have five times more brain cancer by the time they reach their late twenties. 
 
 
How much RF exposure is unhealthy for long periods of time?  There are varying opinions from experts. 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  (see the last 7 paragraphs of  www.ncbi.nlm.nih.gov/pmc/articles/PMC5920374/ ).  A cautious level of 10uW/m2 max is recommended by Baubiologie  for  sleeping area guidelines.  (10 uW/m2  is near the bottom of the "Average" scale on the right-hand side of our RF meter Acoustimeter). A group of German doctors also recommended exposure below 10 uW/m2 average For more info on EMFs and RF exposure see  www.powerwatch.org.uk and www.powerwatch.org.uk/science/intguidance.asp 
 
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 the 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 limits, for example in Italy, Switzerland, Poland, and China it is  0.1 W/m^2  (100,000 uW/m^2)  at 1800 MHz. 
If our RF meter (Acoustimeter model) is showing below the top of the average power scale (below 100,000 uW/m^2) then these government standards are being met (usually by a wide margin).  However, some studies have found adverse health effects at levels far below these government standards (see above paragraphs). The Acoustimeter can measure much lower exposure levels: from 1 to 100,000 uW/m^2. 
 
You can view the full US government standard  https://ieeexplore.ieee.org/document/1626482  Table 9 shows the legal limit for RF exposure of the general public. Enforcement is an issue: microwavenews.com/news-center/cell-phone-carriers-fcc-cozy.   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. 
 
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. 
 
What are RF Electromagnetic Fields?  RF stands for "Radio Frequency", which includes electromagnetic fields (EMFs) from mobile phones, cell and mobile phone towers, Wi-Fi, Bluetooth, and microwaves.  Physically, these are electric and magnetic fields vibrating faster than 3 kHz and usually moving together as waves. For EMFs from home wiring and power lines see AC Fields in Homes
 
What is frequency in Hz, kHz, MHz, or GHz?  Frequency in Hz is how many waves per second. kHz is a thousand waves per second, MHz is a million waves per second, and GHz is a billion waves 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. 
 
Explain Average RF power.  Our RF meter Acoustimeter AM-10 model measures the RF field 6400 times every 1/4 second, and averages those to update the Average RF power displayed in uW/m2 (microWatts per meter square). 
The "u" stands for  "micro" which in scientific notation means 1 millionth.  
Another widely used unit is  "Watts per meter square" (W/m2),  so 1 W/m2  = 1 million uW/m2
The Acoustimeter can measure from 1 to 100,000 uW/m2 (which is up to 0.1 W/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. 
 
What does the RF meter measure?  The RF Meters measure Radio Frequency Electromagnetic Fields (RF-EMF). These RF meters measure the RF field strength in Volts per meter (V/m), and the Acoustimeter model also measures the time-average RF power in uW/m2. These show the RF that people are exposed to, at frequencies from 200 MHz to 8 GHz, but do not display the frequency. There is no easy way to convert between units of V/m and uW/m2 average RF power for modern digital RF signals (like mobile phones & phone towers, or WiFi) because those signals are transmitted in pulses (not "CW"). Online converters for CW would not give the correct answers. So we recommend using an RF meter (like the Acoustimeter AM-10) which can correctly display Average RF power. 
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 Gauss meters at top of page. 
 
The Acoustimeter RF meter provides a much more accurate Average RF power reading than most RF meters.   The Acoustimeter AM-10 was selected for its accuracy, ease of use, wide frequency range (150 MHz-10 GHz), and excellent sensitivity (it can measure weak RF signals), and it displays the Average RF Power. 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. The average power displayed by this meter is the average of 6400 samples updated every 1/4 second. This is a much more accurate method to measure average RF power of modern digital RF signals than used by other RF meters in this price range; most other RF meters (if they measure RF power at all) 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. The manufacturer's web site shows additional information about these meters https://emfields-solutions.com/ 
 
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 the RF Acoustimeter measuring 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 7 paragraphs of  www.ncbi.nlm.nih.gov/pmc/articles/PMC5920374/ ). A study in France  "Study of the health of people living in the vicinity of mobile phone base stations" 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. 
 
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:
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 5G?  Our RF meters can measure 5G signals up to 8 GHz. That includes 5G frequency bands in the range 3.4 - 4.2 GHz and lower frequencies already in use for 2G and 3G which will be re-used for 5G. Many more base-stations/masts located close together will be required for widespread use of 5G, and this will take some years to roll-out. Until at least year 2022 anyone with a 5G mobile phone will usually be connected by 4G, not 5G, except in the center of some main cities. 
High-band 5G (above 24GHz) and mmWave (above 30 GHz) frequencies are not measured by our existing RF meters. Those frequencies (24 GHz and higher) will not be used as the main 5G mobile phone network, but instead will provide local ‘hot-spots’ in the home and open areas where there are many active users.  Also, RF strength at those frequencies is reduced by most exterior walls and tree foliage, since more RF is absorbed at higher frequencies.  
In a few limited places in the USA, as of August 2019 Verizon has launched its own ‘5G’ variant at 28GHz. For example, Verizon’s current ‘Home 5G’ is available in a few places in the USA where a high-band-mast is within a few hundred meters in clear line of sight to an external antenna on your home. At present, the only use of ‘mmWaves’ (above 30 GHz) will be for localized experimental testing and other purposes. ‘mmWave’ 5G will also be used to connect base stations to satellites. Individual mobile phones will still connect to these base stations using lower band (below 6 GHz) frequencies.  
 
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 150 MHz frequency which is the lowest frequency measured by this meter. 
 
Is there an easy way to reduce RF exposure?  For mobile phone conversations you can use wired headphones or speaker so the phone is not next to your head.  You can place the WiFi router away from where you spend a lot of time. You can use the RF Meter to measure RF exposure in areas you spend a lot of time: if it is below 10 uW/m2 Average, and you don't live near any TV or radio towers, then you should have low RF exposure. 
 
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