Top 5 ways to reduce ELF and UHF (microwave) radiation
I get asked a lot about ways to limit exposure to Extremely Low Frequency (ELF) magnetic fields and Ultra High Frequency (microwave range) exposure. Well, people usually ask questions more like, “how do I prevent frying my head with my cell phone?” or “should I be worried about having a clock radio so close to my head when I sleep?”.
Many posts ago I talked about these two types of frequencies and possible health effects. In this post, I list my top 5 ways to decrease the intensities of ELF magnetic fields from wiring and appliances and UHF from wireless sources such as baby monitors and cell phones. In general, the best way to reduce the possible health effects from these two frequencies is simply increase your distance from the source. The inverse square law states that by doubling the distance from any electromagnetic source, the intensity is reduced to 1/4.
Here are my top 5 tips for ELF and UHF (a sneak peek from the forth coming book):
Dr. Brett’s Top 5 Easily Mitigated ELF Sources
1) Clock radio: most people I know have one of these in their rooms. They measure approximately 50 mG (5 μT) right near the clock but drops to 0.6 mG (0.06 μT) at 2 feet. Get clock radios away from your head! Move it at least 2 feet from your head – it may prevent you from whacking the snooze button and get you out of bed!
2) Hair Dryer: 130 mG (13.0 μT) at your head! Granted it is usually not on for long periods but perhaps consider going back to the towel instead. Please do not blow dry your kids hair!
3) Electric Razor: 2230 mG (223 μT) again, right close to the brain. Yes, it is only used for short periods. Yes I know how expensive blades are for razors. Beards are stylish now.
4) Microwave oven: 470 mG (47 μT). Okay, “NO”, microwaves will not kill you and they do not make the food you eat radioactive! However, do put your head near the microwave when it is running. Stand 3 feet back and you will be fine.
5) Transformers: 30 mG – 150 mG ( 3 μT – 15 μT) these are the small black (usually) boxes that you plug into the wall to power many appliances such as laptops, portable DVD players, cordless phone base stations, printers, speakers for computers, baby monitors, routers, game systems, etc. Their purpose is to transform alternating current from the plug which is 110 volts, alternating current into direct current of a smaller voltage. Move them at least 3 feet away from the heads of where people sleep.
Before we examine the mitigation tips for UHF, we need to define some frequently used language in with UHF (microwave radio frequency). With ELF, we are essentially looking at the strength of the magnetic field measured in either mG or μT.
The International Commission on Non-Ionizing Radiation Protection (ICNIRP) set a general public exposure limit of 200 μT (2000 mG). Health Canada and the FCC set a SAR limit of 1.6 W/kg for UHF. The other term you will see regularly used in UHF is power density. Power density is the amount of power for a unit of area. In examining the power density from a radiated source such as a cell phone, the measurements are usually in microwatts per centimetre squared (μW/cm2). While there are no limits per se with power density, the higher the power density, the higher the SAR level.
Dr. Brett’s Top 5 Easily Mitigated UHF Sources
1) Cell Phone: Power Density: 1000-5000 μW/cm2 at ear. SAR levels*: range from 0.3 W/kg to 2.0 W/kg. Yes, I have a smart phone and Yes, I love it! I do however rarely make calls on my cell phone. If I have to make a call that will last more than a couple of minutes I look for a landline or I simply text. Texting gets that UHF away from your head. If I do use my phone for a conversation, I use the speaker phone and hold the phone away from my head. Even a few inches make a big difference!
2) Baby Monitor: Power Density: 2.9 μW/cm2. SAR levels* range from 0.01-0.08 W/kg (FCC limit is 1.6 W/kg). Yes, the SAR level is low but if you have it on all the time, a baby might be exposed 14-16 hours a day! Get that thing away from your child! It works just fine several feet away. You can get “wired” versions of these devices. Voice activated is also better as it is not on all the time. Avoid DECT baby monitors which use more power. Some baby monitors may operate with powers up to 500 mW.
3) Wireless router: Power Density: 0.2 – 1.0 μW/cm2. SAR levels* – difficult to find published data. I love Ethernet cables but I realize that it is a pain to run cables all over your house – I should know as I have pulled Ethernet cables though my 60 year old house for 15 separate jacks! If you must use a router, at least make sure it is at least 3 feet away from where you sleep.
4) Cordless Phones that use DECT technology: Power Density: 205 μW/cm2 at the phone. SAR level* of DECT phones: 0.01 and 0.05 W/kg DECT technology uses high power (up to 500 mW) and is on continuously. Consider either non-DECT cordless phones (approx 5 μW/cm2 ). You can still buy phones with cords that have answering machines.
5) Wireless function in a laptop computer or tablet: SAR levels*: 1.04 W/kg. It is hard to find published SAR levels for laptops and tablets. Since the SAR levels are similar to cell phones, if you can turn off the wireless function, turn it off.
* FCC limits and Health Canada SAR limits are 1.6 W/kg