A quick internet search on the dangers of radiation—often called electromagnetic fields or EMF—coming from our increasingly popular handheld devices produces some pretty intimidating results. Some articles state that there is no link at all between EMF and adverse health effects. Others claim there are clear links between cancer and cell phone use, sometimes citing an even higher risk for children. So, who should we believe? Do we really need to throw out our WiFi routers, our Fitbits, and our smart phones and go off the grid for the sake of our health? What Is Electromagnetic Radiation? A main source of fear of the radiation coming from our cell phones is that it gets confused with other sources of radiation we already know to be harmful. So, let’s break down what exactly is meant by electromagnetic radiation. As discussed in an earlier episode, radiation is a form of energy that describes everything from the optical light we use to see to the X-ray emission that tells us if we have a broken bone. These different types of radiation can be broken up into categories based on their wavelength, which is related to the amount of energy they carry. Short wavelength radiation, like X-rays or gamma rays, have higher energies, while lower energy levels are associated with long wavelength radiation like microwaves and radio waves. A key difference between long and short wavelength light is the ability of short wavelength radiation to ionize the atoms in biological tissue like that in our bodies. When an atom or molecule is ionized, it goes from being neutral to having a charge (i.e. becoming an ion) through removal of an electron. This ionization can cause permanent damage, and so our exposure to it must be limited. Getting the occasional X-ray at your doctor’s office is okay, but the X-ray technician will usually step out of the office when the image is taken, so that she or he is not constantly exposed throughout the day. Longer wavelength radio waves (sometimes called radio frequency emissions or RF emissions for short) are lower energy and not capable of ionizing tissue. Thus, they are used commonly for radio or television broadcasting, satellite communications, and, of course, cell phones. RF emissions are also used for non-communication purposes, most notably in microwaves. The absorption of energy at microwave wavelengths is very efficient in water molecules. Microwaves work by transferring microwave radiation to water molecules, which are then heated much more quickly than in a conventional oven. Our cell phones are also constantly sending and receiving RF emission. When a friend calls your cell phone, that message travels through a network of telephone wires until it reaches a base station that is closest to your phone. That station then sends out radio waves to be detected by a receiver in your phone where the signal is converted into the sound of your friend’s voice. Longer wavelength radiation is not completely harmless, however. In large doses, RF emission can also cause tissue damage if it causes too high a spike in temperature. Your eyes are particularly vulnerable since the blood flow there is low and heat is not as easily dissipated. Obviously harmful doses of RF radiation, however, arise from extreme situations like spending time inside your microwave. They are thus very unlikely to occur from everyday activities. So, we know not to stick our head in the microwave, but what about the lower doses of RF radiation that come from WiFi-enabled devices like our smart phones? Where do we draw the line? Who Monitors EMF? In the U.S., the Federal Communications Commission (FCC) and the Food and Drug Administration (FDA) are the main organizations that influence the amount of EMF exposure we receive. Through their RF safety program, the FCC sets limits on RF emissions from hand-held devices like cell phones that must be met before a device is marketed to the public. Those limits are informed by research studies led by the FDA to understand the impact of EMF from various household items, including microwave ovens, on human health. Limits for RF exposure are quoted in terms of what is called the “Specific Absorption Rate” (or SAR), which quotes the rate in Watts that energy is absorbed per kilogram of the body. The FCC sets an upper limit to this absorption at 1.6 Watts per kilogram for hand-held devices in the U.S.. This limit is more conservative than the 2 Watts per kilogram limit used in Europe and most other countries. Another organization investigating the impact of EMF is the World Health Organization (WHO), which established the International EMF Project in 1996. The Office of Radiation Programs within the Environmental Protection Agency further monitors the health effects of public exposure to EMF, as does the National Cancer Institute. The Occupational Safety and Health Administration (OSHA) and the National Institute for Occupational Safety and Health (NIOSH) both conduct research related to exposure to EMF in workplaces. Most studies investigating the impacts RF emissions are likely conducted by the U.S. military, which has a strong interest in radar and communications through radio transmitters. Is EMF Dangerous? According to the FDA, no studies have been able to unequivocally link cell phones to adverse health effects including cancer, headaches, dizziness, or memory loss. The FDA has not ruled out the possibility of risk, but they go as far to say that it is probably small if it exists at all. In a review for the well-respected Mayo Clinic, doctors concur that there is a lack of convincing evidence. However, the case for harmless EMF is not an obvious one. Some studies have shown links, although they have not been reproduced. Research is also often done on tissue samples rather than entire bodies. Perhaps the biggest challenge to finding a definitive link between cell phones and cancer, for example, is the issue of separating causation from correlation. As discussed in a previous episode, just because two things are correlated (i.e. happen at the same time), it does not mean that one causes the other. A great example of this is the correlation between the lack of pirates with global warming. Looking back over the past few centuries, the number of pirates has steadily declined as the global average temperature has increased. The two trends track each other nicely when plotted together. Obviously, the two are not actually causally linked. If we believed that, we would be able to stop global warming simply by becoming pirates! The problem is that correlation does not have to imply causation. Cancer studies have shown that the average time between exposure to a carcinogen, or possible cancer-causing agent, and a resultant tumor can be on the order of decades. We humans lead highly varied lives with a large range of experiences. So, drawing clear links between a specific kind of exposure (like radiation from your cell phone) to a particular adverse health effect is extremely difficult. One of the largest studies of RF emissions and cancer, the Interphone project, found a tentative link between cell phone usage and glioma in ~25% of the participating groups. However, differences in methodology concerning how that link was drawn resulted in the conclusion that no significant association could be made. However, just as correlation does not imply causation, the lack of evidence is not evidence of absence. In other words, not being able to find a definitive link between RF emissions and adverse health effects does not tell us for sure that link does not exist. In fact, a group of 195 scientists from 39 countries signed a cautionary letter last month asking the United Nations and the WHO to invest more effort into researching the effects of EMF on human health and urge the use of stricter guidelines. How Can I Reduce My EMF Exposure? Although there is no conclusive evidence that EMF poses a health threat, most scientists agree that it can’t hurt to limit our exposure. The easiest way to reduce EMF absorption from your cell phone is to keep it away from your body. Carry your phone in a bag or purse instead of in your pocket, and don’t sleep with it on your pillow at night. Using ear buds during phone calls can reduce the amount of radiation absorbed by your head. If your phone is instead placed in your pocket during those calls, however, you are only shifting that absorption to your chest or hip. Some phone attachments are marketed as shields against RF radiation, but studies have repeatedly shown them to be ineffective. Even worse, because some may interfere with your phone’s operation, your phone may increase its power output to compensate. Of course, the best way to limit exposure to the EMF from cell phones and other WiFi-enabled devices is to limit our use of those devices. Even if future research proves EMF to be harmless, you will still have the benefit of better sleep and more time spent being active or playing outside. Source
