Our Irradiated Lives
Low-level radiation is all around us—but there are ways you can protect yourself.
By Lisa James
The words “radiation exposure” bring images of Fukushima, Chernobyl and Cold War-era mushroom clouds to mind. But those words also apply to going for a CT scan and talking on a cell phone—and sometimes simply descending to the basement.
We are all constantly bathed in a sea of low-level radiation. Some sources pose a cancer risk that is generally accepted; for others it is a point of controversy. Most of this exposure comes from innovations that have made human existence more comfortable and convenient than ever before, including technology that has helped save countless lives.
Electromagnetic energy covers a spectrum that includes both ionizing radiation—the type that can disrupt atoms, including those in living tissue—and non-ionizing radiation. The second category includes radiofrequency (RF) waves, the kind that power cell phones and microwaves, along with the electrical current that powers your house. Some radiation comes from natural sources: the earth, the sun, outer space.
How much radiation is dangerous? “What determines your overall cancer risk from radiation is your exposure over time, and with lower levels of exposure it’s harder to measure,” says David J. Brenner, PhD, director of the Columbia University Medical Center’s Center for Radiological Research in New York City and a member of the National Council on Radiation Protection and Measurements. Brenner notes that cancer rates in the US are already high, so “it’s difficult to measure a very small increase in risk because of this giant background risk. That doesn’t mean the risk is not there. There’s never a level where the risk becomes zero.”
Brenner cites smoking as one known factor that adds to radiation risk, especially that posed by naturally occurring radon gas. Another is genetics. “Perhaps 5% of the population is definitely more sensitive than most,” Brenner says. Age also makes a difference; children are more vulnerable to radiation’s effects than adults.
Brenner is concerned about a lack of research on the topic. Proper response to emergencies, including reactor accidents and terrorist attacks, means “you need to understand the risk. We don’t know how many people got cancer from Chernobyl; estimates range from hundreds to millions. The reason is because we don’t know the effects of low-level radiation.”
While the risks posed by radiation from various sources cannot be eliminated, they can be reduced.
Radiation exposure has doubled over the past two decades, and “that increase has come from medical imaging,” says Rebecca Smith-Bindman, MD, director of the Radiology Outcomes Research Laboratory at the University of California San Francisco and a physician with the UCSF Medical Center.
Smith-Bindman explains that two factors are at work. “One, we’re using many more tests, especially CT scans. Two, the dose per test has gone up. Reduction means reducing the number of tests or reducing the dose per test.” She points out that a single CT scan of the abdomen delivers the same amount of radiation as 1,500 dental X-rays. What’s more, Smith-Bindman says oversight of CT usage is fragmented, with few across-the-board guidelines on issues such as recommended usage and radiation dosage measurement.
“CT is a fantastic tool—it has revolutionized medicine,” says Brenner. “But it is a tremendously used technology and arguably slightly overused.”
Smith-Bindman says, “My goal is not to eliminate medical imaging. My goal is have people become educated consumers and be aware why they are getting the tests they’re getting.”
Protective measures: Keep records of your medical visits, including scans and imaging procedures. If your doctor recommends a CT, Smith-Bindman says you should ask, “Why am I having this test? Is this going to help me?” This is especially true when children are being scanned; for information on the Society for Pediatric Radiology’s ImageGently program, which urges the use of lower dosages for children, visit www.pedrad.org.
There are more cell phones, laptops and other wireless devices in the US than the country’s population of 315 million, offering more mobility than ever before. But a growing number of people are worried that this benefit comes at the price of increased exposure to the RF radiation that powers these devices.
Most investigations into cell phone usage have found no ill effects. But many studies into a possible linkage between cell phones and brain cancer looked at people who had used them for less than 10 years and defined “heavy use” as 30 minutes a day.
However, “people are now using cell phones for thousand of minutes a month,” says Devra Lee Davis, PhD, MPH, cofounder of the Environmental Health Trust (www.ehtrust.org), founding director of the Center for Environmental Oncology, University of Pittsburgh Cancer Institute and author of The Secret History of War on Cancer (Basic Books) and Disconnect (Penguin Group). “If you’re holding a cell phone again your head for thousands of minutes you’re going to have an effect on the brain.” In March, The Federal Communications Commission said that it would explore whether or not it should modify its RF standards.
Davis is especially concerned about the effect cell phones may be having on children. A September 2012 Pathophysiology study found an increase in glioma, a type of malignant brain tumor, in people who started using cell phones before age 20 and had used them for at least 10 years.
“Cell phones have revolutionized the world, much of it for the better,” Davis says. “But we have no idea what they can be doing to the brains of youngsters living in a sea of RF radiation that didn’t exist even five years ago.”
Protective measures: Use corded landlines whenever possible. Keep cell phones away from your head by using a speakerphone or other hands-free device, and don’t keep them in your pocket. Don’t use these devices in weak-signal areas, which cause them to work harder. Don’t let children use them excessively; pregnant women and men who want to become fathers (RF has been found to damage sperm) should also use wireless devices with caution. And “broccoli has compounds in it that can repair damage from lots of things, including cell phone radiation,” says Davis.
Before the country was covered in cell phone towers it was strung together with high-voltage power lines, which have also raised cancer concerns. A French study published in the April 2013 online version of the British Journal of Cancer found a link between living within 50 meters (about 55 yards) of a high-voltage line and leukemia in children; previous studies found mixed results. Conflicting conclusions have come from studies of high-voltage exposure and adult cancer.
A broader spectrum of health concerns, known collectively as electromagnetic hypersensitivity, surround exposure to lower power levels; symptoms reported include fatigue, headache, muscle aches, skin problems and sleep disturbances. While some studies have found no effects, others have found brain wave changes in response to low-power electromagnetic fields (Medical Engineering & Physics 2010).
Protective measures: Avoid living under high-voltage lines if possible. Debra Lynn Dadd, author of Home Safe Home (Tarcher/Penguin), suggests removing powerful electromagnetic emitters such as electric blankets, microwave ovens, and dimmer and timer switches, and unplugging applicances and electronic items when not in use. Annie Bond, author of Home Enlightenment (Rodale), recommends keeping alarm clocks (unless battery operated) and TVs at least eight feet from the bed. Don’t keep your cell phone in your bedroom.
The most significant source of natural background radiation is radon, a gas given off by radioactive elements in the soil. The Environmental Protection Agency estimates that radon, which tends to accumulate in basements, causes about 21,000 lung cancer deaths in the US each year.
Differences in rock formations cause variations in radon levels across the country, with the highest generally found in the mountainous Western states. But there are many exceptions such as the Reading Prong, which stretches from eastern Pennsylvania through northern New Jersey, southern New York and into Connecticut.
Protective measures: Have your home tested for radon. Go to www.epa.gov and type “Citizen’s Guide to Radon” in the Search box, top right. The agency recommends remediation for levels of 4 pCi/L or greater; its website offers advice on finding a company to do the work.
Flying increases exposure to cosmic rays from space, the other major source of natural radiation. Most cosmic rays enter earth’s atmosphere at higher elevations, where the air is thinnest, and at the poles, where the planet’s magnetic field is weakest.
On the ground, scanners at airport security checkpoints use two different forms of radiation. The cylindrical millimeter wave machines use low-power RF beams to look for suspicious items; the blue-box X-ray backscatter devices create a surface picture of the body using low-intensity X-rays.
Radiation from each backscatter scan equals up to three minutes of in-flight exposure, leading to estimates of 100 radiation-induced cancers for every billion scans. In January the Transportation Security Administration pulled these devices from US airports because of privacy concerns about the revealing body pictures they yield, although a new contract has gone to a company that uses backscatter technology. No known health risks are associated with millimeter wave.
Protective measures: If you’re concerned about going through any kind of a scanner get to the airport early and request a manual pat-down. The EPA says there are no practical ways to shield yourself against cosmic rays.
It’s impossible to completely avoid the radiation hazards associated with living in a high-tech age. But there are ways to manage those risks that don’t involve hightailing it to the woods.