Friday, April 8, 2011

7 Ways You're Exposed to Radiation -- When Should You Worry?

Radiation is scary. Amid headlines about nuclear fallout from the Japanese power plants, there’s also mounting concern about potential health risks from other types of radiation exposure, including airport scanners, medical tests, and naturally occurring radiation, such as radon. And there’s been hot debate about whether cell phones cause brain cancer or tumors.

What’s the truth about radiation risks? “The health effects of radiation exposure are cumulative—they build up over a lifetime,” says Stephen Amis, Jr., MD, chair of the department of radiology at Albert Einstein College of Medicine and Montefiore Medical Center in New York City. However, not all forms of radiation exposure are equally dangerous. Here are Dr. Amos’ expert insights on 7 ways you might be exposed to radiation in everyday life—and when to worry.

The current state of the nuclear disaster in Japan.

1. Radiation from the Japanese nuclear disaster. The devastation wreaked by the earthquake and tsunami has left officials still struggling to contain radiation from the damaged Fukushima Daiichi power plant.

Should you worry? No--although minimal levels of radiation have been found in several US states—including traces in milk in Washington state, the Wall Street Journal reports, and air in Michigan—the amount is so low that it poses no threat to Americans' health, says the Environmental Protection Agency. Even in Tokyo, the risk is fairly minimal, though the situation is rapidly changing, with radioactivity detected in some Japanese foods, including spinach grown 70 miles from the reactor.

How does nuclear radiation affect the body?

2. Full-body airport scanners. These machines use backscatter X-rays, a form of ionizing radiation, to detect hidden weapons and other security threats.

Should you worry? No, because the radiation dose is extremely low. A new study found that airport travelers would have to be scanned more than 50 times to get the same dose as that of one dental X-ray, and be scanned 1,000 times to equal one chest X-ray. The researchers estimate that of the 750 million flights taken per year by 100 million passengers, six additional cancers might occur over a lifetime, compared to the 40 million that would be expected for other reasons, such as smoking.

3. Airplane travel. Surprisingly, flying in an airplane at 30,000 feet actually exposes you to more natural radiation from the atmosphere than you’d get from an airport scanner.

Should you worry? No, because the amount is still very small, says Dr. Amis. “The dose from flying from New York City to Los Angeles is slightly more than the natural radiation you’d be exposed to by living in a high-altitude city, such as Denver, Colorado.”

4. Cell phones and wireless devices. Mobiles and laptops use microwaves, a much less harmful type of radiation than the ionizing rays from scanners.

Should you worry? Maybe. Holding a cell phone next to your head may affect brain activity. However, the study published in JAMA reported that it is unclear what effect the change in brain glucose metabolism has on brain health. The bottom line, says Dr. Amis. “There is no scientific proof linking cell phones to any increased risk for brain cancer or tumors.” Still, it might be prudent to use a headset, rather than pressing your mobile to your ear. Environmental Working Group offers a guide to safer, lower radiation cell phone choices.

5. Mammograms. These X-ray tests use ionizing radiation to image the breast.

Should you worry? No, because the benefits of checking women ages 40 and up to catch breast cancer at an early, treatable stage outweigh the risks of the radiation exposure, which is comparable to four chest X-rays, says Dr. Amis.

6. X-rays and CT scans. There’s a growing movement in medicine to document patients’ “radiation load,” so doctors think twice about ordering another CT scan or annual X-rays for patients who have already had extensive imaging tests using ionizing radiation.

Should you worry? Maybe, since the more radiation exposure you have, the more the health risks rise. If your doctor recommends an X-ray or CT, ask if there is another test, such as ultrasound or a MRI (which don’t involve any radiation) that could be used instead, and if findings from an X-ray test would change your treatment. CT scans emit 100 times more radiation than X-rays, so are riskier. However, having five to 10 CT scans only raises cancer risk slightly, so you shouldn’t shy away from a CT scan if it’s crucial to diagnose a potentially serious medical problem. For more information on radiation exposure from medical test, go to Radiologyinfo.org.

7. Radon. This naturally radioactive gas is found in the basements of many homes, in varying amounts.

Should you worry? Yes, if you live in an area with high levels of radon, which triggers about 20,000 cases of lung cancer a year in nonsmokers. The only way to tell if your home has dangerous levels is by testing your home. To learn more, visit the Environmental Protection Agency website.

By Lisa