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Understanding the differences between non-ionizing and ionizing radiation.

*Disclaimer* Moffitt Cancer Center was not involved in the research referenced in this story. Moffitt Cancer Center is solely providing perspective on this area of study.

Cellphones and cancer - a new study or headline seems to pop up in the news all too frequently. Why? Because they emit radiation. Radiation is energy that travels through space in the form of invisible rays, waves or particles too small to see. It occurs in varying levels of power, organized on the electromagnetic spectrum. When comparing the power of radiation emitted by cell phones in relation to other household items, the levels emitted are quite low. You can see in the graphic below that less powerful (or lower-frequency) types of radiation are on the left, moving to the more powerful (or higher-frequency) types of radiation on the right.

Understanding the differences between non-ionizing and ionizing radiation

Radiation produced by X-rays and ultraviolet light – called ionizing radiation - is known to carry enough energy to cause cellular and DNA damage that can lead to cancer. Non-ionizing radiation emitted by cellphones, cellphone towers, Wi-Fi routers, radios, microwaves and other common sources is widely believed to be harmless due to its lack of potency.  It’s interesting to note that cell phones, which are the subject of most news stories related to potential health effects, emit less radiation than other common household items like your microwave or TV remote controls.

One concern about the latest research findings is that, contrary to popular belief, some evidence suggests that non-ionizing radiation may have sufficient potency to cause biological changes that may lead to tumor development in animals. As of yet, there is no evidence to suggest a similar effect in humans.

However, it’s important to understand that some of this research is inherently flawed. For instance, many studies are funded by the cellphone industry, which strongly suggests the possibility of bias. Also, there is a general lack of randomized controlled trials. It would be difficult and expensive to randomly assign specific levels of non-ionizing radiation use to thousands of study participants for at least five years (and to find enough participants who would be willing to adhere to such restrictions). This would be necessary in order to perform a randomized controlled trial that would yield clear and reliable answers.

Still, while animal studies have yielded mixed conclusions about non-ionizing radiation and brain tumors, the highest-quality human studies performed to date have consistently shown no correlation between non-ionizing radiation and cancer risk.

There are simple things you can do to reduce your exposure

Until better information becomes available, you may want to take some steps to reduce your exposure to non-ionizing radiation. For instance, don’t carry your cellphone in a pocket or otherwise wear it on your body, use a wired earpiece rather than holding your cellphone to your ear and don’t sleep with your cellphone next to your pillow.