Whether you call them cell phones, smart phones or mobile devices, it seems like everyone has one. According to the wireless telecommunications industry, the U.S. now has an estimated 300 million mobile subscribers, compared to 110 million subscribers a decade ago. The increase in cell phone use has generated concern about possible health risks related to radiofrequency electromagnetic fields from this technology, and a market for shields as possible protection against the radio waves the phones emit. The Federal Trade Commission (FTC), the nation's consumer protection agency, has some practical tips to help you avoid scams and limit your exposure to electromagnetic emissions from your cell phone.

While health studies about any relationship between the emissions from cell phones and health problems are ongoing, recent reports from the World Health Organization will no doubt convince scam artists that there's a fast buck to be made. Scam artists follow the headlines to promote products that play off the news – and prey on concerned people.

If you're looking for ways to limit your exposure to the electromagnetic emissions from your cell phone, know that, according to the FTC, there is no scientific proof that so-called shields significantly reduce exposure from these electromagnetic emissions. In fact, products that block only the earpiece – or another small portion of the phone – are totally ineffective because the entire phone emits electromagnetic waves. What's more, these shields may interfere with the phone's signal, cause it to draw even more power to communicate with the base station, and possibly emit more radiation.

To limit your exposure to cell phone electromagnetic emissions, the FTC suggests that you:

• Increase the distance between your phone and your head by using a hands-free device, like an earpiece that is wired to the phone, or using the speakerphone feature.
• Consider texting more and limiting your cell phone use to short conversations.
• Wait for a good signal. When you have a weak signal, your phone works harder, emitting more radiation. Phones also give off more radiation when transmitting than when receiving, so tilt the phone away from your head when you're talking, and bring it back to your ear when you're listening.
• A phone's specific absorption rate (SAR) reveals the maximum amount of radiation the human body absorbs from the phone while it's transmitting. SAR testing ensures that the devices sold in the U.S. comply with the Federal Communications Commission (FCC) SAR exposure limit, but the single, worst-case value obtained from this SAR testing is not necessarily representative of the absorption during actual use, and therefore it is not recommended for comparisons among phones. In short, selecting a lower SAR phone will not reliably ensure lower radiation absorption during use. The FCC has more information at Specific Absorption Rate (SAR) For Cell Phones: What It Means For You.

For more information on cell phone use and health issues, see the National Cancer Institute's fact sheet, Cell Phones and Cancer Risk.

This article was previously available as Listen Up: Tips to Help Avoid Cell Phone Radiation Scams.