One of the scariest unknown technology risks of this decade is the issue of radiation from cell phones. There's still an open question about whether long term exposure to these mobile devices will cause damage or disease to human beings.
The Environmental Working Group has a comprehensive new study (download the full report as a PDF) that surveys the scientific research on cellphone heath risks and provides radiation data for most of the current cellphones in use. Here's how the EWG explained the mission of its study:
We at Environmental Working Group are still using our cell phones, but we also believe that until scientists know much more about cell phone radiation, it's smart for consumers to buy phones with the lowest emissions. The U.S. government ought to require cell phone companies to label their products' radiation output so that consumers can do the numbers at the point of sale. It doesn't, so EWG has created this user-friendly interactive online guide to cell phone emissions, covering over 1,000 phones currently on the market.
The EWG study looks at all mobile phones, but since smartphones are becoming a standard tool for businesses and IT professionals, I've drilled down and looked at the list from a smartphone perspective. I've broken out the 10 smartphones that produce the most radiation, the 10 that product the least amount of radiation, and a list of the radiation ratings of some of the most popular smartphones that did not make either of those two lists.
When you look at these lists, keep in mind that the EWG has also included some older models that are no longer being sold but are still used by many workers and consumers. Also note that "W/kg" stands for watts per kilogram, a measurement for power density.
The 10 smartphones with the highest radiation
- T-Mobile MyTouch 3G (1.55 W/kg)
- Blackberry Curve 8330 (1.54 W/kg)
- Palm Treo 600 (1.53 W/kg)
- T-Mobile Shadow (1.53 W/kg)
- Palm Treo 650 (1.51 W/kg)
- Blackberry Curve 8300 (1.51 W/kg)
- Blackberry Bold 9000 (1.51 W/kg)
- Sony Ericsson P910a (1.50 W/kg)
- HTC SMT 5800 (1.49 W/kg)
- BlackBerry Pearl 8120/8130 (1.48 W/kg)
The T-Mobile MyTouch 3G, an HTC smartphone powered by Google Android that debuted to lots of fanfare this summer, topped the list of the worst radiation offenders. However, other popular smartphones dominated the list as well, especially BlackBerries and Treos. The BlackBerry Curve, the best-selling smartphone on the market in 2009, was a close second on the list, and it was joined in the top 10 by its cousins, the BlackBerry Pearl and the BlackBerry Bold.
The 10 smartphones with lowest radiation
- Nokia 9300i (0.21 W/kg)
- Nokia 7710 (0.22 W/kg)
- T-Mobile MDA Wiza200 (0.28 W/kg)
- Samsung Impression SGH-a877 (0.35 W/kg)
- Nokia 9300 (0.44 W/kg)
- Samsung Propel Pro SGH-i627 (0.47 W/kg)
- Samsung Gravity SGH-t459 (0.49 W/kg)
- BlackBerry Storm 9530 (0.57 W/kg)
- Nokia E90 (0.59 W/kg)
- Nokia N96 (0.68 W/kg)
Nokia, with five models in this top 10, and Samsung with three, were clearly the winners in terms of smartphones that emit the least amount of radiation. It's also interesting to note that although both of these companies produce dozens of different models, neither of them had a single model that made the list of the worst radiation offenders. The surprising member of the low-radiation club was the BlackBerry Storm (RIM's first touchscreen device) since so many of the other popular BlackBerries were on the high-emitters list.
Other notables, from lowest to highest
If there's another phone you'd like to look up, here is the full list. Also, when seriously evaluating any smartphone on any of these lists, make sure you click through and look at the EWG page with the details of the phone's radiation emissions using different connections and doing different activities. The number listed is the maximum radiation rating, but it can be deceiving in some cases until you look at the whole picture.
For example, the iPhone 3GS has a rating of 1.19 W/kg, which is a middle-of-the-pack rating. However, 1.19 is its maximum radiation level, which only happens when it is connected in UMTS 1900MHz mode. In its other four modes, it averages 0.63 W/kg, which is more consistent with the lower tier of radiation emitters.
As part of the report, the EWG also provided eight safety tips
for cellphone users who are concerned about radiation. Here is a quick list of the tips. You can click through to the original list for more detail on each of the items.
- Buy a low-radiation phone
- Use a headset or speaker
- Listen more, talk less
- Hold phone away from your body
- Choose texting over talking
- Poor signal? Stay off the phone
- Limit children's phone use
- Skip the "radiation shield"
The EWG also offers a one-page PDF that lists all eight of these tips along with a further explanation of each. IT professionals might consider distributing this PDF to employees who use company cellphones or posting it on the corporate intranet. Of course, you should consult senior management and your legal department before distributing something like this since it involves employee health.
See also: Are cell phones safe? Researchers still uncertain (CNET)
While there isn't conclusive scientific evidence proving that cellphones cause illnesses or diseases in humans, the EWG report does point to research that has shown links between prolonged cellphone use and brain cancer, salivary gland tumors, migraines and vertigo, and decreased male sperm count (from carrying a cellphone in the pocket).
A lot more research still needs to be done, but in the meantime it makes sense for mobile manufacturers to limit cellphone radiation whenever possible and for users to be aware of which phones produce the most radiation so that they can take steps to limit radiation exposure as a precautionary step.
UPDATE 09/14/2009, 9:00 AM EST: I got a note from Daniel Van Hoy, a broadcast engineer, who wrote, "There is a big difference between 'ionizing' and 'non-ionizing' radiation... Cell phones, radios and TV transmissions emit non-ionizing radiation that has a longer wavelength, lower frequency and lower overall energy per photon than UV light, X-rays and gamma rays (a form of radioactivity), which are known as ionizing radiation because they have enough power to eject an electron from its orbit and leave behind a charged ion that can damage cells and tissues." I verified this information to be correct. There's also more on ionizing vs. non-ionizing radiation from the U.S. EPA.