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 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)


Other notables, from lowest to highest

HTC Touch Pro (0.91 W/kg)
Palm Pre (0.92 W/kg)
iPhone (0.97 W/kg)
Samsung JACK i637 (1.04 W/kg)
T-Mobile’s Google G1 (1.11 W/kg)
Blackberry Pearl Flip 8220 (1.14 W/kg)
iPhone 3GS (1.19 W/kg)
Samsung BlackJack II SGH-i617 (1.20 W/kg)
Motorola MOTO Q 9m (1.30 W/kg)
iPhone 3G (1.39 W/kg)
BlackBerry Tour 9630 (unknown)