Questions about whether smartphones and the radio-frequency energy they emit can cause health problems in users were the impetus for an investigation by the Government Accountability Office. What it found was that the Federal Communications Commission's current RF guidance doesn't reflect the latest research and that testing requirements may not identify the possible maximum exposure in some use cases.

GAO now recommends that the FCC "formally reassess and, if appropriate, change its current RF energy exposure limit and mobile phone testing requirements related to likely usage configurations, particularly when phones are held against the body," it wrote in a summary of its July report.

The relationship between the FCC and GAO is apparently as polite as that quote implies, and explains why the FCC is still using guidelines based on 1996 data, while the European Union and other countries have since updated their recommendations to reflect more recent findings. GAO explains in its summary that the no government agency advised the FCC to update its recommendations, and so it didn't, and because the FCC didn't ask to be advised on the matter, it wasn't.

GAO also notes that while federal agencies and the mobile phone industry provide information about the health effects of mobile phone use in device manuals and on their respective Websites, "there are no federal requirements that manufacturers provide information to consumers about the health effects of mobile phone use."

The issue of device RF levels has been a contentious one between politicians and the mobile industry, which has framed it as a nonissue that could make consumers unnecessarily fearful.

Congressman Dennis Kucinich (D-Ohio) was the most recent politician to propose legislation on the issue. On Aug. 6, he introduced a Cell Phone Right to Know Act that requests that a national research program be established to study cell phones' potential effects on users' health, that data be updated about Specific Absorption Rate (SAR)—the amount of RF energy that the body absorbs while using a cell phone—and cell phones carry warning labels that show the device's SAR.

The World Health Organization, in May, put RF electromagnetic fields in a category with lead and mercury, calling them "possibly carcinogenic to humans, based on an increased risk for glioma, a malignant type of brain cancer associated with wireless phone use."

"A labeling law will ensure that cell phone users can decide for themselves the level of risk that they will accept," Kucinich said in a June 30 statement preceding the bill. "Obviously, cell phone companies should not be the ones making that decision for us."

In 2010, the city of San Francisco voted in a favor of a bill requiring retailers to display SAR information beside phones in at least 11-point type. The bill was put on hold, however, after the city was sued by the CTIA, a group that represents the wireless industry.

In response to the GAO report, John Walls, vice president of public affairs for CTIA, said in an Aug. 7 statement that while the group has not yet had a chance to fully review the report, it appreciates the GAO's review of the scientific research in the area.

Walls added, in part, "CTIA continues to defer to the views of scientific experts, federal agencies with expertise and impartial health organizations."

While CTIA and others are nervous about the impact that SAR listings and bills like Kucinich's could have on device sales, the industry has always also known how to make a buck.

At least one app in the Google Play market now takes on the issue. Called Tawkon, it "alerts you when your phone levels spike, and offers tips to help you lower it. Tawkon empowers you to live a healthier lifestyle," says its description in the app store.

A screen shot of the app in action shows it alerting a user: "Radiation exposure warning! Use speaker/handset."

It's advice even the GAO is likely to get behind.

"Some consumers may use mobile phones against the body," says the GAO report, "which FCC does not currently test, and could result in RF energy exposure higher than the FCC limit."