On Friday, a Superior Court judge ordered California to release documents written by the state's Environmental Health Investigations branch that are believed to contain warnings about the risk of cell phone radiation and recommendations aimed to protect public health.

The ruling comes after a lawsuit filed by Joel Moskowitz, the director of the Center for Family and Community Health at UC Berkeley School of Public Health. He sued the state under the California Public Records Act after his request to access the information was denied.

"I would like this document to see the light of day," Moskowitz told KPIX 5, a CBS affiliate in San Francisco, "because it will inform the public that there is concern within the California Department of Public Health that cell phone radiation is a risk and it will provide them with some information about how to reduce those risks."

Moskowitz's concerns are based on new research that suggests a worrisome link between using cell phones regularly for at least a decade and an increased risk of developing brain tumors. He urges cell phone users to limit their physical contact with their mobile devices.

The judge sided with Moskowitz, noting the significant public interest in the DPH's research and public health recommendations based on those findings. The DPH did not immediately comment on the ruling or whether or not it would even release the documents, as state lawyers noted they could appeal the decision.

But the Federal Communications Commission, the governmental agency that oversees the television, radio and telephone industries, wants to reassure the public that the devices are safe.

"The weight of scientific evidence has not effectively linked exposure to radio frequency energy from mobile devices with any known health problems," the FCC maintains. "Some health and safety interest groups have interpreted certain reports to suggest that wireless device use may be linked to cancer and other illnesses, posing potentially greater risks for children than adults. While these assertions have gained increased public attention, currently no scientific evidence establishes a causal link between wireless device use and cancer or other illnesses."

It should be noted that the federal government hasn't developed a national standard for safe RF energy exposure levels, relying instead on non-governmental experts, like the Institute of Electrical and Electronics Engineers and the National Council on Radiation Protection and Measurements, to establish such guidelines. For exposure to RF energy from wireless devices, the allowable FCC Specific Absorption Rate (SAR) limit is 1.6 watts per kilogram (W/kg), as averaged over one gram of tissue. The FCC states, "All wireless devices sold in the U.S. go through a formal FCC approval process to ensure that they do not exceed the maximum allowable SAR level when operating at the device's highest possible power level." The regulation has been in place since 1996.

RF energy, which contains both electric and magnetic energy, is used to provide service not only for cell phones, but to a wide range of telecommunications services, including radio and television broadcasting and satellite communications. But cell phones, which first became widely available in the 1980s and were common by the late '90s, represent the first time humans are regularly exposed to RF energy by devices that are touching or kept close to their bodies for many hours every single day. In 2012, the Italian Supreme Court ruled that a man's cell phone was the cause of his tumor, which grew close to where his cell phone touched his head. The ruling followed a tentative warning issued the previous year by the World Health Organization saying that cell phone usage may cause the development of glioma, a type of tumor that starts in the brain or spine.

Still, public health concerns haven't hindered sales in mobile devices: In the third quarter of 2016, worldwide smartphone shipments totaled more than 363 million, growing the market by more than 5 percent over the previous quarter, according to International Data Corporation, a market intelligence firm. Many of those phones were shipped to the U.S.: A 2013 Pew Research study found that 91 percent of Americans use cell phones. If a conclusive link can be made between long-term cell phone usage and cancer risk, the widespread use of such devices poses a massive public health problem.

Scientists are trying hard to figure it out. Last year, federal researchers at the National Toxicology Program, an interagency group under the National Institutes of Health, released partial findings from a $25 million study that subjected thousands of rats to a lifetime of electromagnetic radiation that attempted to emulate the regular use of cell phones by humans. The rats in the study developed rare cancers in at least two types of cells in their brains and hearts. While some public health advocates may point to this study in an effort to improve regulation of cell phone radiation exposure, scientists have still been unable to establish a conclusive link between cell phone radiation and cancer in humans, and there are fundamental concerns about translating findings from animal experiments to humans.

Many scientists are hesitant to support findings in animal studies, arguing that they are not good predictors of human reactions. In a 2008 paper, Michael B. Bracken, co-director of the Center for Perinatal, Pediatric and Environmental Epidemiology at the Yale University Schools of Medicine and Public Health, explained the problem:

One reason why animal experiments often do not translate into replications in human trials or into cancer chemoprevention is that many animal experiments are poorly designed, conducted and analyzed. Another possible contribution to failure to replicate the results of animal research in humans is that reviews and summaries of evidence from animal research are methodologically inadequate.…The few systematic reviews of the animal literature that have been done also pointed to the poor quality of other animal research, and the difficulty of extrapolating from it to humans.

Even if animal experiments are well designed, there's still the issue of different biological responses.

"The use of animals as stand-ins for humans can give rise to misleading results because of the intrinsic differences between humans and other species," according to the National Anti-Vivisection Society, a nonprofit advocating the end of animal testing. "Human disease and human response to drugs and other chemicals should be studied in human-relevant systems….the differences between other species and humans make translating data from animals to people problematic."

The group points out that just because humans share genetic material with other species doesn't mean their genes are similarly expressed. "This explains why 150 drugs that successfully treated sepsis-like conditions in mice failed in human clinical trials," they say.

Even the scientists behind the major federal study weren't able conclusively to connect the rats' tumors to radiation exposure, with John Bucher, the associate director of the NTP, saying the tumors are "likely related to the exposures." Ultimately, a long-term cohort study on thousands of human subjects may provide better clinical results, but there's no single test for carcinogens, and it would be extremely difficult, perhaps impossible, to isolate cell phone radiation from all the other carcinogenic substances the human test participants would be exposed to on a daily basis.

In 2011, Siddhartha Mukherjee, a cancer expert who teaches medicine at Columbia University, addressed the limits of a population-wide survey of cell phone users. "The carcinogenic effect of a phone might be so subtle that it never registers in such a survey," he wrote in the New York Times. "A phone may cause cancer after a long lag time—say, 20 years—and it may be too early to look for an effect in a general population. The survey data could be incomplete or of poor quality, thus limiting an epidemiologist’s ability to ever find a discernible link."

While the inability to establish a conclusive link between cell phones and cancer is vexing not only to scientists, but for public health advocates who have lodged concerns, mobile companies are happy that we remain in the dark on the issue. CTIA, the Wireless Association, an advocacy group representing the wireless communication industry, has been trying to overturn a new Berkeley city law that requires cell phone retailers to provide consumers with a warning about cell phone use. The notice says, in part, "if you carry or use your phone in a pants or shirt pocket or tucked into a bra when the phone is on and connected to a wireless network, you may exceed the federal guidelines for exposure to RF radiation."

By attempting to suppress the Department of Public Health's document, California appears to be siding with the mobile industry.

"They claim that [releasing the papers] would lead to chaos and confusion among the public," said Moskowitz. "I suspect that they were afraid of the reaction from the telecommunications industry should they publish this document. In fact, they even argued that in their brief."

Considering the frustratingly inconclusive research on the subject, it's unlikely that the California health department's papers reveal anything new. But Moskowitz believes that Friday's ruling will, at the very least, help create more public awareness about a possible health risk that could impact as many as 9 out of 10 Americans. For now, it's probably a good idea to keep your cell phone away from your body when you're not using it.