It’s also possible that longer-term studies and cancer incidence tracking will find larger cancer effects in another five or 10 years — or that how we use cellphones is evolving such that the devices may cause cancer in ways these studies didn’t account for. (These days, many people text instead of talking, and hold their cellphones in their pockets but not on their heads and necks.) That’s why some people look to animal studies to supplement our understanding of the potential biological effects of cellphones.
The effect of mobile phone radiation on human health is a subject of interest and study worldwide, as a result of the enormous increase in mobile phone usage throughout the world. As of 2015, there were 7.4 billion subscriptions worldwide, though the actual number of users is lower as many users own more than one mobile phone. Mobile phones use electromagnetic radiation in the microwave range (450–3800 MHz and 24-80GHz in 5G mobile). Other digital wireless systems, such as data communication networks, produce similar radiation.
Unfortunately, however, we’ll probably never have an RCT on cellphones and cancer in humans. It’d be too difficult and too expensive to randomly assign particular levels of cellphone use to thousands of people and have them stick with those plans for enough time (we’re talking at least five years) to figure out whether certain types of phones or phone use patterns cause cancer to develop. That’s not to mention the fact it’d be nearly impossible to find a group of people willing to not use cellphones and then make sure they actually stick to their promise.
Also noteworthy is that the studies evaluated radiation exposures in different ways. The NTP looked at “near-field” exposures, which approximate how people are dosed while using cell phones. Ramazzini researchers looked at “far-field” exposures, which approximate the wireless RF radiation that bombards us from sources all around us, including wireless devices such as tablet and laptop computers. Yet they generated comparable results: Male rats in both studies (but not mice or female animals) developed schwannomas of the heart at statistically higher rates than control animals that were not exposed.
We tested the garments in a similar setup with the fabric between the phone and the meters. We also tested the garments while sitting on a couch, holding the Gigahertz Solutions monitor against my pregnant belly under the product (blanket/nursing cover) and measuring the reduction of the RF from my cellphone in my hand at normal texting/web-surfing distance.
An analysis of an "eagerly anticipated" study using rats and mice by the National Toxicology Program indicates that due such issues as the inconsistent appearances of "signals for harm" within and across species and the increased chances of false positives due to the multiplicity of tests, the positive results seen are more likely due to random chance. The full results of the study were released in February 2018.
Some people might consider choosing a phone with a low SAR value. Different models of phones can give off different levels of RF waves. But as noted above, according to the FCC the SAR value is not always a good indicator of a person’s exposure to RF waves during normal cell phone use. One way to get information on the SAR level for a specific phone model is to visit the phone maker’s website. The FCC has links to some of these sites here: www.fcc.gov/encyclopedia/specific-absorption-rate-sar-cellular-telephones. If you know the FCC identification (ID) number for a phone model (which can often be found somewhere on the phone or in the user manual), you can also go to the following web address: www.fcc.gov/oet/ea/fccid. On this page, you will see instructions for entering the FCC ID number.
Pong’s research indicates that badly designed cell phone cases can partially block a phone’s antenna, making the device work harder to transmit signals. Due to gaps in the FCC’s cell phone regulations, a phone worn right next to the body and enclosed by a case that obstructs the antenna could expose the user to more radiation than the FCC’s legal limit.
Peer review is a vital part of any scientific study; it brings several more lifetimes of expertise into the room to rigorously check a study for any weak points. Melnick calls the peer reviewers’ choice to change some conclusions an unusual move; “It’s quite uncommon that the peer review panel changes the final determination,” he says, noting if anything, he’s seen peer reviewers downgrade findings, not upgrade them. “Typically when NTP presents their findings, the peer review almost in all cases goes along with that.” In this case, the peer reviewers felt the data—when combined with their knowledge of the cancers and with the study design itself—was significant enough to upgrade several of the findings.
The International Agency for Research on Cancer (IARC) is part of the World Health Organization (WHO). Its major goal is to identify causes of cancer. The IARC has classified RF fields as “possibly carcinogenic to humans,” based on limited evidence of a possible increase in risk for brain tumors among cell phone users, and inadequate evidence for other types of cancer. (For more information on the IARC classification system, see Known and Probable Human Carcinogens.)
Changing technology and methods of use. Older studies evaluated radiofrequency radiation exposure from analog cell phones. Today, cell phones use digital technology, which operates at a different frequency and a lower power level than analog phones. Digital cell phones have been in use for more than two decades in the United States, and cellular technology continues to change (3). Texting and other applications, for example, are common uses of cell phones that do not require bringing the phone close to the head. Furthermore, the use of hands-free technology, such as wired and wireless headsets, is increasing and may reduce exposure by distancing the phone from the body (36, 37).
Radiofrequency radiation is a form of electromagnetic radiation. Electromagnetic radiation can be categorized into two types: ionizing (e.g., x-rays, radon, and cosmic rays) and non-ionizing (e.g., radiofrequency and extremely low frequency, or power frequency). Electromagnetic radiation is defined according to its wavelength and frequency, which is the number of cycles of a wave that pass a reference point per second. Electromagnetic frequencies are described in units called hertz (Hz).