Though some findings were reassuring, others do raise concerns. Specifically, three of the studies—one from Sweden, another from France, and a third that combined data from 13 countries—suggest a connection between heavy cell-phone use and gliomas, tumors that are usually cancerous and often deadly. One of those studies also hinted at a link between cell phones and acoustic neuromas (noncancerous tumors), and two studies hinted at meningiomas, a relatively common but usually not deadly brain tumor.
That’s why randomized controlled trials (RCTs) often yield fairly clear answers about the effectiveness of treatments compared to other study designs. (Fun fact: Scottish doctor James Lind, a clinical trial pioneer, figured out that citrus fruits seemed to have an effect on scurvy using one of the earliest RCTs.) RCTs can also be used to study whether something, like cellphone radiation, can cause disease.
(Some common flaws in these studies: The summaries of the evidence weren’t comprehensive, the researchers often didn’t look at the quality of the studies they found, and they failed to do other simple things that would limit bias from creeping in. They also relied on case-control studies, a poor method to determine causality — more on that soon.) So we didn’t include these eight reviews in our analysis.
While an increased risk of brain tumours from the use of mobile phones is not established, the increasing use of mobile phones and the lack of data for mobile phone use over time periods longer than 15 years warrant further research of mobile phone use and brain cancer risk. In particular, with the recent popularity of mobile phone use among younger people, potentially longer lifetime of exposure, WHO has promoted further research on this group and is currently assessing the health impact of RF fields on all studied endpoints. A cohort study in Denmark linked billing information from more than 358,000 cell phone subscribers with brain tumour incidence data from the Danish Cancer Registry. The analyses found no association between cell phone use and the incidence of glioma, meningioma, or acoustic neuroma, even among people who had been cell phone subscribers for 13 or more years. (4)
The tricky part about measuring the radiation from a cell phone is that the emission strength varies widely over time. There will be strong bursts of varying intensity, followed by quiet periods. This makes it hard to compare "apples to apples". Also, because you are measuring up close to the source, you must use a near field meter AND you must maintain the position of the meter very precisely.
Nice quality vinyl bumper sticker is a not-so-gentle reminder to fellow motorists of the one of the many dangers of cellphone use: distraction! If you ever get the chance, you can also explain the other hazards as well: reaction time, increased permeability of the blood-brain barrier, and possibly brain tumors. Good for cars, trucks, bikes, skates and just about any other moving vehicle.
The NTP studied radiofrequency radiation (2G and 3G frequencies) in rats and mice (33, 34). This large project was conducted in highly specialized labs that specified and controlled sources of radiation and measured their effects. The rodents experienced whole-body exposures of 3, 6, or 9 watts per kilogram of body weight for 5 or 7 days per week for 18 hours per day in cycles of 10 minutes on, 10 minutes off. A research overview of the rodent studies, with links to the peer-review summary, is available on NTP website. The primary outcomes observed were a small number of cancers of Schwann cells in the heart and non-cancerous changes (hyperplasia) in the same tissues for male rats, but not female rats, nor in mice overall.
I can’t count how many times I’ve heard people speculate, joke, or jokingly speculate that their cellphone might be giving them cancer. It comes from a very reasonable place of discomfort — few people understand how radiation works, we put our phones right beside our brains all the time, and technology in general often feels like it ought to be causing some sort of societal ill.
In 2011, the American Cancer Society (ACS) stated that the IARC classification means that there could be some cancer risk associated with radiofrequency radiation, but the evidence is not strong enough to be considered causal and needs to be investigated further. Individuals who are concerned about radiofrequency radiation exposure can limit their exposure, including using an ear piece and limiting cell phone use, particularly among children.
This 2017 review, published in Neurological Sciences, looked at case-control studies on cellphone use, focusing on glioma, meningioma, and acoustic neuromas. This review was interesting because the researchers divided the studies by quality, and higher-quality studies — which tended to be funded by the government and not the cellphone industry — showed a trend toward an increased risk of brain tumors, while lower-quality studies did not. Overall, though, their meta-analysis found an increased risk of brain cancers (mostly gliomas) among people who were using cellphones for 10 or more years, and no increase in the risk of acoustic neuroma.
We are often asked why we don't carry the chips, neutralizers, cutesy bugs, and some other cellphone radiation products that are so heavily marketed on the internet. Our answer is simple and honest: our criteria for including a product in our catalog is that it does what we say it does, and its effectiveness can be demonstrated with an appropriate meter.
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.)
If you're looking for ways to limit your exposure to the electromagnetic emissions from your cell phone, know that, according to the FTC, there is no scientific proof that so-called shields significantly reduce exposure from these electromagnetic emissions. In fact, products that block only the earpiece – or another small portion of the phone – are totally ineffective because the entire phone emits electromagnetic waves. What's more, these shields may interfere with the phone's signal, cause it to draw even more power to communicate with the base station, and possibly emit more radiation.
Over time, the number of cell phone calls per day, the length of each call, and the amount of time people use cell phones have increased. Because of changes in cell phone technology and increases in the number of base stations for transmitting wireless signals, the exposure from cell phone use—power output—has changed, mostly lowered, in many regions of the United States (1).