• A new review of previous research concludes that radiation from cellphones is not likely to increase a person’s risk of brain cancer.
• Their findings align with studies from the past decade that state that the incidence of brain cancers has not increased despite a large increase in the use of mobile devices.
• Experts say the causes of brain cancer are still somewhat of a mystery, but it appears wireless technology is not a risk factor.

There were concerns once that mobile phones could increase a person’s risk of brain cancer because the devices were held close to the head for extended periods of time. Those fears seem to have been laid to rest by recent research.

The latest evidence comes from a research review commissioned by the World Health Organization (WHO) and recently published in Environment International.

Researchers examined 63 studies completed between 1994 and 2022, including participants in 22 countries. Eleven investigators from nine countries assessed these studies. The researchers looked at the effects of radio frequencies from mobile phones, base stations, transmitters, and occupational exposure.

They focused on cancers in the brains of adults and children as well as cancer of the pituitary gland and salivary glands. The risk of leukemia was also examined.

The researchers reported that despite the large increase in the use of wireless technology in the past two decades, there has not been a corresponding increase in brain cancer. They added the risk assessment includes people who frequently have long phone calls and those who have used mobile devices for more than a decade.

In particular, the researchers said:

• There is “moderate certainty evidence” that radiation from mobile phone use close to the head “likely does not increase the risk” of several nervous systems cancers or childhood brain tumors.
• There is “low certainty evidence” that radiation from cordless phone use near the head “may not increase the risk” of glioma, meningioma, or acoustic neuroma.
• There is “moderate certainty evidence” that whole-body radiation from fixed-site transmitters such as broadcasting antennas or base stations “likely does not increase” the risk of childhood leukemia. There is “low certainty evidence” that this type of radiation “may not increase” the risk of childhood brain tumors.
• There is “low certainty evidence” that occupational radiation exposure “may not increase” the risk of brain cancers.

Wael Harb, MD, a hematologist and medical oncologist at MemorialCare Cancer Institute at Orange Coast and Saddleback Medical Centers in California, says he’s impressed with the findings.

“I find this review to be comprehensive and methodologically sound, adding confidence to the growing body of evidence that RF-EMF exposure from mobile phones is not linked to an increased risk of brain tumors like glioma and meningioma,” Harb told Healthline. “The authors carefully evaluated multiple studies and accounted for potential biases and confounders, making their conclusions more robust. Overall, it aligns with prior findings and provides further reassurance that typical mobile phone use is unlikely to pose a significant cancer risk.”

Naveed Wagle, MD, a neuro-oncologist at the Pacific Neuroscience Institute in Santa Monica, California, and an associate professor of translational neurosciences at Saint John’s Cancer Institute in Santa Monica, agrees this latest review is compelling.

“Much of the data [in the past] has been very small studies and limited tumor types,” Wagle told Healthline. “This study allows for the pooling of these studies to give more robust statistical significance. The lack of [increased] tumor risk see in this data set is further reassurance that radio frequency is not a major risk factor.”

Shifting view on cellphones and cancer risk

As of 2013, radiation from mobile phones is classified as “possibly carcinogenic,” or class 2B, by the International Agency for Research on Cancer (IARC), and that classification hasn’t been reassessed since.

An IARC advisory group is recommending that the classification be re-evaluated as soon as possible.

The latest research review is in line with several past studies, including one from back in 2011, that have stated that radiation from mobile phone use does not increase the risk of brain cancer.

“The consensus among experts has shifted over time,” Harb explained. “Early studies raised concerns about the potential carcinogenic effects of radiofrequency electromagnetic fields (RF-EMF), leading to the classification of mobile phone use as possibly carcinogenic by the IARC. However, more recent and comprehensive research, including this WHO-led review, has found little to no evidence supporting a significant link between RF-EMF exposure and brain cancer. Most experts now agree that the body of evidence suggests no consistent association between mobile phone use and increased risk of brain cancer, particularly given the lack of rise in brain cancer incidence despite the global surge in mobile phone use.”

What to know about radiation and mobile phones

The National Cancer Institute has a fact sheet on cellphones and cancer risk.

In it, they explain that mobile devices emit radiofrequency radiation. The radio waves from a cellphone are considered low-frequency and low-energy. The institute says this low-level type of radiation isn’t capable of damaging DNA and increasing the risk of cancer.

In contrast, x-ray machines, radon, and cosmic rays release ionizing radiation that is considered high frequency and high energy. This type of radiation can damage DNA, potentially causing changes to genes that may increase the risk of cancer.

The institute notes that the incidence rates of brain cancer and other central nervous system cancers have remained relatively stable as the use of mobile phones has increased dramatically.

“Based on the current evidence, there is little reason for concern regarding frequent mobile phone use or living near radio transmission towers,” Harb said. “Multiple large studies have found no consistent link between RF-EMF exposure and brain cancer risk. For those who are still cautious, simple measures like using hands-free devices or limiting prolonged phone calls can be adopted, though they are likely unnecessary. The important thing is to stay informed as new research emerges, but right now the risk appears to be minimal.”

What are the risk factors for brain cancer?

The causes of brain cancer still are mostly a mystery to those in the medical field.

“For most brain cancers, we still do not fully understand the causes,” said Harb. “Some known risk factors include genetic predispositions, family history of brain tumors, and exposure to ionizing radiation (such as radiation therapy for other cancers). Age is also a factor, as brain cancer tends to occur more frequently in older adults. Additionally, inherited conditions like neurofibromatosis can increase risk. While environmental factors, such as exposure to certain chemicals, have been suggested as potential contributors, the evidence is inconclusive.”

Wagle agrees the causes of brain cancer are elusive.

“Most brain tumors are sporadic, meaning not due to a clear cause,” he said. “We still do not fully understand the risk factors that lead to tumor formation. A small but significant portion are due to genetic predisposition. This is typically a family history of a specific tumor type. Another rare but established risk factor is radiation exposure, such as nuclear fallout, radiation therapy.”

Erqi Pollom, MD, an associate professor of radiation oncology at Stanford University in California, points to some potential factors.

“There is no definitive evidence that mobile devices are associated with an increased risk of developing cancer,” Pollom told Healthline. “Known risk factors for developing brain cancer include exposure to ionizing radiation [such as from x-rays], having certain genetic disorders, and being immunocompromised. However, some people may develop brain cancer without having any of these known risk factors.”

Takeaway

Experts say the risk factors and causes of brain cancer remain a mystery to medical professionals.

A new review of previous research concludes that the use of mobile phones is not likely to be a cause of brain tumors or other nervous system cancers.

Researchers say there has not been a corresponding increase in brain cancers as the use of cellphones and other electronic gadgets has dramatically increased.