Mobile Phones and Cancer Risk

Daniel Martin
oncologist viewing x ray

Since the invention of cell phones in 1974, people have spent ever increasing amounts of time with their devices. There is conflicting scientific opinion on whether exposure to cell phone radiation increases the risk of developing cancer. Given this uncertainty, many individuals are wondering what the facts are and what they can do to reduce their exposure.

Cell Phone Radiation and Its Effects

The power of electromagnetic energy is defined by frequency. High energy radiation like radon, cosmic rays and x-rays are ionizing radiation, which can cause cancer. Low frequency radiation, such as electromagnetic fields and visible light, are non-ionizing and not known to cause cancer. Cell phones make use of electromagnetic radiation known as radio-frequency (RF) energy, a non-ionizing radiation that is also used in telecommunications like television and radio.

When studying the impact of cell phone radiation on humans, the only regularly observed effect is the heating of tissues. There have also been no notable increases in developing cancer or enhancing carcinogenic effects observed in animal studies. The National Institute of Environmental Health Sciences (NIEHS) investigated the effects of cell phone radiation on rodents in a large-scale study. While they are completing their data review, they released their preliminary findings in May 2016 showing limited evidence of RF causing cancer in rats.

Cell Towers and Exposure Risks

People who live, work and attend school near cell towers may worry that such proximity will increase their risk of cancer. There is little data to back up this idea and there are several points that would argue against it.

  • GSM Antenna
    Radio-frequency (RF) energy waves given off by cell towers do not contain enough energy to damage DNA molecules, which is how strong radiation like gamma rays and UV light causes cancer.
  • RF waves also have a long wavelength which can only focus on a one to two-inch area, making it unlikely they could affect individual cells.
  • Energy levels near RF towers are well below recommended limits and no different from background radiation produced by radio and television broadcasts.

In a British study, researchers compared over 1,000 families with child cancer patients against a control group without cancer. Based on the distance from homes to towers and energy given off, there was no link found between RF exposure during pregnancy and early childhood cancer risk. Another study for the Journal of Genetic Counseling looked for damaged blood cells and DNA as indicators of damage. Their results show that damage in those who lived near cell phone towers was no worse than those who didn't.

Cell Phone Usage and Cancer

There have been many types of epidemiologic studies into whether cell phone use is linked to increased risk of malignant brain tumors. In the largest ever case-control study by Interphone, researchers from 13 countries collaborated to examine any potential links between cell phones and developing head and neck cancer.

  • Most analyses showed no significant increase in cancer related to higher phone use.
  • One analysis showed a modest increase in risk of gliomas in most frequent phone users. However, this finding was dismissed after finding that moderate phone users were at lower cancer risk than non-users.

Other significant, smaller epidemiologic studies have also been conducted in search of cancer caused by phone usage.

  • Brain Damage from using mobile phone
    A Swedish case-study showed no increased risk of cancer among long term phone users between the ages of 20 and 69.
  • Brain cancer patients between age 7 and 19 in Denmark, Norway, Switzerland and Sweden showed no correlation between cell phone use and risk of cancer.
  • A French study showed no association for glioma or meningiomas comparing regular phone users and non-users. However, they did find that the most frequent cell phone users were significantly more at risk.

Reasons for Inconsistent Findings

While the general scientific consensus is that cell phone use does not significantly impact cancer risk, some studies appear to show statistical association. There are several potential reasons for these data discrepancies.

  • Participation bias: Individuals with cancer are more likely to participate in these research studies. Control subjects who do not use or rarely use cell phones are less likely to join.
  • Usage methods and changing technology: Original studies into cell phones looked into exposure from analog cell phones, but digital phones operate at lower frequencies and power. Texting, hands free technology and wired/wireless headsets have become increasingly popular and don't require being close to the head.
  • Recall bias: When data is collected from individuals after they have been diagnosed with cancer, they may remember their cell phone usage differently than healthy subjects. Most people who develop tumors recall more cell phone use on the side of the head where the tumor was discovered, regardless of whether they normally used that side of their head.

Reducing Exposure to RF Energy

While the link between RF waves and cancer is not well established, there are several things that can be done to reduce the risks.

  • Use speaker mode or an earpiece: Moving the phone's RF antenna away from your head will reduce the amount of wave that can reach it. Wired earpieces emit almost no RF waves though the phone can still send small amounts of waves at the waist or in the pocket. Bluetooth earpieces are even better with less than 1/1,000th of the specific absorption rates (SAR) set by the FCC and FDA.
  • Choose a low SAR phone: Different phone models give off different SAR levels, though SAR value on its own is not a foolproof method of indicating user exposure. If you know the FCC ID number of your phone's model, which can be found in user manuals or on the phone itself, you can look up its SAR value on the FCC website. The FCC also provides links to SAR information for several phone makers.

Scant Evidence

On the face of it, there is little scientific proof to demonstrate a causal link between cellphone or cell tower exposure and increased risk of cancer. This is an ever-developing area of scientific research and barring future data which shows otherwise, you shouldn't worry about RF wave exposure. For those who are still concerned about cancer risk, the methods and options outlined above can reduce any potential risk. If you are ever unsure about worries or symptoms, consult with a medical professional.

Mobile Phones and Cancer Risk