i would like to ask if is it possible to get brain tumors or any health risk if i sleep beside a "powerful" WiFi router(eg. Asus RT-AC5300)?

Googled around and found that some people say it's totally fine and some are saying to not sleep beside it...

1 Answer 1


There has been an ongoing debate regarding health risks from the electromagnetic fields being emitted from WiFi routers. The constant radiation exposure is arguably dangerous at close distances and may contribute to serious health issues, especially with long-term “chronic” exposure.

In 2011, the World Health Organization classified radiofrequency electromagnetic fields as “possibly carcinogenic to humans” based on an increased risk for glioma, a malignant type of brain cancer, associated with wireless phone use.

The potential for adverse health effects resulting from exposure to radiofrequency electromagnetic fields, such as those emitted by wireless communication devices, are detailed in a 2011 World Health Organization press release titled, 'IARC Classifies Radiofrequency Electromagnetic Fields as Possibly Carcinogenic to Humans'.

From May 24-31 2011, a Working Group of 31 scientists from 14 countries has been meeting at IARC in Lyon, France to assess the potential carcinogenic hazards from exposure to radiofrequency electromagnetic fields. These assessments will be published as Volume 102 of the IARC Monographs, which will be the fifth volume in this series to focus on physical agents, after Volume 55 (Solar Radiation), Volume 75 and Volume 78 on ionizing radiation (X-rays, gamma-rays, neutrons, radio-nuclides), and Volume 80 on non-ionizing radiation (extremely low-frequency electromagnetic fields).

The IARC Monograph Working Group discussed the possibility that these exposures could induce long-term effects, in particular an increased risk for cancer. The exposure categories involving radiofrequency electromagnetic fields that were discussed and evaluated included:

…occupational exposures to radar and microwaves; environmental exposures associated with transmission of signals for radio, television and wireless telecommunication; and personal exposures associated with the use of wireless telephones.

International experts shared the complex task of tackling the exposure data, the studies of cancer in humans, the studies of cancer in experimental animals, and the mechanistic and other relevant data.


The evidence was reviewed critically, and overall evaluated as being limited* among users of wireless telephones for glioma and acoustic neuroma, and inadequate** to draw conclusions for other types of cancers. The evidence from the occupational and environmental exposures mentioned above was similarly judged inadequate. The Working Group did not quantitate the risk; however, one study of past cell phone use (up to the year 2004), showed a 40% increased risk for gliomas in the highest category of heavy users (reported average: 30 minutes per day over a 10‐year period)

*'Limited evidence of carcinogenicity': A positive association has been observed between exposure to the agent and cancer for which a causal interpretation is considered by the Working Group to be credible, but chance, bias or confounding could not be ruled out with reasonable confidence.

**'Inadequate evidence of carcinogenicity': The available studies are of insufficient quality, consistency or statistical power to permit a conclusion regarding the presence or absence of a causal association between exposure and cancer, or no data on cancer in humans are available.

Dr. Jonathan Same (University of Southern California, USA) and overall Chairman of the Working Group, suggested that

“…the evidence, while still accumulating, is strong enough to support a conclusion... The conclusion means that there could be some risk, and therefore we need to keep a close watch for a link between cell phones and cancer risk.”

The IARC Director, Christopher Wild added,

”Given the potential consequences for public health of this classification and findings, it is important that additional research be conducted into the long term, heavy use of mobile phones. Pending the availability of such information, it is important to take pragmatic measures to reduce exposure such as hands-free devices or texting

Several scientific articles resulting from the Interphone study were made available to the working group and were included in the evaluation.

One of the scientific articles, ’Acoustic neuroma risk in relation to mobile telephone use: results of the INTERPHONE international case-control study.’ determined that

There was no increase in risk of acoustic neuroma with ever regular use of a mobile phone or for users who began regular use 10 years or more before the reference date. Elevated odds ratios observed at the highest level of cumulative call time could be due to chance, reporting bias or a causal effect. As acoustic neuroma is usually a slowly growing tumour, the interval between introduction of mobile phones and occurrence of the tumour might have been too short to observe an effect, if there is one.

A second scientific article also included in the evaluation, ‘Estimation of RF energy absorbed in the brain from mobile phones in the Interphone Study,’ explained

While amount and duration of use are important determinants of RF dose in the brain, their impact can be substantially modified by communication system, frequency band and location in the brain. It is important to take these into account in analyses of risk of brain tumors from RF exposure from mobile phones.

The Federal Communications Commission (FCC) issued a guide on Wireless Devices and Health Concerns addresses the topic of RF exposure.

...the Federal Communications Commission, federal health and safety agencies such as the Environmental Protection Agency (EPA), the Food and Drug Administration (FDA), the National Institute for Occupational Safety and Health (NIOSH) and the Occupational Safety and Health Administration (OSHA) have been actively involved in monitoring and investigating issues related to RF exposure. For example, the FDA has issued guidelines for safe RF emission levels from microwave ovens, and it continues to monitor exposure issues related to the use of certain RF devices such as cellular telephones. NIOSH conducts investigations and health hazard assessments related to occupational RF exposure.

Federal, state and local government agencies and other organizations have generally relied on RF exposure standards developed by expert non-government organizations such as the Institute of Electrical and Electronics Engineers (IEEE) and the National Council on Radiation Protection and Measurements (NCRP).

Since 1996, the FCC has required that all wireless communications devices sold in the United States meet its minimum guidelines for safe human exposure to radiofrequency (RF) energy.

The FCC’s guidelines and rules regarding RF exposure

...are based upon standards developed by IEEE and NCRP and input from other federal agencies...

These guidelines specify exposure limits for hand-held wireless devices determined by the Specific Absorption Rate (SAR).

The SAR is a measure of the rate that RF energy is absorbed by the body. For exposure to RF energy from wireless devices, the allowable FCC SAR limit is 1.6 watts per kilogram (W/kg), as averaged over one gram of tissue.

As of 1996, the FCC has required that

...all wireless devices sold in the US 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.

Several US government agencies and international organizations work cooperatively to monitor research on the health effects of RF exposure.

According to the FDA and the World Health Organization (WHO), among other organizations, to date, the weight of scientific evidence has not effectively linked exposure to radio frequency energy from mobile devices with any known health problems.

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.

Although no scientific evidence currently establishes a direct link between wireless device use and cancer (or other illnesses), some consumers are skeptical of the science and analysis that underlies the FCC’s RF exposure guidelines. Thus, some parties recommend taking precautionary measures to further reduce exposure to RF energy. 

The FCC does not endorse the need for these practices, but provides information on steps you can take to reduce your exposure to RF energy from cell phones. For example,

...wireless devices only emit RF energy when you are using them and, the closer the device is to you, the more energy you will absorb.

Some of the FCC's suggested measures to reduce RF exposure include the following:

  • Use a speakerphone, earpiece or headset to reduce proximity to the head (and thus exposure). While wired earpieces may conduct some energy to the head and wireless earpieces also emit a small amount of RF energy, both wired and wireless earpieces remove the greatest source of RF energy (the cell phone) from proximity to the head and thus can greatly reduce total exposure to the head.
  • Increase the distance between wireless devices and your body.
  • Consider texting rather than talking - but don’t text while you are driving.

Although potentially misleading, some parties recommend considering reported SAR values of wireless devices.

First, the actual SAR varies considerably depending upon the conditions of use. The SAR value used for FCC approval does not account for the multitude of measurements taken during the testing. Moreover, cell phones constantly vary their power to operate at the minimum power necessary for communications; operation at maximum power occurs infrequently.

Second, the reported highest SAR values of wireless devices do not necessarily indicate that a user is exposed to more or less RF energy from one cell phone than from another during normal use

For additional information, see SAR and cell phones.

Third, the variation in SAR from one mobile device to the next is relatively small compared to the reduction that can be achieved by the measures described above. Consumers should remember that all wireless devices are certified to meet the FCC maximum SAR standards, which incorporate a considerable safety margin.

For additional information, see maximum SAR value for each phone.

Some studies have also reported that wireless devices might interfere with implanted cardiac pacemakers

...if used within eight inches of the pacemaker.

Although several studies claim health risks associated with wireless and EMF radiation, there is still much work to be done before definitive statements about EMF safety can be made. Because these health risks are of concern to you, it may be advisable to take precautionary measures by placing your router at an appropriate distance from your body, especially while sleeping. However, it is best to discuss any health-related questions or concerns with your primary care physician or specialist.

As a side note - you may also want to review the specs on the Asus RT-AC5300 router listed on the Asus website and request additional product documentation from the company to review with your primary care physician or specialist.

Supplemental information and resources:

Wireless Devices and Health Concerns Guide

Radio Frequency Safety

CNN's Dr. Sanjay Gupta Explains: Cell phones and radiation

Cell Phone Radiation Safety Tips With Dr Sanjay Gupta on Anderson Cooper 360

  • 3
    While I'm quite sympathetic with the OP and your answer's leaning: This is a very well constructed answer. Down to the wording. What I am currently lamenting is a certain lack of weighing the arguments. Some of your sources provide very weak evidence (small sample, weird experimental setup, differing quality of evidence); your last quote: "improved treatment of cancer" vs "enhanced carcinogenisis". (But overall I hope to get criticised by you soon… ;) Nov 20, 2017 at 20:11
  • 3
    +1 and ditto on @LangLangC! EM Waves as such are obviously not a problem (the whole world’s full of them, but dosage makes the poison. What I‘m curious about: WiFi waves have lower energy levels than the visible spectrum. Shouldn’t it be more safe sleeping near a router than next to a lamp, if the amount of radiation received is comparable? // I wouldn’t worry about it too much, unless a rooter is in one‘s sleeping room close to one’s bed.
    – Narusan
    Nov 20, 2017 at 21:17
  • 2
    @LangLangC Thank you for your kind words and constructive feedback. The topic does seem to lack sufficient evidence other than what appears to be somewhat biased and/or based on conspiracy. I will continue my research with your positions in mind and will edit my answer accordingly. :)
    – Taylor
    Nov 20, 2017 at 22:06
  • @Narusan-sedated Thank you for your contributions. I will also take your thoughts/questions into consideration as I further my research on this topic. Stay tuned! :)
    – Taylor
    Nov 20, 2017 at 22:18
  • 2
    I want to upvote this due to the overall quality, but I have the same problem LangLangC and Narusan expressed. The evidence of harm from low-level EMF sources such as wifi, cell phones, bluetooth, etc. is far from convincing. Keep in mind that all of us have been bombarded with much higher energy EMF 24/7 since the day we were conceived. Radio, television, radar, and extra-terrestrial sources all significantly exceed the power levels emitted by wireless devices (wifi router ~6 watts, TV station ~50,000 watts), so why would these low-power source be harmful while high-power sources are not?
    – Carey Gregory
    Nov 21, 2017 at 1:19

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