Monday, September 15, 2014

Will your wireless router give you cancer?

If you pick up a magnet and move it up and down with your hand, you will be creating electromagnetic radiation. The faster you move the magnet, the higher the frequency of the radiation you create. The higher the frequency of the radiation, the lower is its wavelength. High frequency is also associated with high radiation strength, where strength can be measured in watts (W).

We are constantly bombarded by electromagnetic radiation, which is usually classified based on its frequency (and also wavelength, since frequency and wavelength are inversely proportional). The main types of electromagnetic waves, in order of increasing frequency, are: radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays.

There has been a large amount of research on the health effects of wireless equipment, including wireless routers (figure below from, because of the electromagnetic radiation that they emit. Wireless equipment uses electromagnetic radiation of the radio waves type.

In developing countries, wireless routers are ubiquitous. They are found everywhere – at home, in hotels and businesses, and even in public parks. They allow wireless devices to connect to the Internet, by creating one or more “WiFi hotspots”.

The strength of the radiation emitted by wireless routers, when it reaches humans, is much lower than that emitted by mobile phones. One of the reasons for this is the lower strength of the radiation emitted by wireless routers, which can go from 30 to 500 milliwatts (mW); versus 125 mW to 2 W for mobile phones.

But the main reason for the lower strength of the radiation emitted by wireless routers, when it reaches humans, is that wireless routers normally are located farther away from humans than mobile phones. Radiation strength goes down according to the inverse-square law; i.e., proportionally to 1 divided by the distance between source and destination squared.

Given this, it has been estimated () that the exposure to 1 full year of radiation from a wireless router at home is equivalent, in terms of radiation reaching the body, to 20 minutes of exposure to the radiation emitted by a mobile phone.

If the radiation from wireless routers were to cause cancer, so should the radiation from mobile phones. So, what about mobile phones? Do they cause cancer?

In spite of a large amount of research conducted on the subject, no conclusive evidence has been found that the radiation from mobile phones causes cancer. A representative example of this research is a large Danish study (), whose results have recently been replicated.

Mobile phone radiation, like wireless router radiation, is currently classified by the International Agency for Research on Cancer (IARC) in Group 2B, namely “possibly carcinogenic”. This carries a recommendation of “more research”. Caffeic acid, found in coffee, is also in this group. It is useful to note that neither mobile phone nor wireless router radiation are classified in Group 2A, which is the “probably carcinogenic” IARC group.

When one considers the accumulated evidence regarding cancer risk associated with all types of electromagnetic radiation, the biggest concern by far is sunburn from ultraviolet radiation. The evidence suggests that it causes skin cancer. Chronic non-sunburn exposure to natural ultraviolet radiation, on the other hand, seems protective against most types of cancer (skin cancer included).

Will your wireless router give you cancer? I don’t think so.