Table 1 Information about WLAN health effects and precautions used for experimental manipulation

Are there health risks?

The specific absorption rate (SAR) is the basis for evaluating if high-frequency electromagnetic fields pose a health risk due to immediate effects. The SAR describes how much radiated power is absorbed by human body tissue in a given situation.

For health protection, recommended limit values are

- 0.08 watts per kilo (W/kg) averaged over the whole body

- 2 W/kg locally averaged over body parts e.g. in the head

If the limit values are met, no detrimental health effects on body tissue have been established so far.

SAR values of radio waves of WLAN devices usually remain under the recommended limit value, especially when the device is far from the body. WLAN senders (2.4 GHz) in a laptop placed on a desk emitting with maximum transmitting power have local SAR-values of about 0.1 to 0.2 (W/kg). In unfavourable situations (e.g. laptop on the lap and sender immediately above the thigh), values in the dimension of the recommended limits can occur.

You can find more information at www.emf-forschungsprogramm.de.

Recommendations and precaution

1.) Respect the minimum distances indicated by manufacturers.

2.) The trend to portable and mobile radio applications leads to an overall increase in exposure to high-frequency electromagnetic fields. The Bundesamt für Strahlenschutz (BfS) recommends in general to minimize personal exposure in order to keep possible but not identified health risks low. Simple measures for this purpose are:

- Prefer wired connections if wireless technology can be relinquished

- Avoid placing central WLAN connection points in immediate proximity of places where people stay permanently, e.g. at the workplace

- If existing, enable the distance regulation to reduce maximum radiated power.

More information regarding precautionary measures can be found by following the link www.bfs.de/elektro.