There is no substantial evidence that Wireless networks effect health

Wireless networks operate using the same radio waves used in the broadcast of radio, television and mobile phone signals. A substantial amount of research has been conducted on the safety of wireless networks, with over 50 years of research on radio communications. The current consensus of the scientific community is that there is no substantiated scientific evidence that wireless networks pose any health risk.

The World Health Organisation’s (WHO) latest fact sheet on wireless networks states:

Considering the very low exposure levels and research results collected to date, there is no convincing scientific evidence that the weak RF signals from base stations and wireless networks cause adverse health effects.

Furthermore, the WHO says:

Recent surveys have indicated that RF exposures from base stations and wireless technologies in publicly accessible areas (including schools and hospitals) are normally thousands of times below international standards.

The largest study conducted on the safety of wireless networks found no cause for concern. A University of Pennsylvania study published in March 2007 took 356 measurements at 55 Wi-Fi sites in four countries under conditions that would result in higher than normal exposures. The study found RF fields from WLANs in typical environments operate far below exposure guidelines:

In all cases, the measured Wi-Fi signal levels were very far below international exposure limits (IEEE C95.1-2005 and ICNIRP) and in nearly all cases far below other RF signals in the same environments.

The most recent study conducted in Austria by Gernot Schmid investigated exposure caused by wireless technologies used inside homes and offices. The study tested the exposure levels caused by household devices including four types of baby monitors, two wireless “Bluetooth” headphones and two cordless telephones. The report, published in December 2007, found:

None of the devices considered in this study exceeded the limits according to the ICNIRP guidelines.

Another study by Gernot Schmid, published in December 2007, examined public exposure levels due to wireless LAN devices in public places and found public exposures from WLAN are low compared to ICNIRP limits. The report concluded:

The computational and experimental RF exposure assessment carried out in public WLAN environments revealed that the resulting typical personal exposure caused by WLAN devices is far below the reference level of 10W/m2.

Furthermore, a comprehensive study by the Hong Kong Government, released in October 2007, found exposure levels at public Wi-Fi access points across the state’s territories are well below internationally recommended safety limits. In fact the study found actual measurement around Wi-Fi transmitters were as low as 0.03 per cent of the safety limit. The report states:

Based on the measurement results, it is concluded that Wi-Fi RF exposures in public areas in Hong Kong, including the government premises provided with public Wi-Fi services, are well below the international exposure limits which have been adopted in the CoP [Code of Practice].

The UK Health Protection Agency (HPA) updated their fact sheet in May 2007 saying the signals from Wi-Fi and WLAN equipment operate at very low power levels and pose no health risk:

There is no consistent evidence of health effects from RF exposures below guideline levels and therefore no reason why schools and others should not use WiFi equipment.

In addition, a HPA survey found WLAN emissions were well below the safety guidelines:

The HPA has made measurements of the power density of radio waves generally in and about the offices where WLANs are deployed and these have always been found to be very much below the guideline levels referred to.

The Wi-Fi Alliance, an international association for the Wi-Fi industry, state there is no scientific evidence that these low powered wireless communications devices pose any threat to the user or the general public. Their most recent brochure on health and wireless networks states:

Several studies that record the measurements of radio waves used by WLANs have been conducted by some governments and industry… All of these studies have shown that exposures to the radio waves used by WLANs are substantially below the international safety limits.

An extensive review of the research conducted on mobile phones, base stations and wireless networks by the leading scientific researchers in the field has concluded they pose no short or long term risk to human health. Published in December 2006 by Dr Peter Valberg, a former member of the Harvard School of Public Health, along with current Director of the World Health Organisation’s (WHO) International EMF project Dr Emilie Van Deventer and Former Director Dr Michael Repacholi, the report found:

The accumulated evidence does not establish the existence of adverse short or long term health effects from the signals produced by base station and local wireless networks. In fact, for similar RF exposure intensities (W/m2), the body absorbs about 5 times more of the RF energy from FM radio and TV frequencies (around 100 MHz) than from base station frequencies (around 1 – 2 GHz). It is reassuring to note that radio and TV broadcast stations have been in operation for more than 50 years, and health statistics have not demonstrated adverse health consequences.

Mobile communication services operate at very low power levels. Even with several services operating in the same location, the combined levels are usually many times below the international safety standards.

Wi-Fi signals use a mere 100 milliwatts of power, less than half the power of a mobile phone. Wi-Fi connections are also “silent” until data is transmitted, so emissions are only created during actual transfers of data. Even heavy users accessing hundreds of megabytes of data a day would only end up transmitting for a short period (less than 15 minutes).

Wireless networks contribute a very minute amount of radio frequency energy to the environment. In fact, a nationwide study conducted by the Federal Health Department found that AM radio was by far the most significant contributor of radio frequency emissions in the community (91.2 per cent). Digital mobile phone base stations contributed only 1.4 per cent.

Australian independent EME experts RadHaz Consulting have confirmed that Wi-Fi emissions are extremely low. A 2007 RadHaz home pilot study found Wi-Fi emissions 1-metre from a Wi-Fi access point were on average 100,000 times below the Australian safety standard. At a distance of 3-metres the exposure level reduces even further to be 333,000 times below the safety limit.

To put this in perspective it should be noted that the Australian safety standard already has a significant safety margin built into it.

It is important to note that the community has been living with the far higher environmental exposure from radio and TV broadcasts for many decades with no substantiated scientific evidence of an effect on our health.

The standards that are applied to other radio frequency devices are also applied to wireless networks. Wi-Fi products are designed, built and tested to comply with these strict standards, which include substantial safety margins to protect all members of society, including children and the elderly.

It is reassuring to note there is no scientific evidence of health effects from mobile phone base stations. Considering wireless networks emit less energy, it is highly unlikely they would be capable of causing adverse health effects. The WHO agrees, saying:

From all evidence accumulated so far, no adverse short- or long-term health effects have been shown to occur from the RF signals produced by base stations. Since wireless networks produce generally lower RF signals than base stations, no adverse health effects are expected from exposure to them.

What is a wireless network?

 A wireless local area network (WLAN) is a method of connecting Wi-Fi enabled devices to the internet or each other using radio frequency (RF) transmissions.

A person with a Wi-Fi enabled device such as a PC, mobile phone or PDA can connect to a network when in proximity of an access point. The region covered by one or several access points is called a hotspot. Hotspots can range from a single room to many square miles of overlapping hotspots.

WLANs have quickly become popular and are now found in many educational institutions, homes, businesses and public areas. Organisations and consumers have been keen to take advantage of the flexibility wireless networks can offer. A recent report from In-Stat predicts that the wireless market will grow from 140 million wireless chipsets a year in 2005 to 430 million in 2009. The number of public hotspots is also growing rapidly, with In-Stat analysts estimating there will be 200,000 of them by 2008.

The emergence of new security standards has also increased confidence in WLANs. Users are becoming more familiar with the technology and are increasingly expecting wireless access to be available. There is a wide range of products and standards involved in WLAN technology and more continue to emerge.

The term Wi-Fi (Wireless Fidelity) is often used to refer to the 802.11 standard for wireless networks. It comes from the testing and certification programme run by the Wi-Fi Alliance to ensure wireless products from different manufacturers comply with standards and are interoperable. The Alliance created the branding ‘Wi-Fi CERTIFIED’ which guarantees compliance to the standard and helps consumers feel confident about purchasing a Wi-Fi product.

The Institute of Electrical and Electronics Engineers (IEEE) is the leading authority on the specification and ratification of standards relating to Wi-Fi technology. Current wireless standards originated from the IEEE and most Wi-Fi networks operate predominantly in 2.4 GHz radio band, but also in the 5 GHz band.

It’s worth noting that the 2.4 GHz band is also used by cordless phones, baby monitors, microwave ovens and Bluetooth devices.

Wireless network products are also subject to the same safety standards that are applied to other radio products. These standards are developed by independent scientific organisations, such as the International Commission on Non-Ionising Radiation Protection (ICNIRP). The standards have been widely adopted by governments and health agencies around the world, providing substantial safety margins.

All wireless network products must comply with these standards.