The WiFi blues

The WiFi blues

Philadelphia, the city of brotherly love, has it all. Many in San Francisco want it...

Wireless broadband Internet access (WiFi) seems too good to be true. At

Relatively low cost, anyone can access the Internet anywhere in a city. The whole city

To do this, WLAN antennas must be installed.

One argument for citywide Wi-Fi is that it...digital divide:

The poorer you are, the more limited your access to the Internet and its information is

Resources. Cities like Philadelphia and San Francisco are actively trying to close it down

digital divide. One option is WiFi.

But when weighing the options, virtually nothing is heard about potential health

Risks. Saturating an entire city with Wi-Fi adds to the existing burden of non-ionization

Radiation. This burden, calledElectrosmogof some consists of long term

Exposure to low concentrations of non-ionizing radiation from known sources

such as radio and television signals, electronic and electrical devices and the ubiquitous cell

Phone.

WiFi

Local networks (LANs) connect computers, printers, modems and others

Devices. Traditional LANs physically establish connections using wire cables. Notices

between computers and the other devices on the network are managed by a device

calledrouters.

A wireless LAN eliminates the need for wired cables by using a router that transmits and

receives radio signals. To use a wired LAN, you need to connect the computer or something else

device into a socket. A wire runs from the socket to the router, which does this

Signal traffic between devices in the network.

With a wireless LAN, every device on the network is designed to send a signal

to the router and receive signals back. WiFi routers typically have a range of a

hundred to several hundred feet. The range can be increased by adding a booster

this increases the signal strength.

As with all radio signals, the closer you are to the transmitter (the router).

stronger the signal. Cell phones work on the same principle. The difference is that

Cell phones operate on a different frequency and give off a stronger signal than wireless ones

LANs.

Radio frequencies

Cell phones operate at frequencies in the 3 to 30 GHz range, similar to microwaves

Ovens. Wireless LANs operate at a tenth of this range – 0.3 to 3 GHz, the range of

UHF television broadcasts.GHzstands for GigaHertz, a standard measurement

from high frequency radiation (RFR)–electromagnetic radiation generated by

Sending an alternating electrical current through an antenna. The higher the GHz,

the faster the current changes.

Frequency alone does not measure the potential effect of RFR. As you would do

I think the strength of the signal also plays a role. The strength of a signal is measured

inwatt, a standard measure of electrical energy. For example 100 watts

Light bulb is brighter because it gives off more energy than a 60 watt light bulb.

Think of the effect of waves on the beach: small waves far apart (low strength, low

frequency) versus large waves close together (high strength, high frequency). The

The former is likely to have less impact than the latter.

Radiofrequency exposure is measured using the SAR-specific absorption rate. SAR is

expressed either in milliwatts/kilogram (mW/kg) body weight or milliwatts/cubic

Centimeters (mW/cm2) of exposed body area: the size of the wave and how much of it

it hits your body.

Health risks

WiFi enthusiasts dismiss health risk concerns over output power and SAR

The exposure is well below the minimum standard for cell phones. But cell

Telephone standards are pressed for the short-term load on a cell phone in use

to your head. In addition, the standards are set based on the thermal (heating) effect

of radiation.

Non-thermal effects of cell phones have been documented at exposures below current levels

US standards, including

– memory loss,

– sleep disorders,

– slowed motor skills and reaction time,

– reduced immune function,

– spatial disorientation and dizziness,

- Headache,

– reduced sperm count,

– increased blood pressure and pulse,

– DNA breakage and reduced DNA repair capacity and

– Cell proliferation.

A second problem is that cell phone exposure is sporadic during WiFi

The exposure is constant. A more accurate comparison is the effect of the cell phone

broadcast antennas. These antennas send and receive radio frequency signals

constant.

The signal strength of an antenna is comparable to that of a cell phone only at close range

Reach. The exposure is not the brief pop of a cell phone, but a sustained bath of faint

Strength RFR. In addition to the health effects documented for cell phone use,

Include exposure to cell phone antennas

– increased blood pressure and pulse,

– sleep disorders,

– emotional effects such as increased depression and irritability,

– memory loss and mental fog,

– tiredness and dizziness, and

– increased risk of cancer.

Because of these impacts, the International Association of Fire Fighters (AFL-CIO)

Decided in 2004 that they would not allow cell phone antennas on firehouses.

RFR hypersensitivity

Much of the discussion about the health effects of radiofrequency radiation is framed as concern about people

who are hypersensitive.Hypersensitivityis the technical term for allergies

and similar immune system overreactions. But instead of pollen, RFR

Hypersensitivity is a reaction to non-ionizing substances

Radiation. It seems that an unlucky few are affected while the rest of us stay away from it

Hook.

Research by Olle Johansson and Örjan Halberg from the Karolinska Institute, Stockholm

suggests otherwise. They examined cancer incidence in Europe and the USA

and found a remarkable connection between the increase in certain types of cancer during the

20th century and exposure RFR measured by radio and television broadcasts.

What the hypersensitive really represent is one extreme in a complex landscape of

Impact and risks. Like any other environmental stressor, RFR impacts some

people more than others. And as with other environmental stressors, the greater the

The greater the overall burden, the greater the risk of being one of the “unlucky few”.

Wireless LANs contribute to the existing RFR burden. Just like burning more fossil fuels

adds more smog, more RFR adds more electrosmog. You don't have to

Expose your home or city to the increased strain of WiFi. There is one

viable alternative: a wired LAN. The hype might make it seem less convenient and

more expensive. But what is good sleep worth? Or reduce your risk

Cancer?

resources

International Association of Firefighters. 2004. Position on the health effects of

Radio frequency/microwave radiation (RF/MW) in fire brigade facilities

Base stations for antennas and masts for mobile phone transmission

Transfers. Access at http://www.iaff.org/safe/content/celltower/

celltowerfinal.htm.

Johansson, Olle and Doug Loranger. 2005. Electrosmog. your own health and

Fitness. Broadcast on November 29, 2005. http://yourownhealthandfitness.org/

radiation.html.

Sage, Cindy. 2005. Commentary on San Francisco TechConnect Community Wireless

Broadband Initiative. Sage Associates: September 2005.