Specific Absorption Rate
Radiofrequency radiation deposits energy in the body. The amount depends
on the strength of the RF field. The various international guidelines
for maximum permissible amounts of RF radiation for human exposure are
designed to prevent heating, the only known consequence of the energy
deposition (Ahlbom and Feychting, 2003). For details on the exposure
limits, see "Primer - Wireless Phones - Exposure
Limits".
The
Specific Absorption Rate, or SAR, indicates the amount
of energy from radiofrequency radiation (RFR) that is absorbed by the
body when a wireless phone is used. It is defined as the rate of energy
absorption per unit mass, and is expressed in units of watts per kilogram
(W/kg). The internal SAR cannot be measured directly in the body, but
is estimated by theoretical calculations.
Governments
or governmental agencies in individual countries have established the
maximum permissible SAR values for wireless phones. In many cases the
values are based on standards recommended by the International Commission
on Non-Ionizing Radiation Protection (ICNIRP) or other independent organizations.
Many countries require SAR values of a phone to be published by the
manufacturer. The actual SAR of a phone while in use is usually well
below the maximum permissible value, since the phone uses the least
power needed to reach the nearest base station. More information on
SAR is found at the following web sites:
World
Health Organization. www.who.int/peh-emf
Go to the section on EMF standards. You will find a map of the world,
and you can click on regions/countries to ascertain the standards that
apply there for electromagnetic fields protection.
Mobile Manufacturers Forum
www.mmfai.org
The MMF is an international association of
radio communications equipment manufacturers. Its members include Alcatel-Lucent,
Ericsson, Mitsubishi Electric, Motorola, Nokia, Panasonic, Philips,
Sagem, Samsung, Nokia-Siemens Networks, Sony Ericsson and TCL & Alcatel
Mobile Phones. On the site there is a health issues section that includes
SAR information on many of the models produced by these companies.
UK.
Government.www.ofcom.org.uk This site gives general information about mobile phones and health.
There is more information on the website of the Health Protection Agency www.hpa.org.uk
USA.
Food and Drug Administration (FDA). www.fda.gov/cellphones/
The FDA and the Federal Communications Commission (FCC) jointly operate
this site. It has a series of questions and answers covering wireless
phones, radiofrequency energy, base stations, safety standards, and
SAR values for phones.
Federal
Communications Commission.
The FCC requires wireless phones to comply with a safety limit of 1.6
W/kg for SAR to the head. SAR information can be found at. www.fcc.gov/oet/rfsafety
or at www.fcc.gov/cgb/sar/
ICNIRP.
www.icnirp.de
The publications page lists reviews, guidelines, and statements published
by ICNIRP. Several can be downloaded free of charge. Many countries
in the world follow ICNIRP guidelines.