Cell Phones possibly carcinogenic

[Ahmed_07]

The World Health Organization (WHO) announced that radiation from cell phones can possibly cause cancer.
According to the WHO's International Agency for Research on Cancer (IARC), radiofrequency electromagnetic fields have been classified as possibly carcinogenic to humans (group 2B) on the basis of an increased risk for glioma that some studies have associated with the
use of wireless phones.


Human exposures to RF-EMF (frequency range 30 kHz—300 GHz) can occur from use of personal devices (eg, mobile telephones, cordless phones, Bluetooth, and amateur radios), from occupational sources (eg, high frequency dielectric and induction heaters, and high-powered pulsed radars)
For workers, most exposure to RF-EMF comes from near-field sources, whereas the general population receives the highest exposure from transmitters close to the body, such as handheld devices like mobile
telephones.
The most important factors that determine the induced fields are the distance of the source from the body and the output power level. Additionally, the efficiency of coupling and resulting field distribution inside the
body strongly depend on the frequency, polarisation, and direction of wave incidence on the body, and anatomical features of the exposed person, including height, body-mass index, posture, and dielectric properties of the tissues. Induced fields within the body are highly non-uniform, varying over several
orders of magnitude, with local hotspots.


Holding a mobile phone to the ear to make a voice call can result in high specific RF energy absorption-rate (SAR) values in the brain, depending on the design and position of the phone and its antenna in relation to the head, how the phone is held, the anatomy of the head, and the quality of the link between the base station and phone.


When used by children, the average RF energy deposition is two times higher in the brain and up to ten times higher in the bone marrow of the skull, compared with mobile phone use by adults.
Use of hands-free kits lowers exposure to the brain to below 10% of the exposure from use
at the ear, but it might increase exposure to other parts of the body. Epidemiological evidence for an association between RF-EMF and cancer comes from cohort, case-control, and time-trend studies.
The populations in these studies were exposed to RF-EMF in occupational settings,
from sources in the general environment, and from use of wireless (mobile and cordless) telephones, which is the most extensively studied exposure source. One cohort study and five case-control studies were judged by the Working Group to offer potentially useful information regarding associations between use of wireless phones and glioma.


References:

The lancet oncology,Published Online: 22 June 2011