SAR is the amount of radio frequency energy absorbed by the body when using a mobile phone. India has adopted a stringent SAR limit of 1.6 watts per kg. Also directions have been given to prominently display the SAR value on every handset.
The risks of long-term exposure to radio frequency waves have been established in a recent study. Younger children should be discouraged from using cellular phones, because their skulls are thinner than adults and cells are more likely to be sensitive to mobile-phone radiation.
Source: The Hindu, 7th Feb., 2012.