Indeed cellphone has become an additional appendage for everyone.
First of all, you should know the SAR(specific absorption rate) value of your mobile. SAR is the rate at which radiation is absorbed by the human body, measured in watts per kg (W/Kg). To check SAR level dial *#07# will get details of it.
For my smartphone, it shows
India SAR 1g limit: 1.6 W/Kg
Head SAR: 0.962 W/Kg
Body SAR : 0.838 W/Kg(Distance 15 mm).
SAR limit for cellphone is 1.6 W/Kg which is for 6 minutes. It has a safety margin of 3 to 4 times, so a person should not use mobile for more than 18 to 24 minutes. Probably now every one mind arise a question of what would be the consequences. According to the interphone study report in May 2010:
Conclusion: No overall increase risk, but the suggestion of an increased glioma – heavy users and ipsilateral exposure.
Heavy users (1/2 hour per/day ) over 8 to 10 years: doubled quadrupled brain tumour risk.
To reduce exposure to RF Energy (Mitigation):
a. Don’t put your phone directly to your ear, better use headphone/Bluetooth or in speaker mode. Most important if possible don’t make your phone direct contact with ear keep minimum 15 mm away.
b. The best practice is to keep your mobile away from you as much as possible.
c. While sleeping keep away minimum distance 50cm. You may sleep but your mobile is ON all the time.
d. While using blue tooth headset make sure you don’t put mobile in any of your pockets better keep it as far as away or else in your bag (keep the mobile at a distance of 12 inch from your body). The reason behind is blue tooth headset radiate 10 mW and smartphone is 1 W. Blue tooth radiation is 100 times less which pretty good but smartphone radiation will continuously hitting your body which is not good.
e. If possible use SMS (not that WhatsApp).
f. Talk for short durations will also help.
g. The ideal way is to use a landline when available.
h. I strongly recommend don’t use a cellphone when its signal is weak. The reason is cellphone automatically emit more amount of radiation to connect to the nearest base station.
i. Children should use a cellphone only in an emergency because their skull is small so that radiation penetrates into deep which cause huge damage.