Check Radiation level (SAR) of your Smartphone by USSD code *#07#
Smartphone has so much penetrated in our daily life that now no one can think of without it. Excessive use of smartphone may cause health problems but if you are even using less a smartphone with bad SAR, that is most dangerous.
                                 
Here SAR stands for Specific Absorption Rate which is a measure of the amount of radio frequency energy absorbed by the body when using a mobile phone. Federal Communications Commission (FCC) has adopted limits for safe exposure to radio frequency (RF) energy  which is  1.6 watts per kilogram (1.6 W/kg).  Any smartphone  at or below this SAR levels is “safe” to use.
You can check Radiation level in terms of SAR of your smartphone by dialing a USSD code*#07#, if results shows SAR below 1.6 watts per kilogram (1.6 W/kg) then it is OK otherwise you are advised to change your smartphone immediately.

Here are SAR level of some popular smartphones in the market.
iPhone 6:>>  1.59 W/kg
LG G3:>> 0.99 W/kg
LG G2:>> 1.44 W/kg
Samsung Galaxy Note 2:>> 0.42 W/kg
Samsung Galaxy Note 3:>> 1.07 W/kg
Samsung Galaxy Note 4:>> 1.20 W/kg
Samsung Galaxy S5:>> 1.28 W/kg
HTC One (M8):>> 1.29 W/kg

Interestingly iPhone 6 have just 0.01 below the threshold level of SAR
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