“When phone’s battery is low to last bar, don’t answer the phone, because the radiation is 1,000 times stronger.”
This statement is inaccurate; the following points explain why:
1. When a phone’s battery is low, the power management subsystem of the phone forces it to use LESS power in order to conserve energy, in order to give the user a longer battery life.
This is why sometimes you might realize that your call quality is worse when you’re running very low on battery.
2. When the phone’s “network signal” level is low, it boosts the power of the cellular radio in order to compensate for the low signal, in order to maintain a connection. However, the cellular radio’s power is capped due to FCC regulations, which is set at a level that is 100 times less than what is considered “safe radiation”.
3. When a phone is on standby, like when it is on the table and you are not using it, its cellular radio consumes 1,000 times less power than when you are using it during a phone conversation. This is how mobile devices work.
Therefore in any case when you use a mobile phone, its cellular transmission power will increase considerably no matter what because that’s how they work; if it is low on battery though, then it will increase less than when it is fully charged. And when the power does increase, there is a maximum capacity that it can reach (it is not infinite), which is still within a safe range.
And last but not least, mobile phone antennas are directional antennas and are designed to radiate away from the person’s head, because of two main reasons. First, if the signal were to traverse through the head it would kill the signal, because the human body acts as an absorber for electromagnetic waves, so from an engineering point of view it would be very inefficient to waste power by radiating in the direction where you know the person’s head will be; it’s lost power, simply. And second of all it wouldn’t be safe to design such a device, and so all the regulatory institutions round the world would have banned such devices from the consumer market to begin with.