Mobile phones release low radiofrequency energy which is a form of non-ionizing radiation. The frequent exposure of the body to this forces it to absorb the energy which can lead to serious health issues.
In fact, the World Health Organization (WHO) has labelled mobile phones radiation as possibly carcinogenic to humans. Accordingly, these are ways to reduce radiation when you use your mobile phone.
Use the speakerphone
You may not use speakerphone in public. However, when you are at home, you can use your speakerphone.