Smartphones give off a form of energy known as radiofrequency (RF) waves, and concerns have been raised about the safety of cell phone use. The German Federal Office for Radiation Protection has measured the level of radiation smartphones emit.

With respect to cancer, concern focuses on whether cell phones might increase the risk of brain tumors or other tumors in the head and neck area. Cell phones work by sending signals to (and receiving them from) nearby cell towers (base stations) using RF waves. This is a form of electromagnetic energy that falls between FM radio waves and microwaves. RF waves don’t have enough energy to cause cancer by directly damaging the DNA inside cells. However, phone is typically held against the side of the head when in use. The closer the antenna is to the head, the greater a person’s expected exposure to RF energy. The body tissues closest to the phone absorb more energy than tissues farther away.

Factors tat can affect the amount of RF energy to which a person is exposed, include the amount of time the person is on the phone;
whether or not the person is using the speaker mode on the phone or a hands-free device; the distance and path to the nearest cell phone tower; the amount of cell phone traffic in the area at the time; and of course, the model of phone being used. Different phones give off different amounts of energy.

Every smartphone comes with a Specific Absorption Rate (SAR) value that quantifies the amount of radiofrequency waves emitted from a smartphone.

A list compiled by German Federal Office for Radiation Protection (Bundesamt fur Strahlenschutz) and published by Statista.com includes the level of radiation new and older smartphones emit.

According to the database of the SAR measurements, the current smartphone creating the highest level of radiation is the Xiaomi Mi A1. Another Chinese phone is in second place - the OnePlus 5T. In fact, the two companies are represented heavily in this list, with 8 of the top 16 handsets being made by one of them. Premium Apple phones such as the iPhone 7 and the recently released iPhone 8 are also here to be seen, though, as are the latest Pixel handsets from Google.

While there is no universal guideline for a 'safe' level of phone radiation, the German certification for environmental friendliness 'Der Blaue Engel' (Blue Angel) only certifies phones which have a specific absorption rate of less than 0.60 watts per kilogram.

Samsung Note 8 seems to be least prone to radiations and out of the 16 enlisted smartphones, eight are from Samsung.

This contrasts with their major rival Apple. Two iPhones occupy a place in the list of phones which emit the most radiation, compared to none from Samsung.