What is the SAR value in smartphones and why is it dangerous

The SAR value indicates the energy absorption of radiation from the phone on our body, here's how it is measured and how dangerous it can be for health

With the increasing use of smartphones many people have begun to learn about the radiation emitted by cell phones and the dangers that these can have on human health. The radiation of smartphones, for those who do not know, are expressed with the SAR value.

The SAR value, even if it is often one of the most underestimated elements, would be one of the first information to check before buying a smartphone. A low radiation value in fact would mean to have in your pocket, at hand or at night near the bed a device little "polluting". On the contrary a high value of radiation would mean to have always near us a device highly harmful to our health. The radiation emitted by our smartphones are electromagnetic radiation, such as those of Wi-Fi routers, radar sensors and microwave ovens. Usually in smartphones depending on the phone provider and model the radiation has a value between 450 and 2100 MHz.

What is the SAR value

The SAR value (Specific Absorption Rate) is a number that measures the rate at which energy is absorbed by the human body when exposed to radio waves. It is used in different fields with different formulas, in mobile telephony the SAR defines the energy absorbed by a particular mass of human tissue within a certain period of time. Not surprisingly, SAR is calculated in units of power per mass (W / kg). It is important to ensure that a device does not exceed the maximum limits set for our safety. SAR measurements are usually performed on the whole body or on tissue samples and tests are done during a call that is the time when the device emits a greater number of electromagnetic waves. In order to have a greater number of results, the test is repeated several times at various distances from the human head to understand when the proximity of the smartphone may increase the risk of exposure to radiation. What are the safety limits of the SAR value for smartphones? In Europe the limit is 2 W / kg in a sample of 10 grams of tissue. In the United States the value must be less than or equal to 1.6 W / kg.

Is a high SAR value dangerous for humans?

At the moment, several researches have been carried out to understand how the radiation of smartphones affect the human body, but still there are no official and fully reliable and universally recognized findings. Tests carried out in laboratories on guinea pigs with an exposure of about 10 hours per day has caused in some specimens the growth of cancer cells. But it is still not clear the relationship with the human body that has a better ability to absorb this type of radiation. In any case, waiting for the confirmation of science, it is always advisable to buy a smartphone that does not exceed the SAR limit values imposed by Europe and listed above.

Phones with high SAR

It is widely believed that the phones with higher SAR value and therefore potentially more harmful are almost all those of Chinese manufacturers. In reality this is not the case. It is true that some Chinese smartphones have quite high SAR values. All the phones on the market however do not exceed the 2 W/kg threshold imposed by the European Union. At the moment among the phones on the market the one with the highest value is the Xiaomi Mi A1 (1,75 W/kg). SAR value of 1.68 W/kg for OnePlus 5T. The Samsung Galaxy Note 8 is by far the phone with the lowest SAR value: 0.173 W/kg.