I was informed that when we type something on the cell phone, touching the screen many times, electrical charges are transferred to our body and over time this can cause us harm. It is true?"
As far as we know, the charges that appear when typing, as the cell phone's screen is capacitive, are extremely small and dissipate easily and quickly as soon as you take your finger off the screen. Thus, due to their intensity, there is no danger of doing harm, especially because the loads that we accumulate when walking on a carpet or when we touch objects that are loaded with more load such as a car are often greater.
