Not only is it inefficient, but it's also potentially dangerous.
An EMF field strong enough to charge a smartphone is going to have health ramifications.
Why EMFs = DNA Damage…
Ionizing radiation can also cause DNA damage. This is an undisputed fact, and explains why any time you have ever gotten an X-ray (a form of ionizing radiation) , you have likely been given a protective lead apron to cover your torso and shield your organs from exposure. (p. 3)
One of the most concerning aspects of this process is when the ionizing radiation passes through the nucleus of your cells where most of your DNA is stored. It has enough energy to directly break some of the covalent bonds in your DNA. This is the way that ionizing radiation causes genetic damage, which can then lead to cell death or cancer. (p. 6)
Nonionizing radiation from your wireless devices actually creates carbonyl free radicals — instead of the hydroxyl radicals that ionizing radiation gives rise to — that cause virtually identical damage to your nuclear DNA, cell membranes, proteins, mitochondria, and stem cells. (p. 7)
The German EMF researcher Franz Adlkofer used a comet assay, which is a very sensitive test for DNA damage, in a 2008 study. He found that very low intensity EMF exposure at 1.8 GHz produced large numbers of DNA breaks. It actually produced more DNA damage than 1,600 chest X-rays. (p. 103)
From Dr. Mercola’s excellent book EMF*D: 5G, Wi-Fi & Cell Phones: Hidden Harms and How to Protect Yourself which I reviewed here…
