The Physics of EMFs
It helps to know how EMF waves influence the environment in order to understand why they could pose a danger, especially in light of the absence of rigorous testing despite widespread and explosive use in our society.
An electromagnetic field consists of two parts: an electrical field and an associated magnetic field, positioned at right angles to each other. Because a changing electric field will create a similarly changing magnetic field, and vice versa, the two fields reinforce each other as the waves propagate through space.
These waves go on forever (though the strength diminishes as the waves spread out) until they encounter a substance that will cause an interaction.
Because the First Law of Thermodynamics holds that energy can be neither created nor destroyed (only converted to different forms) understand that when you hear talk about EMFs being 'absorbed' or 'blocked' by your body, those descriptions are somewhat misleading. In order for the energy to not simply pass through the body unchanged, the waves must interact somehow with your body to create some kind of effect that uses the energy.
This means that the wave does not simply disappear; its energy is used to displace electrons, combine or split molecules, or modify cells in the area in some other way.