Given the large number of emails I've received, consulting and discussing certain aspects of my previous article on health wifi and proceed to expand it a little more. As we had previously been classified electromagnetic waves in ionizing and non ionizing ionizing waves (3000 THz) are harmful, so these or near, all the others, which find wireless systems are regulated at European level, for the reason that despite a wave of non-ionizing radiation can be different effects on the subject in consequence of the power levels used. These effects of non-ionizing waves are classified as thermal effects, photochemical and athermal. These effects are reflected in the tables of specific absorption rates tables also known as SAR values of W / Kg. or mW/cm2 and media exposure times of 6 min. Perhaps the most worrying are the thermal effects in non-ionizing waves to find that absorption values at or above 4W/Kg. The body temperature would increase by 1 C would be considered a harmful non-ionizing wave. Athermal effects of non-ionizing waves are still in experimental stage yet are regulated at the level of "recommendation." It should be noted that the WHO has found no adverse effect on non-ionizing waves (under the European regulatory maximum levels) on health in more than 100 studies. Terminates with a small list of powers and health: European Policy 0.45mW/cm2 = electromagnetic absorption in tissue (SAR) 4mW/cm2 = Possibility of thermal effects, photochemical or athermal 40mW/cm2 = Possible adverse effects on the subject. 60mW/cm2 = health risk threshold.