Chemistry IS physics. The entirety of the chemical soup in which we live is a lumpy energy gradient. Adding previously unknown energy forms, wave forms, or amounts of penetrating energy to a biological system is unpredictable at best, and has been demonstrated to disrupt function.

Chemical concentration gradients, and the chemical pressure waves that move across them depend on an energetic potential for the function of the biochemical mechanism to operate. Adding the wrong kind or amount of energy to a system can alter the progression of a reaction even to the point of reversing it.

Any energy that can be absorbed will have an effect. It need not be ionizing radiation, and it need not be the DNA that is the recipient of the energy. Epigenetic effects can cause genes to be expressed in negative ways that can even be inherited. The epigenetic states depend on chemical and energetic states in their environment to function in ways beneficial to us.

In addition, our bodies produce EM fields as part of their function. It would be speculation on my part to say that disrupting these fields, with which we evolved, may not be safe, but precaution is always warranted when dealing with novel technologies. There are no fifty year studies of cell phones, and absence of evidence is not evidence of absence.