Does the electricity with which we power our world pose significant health hazards from the resulting electromagnetic fields? Several authors¹,² have speculated that 'stochastic resonance'³ — a nonlinear phenomenon in which the addition of noise to a system increases its response to an external signal — may allow biological cells to detect and respond to very weak external electric fields far below the thermal noise limit⁴,⁵, and thus possibly cause harmful effects. Here we examine this question using a recent theory of Bezrukov and Vodyanoy⁶ for the effect of non-equilibrium noise on a voltage detector (such as a biological ion channel⁷). We show that with parameters appropriate for typical biological cells, adding noise does not make a far-from-detectable signal detectable.

1. Departments of Surgery and of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois 60637, USA
   e-mail: Email: dastumia@surgery.bsd.uchicago.edu
2. Department of Physics, Yale University, New Haven, Connecticut 6520, USA
3. Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA