FREE-RADICAL MECHANISM FOR THE EFFECTS OF ENVIRONMENTAL ELECTROMAGNETIC-FIELDS ON BIOLOGICAL-SYSTEMS

The radical pair mechanism is discussed as a possible route whereby a magnetic field of environmental strength might affect a biological sys tem. It is well established as the origin of reproducible field effect s in chemistry, and these can be observed even at very low magnetic fi eld strengths, including that of the geomagnetic held. Here it is atte mpted to give a description which might assist experimentalists workin g in biological laboratories to devize tests of its relevance to their work. The mechanism is well understood and a specific theoretical app roach is taken to explore and emphasize the importance of the lifetime of the radical pair and the precise chemical natures of the radicals which comprise it in affecting the size of the low-held effect. Furthe r subsequent processes are likely necessary to cause this primary effe ct to attain biological significance. Arguments are provided to sugges t that the encounters of freely diffusing pairs (F-pairs) of radicals are unlikely to produce significant effects in biology.