Experimental methodology for non-thermal effects of electromagnetic radiation on biologics

Abstract

Appropriate equipment is needed for research on the effects of radio-frequency radiation from radio-frequency identification (RF-ID) systems on biological materials. In the present study, a complete test system comprising assembled hardware and custom-built software was developed for a research project investigating whether RFID radiation produces significant effects in biologics. Furthermore, we document a method for determining specific absorption rate (S.A.R.) using vials containing 1.5 cc of saline to represent biological samples. This methodology yielded S.A.R. values of approximately 30 W kg-1(-9 dBm) and 150 W kg-1(-6.5 dBm) for 915 MHz and 320 W kg-1 (-9 dBm) and 450 W kg-1 (-6.5 dBm) for 2.45 GHz. Finally, the key system components - the transverse electromagnetic (TEM) cell, vial and saline solution -- were modelled using CST Microwave Studio®. Through modelling, we obtained values for the absorption as a percentage of the incident power - 0.2% for 915 MHz and 7.32% for 2.45 GHz. These values approximately matched those calculated - 0.36% for 915 MHz and 5.0% for 2.45 GHz. Errors in the calculated absorption were due primarily to the precision of the power meters relative to the power levels being detected, and indicate that further study may be required.