Bioelectromagnetics 21:508 ^ 514 (2000) Recommended Minimal Requirements and Development Guidelines for Exposure Setups of Bio-Experiments Addressing the Health Risk Concern of Wireless Communications Niels Kuster* and Frank SchÎnborn Laboratory for EMF and Microwave Electronics, Swiss Federal Institute of Technology (ETH) Zurich, Switzerland The evidence currently available on the potential health effects from electromagnetic field (EMF) exposure has been largely judged as being too tentative and inadequate to meet criteria for assessing health risks. Some of the main reasons for these shortcomings lie in the incomplete description of the exposure and poorly characterized dosimetry. Well-defined exposure conditions are essential to obtain reproducible and scientifically valuable results. To facilitate the development of optimized setups for specific bio-experiments, this paper lists basic requirements and provides development guidelines for evaluation, optimization, construction, and verification of exposure. In addition, definitions of minimum performance requirements for setups addressing the health risk concern of wireless com- munications are suggested. Bioelectromagnetics 21:508±514, 2000. ß 2000 Wiley-Liss, Inc. Key words: radio frequency; mobile phones; dosimetry; exposure setups; exposure conditions INTRODUCTION Although well-de®ned exposure conditions for biological experiments are an obvious and indispen- sable prerequisite for interpretation and repeatability of results, the dif®culties involved in obtaining such conditions have been severely underestimated by most groups conducting radio frequency (RF) experiments. Consequently, design and characterization of exposure setups have become top priority within most research programs addressing the health effects of RF expo- sures (e.g., WHO [Repacholi, 1998], WTR [Carlo, 1998], COST244 [COST 244bis, 1999]). Indeed, the design and realization of exposure setups is a con- siderable engineering and scienti®c challenge requir- ing profound knowledge of numerical simulation methods and especially their application, near-®eld measurement techniques, open and closed transmis- sion systems, anatomy, dosimetry, material science and more. Various reviews on exposure setups and their experimental and numerical dosimetry have been published, e.g., Guy [1974]; Durney et al. [1986]; Chou et al. [1996]; Kuster et. al. [1997]; Chou et al. [1999]; Guy et al. [1999]. Several authors have also listed requirements for exposure setups, e.g., Stuchly and Stuchly, 1986; Valberg, 1995; Kuster, 1997; Scho Ènborn, et al., 1999. Table 1 summarizes and extends these requirements in a list subdivided into `Biological Requirements', `Electromagnetic Require- ments' and `Other Requirements'. This list can serve as a checklist for all parameters that should be consi- dered in the evaluation of a particular setup. However, such a list is of a rather general and qualitative nature and thus of limited practical usage. The objective of this paper is to suggest guide- lines and a procedure for design, optimization, con- struction, and veri®cation of exposure setups in order to facilitate the development and utilization of ex- posure setups which meet all the strict requirements for sound biological experiments. In addition, an attempt is made to de®ne reasonable and achievable minimum quantitative requirements for bio-experiments addres- sing health concerns about wireless communications. It can be expected that this topic will be the main focus of studies in bioelectromagnetics in the near future. In particular, these minimum requirements might be of bene®t not only as a yardstick for setup designers, but ß 2000 Wiley-Liss, Inc. ÐÐÐÐÐÐ *Correspondence to: Niels Kuster, Laboratory for EMF and Microwave Electronics, ETH Zurich, CH-8092 Zurich, Switzer- land. E-mail: kuster@ifh.ee.ethz.ch Received for review 17 August 1999; Final revision received 29 November 1999.