ABSTRACT
CONTENTS 8.1 Introduction ....................................................................................................................... 277 8.2 Types of Standards ........................................................................................................... 278
8.2.1 Emission versus Exposure Standards............................................................... 279 8.2.2 Voluntary versus Mandatory Standards .......................................................... 279
8.3 Relevant Authorities......................................................................................................... 280 8.3.1 Nongovernmental and International Organizations ...................................... 280 8.3.2 Multinational and National Bodies ................................................................... 281 8.3.3 Local Government................................................................................................ 282
8.4 Basis for Exposure Standards ......................................................................................... 283 8.4.1 Scientific Methodology........................................................................................ 283
8.4.1.1 Types of Studies.................................................................................... 284 8.4.1.2 Multiple Tiers ........................................................................................ 285 8.4.1.3 Safety Factors......................................................................................... 285 8.4.1.4 Exposure Limits .................................................................................... 285 8.4.1.5 Other Quantitative Measures ............................................................. 287 8.4.1.6 Scientific Uncertainty ........................................................................... 287
8.4.2 Political Process and Precaution........................................................................ 288 8.5 Discussion .......................................................................................................................... 289
8.5.1 Technology Leading Health Research .............................................................. 290 8.5.2 Unregulated Portions of the Spectrum............................................................. 290 8.5.3 Disparities in Standards ...................................................................................... 290 8.5.4 Risk Perception and Communication ............................................................... 290 8.5.5 Need for Periodic Evaluation............................................................................. 291
Acknowledgment....................................................................................................................... 291 References ................................................................................................................................... 291
The strength of electromagnetic fields (EMF) to which humans are exposed has been increasing gradually with the growth of electric power generation and transmission, the development of new telecommunication systems, and advances in medical and industrial applications. Although the health effects of EMF on humans have been of research interest for several decades, development of standards that incorporate the limits of
human exposure to nonionizing radiation (NIR) has occurred more recently for some parts of the electromagnetic frequency spectrum. Historically, emerging technologies have triggered the development of EMF standards
in different parts of the spectrum. In the radio frequency (RF) fields range, limits to protect human health were introduced in the 1950s, soon after the introduction or proliferation of radar and radio and television broadcasting. The need for exposure standards was highlighted by the observation of acute thermal injury in people exposed to high-level RF fields, especially in the microwave range. The United States and the Soviet Union were the first countries to develop RF standards, but their limits were based on different scientific evidence. With the introduction of industrial equipment, such as induction heaters and heat sealers, later standards recognized the vastly expanded use of the electromagnetic spectrum, especially at lower-frequency RF. Early RF standards were aimed at restricting thermal effects seen at high levels of exposure [1]. However, scientists in both the East and the West continue to postulate that nonthermal effects could also be important, and this has been the driving force for RF research for some decades. In the extremely low frequency (ELF) region, an epidemiological study by Wertheimer
and Leeper [2] was the key publication suggesting that there could be a health concern with exposure to ELF magnetic fields. Their studies suggested that exposure to ELF fields from high current configurations in power lines seemed to be associated with an increased incidence of childhood leukemia. This was supported by a few of the subsequent studies, including those by Savitz and coworkers [3] and more recently by two pooled analyzes by Ahlbom et al. [4] and Greenland et al. [5]. Research results drove legislation for both RF and ELF fields. More recently, the well-
publicized putative link between ELF magnetic fields and childhood leukemia and the growing exposure to new technologies at home and in the workplace, e.g., computer monitors and televisions, microwave ovens and mobile phones, have triggered public concern and calls for control and regulation limiting public and occupational EMF exposure. This chapter describes the available types of EMF standards, and includes an overview
of the standard-setting bodies involved in NIR at the international and the national level. It also provides a discussion of the methodology for developing standards, which entails both a scientific approach and a political process. Finally, a snapshot on trends in worldwide NIR exposure standards is given.
