## 4 Internationalization of Bioelectromagnetics Research
### Comprehensive Assessments of Environmental Exposures  
In the mid-1970s, [PERSON] and [PERSON] carried out the first comprehensive survey of environmental RF fields in urban environments for the U.S. Environmental Protection Agency (EPA) [18]. This survey showed that the strongest environmental RF fields in U.S. urban areas were produced by FM radio and VHF television broadcasting stations; exposure levels in publicly accessible spaces were far below the exposure limits then in effect. However, other measurements by [PERSON] showed that RF exposures close to high-powered FM broadcast station antennas could easily exceed general public or occupational exposure limits [19]. The U.S. Federal Communications Commission (FCC) adopted its first exposure limits in 1985, and later produced a series of technical bulletins providing guidance for implementing the Commission's exposure limits, focusing on exposures from broadcast transmitters and other high power sources that were of regulatory concern. Following the increased public concern about possible health effects from environmental RF sources, numerous surveys have measured environmental RF fields from diverse technologies including broadcast transmitters, cellular base stations, mobile phones and other communications sources in environments as diverse as schools, workplaces, homes, trains and other vehicles (e.g., [20]). Recently, [PERSON] et al. carried this farther, estimating organ-specific exposures from environmental exposures to RF fields [21]. These studies together present a detailed picture of environmental RF exposures, nearly all of which are at levels far below internationally accepted safety limits. These surveys were enabled by advances in instrumentation for exposure assessment over the years. The EPA-sponsored survey in the mid-1970s employed a van filled with calibrated antennas and spectrum analyzers that the investigators drove around the country and set up in chosen locations. Since then, portable instrumentation has been developed to allow frequency-selective measurements, for example the Narda SRM 3000 selective radiation meter (first referenced in the RF bioeffects literature in 2010) that combines a three-axis electric field probe and spectrum analyzer in an accurate and sensitive (but quite expensive) handheld instrument. This frequency selectivity enables the user to distinguish the source of a measured signal, and in advanced instrumentation, such as the Narda SRM 3000. even down to the particular wireless channel utilized by a cellular service or Wi-Fi network. Broadband handheld RF meters have been available for many years, chiefly intended for use in occupational settings for worker protection, and remain widely used for that purpose. More recently, a variety of inexpensive RF exposure meters have appeared on the consumer market that allow consumers to measure RF fields in their homes to address their health concerns, and, apparently for other purposes as well. For example, Amazon.com lists dozens of inexpensive RF meters; one unit (the Erickhill EMF meter, USD 39) is sold as a 'great tester for home EMF inspections' as well as for 'ghost hunting'. Such meters have very high sensitivity (needed to measure environmental RF fields at levels that would be found in most nonoccupational environments). Some have RF pulse detectors of very high sensitivity and emit 'clicks' reminiscent of Geiger counters in the presence of signals from Wi-Fi and other digital networks. Due to their high sensitivity and uncertain accuracy [22] they are unsuitable for occupational safety evaluations.