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JULES COHEN & ASSOCIATES, P.C. <br /> CONSULTING ENGINEERS <br /> WASHINGTON, D.C. 20036 <br /> RADIO FREQUENCY EXPOSURE CONSIDERATIONS <br /> APPLICABLE TO PERSONAL COMMUNICATIONS SYSTEMS <br /> Pursuant to a request from American Personal Communications (APC), a study has <br /> been made of the radio-frequency exposure considerations applicable to Personal Communications <br /> System base stations. The results of that study are provided below. <br /> As described more fully below, the conclusion of the study is that the maximum level <br /> of exposure to radio-frequency energy for a person walking or standing in the near vicinity of the <br /> antenna would be approximately 200 times below the maximum permissible exposure level set <br /> by the most commonly applied safety standard. Furthermore, since that standard incorporates a <br /> safety factor of 50 below the threshold level where experiments suggest the possibility of adverse <br /> health effects, the base station total safety factor below that threshold level is 200 times 50, or <br /> • 10,000. <br /> Base stations operated by APC transmit in the frequency band 1930 to 1945 megahertz <br /> (millions of cycles per second - abbreviated as MHz) to mobile units. The maximum transmitter <br /> power output is only 20 watts. To provide satisfactory service, an antenna is used that directs the <br /> power toward the horizon, with very little power directed downward. The maximum equivalent <br /> power directed to_the_horizon_is_normall3_noin-excess-of-20-0-watts. <br /> In addition to the transmission described in the above paragraph, each base site is <br /> equipped with two microwave relay transmitters used to interconnect base sites. These systems <br /> use transmitter output of only 0.05 watt and operate at a frequency of approximately 38,000 MHz. <br /> The antennas used for this service are highly directional and make a negligible contribution to the <br /> total radio-frequency exposure at the site. <br /> • The protection standard used most widely in the United States, and one that is in <br /> excellent agreement with international standards, is that adopted by the American National <br /> Standards Institute (ANSI) in 1992. The standard (ANSI/IEEE Standard for Safety Levels with <br />