  In a recent Letter [J. Phys. Soc. Jpn. 71, 432 (2002)], we reported a
preliminary calculation and concluded that public exposure to mobile phones can
be enhanced by microwave reflection in public spaces. In this paper, we confirm
the significance of microwave reflection reported in our previous Letter by
experimental and numerical studies. Furthermore, we show that "hot spots" often
emerge in reflective areas, where the local exposure level is much higher than
average. Such places include elevators, and we discuss other possible
environments including trains, buses, cars, and airplanes. Our results indicate
the risk of "passive exposure" to microwaves.
