Table 1.
EMF, electromagnetic field; +, increase; -, decrease; N, no change; RF, radio frequency; SHF, super high frequency; UHF, ultra high frequency; VHF, very high frequency; HF, high frequency; MF, medium frequency; LF, low frequency; VLF, very low frequency; SLF, super low frequency; ELF, extremely low frequency; CRT, cathode ray tube.
aRadio spectrums were divided into nine group according to Tanenbaum (2002), Beasley and Miller (2008).