High-voltage power lines and substations conveying 50Hz frequency current, which itself does not produce high-frequency electromagnetic radiation, the main hazard is when the transmission voltage is higher, around the wire or substation near the generation of frequency electric field and frequency magnetic field, easy to produce harm to the human body. Secondly, the electromagnetic noise generated (mainly below 30MHz) will interfere with broadcasting and radio communication when it is strong. Monitoring results show that: (1) under the high-voltage power lines, 110KV double line under the range of several hundred to 2000V/m, 220KV double line tower under the 3000V/m or so, are less than the limit value of 4KV/m; 500KV line under the 5000V/m or so, more than the limit value of 4KV/m; (2) high-voltage substations, open 110KV and 220KV main transformer 1.5 meters, the I-frequency field strength as high as 2050-3200MHz. Field strength as high as 2050-3200V/m; if the whole indoor and underground substations, due to the role of building shielding, substation outdoor and substation ground IF field strength value is basically the same as the background value of the environment (below 10V/m). (3) all indoor and underground substation 20 meters away from the electromagnetic noise value is basically less than the limit of 55 dBμV/m.
Generally speaking, the radar system, television and radio transmission systems, radio frequency induction and media heating equipment, radio frequency and microwave medical equipment, a variety of electroprocessing equipment, communications transmitter stations, satellite earth communication stations, large electric power stations, power transmission equipment, high-voltage and ultrahigh voltage Power transmission equipment, high voltage and ultra-high voltage transmission lines, subway trains and electrical trains, as well as most of the household appliances, etc. can produce various forms, different frequencies, different intensity of electromagnetic radiation sources.
But some countries set the safety distance of high-voltage lines to a few hundred meters, I think that's mainly for the ten-thousandths of a millionth of a millionth of a millionth of a millionth of a millionth of a millionth safety and long-term construction considerations. In addition the effect of electromagnetic radiation, just one of the considerations, until now there is no exact scientific basis, we have no need to aggravate their minds before the country's new regulations come out. But then again, long-term living near high-voltage lines or bad ah.