Re: Have your say on the future of EMF guidelines
Wayne, I do happen to have an instance of human response to canceling fields. I was called in to the residence of a health practitioner who is sensitive to magnetic fields over about 2 mG. She would not use the lights in the bedroom/bathroom since she was disturbed by the effect.
I found high fields, up to 30 mG in those areas. The cause of the fields was that the feed supplying the bathroom light switch box was jumped from the receptacle circuit, but only the hot was used. Why? The original feed's hot had been capped off at the breaker box. I found continuity to ground: probably shorted from a sheet rock nail or whatever. The original electrician had capped it off, but did not also cap off the neutral. Instead he used the hot from the recept circuit but not its neutral.
So he had the hot coming in around the bedroom and the neutral going back directly through the floor down to the entrance. This set up a net current loop creating the high fields.
Now to get to your question about whether balancing the fields still does not remove the effects on humans: the sensitive lady was in the room when we were working on the problem. The electrician switched on one light. She exclaimed, "that's better". The electrician grinned (he was typically skeptical) and said, "I turned it on, not off". He thought he had her. I measured with a gaussmeter and a clamp-on ammeter. His turning the light on actually reduced the field and net current since we were dealing with a 3-wire circuit and there was some balancing.
The physics of balancing of magnetic fields is that they do actually cancel. Just as in the sea with waves from two directions, if a crest and trough coincide you get no wave. Gone.
And just a note on shielding net current fields. No material shields net current fields. Only balanced fields can be shielded.
Karl