OK - sort of DIY...
We live fairly close to an electricity substation. It's housed in a building which is approximately single-garage-sized. The building is at the bottom of our 30ft garden - so we sleep perhaps 40ft away from it.
There have often been rumours of dangers to health due to close proximity to substations. But when I search, there is nothing concrete. I do notice, however, that our portable phone makes a weird buzzing noise, which ascends and descends about once a second. The base frequency (without it's 1Hz modulation) is, I guess, very similar to mains humm - i.e. about 50Hz.
I know that it could just be a crappy phone/power supply (BT Synergy 4500). And I've tried turning everything else in the house off. But in the back of my mind is the constant nagging doubt that it is some form of magnetic emission from the substation. From what I read, the electrical element cannot get through any building materials - just the magnetic waves.
How would I go about measuring such an emission?