How do electric and magnetic fields affect electronic circuits?
I'm just answering the magnetic field part of the question: -

31.869 µT (3.2 × 10−5 T) is the strength of Earth's magnetic field at 0° latitude, 0° longitude so hopefully you can put that into context with the 60 µT requirement. I'd say that if the equipment were moving fast there could be induced voltages in cables of sensitive equipment but without knowing anything about the circuit I cannot say.

Anyway, motional emf = vBL

Where v is velocity in m/s, B is flux density and L is length of wire. This applies to an open circuit wire.

Here's my thoughts on the E-field side: -

It's really tricky to generalize how the E-field will affect a "general circuit". All I can say is that it can create a voltage in space of 10V/metre and across a gap of (say) 1mm is creates a voltage of 10mV RMS. But what is that "sort" of gap on a PCB and how "collapsable" is the field in the presence of a moderately low impedance across that 1mm. If I assumed that there is likely to be an accompanying H-field i.e. there is a proper electromagnetic field then I could argue that the impedance source is 377 ohms (impedance of free space) but then the accompanying H field will also induce a voltage so, I'm backing out of answering this part because it's beyond my skillset.