Ketchen E E, Porter W E, Bolton N E
Am Ind Hyg Assoc J. 1978 Jan;39(1):1-11. doi: 10.1080/0002889778507706.
The biological effects of the interaction of stationary magnetic fields (SMF) with man and other animals have been reviewed. The lowest detectable limit of interaction between higher animals and a SMF is 80 to 100 G. The recommended limit on an extended-period basis for whole-body or head exposure is 200 G. Higher limits of magnetic-field exposure for limited periods of time are contained within this report.