There is a need to improve the biological data, dosimetry, and risk assessment methodology used for setting guidelines for occupational exposures to extreme-low-frequency magnetic fields.
This paper illustrates how a probabilistic approach can be used to determine priorities for future research based upon the analysis of biological and dosimetric variables that affect stimulation of the heart by magnetically-induced currents.
A model was constructed to predict a level of whole-body magnetic-field exposure below which no cardiac stimulation is expected (Bncs), For each iteration of the model, a value was selected from cardiac stimulation threshold, shape factor, and conductivity distributions by Latin Hypercube sampling, and a value for Bncs was computed.
The very wide range of simulated Bncs magnetic-field values obtained indicates that there is considerable uncertainty about what constitutes a « safe » level of exposure.
The results show that the major occupational-exposure guidelines are very conservative with respect to risks of cardiac stimulation.
The minimum B value computed (0.01 T) by either a circular-loop model or an ellipsoid dosimetric model is ten times the highest recommended workday exposure value in a guideline.
The lowest 5% B value calculated for a circular-loop model is about 50-times the ICNIRP occupational exposure limit ; the lowest 5% B value calculated for an ellipsoid model is more than 100 times the ACGIH occupational exposure limit. (...)
Mots-clés Pascal : Champ magnétique, Basse fréquence, Homme, Maladie professionnelle, Marqueur biologique, Dosimétrie, Facteur risque, Guide technique, Irradiation non ionisante, Modélisation, Coeur, Stimulation
Mots-clés Pascal anglais : Magnetic field, Low frequency, Human, Occupational disease, Biological marker, Dosimetry, Risk factor, Technical handbook, Non ionizing irradiation, Modeling, Heart, Stimulation
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0477013
Code Inist : 002B30B01B. Création : 22/03/2000.