Task-based estimation of past exposures to 60-hertz magnetic and electric fields at an electrical utility.
Objectives Past exposures of electric utility workers to extremely low-frequency (ELF) magnetic (B) and electric fields (E) in Québec were estimated.
Methods The current intensities were measured and durations of exposures determined for tasks or work locations in 14 job categories.
Past task or location intensities were extrapolated from the present on the basis of interviews with long-term workers and utility personnel.
Past task or location durations were estimated for the long-term workers.
Time-weighted average (TWA) exposures for past periods were reconstructed for jobs from the intensity and duration estimates.
Results Magnetic fields were estimated to have increased the most over time for substation and distribution-line jobs.
Magnetic field exposures for jobs in the generation and transmission of electricity were estimated to have increased very little.
For substation jobs, the ratios of magnetic fields in 1945 to those in 1990 ranged from 0.42 to 0.69 ; the corresponding figures for distribution-line jobs ranged from 0.36 to 0.94.
For electric fields in substations, the estimated increase over time was less than for magnetic fields, the 1945 : 1990 ratios ranging from 0.59 to 0.88.
For the distribution line jobs, the 1945 :
1990 ratios for electric fields were less than 1.0 in 4 cases (0.6 to 0.89), more than 1.0 in 3 others (1.13 to 2.01) and unchanged in I. (...)
Mots-clés Pascal : Champ électromagnétique, Extrême basse fréquence, Compagnie électricité, Homme, Exposition professionnelle, Rétrospective, Activité professionnelle, Poste travail, Relation dose réponse, Temps exposition, Champ électrique, Champ magnétique, Epidémiologie, Médecine travail, Québec, Canada, Amérique du Nord, Amérique
Mots-clés Pascal anglais : Electromagnetic field, Extremely low frequency, Electric utility, Human, Occupational exposure, Retrospective, Professional activity, Workplace layout, Dose activity relation, Exposure time, Electric field, Magnetic field, Epidemiology, Occupational medicine, Quebec, Canada, North America, America
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 98-0079138
Code Inist : 002B30B04. Création : 14/05/1998.