Abstract
This study was initiated to determine and compare daily occupational exposure (OE) and non-occupational exposure (NOE) of three employee groups of teachers, maintenance workers and secretarial staff in a Canadian school district. The time-weighted average (TWA) individual OE for subjects ranged from 0.4–3.8 milligauss (mG), and the TWA NOE ranged from 0.2–7.1 mG. TWA OE and NOE were 1.2 mG and 1.5 mG for teachers, 1.8 mG and 1.2 mG for maintenance workers, and 2.9 mG and 2.1 mG for secretarial staff. The differences between TWA OE and NOE of each group and also among the three groups were not statistically significant. OE and NOE of secretarial staff exceeded 10 mG 9.0% and 6.4% of the time–significantly (p<0.001) higher rates than those of OE and NOE of teachers (1.0% and 1.4%) and maintenance workers (2.8% and 0.1%). Exposures were well below recommended criteria.
Résumé
Cette étude a été menée pour déterminer et comparer l’exposition professionnelle (EP) et l’exposition non professionnelle (ENP) quotidiennes de trois groupes d’employés, à savoir le personnel enseignant, le personnel chargé de l’entretien et le personnel des services de secrétariat, dans un district scolaire du Canada. S’agissant de l’EP, la moyenne individuelle pondérée en fonction du temps, se situait entre 0,4 et 3,8 milligauss (mG), et entre 0,2 et 7,1 milligauss pour l’ENP. La moyenne individuelle pondérée en fonction du temps pour l’EP et pour l’ENP étaient de 1,2 mG et 1,5 mG respectivement pour le personnel enseignant, de 1,8 mG et de 1,2 mG respectivement pour le personnel chargé de l’entretien, et de 2,9 mG et 2,1 mG respectivement pour le personnel des services de secrétariat. Les différences entre les moyennes pondérées en fonction du temps de l’EP et de l’ENP de chaque groupe ainsi que parmi les trois groupes ne sont pas apparues statistiquement significatives. L’EP et l’ENP du personnel des services de secrétariat dépassaient 10 mG dans 9% et 6,4% du temps, soit des taux nettement plus élevés (p<0,001) que ceux de l’EP et de l’ENP du personnel enseignant (1% et 1,4%) et du personnel chargé de l’entretien (2,8% et 0,1%). Ces taux d’exposition étaient bien inférieurs aux recommandations.
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