Four hundred and forty personal air measurements were carried out on 54 workers, employed in the main processes in six different factories (6-13 in each).
Potential exposure was to lead, benzene and dust.
Ten randomly repeated hygiene surveys were carried out over 1 year.
In order to estimate the magnitude of the variability in workers'exposure over time, its sources, the variance between workers and the variance within a worker, a nested unbalanced analysis-of-variance model was fitted to the log-transformed data.
Of the total exposure variance, the within variance of a worker's exposure over time was 51% (geometrical standard deviation, GSD=3.1) and the between workers, factories and air contaminants variance was 49%. The exposure variance between all the workers was due mainly to variance between workers within the same factory (67%). Outdoor locations, mobility of the worker and mobility of the sources of exposure result in a positive influence on both the variance between (26%, ANOVA) and the variance of a worker over time (39%, regression).
These variables are therefore important in the sampling strategy of workers'exposure.
For valid compliance testing and assessment of workers'exposure the mean and the within-and between-variance of the workers'exposure over time should be considered.
The exposure should be measured several times a year randomly in order to prevent workers misclassification.
To assess yearly exposure, a GSD=3. (...)
Mots-clés Pascal : Composé chimique, Industrie, Exposition professionnelle, Médecine travail, Homme, Variabilité, Etude temporelle, Temps exposition, Etude longitudinale, Hygiène travail, Israël, Asie, Etude cohorte, Analyse variance, Analyse statistique
Mots-clés Pascal anglais : Chemical compound, Industry, Occupational exposure, Occupational medicine, Human, Variability, Temporal study, Exposure time, Follow up study, Occupational hygiene, Israel, Asia, Cohort study, Variance analysis, Statistical analysis
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 97-0455119
Code Inist : 002B03L01. Création : 03/02/1998.