Variations in exposure to inhalable wood dust in the Danish furniture industry. Within- and Between-worker and factory components estimated from passive dust sampling

Abstract

Variability of exposure to wood dust at large factories in the Danish furniture industry was studied. Three repeated exposure measurements of 292 workers at 38 factories were included in the study. The measurements were carried out by use of personal passive dust monitors. The components of variance were estimated by means of a random effects ANOVA model. The ratio of within- to between-worker variance was 1.07. Based on this result, and three repeated exposure measurements, the observed relation between health outcome and exposure will be attenuated to 74% of the true value. Grouping by factory showed very poor exposure contrast, as the contrast in exposure level among factories was as low as 0.15.