It has been a matter of concern whether fiber shape of cellulose containing dusts might be responsible for health complaints and respiratory diseases with lung function impairment. Therefore, inhalable dust and fiber dust concentrations were determined in our study simultaneously. The results of the ambient monitoring revealed very high dust exposures for the inhalable dust fraction, whereas the respirable fraction was considerably low (Table 2). This might lead to the suggestion that in our study the potential for the detection of adverse effects on the lower respiratory tract could be small.
However, a significant decrease of FVC of 8.5% was found with relation to cumulative dust and fiber exposure (8.3%). This effect was found despite a relatively low respirable dust fraction of 4.5% on average and after adjustment for important confounding factors. The parameter estimates show a dose-response relationship with relation to cumulative exposure indexes based on a high number of dust measurements. Moreover a significant decrease of FEV1 of 6.3% was found for workers with a cumulative exposure > 25 dust-years compared to the reference group. FEV1/FVC ratio is not significantly increased with increasing cumulative exposure. This indicates that a restrictive pattern of lung function impairment occurs with increasing cumulative exposure to soft tissue paper dust. canadian health&care mall
When interpreting the results of our study, it should be considered, that compared to other studies, very high dust exposure was detected on average exceeding the threshold limit value of 10 mg/m. Due to these high exposures and due to the study design of a cross-sectional study, a healthy worker effect is likely to occur and might lead to an underestimation of the adverse effects described. Workers with manifest respiratory diseases and severe lung function impairment are not able to work under dusty conditions at paper machines or combiners.