| Popis: |
Background: Exposure to toner, a substance used in photocopiers and printers, has been associated with siderosilicosis and other adverse effects. However, these findings are limited, and there is insufficient evidence on the long-term effects of toner exposure. Using longitudinal analysis, this study aimed to examine the effects of work involving toner exposure on the respiratory system over time.Methods: We conducted a prospective cohort study in a Japanese toner and copier manufacturing enterprise between 2003 and 2013. The cohort included a total of 1468 workers, which comprised 887 toner-handling workers and 581 non-toner-handling workers. We subdivided the toner-handling workers into two groups according to the toner exposure concentration, based on the baseline survey in 2003. We compared the chest X-ray results, respiratory function indicators, and serum and urinary biomarkers of inflammation, allergy, and oxidative stress among three groups: high-concentration toner exposure group, low-concentration toner exposure group, and non-toner-handling group. To consider the effects of individual differences on longitudinal data, we used a linear mixed model.Results: The chest X-ray results and most of the biomarkers and respiratory function indicators were similar for the non-toner-handling and toner-handling groups. There were no significant yearly changes in the percentage of vital capacity (%VC) and peak expiratory flow rate (PEFR) in the high-concentration toner exposure group, while there was a significant yearly increase in %VC and PEFR in the low-concentration toner exposure group and non-toner-handling group. Regarding interleukin-8, we did not observe a significant yearly change in the toner-handling group but observed a significant yearly increase of 0.1 pg/ml in the non-toner-handling group.Conclusions: Toner-handling work was not associated with the deterioration of respiratory function and an increase in biomarker values for inflammation, allergy, and oxidative stress. This finding suggests that toner-handling work is irrelevant to the onset of respiratory disease and has minimal adverse effects on the respiratory system under the well-managed work environment. |
