A 10-year Follow-up Cohort Study of the Health Effects in Toner-handling Workers

Abstract

In this study, we compare the results of a cross-sectional survey and secular changes between tonerhandling workers and non-toner-handling workers, focusing on blood tests, urinalysis, respiratory function tests, and chest imaging results as indices of health effects. Of 116 employees who participated in the survey conducted at an office equipment manufacturer in Japan, 65 male employees who could be followed up for 10 years were included in the analysis. Thirty-eight workers engaged in toner-handling operations were considered toner-handling workers, and 27 not engaged in these operations were considered non-toner-handling workers. The blood tests (WBC, CRP, IgE, KL-6, and SP-D), urinalysis (8-OHdG), respiratory function tests (PEFR, VC, %VC, FEV 1.0 , and FEV 1.0% ), chest radiography, and chest CT results were compared between both groups. Non-toner-handling workers had significantly higher 8-OHdG/Cre at baseline and KL-6 at year 10 than did toner-handling workers. There were no significant differences between the results of the cross-sectional survey and a longitudinal survey of respiratory function test results. We conclude that there were no adverse health effects due to toner exposure.

Results of a Series of Epidemiological Investigations on Health Effects in Toner-Manufacturing Workers

“…Most parameters showed no significant difference between the toner-handling group and the non-handling group during the ten years of investigation. The Yanagi paper [11] showed no statistically significant differences between groups for CRP, IgE, SP-D, and 8-OHdG/Cre throughout the 10-year observation period. However, KL-6 was significantly higher in the toner non-treatment group than in the toner treatment group.…”

“…No significant effect was observed in the estimated average dust concentration and cumulative toner age. The Yanagi paper [11] found no statistically significant difference between baseline and 10-year toner-handling and non-toner-handling groups. They also compared the difference in the annual decline in respiratory function between all participants and his 10-year non-smoker, examining changes in respiratory function over time with and without toner exposure.…”

“…In the Hasegawa paper [14], two-way analysis of variance (ANOVA) and post hoc Tukey test, Mann-Whitney U test, multiple regression analysis, and Pearson's chi-square test were conducted. In the Yanagi paper [11], normality was assessed with the Shapiro-Wilk test, Mann-Whitney U test, and Student's t test. Changes in respiratory function over time due to toner exposure were estimated by stepwise multiple regression analysis.…”

“…Each establishment's survey method used the same items and procedures as much as possible. The findings of five of the six companies surveyed were published in an English academic paper [11][12][13][14][15]. Table 1 shows the survey period profile and items at each tonermanufacturing company.…”

“…Our department has conducted studies on the health effects of toner handling workers and published several papers [11][12][13][14][15][16][17][18][19][20][21]. This paper presents the 10-year cohort of papers we have submitted and published to date and outlines the health effects of toner p article exposure among toner handling workers.…”