title: A 4-Year Follow-up Cohort Study of the Respiratory Functions in Toner-handling Workers.
abstract: BACKGROUND
  Focusing on the respiratory function for health effect indices, we conducted a cross-sectional study on workers who did and did not handle toner to compare the longitudinal changes.
  
  
  METHODS
  Among 116 individuals who worked for a Japanese business equipment manufacturer and participated in the study, the analysis included 69 male workers who we were able to follow up for 4 years. We categorized the 40 workers engaged in toner-handling work as the exposed group and the 29 workers not engaged in these tasks as the referent group, and compared their respiratory function test results: peak expiratory flow rate (PEFR), vital capacity (VC), predicted vital capacity (%VC), forced expiratory volume in 1 second (FEV1), and forced expiratory volume in 1 second as a percent of forced vital capacity (FEV1%).
  
  
  RESULTS
  The cross-sectional study of the respiratory function test results at the baseline and at the 5(th) year showed no statistically significant differences in PEFR, VC, %VC, FEV1, and FEV1% between the exposed and referent workers. Also, respiratory function time-course for 4 years was calculated and compared between the groups. No statistically significant differences were shown.
  
  
  CONCLUSIONS
  Our study does not suggest any toner exposure effects on respiratory function. However, the number of subjects was small in our study; studies of larger populations will be desired in the future.
authors.affiliation: Institute of Industrial and Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Yanagi
authors.affiliation: Institute of Industrial and Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Kitamura
authors.affiliation: Institute of Industrial and Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Mitsuhito
authors.initials: M
authors.lastname: Mizuno
authors.affiliation: Institute of Industrial and Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Hata
authors.affiliation: Institute of Industrial and Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Uchiyama
authors.affiliation: Institute of Industrial and Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kuga
authors.affiliation: Institute of Industrial and Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Matsushita
authors.affiliation: Institute of Industrial and Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Shizuka
authors.initials: S
authors.lastname: Kurosaki
authors.affiliation: Institute of Industrial and Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Masamichi
authors.initials: M
authors.lastname: Uehara
authors.affiliation: Institute of Industrial and Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Ogami
authors.affiliation: Institute of Industrial and Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Higashi
keywords: cohort analysis; photocopying; respiratory function test