A cohort study of toner-handling workers on inflammatory, allergic, and oxidative stress markers: cross-sectional and longitudinal analyses from 2003 to 2008.

Abstract

This study examines the relationship between toner exposure and its health effects in terms of biomarkers which are known to assess the damages to humans caused by toxic material exposure. The subjects were 1504 male workers aged below 50 in 2003 in a Japanese toner and photocopier manufacturing company. Personal exposure measurements, pulmonary function tests, chest X-ray examinations, biomarker measurement, and a questionnaire about respiratory symptoms were conducted. We will report about biomarker measurement in this study. Cross-sectional survey studies and a longitudinal study from 2003 to 2008 were conducted. Few significant findings were associated with the toner exposure in both the cross-sectional and the longitudinal studies. The higher toner exposure concentrations did not induce effects on increasing biomarkers. There was no evidence of excessive inflammatory, allergic, or oxidative stress reaction in toner-handling workers as compared to non-handling workers, despite some sporadically significant findings. There are no other reports of a longitudinal epidemiological study with regard to toner exposure; this report significantly contributes to toner exposure literature. Although in the current well-controlled working environment, the toner exposure concentrations are quite low; further studies are needed to completely understand the health effects toner may have, however small they may be.