Hiroko Kitamura

Cross-sectional study on respiratory effect of toner-exposed work in manufacturing plants, Japan: pulmonary function, blood cells, and biochemical markers

The aim of the study is to examine the relationship between toner-exposed work and health indices related to respiratory disorders and to confirm the baseline of a cohort study to clarify the effect of toner exposure in manufacturing plants. Subjects were 1614 male workers (809 toner-exposed workers and 805 referents) who were engaged in toner manufacturing plants in Japan (Fuji Xerox Co., Ltd). The age of subjects was from 19 to 59 years, and the average age was 40.2 years(median 40 years, SD 7.67). We conducted a pulmonary function test (PEFR, VC, FVC, FEV1.0%, V25/Ht) and a blood cell test (RBC, Hb, Hct, Plt, WBC, cell contents of WBC) and measured biochemical indices in blood (ALT, AST, γ-GTP, CRP, IgE) and 8-hydroxy-2’-deoxyguanosine (8-OHdG) in urine. Student t-test and logistic regression analysis were applied to compare between the toner-exposed workers and the referents and to analyze the relationship among indices of effects and independent factors. There was no significant difference between the two groups in blood cell count and biochemical indices. Inflammation- and allergy-related markers such as 8OHdG and IgE also showed no significant difference between toner-exposed workers and the referents. The influence of smoking on pulmonary function indices was observed, but there was no relationship between the pulmonary function and toner-exposed work. In this article, we report a preliminary cross-sectional analysis in the subjects of a cohort study. No difference in pulmonary function indices was observed between the toner-exposed workers and the referents, and there was no consistent relationship between the exposure status and examined indices; however, the prevalence of subjective respiratory symptoms was higher in the exposed workers as presented in another report. Further analysis is important in the ongoing cohort study to clarify the effect of toner exposure on respiratory systems.

Cross-sectional study on respiratory effect of toner exposure

In this baseline study, part of a cohort study to clarify the effect of toner exposure on the respiratory system, we surveyed 803 male toner workers and 802 referents with regard to their subjective respiratory symptoms and chest X-ray results. We also examined individual exposure history, current working conditions, and personal exposure levels to toner. There was a significantly higher prevalence of “coughing and sputum” related complaints among toner-exposed workers in the 30 and 40-year age groups. The group with toner-exposure history showed a higher odds ratio, by logistic regression, in relation to all questions regarding coughing. Mild fibrotic changes were observed in the chest X-rays of four workers who had engaged in toner-exposure work for at least a decade or more, and all four had reported allergic disease. Although we observed a tendency of higher prevalence of “coughing and sputum” in toner-exposed workers, the possibility of information bias cannot be eliminated. It should also be noted that this tendency did not exceed that of the general public. Further analysis is required in this ongoing 10-year cohort study to clarify the effect of toner exposure on the respiratory system.

Relationship between smoking and a new index of arterial stiffness, the cardio-ankle vascular index, in male workers: a cross-sectional study

BackgroundCigarette smoking is one of the major factors that increases arterial stiffness. The purpose of this study was to examine further the relationship between smoking status and arterial stiffness using a new index, the cardio-ankle vascular index (CAVI), in male Japanese workers.MethodsThis cross-sectional study included 4,729 male Japanese workers undergoing annual health checkups. CAVI was measured at the time of the annual health checkup between April 2007 and March 2008. The subjects were divided into three groups, smokers (n = 1,913), former smokers (n = 1,481) and non-smokers (n = 1,348) according to their responses to a questionnaire. We compared the CAVI in the three groups after adjusting for age. Multiple regression analysis was used to examine the association between CAVI and the number of cigarettes smoked per day in order to examine whether there was a dose–response relationship between smoking and CAVI.ResultsThe mean CAVI for each group was 7.81 ± 0.02 for smokers, 7.70 ± 0.02 for former smokers and 7.64 ± 0.02 for non-smokers. A significant difference was observed between each group. According to the results of multiple regression analysis, the standardized β of the number of cigarettes smoked per day was 0.09 (p < 0.01). This confirmed a positive association with CAVI.ConclusionsOur study demonstrated that there is a significant association between the number of cigarettes smoked per day and arterial stiffness, as measured by CAVI.

Relationship between Overtime Work Hours and Cardio-ankle Vascular Index (CAVI): A Cross-sectional Study in Japan

Relationship between Overtime Work Hours and Cardio‐ankle Vascular Index (CAVI): A Cross‐sectional Study in Japan: Koichi HATA, et al. Department of Work Systems and Health, Institute of Industrial Ecological Science, University of Occupational and Environmental Health, Japan—

A Cohort Study on Self-Reported Respiratory Symptoms of Toner-Handling Workers: Cross-Sectional and Longitudinal Analysis from 2003 to 2008

This study examines the relationship between toner-handling work and its health effects on self-reported respiratory symptoms. The subjects were 1,504 male workers in a Japanese toner and photocopier manufacturing company. Personal exposure measurement, pulmonary function tests, chest X-ray examination, measurement of biomarkers, and a questionnaire about self-reported respiratory symptoms were performed annually. This study discusses the questionnaire results. We found that the toner-handling group showed significantly higher prevalence of breathlessness than the never-toner-handling group. The significant reduction of pulmonary function and fibrosis change in the chest X-ray examination associated with breathlessness were not observed. However the morbidity of asthma was higher compared to the Japanese population in both of the toner-handling group and the never-toner handling group, the effect of toner exposure was not clarified. Nevertheless, while the toner exposure levels in the current well-controlled working environment may be sufficiently low to prevent adverse health effects, further studies are needed to assess the more long-term latent health effects of toner exposure.

A cohort study using pulmonary function tests and x-ray examination in toner-handling workers: cross-sectional and longitudinal analyses from 2003 to 2008.

Objectives: This study uses pulmonary function tests and chest x-ray examinations to examine the relationship between toner-handling work and its health effects. Methods: The subjects were 1504 male workers in a Japanese toner and photocopier manufacturing company, in the age range from 19 to 50 years in 2003. Personal exposure measurements, pulmonary function tests, chest x-ray examinations, biomarker measurements, and a questionnaire about respiratory symptoms were conducted. The present study reports the results of pulmonary function tests and chest x-ray examinations conducted in the subjects, which includes a cross-sectional study on the toner handling and non-handling workers and a longitudinal study from 2003 to 2008. Results: Few significant findings were suspected to be caused by toner exposure found in pulmonary function indices in both the cross-sectional and longitudinal studies. Any obvious fibrotic findings in chest x-ray findings related to the toner exposure could not be found out. Conclusion: No evidence of adverse effects on pulmonary function indices and chest x-rays was present in the toner-handling workers as compared to the nonspecifically exposed workers. Although the toner exposure concentration is quite low in the current well-controlled working environment, even among the toner-handling workers, we would like to continue this study in the future to verify the toner exposure health effects.

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

Objectives: 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. Methods: 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. Results: 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. Conclusion: 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.

Distributions and ranges of values of blood and urinary biomarker of inflammation and oxidative stress in the workers engaged in office machine manufactures: evaluation of reference values

Abstract Background: Interleukins, interferons and oxidative DNA products are important biomarkers assessing the inflammations and tissue damages caused by toxic materials in the body. We tried to evaluate distributions, reference values and age related changes of blood levels of inflammatory cytokines, C-reactive protein (CRP), IgE and urine levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG) among workers in a cohort study evaluating the health influences of toner particles. Methods: A total of 1366 male workers under age 50 years (age 19–49 years; 718 exposed and 648 not exposed to toner particles) in a cross sectional study of 1614 (categorized as 809 exposed and 805 not exposed, age 19–59 years) workers in a photocopier company has been followed prospectively as the cohort. Blood levels of interleukin (IL)-4, IL-6, IL-8, interferon-γ (IFN-γ), CRP, IgE and urine 8-OHdG were measured annually for 5 years. Results: Reference values of the biomarkers are; CRP: 0.01–0.63×10-2 g/L, IgE: 6–1480 IU/mL, IL-4: 2.6–76.1 pg/mL, IL-6: 0.4–4.9 pg/mL and 8-OHdG: 1.5–8.2 ng/mgCr. We could not evaluate reference values for IL-8 and IFN-γ because most of the values were below the sensitivity limits (2.0 pg/mL and 0.1 IU/mL, respectively). There were no differences of the biomarker levels between the toner exposed and the control workers. We observed a statistically significant age related decrease of serum IL-4 levels. Conclusions: This is the first report assessing the distributions and reference values of inflammatory biomarker levels in a large scaled cohort. We observed age related changes of some of the biomarkers. We could not detect any differences of the studied biomarker values between the toner exposed and the control workers.

A cohort study of the acute and chronic respiratory effects of toner exposure among handlers: a longitudinal analyses from 2004 to 2013

This study examines the acute and chronic respiratory effects of toner exposure based on markers for interstitial pneumonia, oxidative stress and pulmonary function tests. A total of 112 subjects working in a Japanese toner and photocopier manufacturing company participated in this study in 2004. We annually conducted personal exposure measurements, pulmonary function tests, chest X–ray examinations, biomarkers, and questionnaires on respiratory symptoms to the subjects. We report in this paper the results of the analysis of combined annual survey point data from 2004 to 2008 and data from three annual survey points, 2004, 2008, and 2013. During these survey periods, we observed that none of subjects had a new onset of respiratory disease or died of such a disease. In both the analyses, there were no significant differences in each biomarker and pulmonary function tests within the subjects, nor between a toner–handling group and a non–toner–handling group, except for a few results on pulmonary function tests. The findings of this study suggest that there were no acute and chronic respiratory effects of toner exposure in this cohort group, although the number of subjects was small and the level of toner exposure in this worksite was low.

A 4-Year Follow-up Cohort Study of the Respiratory Functions in Toner-handling Workers.

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 5th 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. Conclusion 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.