Abstract 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.
To clarify the long-term health effects from radiation exposure in emergency workers who responded to the radiation accident at the Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Company, which was hit by a tsunami caused by the 2011 off the Pacific coast of Tohoku earthquake, the Epidemiological Study of Health Effects in Fukushima Emergency Worker (currently, the Epidemiological Study on the Health Effects of Radiation Workers) was initiated in 2014. We aimed to compile the results of the Health Examination Study conducted from January 2016 to March 2019 to demonstrate the characteristics of the study participants during this period. We included individuals who completed the first health examination and provided consent to use their survey results in our study. A total of 5,718 people were included, among which 5,707 (99.8%) were men. The mean age of the study participants was 51.6 years at the time of the health examination. Compared to Japanese men, the study participants were more likely to have obesity, to be current smokers, and to consume alcohol at least once a month. There were no significant differences in the blood test results between the study participants and healthy Japanese men. To clarify the long-term health effects of radiation exposure on the emergency workers, it is important to make efforts to prevent the study participants from dropping out of the cohort over time and to keep them participating in the Health Examination Study.
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.
Abstract Background With the COVID-19 pandemic, the idea of universal mask wearing to prevent infecting others when one becomes infected has prevailed among people. In general, any workplace is not exempt and workers are required to wear a mask while working at the sites. Objectives This study aims to integrate information to assist workers to select effective protectors for the prevention of droplet infection even at workplaces without occupational health personnel. Methods A total of 94 studies were included in this study: 91 studies were identified in MEDLINE, which was used for the literature search, and an additional three studies were identified from other information sources. The studies were checked to eliminate duplication and narrowed down to 31 based on the titles and abstracts. The contents of the 31 studies were read through and then 19 studies were extracted for careful reading. Results and Conclusions Regarding the protectors used at workplaces, it was suggested that (1) workers continue to use respiratory protectors as needed at sites where respiratory protectors such as an N95 respirator had to be used even before the spread of COVID-19 and (2) wear surgical masks, multi-layer cloth masks, or hybrid fabric masks made of several types of fabrics that are recommended in terms of preventing dissemination of droplets and protecting against inhalation of droplets, selected according to the working conditions, taking account of air permeability, breathability, and durability.
A cohort of children prenatally exposed to the 1945 atomic bombings in Japan revealed harmful effects of ionizing radiation in a variety of measures of cognitive function, including mental retardation. Here we examined cognitive function in the non-affected, now elderly, cohort.From 2011-2015, using the Cognitive Abilities Screening Instrument and a maternal uterine radiation dose estimated with the 2002 dosimetry system, we evaluated 303 prenatally exposed subjects and their non-exposed controls from the Adult Health Study of the Radiation Effects Research Foundation, excluding those who had shown marked cognitive effects earlier. About 11% of the subjects were exposed to more than 250 mGy. We examined a self-reported disease history and, using regression analysis, evaluated the relationship between cognitive function and radiation exposures, adjusting for demographic factors.None of the subjects reported a history of dementia. We also did not find a significant radiation effect on cognitive function overall or in any gestational-week group. Education was associated with a significant effect, but educational level was not associated with radiation dose.We found no significant radiation effect on cognitive function among 65- to 70-year-old subjects who were prenatally exposed to the bombings and did not have marked childhood cognitive function deterioration. The limitations of this study include a small sample size and potential bias pertaining to non-participation in the Adult Health Study or refusal of Cognitive Abilities Screening Instrument evaluation. Further investigations using various endpoints in other populations prenatally exposed to radiation are warranted.
The purpose of this research was to evaluate the relationship between overtime work hours and CAVI, a new index of arterial stiffness.We measured CAVI of Japanese workers (3,862 men) aged 26 to 59 years. Simultaneously, we obtained information on their monthly overtime work hours for the past few months using a self-administered questionnaire, with responses divided into five groups: <45, ≥45 and <60, ≥60 and <80, ≥80 and <100 and ≥100 hours/month. We calculated the odds ratios of CAVI≥9.0 for each group of overtime work hours.In the full sample, there was no significant association between the average CAVI and overtime work hours. Taking<45 overtime hours/month as the reference category, the odds ratios of CAVI≥9.0 were as follows: OR=1.11, 95% CI=0.73-1.69 (≥45 and <60 hours/month); OR=0.92, 95% CI=0.48-1.76 (≥60 and <80 hours/month); OR=1.50, 95% CI=0.50-4.49 (≥80 and <100 hours/month); and OR=2.65, 95% CI=0.82-8.54 (≥100 hours/month). However, for workers in their 50 s, the odds ratio of CAVI≥9.0 was significantly higher among subjects with≥100 hours/month than among those with<45 hours/month (OR=4.26, 95% CI=1.2-15.1) CONCLUSIONS: The present study suggests that CAVI is more likely to be 9.0 or higher in workers in their 50 s when they work≥100 hours of overtime per month.
Endothelin (ET)-1(1-31) is a novel 31-amino acid-length peptide derived from big ET-1 by chymase or other chymotrypsin-type proteases and is a major ET derivative in human neutrophils. In this study, we revealed that ET-1(1-31), but not big ET, exhibited chemotactic activities toward human neutrophils and monocytes as an inflammatory mediator, although the effects were less potent than those of formyl-methionyl-leucyl-phenylalanine or interleukin-8. However, the chemotactic effects of ET-1(1-31) were much greater than those of the 21-amino acid ET-1, ET-1(1-21). Checkerboard analyses revealed that the effects are chemotactic rather than chemokinetic. The effects of ET-1(1-31) are not mediated by interleukin-8 or monocyte chemoattractant protein-1. The chemotactic effects and an increase in intracellular-free Ca(2)(+) caused by ET-1(1-31) were significantly inhibited by BQ123, an ET(A) receptor antagonist, but not by BQ788, an ET(B) receptor antagonist, suggesting that ET-1(1-31) mediates chemotaxis through an ET(A) or ET(A)-like receptor.
A woman in her 20s presented to our clinic with a lower gastrointestinal infection. When we administered intravenous antibacterial and vitamin infusions, she developed anaphylaxis. We performed skin tests to investigate the cause, and an intradermal test was positive for a 1% intravenous vitamin complex. We then performed a component-specific test, which was positive for thiamine disulfide phosphate, a vitamin B1 derivative. We therefore diagnosed anaphylaxis due to thiamine disulfide phosphate. No previous reports have described cross-reactivity between vitamin B1 derivatives. In our case, however, the patient tested positive for fluthiamine hydrochloride, suggesting cross-reactivity. Intravenous vitamin complexes are used in daily clinical practice and should be administered with caution because of the possibility of anaphylaxis, although it occurs infrequently.
