Estimating core body temperature using electrocardiogram signals.

Suppressing the elevation in core body temperature is an important factor in preventing heatstroke. However, there is still no non-invasive method to sense core body temperature. This study proposed an algorithm that estimates core body temperature based on electrocardiogram signals. A total of 12 healthy men (mean age ± SD = 39.6 ± 13.4) performed an ergometric exercise load test under two conditions of exercise load in an environmental chamber adjusted to a temperature of 35°C and humidity of 50%. Vital sensing data such as electrocardiograms, core body temperatures, and body surface temperatures were continuously measured, and physical data such as body weight were obtained from participants pre- and post-experiment. According to basic physiological knowledge, heart rate and body temperature are closely related. We analyzed the relationship between core body temperature and several indexes obtained from electrocardiograms and found that the amount of change in core body temperature had a strong relationship with analyzed data from electrocardiograms. Based on these findings, we developed the amount of change in core body temperature estimation model using multiple regression analysis including the Poincaré plot index of the ECG R-R interval. The estimation model showed an average estimation error of -0.007°C (average error rate = -0.02%) and an error range of 0.457-0.445°C. It is suggested that continuous core body temperature change can be estimated using electrocardiogram signals regardless of individual characteristics such as age and physique. Based on this applicable estimation model, we plan to enhance estimation accuracy and further verify efficacy by considering clothing and environmental conditions.

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

In this study, we compare the results of a cross-sectional survey and secular changes between toner-handling 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, FEV1.0, and FEV1.0%), 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.

Effects of toner-handling work on respiratory function, chest X-ray findings, and biomarkers of inflammation, allergy, and oxidative stress: a 10-year prospective Japanese cohort study.

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 the 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 the longitudinal data, we used a linear mixed model. RESULTS: Similar chest X-ray results, the biomarkers, and most of the respiratory function indicators were found in the non-toner-handling and toner-handling groups. There were no significant yearly changes in the percentage of vital capacity (%VC) in the high-concentration toner exposure group, while there was a significant yearly increase in %VC in the low-concentration toner exposure group and non-toner-handling group. The yearly change in each group was as follows: high-concentration toner exposure group, - 0.11% (95% confidence interval [CI], - 0.29 to 0.08; P = 0.250); low-concentration toner exposure group, 0.13% (95% CI, 0.09-0.17; P < 0.001); and non-toner-handling group, 0.15% (95% CI, 0.01-0.20; P < 0.001). CONCLUSIONS: In our 10-year prospective study, 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 a well-managed work environment.

Health Effects of Toner Exposure Among Japanese Toner-Handling Workers: A 10-Year Prospective Cohort Study.

The main objective of this study was to evaluate the risk of the respiratory diseases, i.e. pneumoconiosis, lung fibrosis, granulomatous pneumonitis, lung cancer and bronchial asthma, which have been reported as related to toner exposure. The second main objective was to clarify the association between toner exposure and parameters related with toner-handling worker's health. We conducted a 10-year prospective cohort study from 2004 to 2013 in 296 Japanese toner-handling workers. The evaluation of toner exposure and medical health check were performed once a year. There was no obvious evidence of occurrence of lung diseases. We also investigated several health parameters to recognize the change of respiratory health before onset of pneumoconiosis, lung fibrosis, lung cancer and bronchial asthma. However there were some sporadic statistically significant findings, to bring all health parameters, we did not find obvious evidence that toner exposure would cause adverse health effects as a whole. We concluded that the possibility that toner exposure would cause adverse health effects was quite low.

The respiratory effects of toner exposure according to long-term occupational toner handling history: A longitudinal analysis, 2004-2013.

OBJECTIVES: This report shows the relationship between toner exposure and respiratory effects for individuals with a longterm occupational toner-handling history, from 2004 to 2013. MATERIAL AND METHODS: Authors studied 752 Japanese male workers in toner handling workshops. A total of 673 men who participated in an annual monitoring survey were analyzed in this study. The following monitoring was performed in the same season each year: personal exposure measurements, biological markers, respiratory function tests, a chest X-ray, chronic respiratory symptoms and incidences of respiratory diseases. To evaluate the toner exposure effect, the exposure categories suitable for each evaluation index were established. RESULTS: For those with an occupational toner-handling history, the mean occupational toner-handling period was 14.36 years (standard deviation = 6.62); one participant had 35 years of exposure, which was the longest and one participant had 1 year of exposure which was the shortest. There were no statistically significant differences in the rate of change of respiratory function tests. An ANOVA conducted on blood and urine test results showed that statistically significantly differences were observed for a few items but all the values were very low and within the standard range. CONCLUSIONS: Authors conducted a 10-year ongoing study, but no obvious negative influences on health were attributed to toner exposure. In a work environment where adequate administrative controls are in place, personal toner exposure levels may be expected to be low, with no adverse effects on human health. Int J Occup Med Environ Health 2018;31(6):809-822.

Oxidative DNA damage in the rat lung induced by intratracheal instillation and inhalation of nanoparticles.

Nanoparticles are widely used as useful industrial materials. Therefore, their possible adverse health effects must be appraised. We assessed and compared the oxidative DNA damage caused by four different nanoparticles (TiO2, NiO, ZnO and CeO2). The effects of the administration methods, intratracheal instillation and inhalation, were also evaluated. Rats were subjected to intratracheal instillations or 4 weeks of inhalation exposure to the nanoparticles, and the 8-hydroxydeoxyguanosine (8-OHdG) levels in the lung were analyzed by an HPLC-EC detector method. The 8-OHdG levels were increased in a dose-dependent manner with the inhalation of NiO. ZnO also increased the 8-OHdG levels with inhalation. In comparison with the control, the 8-OHdG levels were significantly and persistently higher with the CeO2 nanoparticle administration, by both intratracheal instillation and inhalation. In contrast, there were no significant differences in the 8-OHdG levels between the control and TiO2 nanoparticle-treated groups, with either intratracheal instillation or inhalation during the observation period. These results indicated that NiO, ZnO and CeO2 nanoparticles generate significant amounts of free radicals, and oxidative stress may be responsible for the lung injury caused by these nanoparticles. In addition, both intratracheal instillation and inhalation exposure induced similar tendencies of oxidative DNA damage with these nanoparticles.

Cancer Risks of Hexavalent Chromium in the Respiratory Tract.

Hexavalent chromium (Cr(VI)) compounds are recognized as carcinogens in the respiratory tract, giving rise to cancers of the lung, nose and nasal sinuses, especially in certain occupational environments. Inhalation exposure of Cr(VI)-containing particles, dusts and fumes commonly occurs in chromium-related occupational environments, such as chromium production, plating, welding of chromium-containing metals and alloys, electroplating, chromium-containing pigments and paints. Epidemiological surveys of chromium compounds have shown strong associations between exposure to Cr(VI) and mortality due to lung cancer, as well as positive associations with cancers of the nose and nasal cavity. Nasal symptoms, such as nasal irritation, ulceration and perforation of the nasal septum, nasal turbinate engorgement and hypertrophy, are important signs for the early diagnosis of lung cancer and cancers of the nose and nasal cavity in those with an occupational history of Cr(VI) exposure. Cr(VI) exposure in the workplace remains a serious problem as a cause of lung cancer and cancers of nose and nasal cavity, especially in relatively small enterprises that use chromium compounds. Appropriate protection for workers should be considered in occupations that involve exposure to chromium compounds.

Assessment of Pulmonary Toxicity Induced by Inhaled Toner with External Additives.

We investigated the harmful effects of exposure to a toner with external additives by a long-term inhalation study using rats, examining pulmonary inflammation, oxidative stress, and histopathological changes in the lung. Wistar rats were exposed to a well-dispersed toner (mean of MMAD: 2.1 µm) at three mass concentrations of 1, 4, and 16 mg/m3 for 22.5 months, and the rats were sacrificed after 6 months, 12 months, and 22.5 months of exposure. The low and medium concentrations did not induce statistically significant pulmonary inflammation, but the high concentration did, and, in addition, a histopathological examination showed fibrosis in the lung. Although lung tumor was observed in one sample of high exposure for 22.5 months, the cause was not statistically significant. On the other hand, a persistent increase in 8-OHdG was observed in the high exposure group, indicating that DNA damage by oxidative stress with persistent inflammation leads to the formation of tumorigenesis. The results of our studies show that toners with external additives lead to pulmonary inflammation, oxidative stress, and fibrosis only at lung burdens beyond overload. These data suggest that toners with external additives may have low toxicity in the lung.

Evaluation of an emergency treatment training program for occupational health nurses.

OBJECTIVES: The purpose of this study was to evaluate the appropriateness and usefulness of the first aid training program developed for occupational health nurses (OHNs) to improve their basic skills of first aid treatment. METHODS: This was a case-control study. The subjects were 69 nurses who were stationed in workplaces in Japan (intervention group: n=35; waiting-list control group: n=34). The training program was developed using the method of instructional design (ID) and composed of basic life support (BLS) training, basic first aid training, and simulation training. This study was conducted from April to August 2012. The training was evaluated using the Kirkpatrick model of training evaluation: level 1 (reaction), level 2 (learning), level 3 (behavior), and level 4 (results; this level was omitted). For level 1, the training contents were evaluated on a visual analog scale (VAS) of 0 to 10 points on the basis of whether the programs' contents were interesting, understandable, and applicable in the workplace. For level 2, a knowledge test (15 true/false questions) was used. For level 3, the practical application of activities relating to the emergency system was evaluated. RESULTS: There were no significant differences in the attributes and characteristics of the subjects of the workplaces between the intervention and the waiting-list control groups. The score for reaction (level 1) were 8.5-9.7 points. In the knowledge test (level 2), there was no significant difference in the score before training between the intervention (11.0 points) and the waiting-list control groups (11.1 points). However, the score three months later showed a significant difference between the intervention (12.5 points) and the waiting-list control groups (11.0 points). The score after training was significantly higher than the score before the training that the intervention group received. For evaluation of behavior (level 3) three months later, the ratios of implementation of management and review of necessary items, review of task, and discussion with OHNs on emergency systems were significantly high in the intervention group. CONCLUSIONS: The evaluation of the first aid training programs for OHNs in this study showed high satisfaction of the participants and indicated improved knowledge and contributions to the waiting-list control group. We consider the contents of the program as appropriate.

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.

Extremophilic polysaccharide nanoparticles for cancer nanotherapy and evaluation of antioxidant properties.

Polysaccharides that show finest bioactivities and physicochemical properties are always promising for bionanoscience applications. Mauran is such a macromolecule extracted from halophilic bacterium, Halomonas maura for biotechnology and nanoscience applications. Antioxidant properties of MR/CH nanoparticles were studied using biochemical assays to prove the versatility of these test nanoparticles for biomedical applications. Here, we demonstrate the prospects of extremophilic polysaccharide, mauran based nanoparticles for scavenging reactive oxygen species in both in vitro and ex vivo conditions. 5-fluorouracil loaded MR/CH nanoparticles were tested for anticancer proliferation and compared their therapeutic efficiency using breast adenocarcinoma and glioma cells. Fluorescently labeled nanoparticles were employed to show the cellular uptake of these nanocarriers using confocal microscopic imaging and flow cytometry.

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 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. 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.

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.

[Certified occupational physician system of Japan Society for Occupational Health].

Certified Occupational Physician System (COPS) of Japan Society for Occupational Health has been in existence for 21 years, since 1992. UOEH has supported this system as a secretary general. In this report, we review the 2012 revision of COPS. With the new title of Certified Associate Occupational Physician (CAOP), this revision was established to produce well-educated and experienced occupational physicians. The title of COP is not competitive but independent to other titles such as occupational physician, medical advisor in industrial health or industrial health consultant. In addition, the aim of COPS is not the replacement to these existing systems. Furthermore, the COP should be active in industrial and occupational health, and should cooperate with existing systems through the sharing of experience and knowledge.

Activities of private clinic- or hospital-based occupational physicians in Japan.

The present study was initiated to examine the activities of private clinic- or hospital-based occupational physicians (OPs) and to identify difficulties the OPs encountered in their occupational health service (OHS). A questionnaire was sent by mail to 557 OPs in Kyoto prefecture, Japan. Effective answers were obtained from 86 OPs who were private practitioners or physicians in hospitals and served as OPs on a part-time basis. Considering 3 h as a unit, a majority (92%) served <1 to 2 units/month. The leading fields of OHS provided by the OPs were general health examination and its follow-up, prevention of overwork, and mental health care, as well as support of workers on sick leave to return to work. OPs wished to allocate more time for maintenance and management of work and the work environment, mental health care, work area rounding, and attendance at the safety and health committee meetings. Difficulties were encountered most often in the management of mental ill health and overwork, and support of employees' return to work. Many OPs also reported difficulties with industrial hygiene-related issues such as risk assessment, and maintenance and management of work and the work environment. The present survey identified difficulties that were frequently encountered by private clinic- and hospital-based OPs in their practice of OHS; these include issues on mental health, overwork and industrial hygiene. The needs to offering OPs specific opportunities to gain information and skills in these areas are stressed.

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.

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.

Descriptive study of external employee assistance program providers (EAP) in Japan.

The mental health problems of employees have become a major occupational health issue in Japan. External employee assistance program providers (EAP) have become important in mental health care for workers, but their activities are poorly documented. This descriptive study was undertaken to clarify the status and future tasks of EAP in Japan. The subjects were all EAP (n=27) registered in the Japanese Chapter of Employee Assistance Professionals Association. The questionnaire survey was conducted in January 2007. We received 13 replies, a response rate of 54.2%. Most EAP provided seminars, stress checks, stress management, counseling, and support for a return to work. The number of EAP contracted with small-scale enterprises was small. EAP communicated infrequently with companies. To promote the use of EAP, their advertising, education and training of staff, accumulation of scientific evidence, development of an official certification system for staff, and improvement of contents of EAP services were cited.

Dispersion of single-walled carbon nanotubes modified with poly-l-tyrosine in water.

In this study, complexes composed of poly-l-tyrosine (pLT) and single-walled carbon nanotubes (SWCNTs) were produced and the dispersibility of the pLT/SWCNT complexes in water by measuring the ζ potential of the complexes and the turbidity of the solution were investigated. It is found that the absolute value of the ζ potential of the pLT/SWCNT complexes is as high as that of SWCNTs modified with double-stranded DNA (dsDNA) and that the complexes remain stably dispersed in the water at least for two weeks. Thermogravimetry analysis (TGA) and visualization of the surface structures of pLT/SWCNT complexes using an atomic force microscope (AFM) were also carried out.

Binding of human serum proteins to titanium dioxide particles in vitro.

OBJECTIVES: To determine the capacity of human serum proteins to bind to titanium dioxide (TiO(2)) particles of different polymorphs and sizes. METHODS: TiO(2) particles were mixed with diluted human serum, purified human serum albumin (HSA) or purified human serum gamma-globulin (HGG) solutions. After incubation at 37°C for 1 h, the particles were sedimented by centrifugation, and proteins in the supernatant, as well as those bound to the particles, were analyzed. RESULTS: The total protein concentration in the supernatant was lowered by TiO(2), whereas the albumin/globulin ratio was elevated by the particles. Incubation with TiO(2) also lowered the immunoglobulin, pre-albumin, beta2-microglobulin, ceruloplasmin and retinol-binding protein levels, but not ferritin levels, in the supernatant. After sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), proteins in the supernatant, especially HGG, were observed to decrease, while those released from the particles (after adding 1% SDS and heating) increased, depending on the dose of TiO(2). Purified HGG and HSA were also bound to TiO(2), although the former appeared to have a higher affinity. All the proteins tested showed the highest binding potency to the amorphous particles (<50 nm) and the lowest to the rutile particles (<5,000 nm), while binding to anatase particles was intermediate. The affinity to the larger anatase was higher than that to smaller anatase particles in most cases. CONCLUSIONS: Human serum proteins, including the two major components, HSA and HGG, are bound by TiO(2) particles. The polymorph of the particles seems to be important for determining the binding capacity of the particles and it may affect distribution of the particles in the body.

Work-family conflict and prolonged fatigue among Japanese married male physicians.

PURPOSE: Fatigue experienced by physicians may not only endanger their own health but may also affect the safety of patients. Such fatigue may be associated with the work environment and personal factors such as work-family conflict (WFC). This study aimed to determine the association between WFC and prolonged fatigue among Japanese married male physicians. METHODS: Physicians who graduated from a Japanese medical school answered a mailed anonymous self-report questionnaire. For assessment of WFC and prolonged fatigue, the Japanese versions of the WFC scale and the Checklist of Individual Strength questionnaire (CIS) were used. Prolonged fatigue was defined as the upper quartile of total CIS scores. The WFC scale comprises six dimensions. Total scores were divided into tertiles: low, intermediate, and high levels of WFC. A multiple logistic regression analysis was performed to examine the association between WFC and prolonged fatigue. RESULTS: A total of 540 male physicians answered the questionnaire, and the data of 444 married male physicians were analyzed. The data were then adjusted for age and work condition factors. Prolonged fatigue was significantly associated with high strain-based work interference with family (WIF; corrected odds ratio, 5.56; 95% confidence interval, 2.55-12.1), intermediate strain-based WIF (2.53, 1.25-5.10), high time-based family interference with work (FIW; 1.92, 1.08-3.40), and there was a weak association with high strain-based FIW (1.93, 0.98-3.83). CONCLUSIONS: Employers should take measures to improve working conditions in hospitals, and give physicians the opportunity to learn how to cope with WFC. These measures could ultimately help prevent prolonged fatigue.