It has been suggested that the recent increase in inflammatory diseases is related to an increase in environmental chemicals and psychiatric stress. To investigate the effect of chronic topical exposure to chemicals and isolation stress, low-dose formalin (a mild contact sensitizer and an irritant), 2,4,6-trinitrochlorobenzene (TNCB; a potent contact sensitizer) and sodium lauryl sulphate (SLS; an irritant) were applied to mouse ears at 7-d intervals under no-stress or stress conditions. Skin reactions (ear swelling) elicited by formalin and TNCB increased time dependently. At the chronic stage, a significant skin reaction peaking at 1 h after application was elicited on the formalin-treated sites, while a shift from a delayed-type hypersensitivity to an immediate-type response was observed on the TNCB-treated sites. At the formalin-treated sites, genes related to neurogenic inflammation, i.e., bradykinin (BK) B2 receptor, IL-6, and membrane metallo endopeptidase (NEP) mRNA were upregulated. In the TNCB-treated sites, marked upregulation of IFN-γ, IL-1β, IL-4, and IL-6 mRNA was observed in addition to B2 receptor mRNA. Pretreatment with HOE140, the B2 receptor antagonist suppressed these skin reactions. Increased skin sensitivity to an unrelated chemical, ethanol, and thermal stimuli were elicited in formalin and TNCB-treated mice. Cortisol levels in formalin-treated mice and IgE levels in TNCB-treated mice were elevated respectively. Stress markedly amplified the skin reactions and gene expression related to neurogenic inflammation. SLS did not induce any changes. It was concluded that chronic topical exposure to low-dose noxious chemicals and stress could easily induce skin sensitivity relating to the BK-B2 pathway and nociceptive sensitization reflecting neural sensitization.

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Few studies have examined the individual and social impact of smoking behavior in the Japanese population. The purpose of this study was to clarify the association between smoking behavior and socio-demographic factors, lifestyle, mental health and work characteristics of Japanese civil servants. A self-administered questionnaire survey of 1,439 employees (821 men and 618 women) aged 20-64 yr was conducted in a local government department in 2001. The questionnaire included items on socio-demographic factors, education level, grade of employment, lifestyle, affect balance scale, and work characteristics. Smoking status was divided into current smoker, ex-smoker and never smoked. Multiple logistic regression analysis was performed to evaluate the relationship between smoking and the other items. Men presented a higher smoking prevalence rate than women (53.1% vs. 4.9%). In men, a strong relationship between current smoker and advanced age (40 yr or older), low education level, less physical activity, irregular breakfast and negative affect balance was found. Among men with a low education, the prevalence of smoking cessation was significantly lower in comparison to men with a high education. In women, being young (20-29 yr), unmarried (single or other), having a hobby, and irregular breakfast were associated with smoking behavior. Furthermore, smoking cessation was significantly associated with having a hobby and negative affect balance. The above results suggest that socio-demographic, lifestyle and mental health characteristics are independently associated with current smoking. These factors should be considered in smoking cessation policies as program components.

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The aims of the present study were to develop and validate the Japanese version of the checklist individual strength questionnaire (CIS) which is used to measure prolonged fatigue not only in the general population but also in the working population. We obtained permission to use CIS from its author and translated the questionnaire into Japanese. Then, the Japanese version of the questionnaire was translated back into English by a bilingual person. The author of the original version agreed that the back-translated version was conceptually and linguistically equivalent to the original CIS. To validate CIS, 399 workers (66.7% were men) from different companies answered the Japanese version of the CIS (CIS-J), Maslach burnout inventory-general survey (MBI-GS), Beck Depression Inventory-II (BDI-II), visual analogue scale (VAS) questionnaires for subjective fatigue, number of overtime hours and number of hours of sleep. Cronbach's α for the total CIS-J score was 0.91. The test-retest reliability assessed with an intra-class correlation coefficient was 0.82. Although confirmatory factor analysis did not show an ideal model fit, the correlation coefficients between the total CIS score and the MBI-GS exhaustion score, the BDI-II score and the VAS score were 0.58 (p<0.01), 0.66 (p<0.01) and 0.63 (p<0.01), respectively. The less workers slept and the longer they worked, the higher their total CIS score became. CIS-J showed good reliability and acceptable validity in the working population. Thus, it could be useful for studying fatigue among Japanese working populations.

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The aim of this study was to elucidate the usable predisposing factors of sleep-disordered breathing (SDB) in the workplace. A total of 353 male workers who complained of SDB related symptoms such as witnessed snoring, recurrent awakening from sleep, urination during the night, morning headache, and excessive daytime sleepiness were included in the analysis. We examined hyoid-mental distance (HMD), modified Mallampati score (MMS), and the narrowness of the pharynx with tonsillar hypertrophy as the predisposing physical findings of SDB. We used the number of 3% or more oxygen desaturation events per hour (ODI3) as the indicator of SDB. The mean values (S.D.) of all subjects were 44.3 (8.9) yr (19-66 yr) of age, and 25.9 (3.8) Kg/m² body mass index (BMI). A significant difference in ODI3 was found between the HMD classes, and also between the subjects with and without tonsillar hypertrophy. Mean ODI3 adjusted for age, BMI, and alcohol consumption on the day of monitoring was high in the group of short HMD and the group of tonsillar hypertrophy (+). For MMS, though ODI3 did not appear to be significantly different, mean ODI3 was high in the MMS-IV. In conclusion, short HMD and tonsillar hypertrophy are the important findings predicting SDB identified by pulse oximetry. These findings would be beneficial in the workplace for selection of subjects who should be encouraged to undergo pulse oximetry for detection of SDB.

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A cross-sectional study was conducted to explore what work-related factors were associated with job stress among pediatricians in Japan, as determined by the demand-control-support model and psychosomatic symptoms. We sent an anonymous questionnaire to a random sample of 3,000 members selected from the nationwide register of the Japan Pediatric Society and received 850 responses (response rate, 28%). Data from the 590 respondents who worked more than 35 h per week as a pediatrician and had no missing responses in the questionnaire were analyzed. We measured workload-related variables (e.g. working hours, work schedule) and recovery-related variables (e.g. workdays with no overtime, days off with no work in the past month) as exposure variables, and psychosocial job stressors (the Brief Job Stress Questionnaire) and psychosomatic symptoms as outcome variables. Longer working hours per week was significantly associated with greater job demand, lower job control and more psychosomatic symptoms (p<0.05). After adjusting for working hours, more workdays with no overtime was significantly associated with lower job demand, greater job control and fewer psychosomatic symptoms (p<0.05). Our findings suggest that long working hours is a risk factor for job stressors and psychosomatic symptoms, and that workdays with no overtime is a protective factor which may facilitate recovery. Controlling working hours and encouraging non-overtime workdays may be important for reducing job stressors and psychosomatic symptoms among pediatricians in Japan.

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The control banding method, or "control banding", is a simplified risk assessment system for chemical handling tasks. This system is supposed to provide assessment results of reasonable quality without expert involvement. The objective of this study was to evaluate the appropriateness of control banding judgment on the basis of workplace safety. A common approach for assessing workplace risk, which is called "comprehensive risk assessment" in this study, is to measure workers' exposure and compare it with relevant occupational exposure limits. Risk assessment was performed with control banding (COSHH Essentials, UK) at 12 workplaces of a petroleum company in Japan, where health risks had already been assessed separately through comprehensive risk assessment by experts and control technologies implemented accordingly. The obtained control banding judgments were then examined with regard to their adequacy by comparing them with existing control technologies. There was majority of cases (seven) where judgments by control banding were identified as "over-controlled"; there was no judgments identified as "under-controlled". Control banding also requested the seeking of expert advice in the majority of cases (eight). Thus, it was demonstrated that control banding tends to provide safe-sided judgment. A possible interpretation of this is that control banding is inherently designed to secure workplace safety by compensating for its insufficient exposure information with safe-sided judgment criteria and by requiring experts' intervention in high-risk cases. Control banding could be widely and effectively utilized in Japan, especially by employers in small enterprises, provided that the above characteristics are pre-acknowledged and health experts are made available. To this aim, it is essential to develop new local health experts and establish institutional mechanisms for facilitating employers' access to expert advice. It should however be noted that the number of workplaces evaluated in this study was small.

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We evaluated the possibility of applying field-portable x-ray fluorescence (FPXRF) analysis as a rapid, on-site and near real-time method for evaluating airborne lead contamination in Korean workplaces. A total of 287 airborne lead filter samples were measured in 12 lead-using workplaces during routine industrial hygienic monitoring procedures as required by Korean government regulations. All filter samples were collected using the standard industrial hygiene sampling protocol described in NIOSH Method 7300 using closed-face 37-mm cassettes with preloaded cellulose ester membrane filters with a pore size of 0.8 μm. The samples were first analyzed using the non-destructive, FPXRF analytical method (NIOSH method 7702), and then subsequently analyzed using inductively coupled plasma atomic emission spectrophotometry (ICP) (NIOSH method 7300) as a reference analytical method. Pair-wise comparison of filter samples using the paired t-test revealed no statistically significant differences between the two methods over a wide range of airborne lead levels (0.018-0.201 μg/m³) either over the industries assessed or separately in the 12 lead-using workplaces. Linear regression of the data between the ICP and FPXRF methods produced a slope of 1.03, a y-intercept of 0.13 μg/sample, and a coefficient of determinant (r²) of 0.975 for all the data. For samples in the range from 0 to 100 μg, the corresponding values were 1.07, -1.20 μg/sample, and 0.925, respectively. There were no significant differences in the regression analyses of the three industry types (r²=0.964-0.982). Our data suggest that FPXRF data are highly correlated with those from the laboratory-based ICP method in terms of accuracy, precision, and bias. Therefore, FPXRF can be used for the rapid, on-site analysis of lead air-filter samples for values up to 26 μg/sample prior to laboratory confirmation by the ICP method.

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Synthetic pyrethroids such as cypermethrin, deltamethrin and permethrin, which are usually used in pest control operations, are metabolized to 3-phenoxybenzoic acid (3-PBA) and excreted in urine. Though 3-PBA can be used to assess exposure to pyrethroids, there are few reports describing urinary 3-PBA levels in Japan. This study aimed to investigate the seasonal variation of the exposure levels of pyrethroids and the concentration of urinary 3-PBA among pest control operators (PCOs) in Japan. The study subjects were 78 and 66 PCOs who underwent a health examination in December 2004 and in August 2005, respectively. 3-PBA was determined using gas chromatography-mass spectrometry. The geometric mean concentration of urinary 3-PBA in winter (3.9 μg/g creatinine) was significantly lower than in summer (12.2 μg/g creatinine) (p<0.05). Geometric mean concentrations of urinary 3-PBA in the spraying workers and the not-spraying workers within 2 d before the survey were 5.4 μg/g creatinine and 0.9 μg/g creatinine for winter with a significant difference between the groups (p<0.05), and 12.3 μg/g creatinine and 8.7 μg/g creatinine for summer (p>0.05), respectively. A significant association of 3-PBA levels and pyrethroid spraying was thus observed only in winter. In conclusion, the results of the present study show that the exposure level of pyrethroids among PCOs in Japan assessed by monitoring urinary 3-PBA was higher than that reported in the UK but comparable to that in Germany. Further research should be accumulated to establish an occupational reference value in Japan.

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School teaching is regarded as a stressful occupation. The present study aimed to compare the likelihood of having minor psychiatric disorders (MPD) among school teachers with that among civil servants, and to investigate what factors were specifically associated with MPD in teachers. We conducted a questionnaire-based survey of 403 teachers employed at state schools and 611 civil servants as a comparison group in a medium-sized city in Japan. The response rate was 59.6% for teachers and 62.0% for civil servants. Mental health was assessed using the 28-item General Health Questionnaire (GHQ-28), according to which those with a score of six or higher were considered to have MPD. Logistic regression analysis was used to identify the factors associated with MPD. Although the proportion of subjects with MPD among teachers was greater than that among civil servants, the difference in the proportion was not statistically significant in the multiple logistic regression analysis adjusted for potential confounders. In a separate analysis of the teachers, reduced job satisfaction and shorter time spent of leisure were significantly associated with an increased likelihood of having MPD. In the group of civil servants, longer working hours, reduced life satisfaction, a history of sick leave, and physical illness were associated with an increased likelihood of having MPD. When this analysis was conducted separately for male and female teachers, job dissatisfaction alone was associated with MPD only in female teachers. Poor mental health of Japanese school teachers, female teachers in particular, was found to be associated with job dissatisfaction.

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Despite long-standing concerns regarding the effects of working hours on the performance and health of medical residents, and the patients' safety, prior studies have not shown an association of excessive sleepiness with the number of sleeping hours and days of overnight work among medical residents. In August 2005, a questionnaire was mailed to 227 eligible participants at 16 teaching hospitals. The total number of sleeping hours in the last 30 d was estimated from the average number of sleeping hours during regular days and during days with overnight work, and the number of days of overnight work. Multiple logistic regression analysis was used to adjust for potentially associated variables. A total of 149 men and 47 women participated in this study. The participation rate was 86.3%. Among the participants, 55 (28.1%) suffered from excessive sleepiness. Excessive sleepiness was associated with sleeping for less than 150 h in the last 30 d (corrected odds ratio [cOR]=1.57; 95% confidence interval [CI], 1.02-2.16). The number of days of overnight work in the last 30 d showed no association with excessive sleepiness. Excessive sleepiness was also associated with smoking (cOR, 1.65; 95%CI, 1.01-2.32). Medical residents who slept for less than 150 h in the last 30 d and smoked had a significantly higher risk of excessive sleepiness on duty.

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The garment manufacturing process is a labour intensive task. The workers in this are employed in three different sections namely cutting, stitching and finishing. As these workers perform repetitive tasks throughout the workday, they face several work related problems. The aim of this study was to assess the level of awareness of health problems among garment workers and their attitudes and practices to prevent the same. In a cross-sectional study (n=216) the workers employed in the three sections had high levels of knowledge of the health problems, but the knowledge of personal protective equipment differed by section. More than one half of the workers in all the sections were aware of the benefits of personal protective equipment (PPE), but only a few workers in the cutting section were using PPE. There was a wide gap between their knowledge level and practice with protective devices.

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