Idiosyncratic generalized skin disorders resembling serious drug hypersensitivities have reportedly occurred after occupational exposure to trichloroethylene. However, factors associated with the disorders remain unknown except for trichloroethylene exposure. This study aimed at clarifying whether infectious diseases contributed to the development of rash or hepatitis in patients with trichloroethylene-related generalized skin disorders. Fifty-nine patients consecutively hospitalized between March 2002 and December 2003 and 59 healthy exposed workers selected on an age-matched basis in the patients' factories were enrolled in the study. Information on possible risk factors for rash and hepatitis was collected with structured checklists. Antibody titers were measured for hepatitis A, B and C viruses, Mycoplasma pneumoniae, herpes simplex viruses 1 and 2, Epstein-Barr virus, cytomegalovirus, human herpesvirus 6, measles and rubella virus. Thirty-six cases (59%) showed exfoliative dermatitis, 17 (28%) erythema multiforme, 4 (7%) Stevens-Johnson syndrome, and 4 (7%) toxic epidermal necrolysis. Before the onset of rash, 16 (27%) cases had received medication prescribed for the preceding fever, a main first symptom of the disorders. Marked increases in anti-human herpesvirus 6 IgG titer (≥256), which indicated viral reactivation, were noted in 14 (25%) patients, while no abnormal increase was detected in the controls (p<0.001). Anti-measles IgM titer was positive in 2 (7%) cases but not in the controls (p=0.49). The involvement of other known risk factors of rash or hepatitis was ruled out. These results suggest that part of trichloroethylene-related generalized cutaneous disorders occurring in China and drug-induced hypersensitivity syndrome overlap in terms of human herpesvirus 6 reactivation.
Carcinogenicity and chronic toxicity of 1,2-dichloroethane (DCE) were examined by inhalation exposure of groups of 50 F344 rats and 50 BDF1 mice of both sexes to DCE vapor or clean air as control for 6 h/d, 5 d/wk and 104 wk. The rats were exposed to 10, 40 or 160 ppm (v/v) DCE, while the mice were exposed to 10, 30 or 90 ppm. The 2-yr exposure to DCE produced a dose-dependent increase in incidences of benign and malignant tumors, including subcutaneous fibroma, mammary gland fibroadenoma and peritoneal mesothelioma in male rats; subcutaneous fibroma and mammary gland adenoma, fibroadenoma and adenocarcinoma in female rats; and bronchiolo-alveolar adenoma and carcinoma, endometrial stromal polyp, mammary gland adenocarcinoma and hepatocellular adenoma in female mice. No exposure-related change in the incidence of non-neoplastic lesions or in any hematological, blood biochemical or urinary parameter occurred in any DCE-exposed rat or mouse group. The types of tumors and their target organs found in this study were consistent with those observed in rats and mice administered DCE by gavage in a NCI study. Selection of the exposure concentrations was considered appropriate with reference to the maximum tolerated dose for the highest doses and an occupational exposure limit of DCE for the lowest dose. The present findings suggest that those carcinogenic responses be primarily considered for standard setting of occupational and environmental exposure to DCE.
To evaluate the safety of rock wool (RW) fibers, we examined the biopersistence of RW fibers in the lungs of rats, based on the changes of fiber number and fiber size in the length and width, in a nose-only inhalation exposure study. Twenty male Fischer 344 rats (6 to 10 wk old) were exposed to RW fibers at a fiber concentration of 70.6 (20.4) fiber/m3 and a dispersion density of 30.4 (6.6) mg/m3 [arithmetic mean (SD)] continuously for 3 h daily for 5 consecutive days. Five rats each were sacrificed shortly after exposure ended (baseline group) and at 1, 2, and 4 wk after exposure, and their lung tissues were ashed by a low temperature plasma-asher. The numbers and sizes of fibers in the ash samples were determined using a phase contrast microscope and a computed image analyzer. The fiber numbers in the lungs at 4 wk after exposure had significantly decreased from the baseline value, i. e. shortly after exposure (p<0.05). The half-lives of RW fibers calculated using the one-compartment model were 32 d for total fibers and 10 d for fibers longer than 20 μm in length. Fiber number was 53.6% of the baseline at 4 wk after exposure (baseline group=100%). Likewise, fiber sizes had significantly decreased at 4 wk after exposure (p<0.05), probably because fibers had been dissolved in body fluid, phagocytosed by alveolar macrophages or discharged from the body by mucociliary movement. In future studies, it will be necessary to examine the carcinogenicity of RW fibers through long-term inhalation studies.
To determine the associations between urinary catecholamines and cortisol and subjective complaints of fatigue in shiftworkers, we conducted a field survey of 113 male shiftworkers at a manufacturing company in South Korea from late October to late November in 1999. The shiftwork system in the company was the backward rapidly rotating 4-crew 3-shift, with the morning shift starting at 7:30 AM. Using a self-report questionnaire, we assayed demographic characteristics, past medical history and working hours, as well as subjective complaints of fatigue in 3 categories of questionnaire. We found that, among workers with less than 5 yr of shiftwork experience, the concentrations of norepinephrine, epinephrine (Epi), and dopamine during the afternoon shift were positively correlated with Set II (difficulties in concentration) and Set III (projection of disintegration) of subjective fatigue symptoms. In addition, Epi concentrations were positively correlated with Set I (drowsiness and dullness), II, and III of subjective fatigue symptoms during the night shift. However, among workers with 5 or more years of shiftwork experience, there was no significant positive correlation between urinary catecholamine and subjective fatigue symptoms. In the long term shiftwork experience group, only the complaints scores of Set II fatigue symptoms (difficulties in concentration) during the morning shift were significantly higher than those of the short-term shiftwork experience group within the same shift.
The present study examined the effects of pre-entry experiences (i.e. career maturity), as well as support networks (i.e. informational and friendship), on newcomers' mental health (i.e. depression, self-esteem, psychosomatic symptoms, and work motivation). We performed a longitudinal study of 890 men and women who first entered the workplace in 2003. Surveys were distributed at two time points: just prior to entering the workplace, and two months after entering. Results indicated that career maturity related positively to newcomers' mental health, and newcomers with high career maturity were more successful in establishing positive relationships with superiors and co-workers. Although, informational support networks positively related to work motivation, friendship networks did not show any direct effects on mental health. These results underscore the crucial roles of career maturity and informational networks in facilitating the transition to the workplace. The results also provide empirical support for an expanded view of the importance of pre-entry experiences to workplace newcomers' mental health.
Nasal, respiratory, reproductive and developmental toxicities of propylene oxide (PO) were examined by exposing male and female Sprague-Dawley rats to PO vapor by inhalation at a concentration of 0 (control), 125, 250, 500 or 1,000 ppm for 6 h/d, 7 d/wk, during a 5- to 6-wk period, including premating, mating and postmating or gestation. The inhalation exposure to 1,000 ppm PO seriously affected parental survival, the upper and lower respiratory tract, male and female reproductive systems, motor function, and fetal survival and development, whereas the exposure to 500 ppm or less primarily caused nasal lesions without any sign of reproductive or developmental toxicity. Because atrophy of the olfactory epithelium in the male rats exposed to 250 ppm was the most sensitive endpoint for PO toxicity, the NOAEL was determined to be 125 ppm for the nasal endpoint. An additional inhalation experiment was carried out to further examine developmental toxicity by exposing pregnant rats to 0, 125, 250, 500, 750 or 1,000 ppm PO during a 2-wk period of gestation, Day 6 through Day 19. The 2-wk inhalation experiment revealed that reduced fetal body weights and delayed ossification occurred in association with significantly reduced body weights of the dams exposed to 750 and 1,000 ppm, whereas neither fetal death nor teratogenicity occurred at those two exposure levels. It was concluded that the developmental toxicity of fetal death was manifested at parentally toxic exposure levels above 500 ppm, a level which seriously affected parental survival, the upper and lower respiratory tracts and reproductive system.
Healthcare workers (HCWs) are exposed daily to the risk of injury by needlesticks and other medical instruments. However, the psychiatric impacts of such injuries have not been evaluated. The aim of this study was to evaluate the mental health status of HCWs with experiences of needlestick and sharps injuries. A cross-sectional written survey was performed. The psychological symptoms before injury and current status were measured using the Beck Depression Inventory (BDI), Hamilton Anxiety Scale (HAM-A) and Perceived Stress Scale (PSS). The proportions of HCWs with and without needlestick and sharps injuries were 71.1% (n=263) and 28.9% (n=107), respectively. HAM-A and BDI scores were significantly higher among HCWs with injury experiences (p<0.01). HCWs with injury experiences exhibited higher PSS and BDI scores after the injury and higher levels of anxiety and depression. Particular attention should be directed towards the psychological consequences of needlestick and sharps injuries in HCWs.
Myoga is a fragrant plant which is the special product of Japan and is cultivated throughout Japan. According to our earlier investigation (unpublished data) of myoga cultivators in Japan, 8 of 35 cultivators experienced contact dermatitis in the harvest season. The purpose of this study was to assess the allergenicity of myoga and its major volatile components. The volatile components of myoga were analyzed by gas chromatograph (GC). They included a-pinene, β-pinene and R-(+)-limonene. We performed a toxicity study of each of the major fragrant components of myoga using acute dermal irritation assays and the Guinea-Pig Maximization test (GPMT) in order to probe the mechanism of allergic contact dermatitis. In acute dermal irritation assays, α-pinene, β-pinene and limonene showed positive responses at concentrations of 4%; limonene oxide at 20% and myoga showed a positive response at concentrations of 100%. From the results of the GPMT, according to Kligman scores, limonene oxide was identified as an extreme skin sensitizer and myoga as a mild skin sensitizer. The results of the present study show that R-(+)-limonene is the most important allergen amongst the chemical components of myoga, and we consider it to be the reason why myoga cultivators experience allergic contact dermatitis.
Although the effect of disorders on psychological well-being is well-known, there are few studies focusing on oral conditions at the worksite. The present study examined the association between psychological well-being and oral conditions of Japanese workers. A cross-sectional study was performed using data from 1381 Japanese civil service officers aged 20-59 yr old. Psychological well-being was measured with the 12-item version of the General Health Questionnaire (GHQ-12) in a comprehensive health questionnaire, while measures for oral condition included self-rated oral health, oral symptoms and clinical indicators: dental caries, periodontal status and number of missing teeth. The mean GHQ scores according to the levels of each oral condition were estimated by analysis of variance, separately for males and females. Higher scores corresponded to poorer psychological well-being. Age, gender, smoking and type of occupation were adjusted in a multivariate analysis. Psychological well-being was not associated significantly with dental caries, periodontal status or number of missing teeth. The adjusted means of the GHQ scores for `conscious of appearance of mouth' were significantly different among the categories for both genders (male: p<0.001, female: p=0.018). For five of six oral symptoms, the adjusted means of GHQ scores were lowest for those respondents who rated their oral symptoms as `never or hardly ever.' Our results did not show that psychological well-being was associated with oral conditions measured by clinical indicators. However, an association was found between some oral symptoms and psychological well-being. Absence of oral symptoms seems to be related to better psychological well-being.
As job stress is now one of the biggest health-related problems in the workplace, several education programs for supervisors have been conducted to reduce job stress. We conducted a supervisor-based randomized controlled trial to evaluate the effects of an education program on their subordinates' psychological distress and job performance. The subjects were 301 employees (46 supervisors and 255 subordinates) in a Japanese sake brewery. First, we randomly allocated supervisors to the education group (24 supervisors) and the waiting-list group (22 supervisors). Then, for the allocated supervisors we introduced a single-session, 60-min education program according to the guidelines for employee mental health promotion along with training that provided consulting skills combined with role-playing exercises. We conducted pre- and post-intervention (after 3 months) surveys for all subordinates to examine psychological distress and job performance. We defined the intervention group as those subordinates whose immediate supervisors received the education, and the control group was defined as those subordinates whose supervisors did not. To evaluate the effects, we employed a repeated measures analysis of variance (ANOVA). Overall, the intervention effects (time × group) were not significant for psychological distress or job performance among both male (p=0.456 and 0.252) and female (p=0.714 and 0.106) subordinates. However, young male subordinates engaged in white-collar occupations showed significant intervention effects for psychological distress (p=0.012) and job performance (p=0.029). In conclusion, our study indicated a possible beneficial effect of supervisor education on the psychological distress and job performance of subordinates. This effect may vary according to specific groups.
In order to examine the relationship between the intention to stay on the job and job satisfaction among Japanese nurses, and to obtain clues for preventing turnover, we conducted a questionnaire survey. The subjects involved in the survey included 625 female nurses (registered nurses, licensed practical nurses and assistant nurses) working in 4 small and medium-sized private hospitals, excluding directors of nursing. Of the 625 questionnaires distributed, 556 (89.0%) were returned. After excluding the questionnaires with missing values, 480 questionnaires were analyzed (effective response rate, 76.8%).The average age of the respondents was 32.8 yr (range: 20-65). The content of the questionnaire was nurse attributes, job satisfaction (30 items) and intention to stay on the job. For job satisfaction, factor analysis (principal factor method and promax rotation) was performed, and factors with an eigenvalue of ≥1 were extracted. Six factors were extracted by factor analysis. These factors were interpreted as "Work as specialists" (1st factor), "Relationship with superiors" (2nd factor), "Comfortable life" (3rd factor), "Relationship among nurses" (4th factor), "Communication with physicians" (5th factor) and "Working conditions" (6th factor). The factor scores were calculated and used as a scale for the evaluation of job satisfaction. To investigate the factors associated with intention to stay on the job among nurses, the standard partial regression coefficient was computed by multiple linear regression analysis, with intention to stay on the job as the dependent variable, and nurse attributes and job satisfaction (factor scores) as independent variables. Various factors including the organizational culture of each hospital may affect the relationship between job satisfaction and the intention to stay on the job. In order to adjust for these factors, differences among hospitals were included in the statistical model as independent variables. The result of the multiple regression analysis suggests that the intention to stay on the job was higher among nurses who were older and more satisfied with work as specialists (1st factor) and working conditions (6th factor).
The aims of the present study were to clarify the work environment contamination by antineoplastic drugs in a hospital ward and to assess the genotoxic risks to nurses who routinely handle antineoplastic drugs in Japan. The exposed group consisted of 19 female nurses who routinely handled antineoplastic drugs. The control group consisted of 18 female nurses who did not handle antineoplastic drugs in the same hospital as the exposed group. The genotoxicity of the 19 antineoplastic drugs used in the hospital ward and 8 wipe samples of the workbench after handling of antineoplastic drugs were measured using the umu assay. Lymphocyte DNA damage (tail length) was measured with alkaline methods of the single cell gel electrophoresis assay (comet assay). Of the 19 antineoplastic drugs, dacarbazine, bleomycin, daunorubicin, doxorubicin, pirarubicin, carboplatin, cisplatin and etoposide induced genotoxicity. Of the 8 sampling d, the umu activity of the wipe sample was positive on 3 d. Contamination of the workbench was found when the nurses handled more drugs than on other days. The medians of the tail length in the comet assay were 8.5 and 5.1 μm, respectively, for the exposed and control groups, with a significant difference (p=0.004 by Mann-Whitney's U-test). In the present study, the nurses of the exposed group were considered to have been exposed to antineoplastic drugs and lymphocyte DNA damage of the exposed group was suggested to be induced by antineoplastic drugs.