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We discuss two potentially challenging problems faced by the ecommerce industry. One relates to the problem faced by sellers while uploading pictures of products on the platform for sale and the consequent manual tagging involved. It gives rise to misclassifications leading to its absence from search results. The other problem concerns with the potential bottleneck in placing orders when a customer may not know the right keywords but has a visual impression of an image. An image based search algorithm can unleash the true potential of ecommerce by enabling customers to click a picture of an object and search for similar products without the need for typing. In this paper, we explore machine learning algorithms which can help us solve both these problems.

The aim of this study was to identify psychosocial work characteristics associated with long sick leave in a large population of male Japanese employees in multiple workplaces. We ex- amined various psychosocial work characteristics (job overload, job control, supervisor support, coworker support, support by family and friends, role ambiguity, role conflict, intragroup conflict and intergroup conflict) of employees in six factories at the base line. We then conducted a follow- up survey on the recorded long sick leaves of ≥30 continuous days taken by the employees due to any medical condition. We found 574 cases of long sick leave out of 15,531 subjects during an aver- age 5.07-yr follow-up. The results showed that high supervisor support was significantly associated with a decrease in the hazard ratio (HR) of long sick leave after adjustment for several confounding factors (95%CI; 0.69-0.97). High role ambiguity also tended to increase HR, but without reaching significance (95%CI; 0.99-1.41). The results suggest that supervisor support in the workplace may be important to reduce long sick leave in Japanese male employees.

Background: The relationship between passive smoking and sleep is uncertain. Purpose: To examine the association of passive/active smoking with sleep disturbances. Method: 732 women and 1,896 men, working in a suburb of Tokyo, were surveyed using a self-administered questionnaire. Information on smoking, passive smoking exposure, and sleep was elicited. Exposure levels to passive smoking were assessed separately at work and at home as no, occasional, or regular exposure. Risk of sleep disturbances according to smoking status was estimated using logistic regression with odds ratios (OR) and 95% confidence intervals (CIs) as measures of association. Results: Compared to never smokers, odds of difficulty awakening in the morning (DAM) in current smokers were significantly higher for women (OR 1.95) and men (OR 1.50), while increased difficulty initiating sleep (OR 1.88) and decreased early morning awakening (OR 0.31) were found only in women. Never smoking men occasionally exposed to passive smoking at work but not at home had increased odds (OR 1.81) of short sleep duration (SSD

To assess the relationship between blood concentrations of manganese (Mn) and intrauterine growth restriction (IUGR), Mn levels in the umbilical cord blood (UCB) and the mother whole blood (MWB) samples were measured in apparently healthy mothers and their newborns. Measurement was conducted by an inductively coupled plasma mass spectrometry. Manganese concentrations in MWB were significantly lower (p

Effects of nine social life indicators on age-adjusted and age-specific annual suicide mortality of male and female Japanese population in the years 1953-96 were investigated by multiple regression analysis on time series data. Unemployment rate was significantly related to the age-adjusted mortality in both males and females. Also, female labour force participation was positively related to the male mortality; persons and 65 and above was inversely related to the male mortality. Results on the age-specific mortality indicated that: during the 44 yr, (1) unemployment significantly related with the mortality of young, middle-aged and elderly males and young females; (2) female labour force participation significantly related with the mortality of young and elderly males and young females; aged population significantly related with the mortality of middle-aged and elderly males; (4) young population significantly related with the mortality of young and middle-aged males and females; (5) divorce significantly related with the mortality of middle-aged and elderly males and young males and females; (6) persons employed in primary industries significantly related with the mortality in middle-aged males and young males and females; and (7) population density significantly related with the mortality of middle-aged males and young females.

Active smoking is a risk factor for occupational injury, whereas its association with passive smoking is unknown. To evaluate the contribution of active and passive smoking to non-fatal occupational injury in manufacturing sectors, 2302 randomly selected workers aged 16-83 years working in 244 small- and medium-scale enterprises in Yashio city, Japan, were surveyed by means of a self-administered questionnaire. Smoking history, exposure to passive smoking, and occupational injury were evaluated by self-report. Exposure levels to passive smoking were assessed separately at work and at home as never, occasional, or regular exposure. Overall, 61.4% of men and 22.3% of women were current smokers. Among never smokers, 62.2% of men and 68.6% of women reported exposure to passive smoking either at work or home. Prevalence of occupational injuries was 36.2% for never, 43.3% for former, and 41.2% for current smokers among men and 19.7% for never, 22.2% for former, and 25.2% for current smokers among women. Among never smoking men, odds ratios (ORs) of occupational injury were 2.11 when regularly exposed to passive smoking at work or at home (p=0.025), 2.27 at work (p=0.015), and 3.08 at home (p=0.106), in comparison to never smoking men who were never exposed to passive smoking either at work or at home (referent group). These associations were attenuated to be non-significant, after controlling for potential confounders. Never smoking men with occasional exposure to passive smoking were not significant ORs (1.11-1.19). In contrast, current and former smoking men had significant increases in adjusted ORs (1.57-2.00). In women exposed to smoking there was a non-significant increase in occupational injury. The present study indicates an expected increase in the risk of, occupational injury for current and former smoking men and suggests that exposure to passive smoking is a possible risk factor for never smoking men.

To examine the effects of exposure to manganese (Mn) on the cellular and humoral immune system in men, T lymphocyte subpopulations, B (CD19+) lymphocytes, natural killer (NK) cells, and serum immunoglobulins (i.e., IgG, IgA and IgM) together with total T (CD3+) lymphocytes and total lymphocytes were measured in blood samples from 21 welders mainly exposed to Mn fume with blood Mn (BMn) concentrations of 0.6-2.3 (mean 1.4) microg/dl and 21 healthy controls working in the same factory (BMn concentrations: 0.7 to 1.7, mean 1.1 microg/dl). The workers engaged in welding for 6 to 36 (mean 17) yr. All the study subjects were divided into 3 equally sized groups (n=14 for each group) according to BMn concentrations. Numbers of CD8+ T, total T (CD3+), B (CD19+), and total lymphocytes were significantly lower in high-BMn group than those in low-BMn group; the numbers of CD8+ T lymphocytes were significantly lower in moderate-BMn group compared to low-BMn group. After adjusting for age and smoking, significant inverse correlations between BMn concentrations and CD4+CD45RA+ T, CD4+ T, CD8+ T, CD3+ T, and total lymphocytes were found. We conclude that T lymphocytes, especially CD8+ and CD4+CD45RA+ T lymphocytes, as well as CD19+ B lymphocytes are affected by exposure to Mn fume.

We examined the effects of pesticides on the central and peripheral nervous system in the setting of a tobacco farm at a developing country. Maximal motor and sensory nerve conduction velocities (MCV and SCV, respectively) in the median, sural and tibial nerves, postural sway, and brain-evoked potentials (auditory event-related and visual-evoked potentials) were measured in 80 male tobacco farmers and age- and sex-matched 40 controls in Kelantan, Malaysia. Median SCV (finger-wrist) in farmers using Delsen (mancozeb, dithiocarbamate fungicide), who showed significant decrease of serum cholinesterase activities, were significantly lower compared with the controls. Sural SCV in farmers using Fastac (alpha-cypermethrin, pyrethroid insecticide) and median MCV (elbow-wrist) in farmers using Tamex (butralin, dinitroaniline herbicide) were significantly slowed compared with their respective controls. In Delsen (mancozeb, dithiocarbamate) users, the power of postural sway of 0-1 Hz was significantly larger than that in the controls both in the anterior-posterior direction with eyes open and in the right-left direction with eyes closed. The former type of sway was also significantly increased in Tamaron (methamidophos, organophosphorus insecticide) users. In conclusion, nerve conduction velocities and postural sway seem to be sensitive indicators of the effects of pesticides on the central and peripheral nervous system.

This study was conducted to assess the relationship between blood lead levels and pregnancy-induced hypertension. Participants were 110 pregnant women, of whom 55 were hypertensive, 27 +/- 5.6 yr of age (mean +/- standard deviation) (range = 17-40 yr); the other 55 women were age- and gravidity-matched normotensive controls. Participants were selected on the basis of their medical history and the results of a questionnaire-based interview. Subjects were at gestational ages 37 +/- 2.5 wk (range = 30-41 wk) and were not occupationally exposed to lead. Blood samples were collected within 24 hr after delivery, and blood lead levels were measured. For the hypertensive cases, blood lead levels were 5.7 +/- 2 microg/dl (range = 2.2-12.6 microg/dl [0.27 +/- 0.10 micromol/l; range = 0.11-0.60 micromol/l]), which were significantly higher than those of the control group (i.e., 4.8 +/- 1.9 microg/dl; range = 1.9-10.6 microg/dl [0.23 +/- 0.09 micromol/l; range = 0.09-0.51 micromol/l]). There were no significant differences in blood lead concentrations among hypertensive subjects with proteinuria (n = 30) and those without proteinuria (n = 25). Results of this study indicated that low-level lead exposure may be a risk factor for pregnancy hypertension.

BACKGROUND: The relationship between occupational class and exposure to job stressors among employed men and women in Japan remains unclear. METHODS: Data of 16,444 men and 3,078 women were analyzed. The information was obtained from answers to a questionnaire distributed among employees of nine companies in Japan between 1996 and 1998 (average response rate, 85%). The International Standardized Classification of Occupations was used to classify respondents into eight occupational categories. The Job Content Questionnaire was used to measure job demands, job control, worksite support, and job insecurity. The associations between occupational class and job stressors, as well as job strain, were examined controlling for age, education, marital status, chronic medical condition, and personality traits, such as neuroticism and extraversion. RESULTS: Men and women in high-class occupations (e.g., managers and professionals) had significantly greater job control, while job demands and worksite social support were not greatly different among occupations. A clear occupational class gradient in job insecurity was observed in women. A greater prevalence of high job strain was observed in low-class occupations compared to high-class occupations in both men and women. The occupational class gradient in job strain was greater for women. These patterns did not change after controlling for other covariates. CONCLUSION: The present study suggests an occupational class gradient in job strain for employed men and women in Japan. Japanese women workers may have a greater occupational class gradient in job strain and job insecurity than men.

To disclose the effects of chromium (Cr) on olfactory function, olfactory threshold tests were conducted on 27 male plating workers (Cr workers) with signs and symptoms of olfactory irritation but without nasal septum perforation or ulcer and on 34 male control subjects in Korean plating factories. The Cr workers had been exposed to Cr fume for 0.9 to 18.2 (mean 7.9) years; their blood Cr concentrations (0.16-3.69, mean 1.29 microg/dl) were significantly higher than those of the 34 control subjects (0.04-1.95, mean 0.55 microg/dl). Scores on recognition thresholds among the Cr workers were significantly higher than those of the control subjects (p0.05) and related positively and significantly to the exposure periods of the 27 Cr workers (p0.05). Olfactory thresholds were not significantly different between the Cr workers with and without nasal signs or symptoms, except that the scores on the recognition threshold were significantly higher in those experiencing difficulty with smell (p0.05). It is suggested that olfactory threshold is affected by Cr without development of nasal septum perforation or ulceration.

An invited report on national occupational health research priorities, agenda and strategy of Japan was delivered in the NORA (National Occupational Research Agenda) Symposium 2001, USA. The third NORA Symposium was held by the US National Institute for Occupational Safety and Health (NIOSH) in Washington DC on June 27, 2001. The national conference in Japan entitled "Conference on Occupational Health Research Strategies in the 21st Century" was organized by the Japanese Ministry of Labour (Currently, Ministry of Health, Labour and Welfare) in the years 1998-2001, and the national occupational health research agenda and strategy for the next decade in Japan was identified. A total of 50 Conference members, i.e., representatives from various fields of occupational health in Japan, ranked 58 comprehensive research topics, yielding short-term (5-year) and long-term (6-10 year) priority research topics. Overall (10-year) priority research topics were calculated by combining the short-term and long-term priority scores. Together with the ranking by 145 extramural occupational health specialists, it was identified that work stress (i.e., one of the 58 research topics) was the first overall priority research topic for the next 10 years in Japan. Three other topics, i.e., elderly workers, women workers and maternity protection, and mental health and quality of work and life, were the second group of priority topics; and hazard and risk assessment and biological effect index were the third priority group. Based on the scores for the short-term and long-term priority research topics, all 58 research topics were classified into three key research areas with 18 key research issues (National Occupational Health Research Agenda, NOHRA). Finally, eight implementation measures of national strategy for the Japanese Government to promote occupational health research were introduced.

In order to determine the efficacy of a detector tube method in formaldehyde (HCHO) measurement, we performed a chamber experiment and a field study. The experiment clearly showed that the value obtained by the detector tube method was significantly correlated to that obtained using an active-DNPH method, and was not influenced by the coexistence of toluene, xylene or carbon monoxide, but was by acetaldehyde. In the field study, we investigated 171 rooms in 81 houses. Indoor air was simultaneously sampled for 30 minutes by both an active-DNPH method and the detector tube method. The mean HCHO concentration in the 171 rooms was 0.110 +/- 0.089 ppm determined by the active-DNPH method and 0.12 +/- 0.10 ppm by the detector tube method. Regression analysis showed that the two measures closely correlated with a regression equation Y=1.057 X + 0.002 (r=0.912, p

This study aims to evaluate the validity and reliability of a Japanese version of the Arthritis Impact Measurement Scales, version 2 (AIMS2) for patients with rheumatoid arthritis (RA). The Japanese version of the AIMS2 questionnaire was administered to 1643 patients with classical or definite RA at 11 hospitals nationwide in Japan. Reliability was assessed by a test-retest procedure, 4 weeks apart, using 75 randomly selected patients. Internal consistency was measured by Cronbach's α, and factor analysis was used to obtain the proportion of variance explained by the first factor in principal component analysis. The validity of the AIMS2 scales was assessed by internal standards. Internal consistency (α coefficients, 0.84-0.94), test-retest reliability (intraclass correlation coefficients, 0.75-0.93), and factor analysis (0.62-0.85) of the AIMS2 health status scales proved that they are highly reliable in the Japanese version. Validity, as measured by the relationships among the scores on the questionnaire items, was also sufficiently secured. The validity and reliability of the Japanese version of the AIMS2 are sufficient for all practical purposes when compared with the original and with other translated versions of the questionnaire.

The most common method of evaluating beneficial impacts of environmental policies is cost-benefit analysis (CBA). In the present review, CBA methods for air pollution impacts are reviewed. Three types of air pollution effects are identified, including health, productivity, and amenity. Market valuation, stated preference methods, and revealed preference methods are identified for valuing benefits. Three types of costs are deseribed, including private sector costs, societal costs, and governmental regulatory costs. A benefits valuation approach based on Freeman's principals is described. A costs valuation approach based on U.S. Environmental Protection Agency and Dixon et al. principals is deseribed. Limitations associated with estimates of benefits and costs are summarized. Input assumptions and results are compared for several existing air pollution control analyses. The importance of CBA in environmental policy studies is discussed. Our conceptual approaches should be useful in analyses of urban air pollution impacts and air pollution prevention policies.

Objectives: To examine the effects of metallic mercury vapour on the cellular and humoral immune system. Methods: We measured T lymphocyte and natural killer (NK) cell subpopulations, B lymphocytes, and serum immunoglobulins (i.e. IgG, IgA and IgM) together with total T (CD3+) lymphocytes and total lymphocytes in blood samples from 20 male, fluorescent-lamp makers (mercury workers) and the same number of gender-, age- and smoking-matched controls. Urinary concentrations of inorganic mercury (UHg) in the 20 workers ranged from 1.8 to 163.5 (mean 44.8) μg/l. They had been exposed to mercury vapour for 4 to 62 (mean 31) months. Results: Numbers of CD4+CD45RA+ (suppressor-inducer) T lymphocytes and total CD4+ T lymphocytes in the mercury workers were significantly smaller than those in the controls (paired-sample t-test, P < 0.01). The number of CD57+CD16+ NK cells was inversely correlated with UHg. Conclusion: It is suggested that numbers of CD4+CD45RA+ T lymphocytes and CD57+CD16+ NK cells are inversely affected by exposure to metallic mercury vapour in workers, with an average urinary inorganic mercury concentration of 45 μg/l being found.

To evaluate the protective effects ofGinkgo biloba extract (GBe) which has antioxidant activity against peripheral neuropathy due to diabetes mellitus, slow axonal transport and morphology of sciatic nerve including endoneurial microvessels were examined in 12 rats with diabetes mellitus induced by streptozotocin (STZ, 60mg/kg, b.w., i.p.). Six of the diabetic rats were treated with 0.1 % of GBe for 6 weeks from one week after the STZ injection. Serum glucose and lipid peroxide levels in GBe-treated diabetic rats were significantly lower than those in untreated diabetic rats (p

Aims. In Japan, smoking prevalence in males has been among the highest among industrialized countries, while the prevalence in females has remained relatively low. There have been long-term declining trends since the early 1970s. In the mid-1980s, the public tobacco monopoly was privatized and the tobacco market was liberalized in Japan. This study examines whether the trends in smoking prevalence changed at the time of these market changes . Design and measurements. Smoking prevalence data, tabulated by age group and sex, were plotted over the period 1975-95. Trends of smoking prevalence were then analyzed by using linear regressions, and their changes at the time of monopoly privatization and market liberalization were examined by Chow tests. Findings. The trends in smoking prevalence changed at the time of the monopoly privatization and trade liberalization in both males and females, except for the males in their twenties and thirties. Rates of decline in smoking prevalence diminished in many age groups and prevalence for younger females started to increase. Conclusions. Market changes, that result from the privatization of a public tobacco monopoly and trade liberalization, may adversely affect smoking prevalence in many age groups and in both sexes, unless effective countermeasures are taken.

To clarify the effects of perceived job stress on the immune system, a cross-sectional study was conducted in 116 male Japanese workers of a nuclear electric power plant (age, 20 to 39; mean, 31 years). Perceived job stress, i.e., psychological job demand, job control, worksite social support, and job strain, was assessed by means of the Japanese version of the Job Content Questionnaire. The job strain score was calculated as the ratio of the job demand score to the job control score. Blood samples were taken from all workers, and numbers of T and natural killer cell subpopulations, B lymphocytes, total lymphocytes and white blood cells, and serum concentrations of immunoglobulins (IgG, IgM, IgA, IgE and IgD) in their blood were measured. The workers were divided into higher and lower strain groups according to their job strain scores. The number of CD4+ CD45RA+ T lymphocytes in the higher strain group having the job strain score of 0.5 or more (41 workers) was significantly smaller than that in the lower strain group having the score of less than 0.5 (75 workers). In contrast, the serum IgG concentration in the former group was significantly higher than that in the latter group (analysis of covariance with age and smoking as covariates). Also, the numbers of total CD4+ T and total T (CD3+) lymphocytes and of white blood cells in the former group were significantly smaller than those in the latter group. After controlling for age and smoking by the partial correlation coefficient in all 116 workers, the number of CD57+ CD16+ natural killer cells was inversely correlated with job demand and with job strain; the number of CD8+ T lymphocytes was positively correlated with worksite social support; and serum IgG and IgM concentrations were positively correlated with job strain. It is suggested that higher job strain decreases the number of CD4+ CD45RA+ T lymphocytes in male Japanese workers but increases serum IgG concentrations.

To examine the effects of 2,5-hexanedione (HD) on the glucose metabolism in the spinal cord, glucose utilization rate (GUR) and distribution volume of glucose (DV) were measured in the white matter and anterior horn of the spinal cord in 8 rats exposed to HD for 4 weeks and in 10 control rats. The GUR and DV were determined by the quantitative microdetermination method using non-tracer 2-deoxyglucose based on the three-compartments model of Sokoloff. GURs in the white matter and anterior horn and DV in the anterior horn in the HD-exposed rats were significantly lower than those in the control rats. In the multiple regression analysis, GUR in the white matter of HD-exposed rats was significantly related to blood HD concentration. It is suggested that the decrease of GUR in the white matter is a major effect of HD in the spinal cord.

To clarify reasons for drinking in relation to problem drinking behavior, 494 male students, aged 15 to 18 years old and attending high schools in Tokyo, Japan, were examined by self-rating questionnaires including the Kuriharna Alcoholism Screening Test (KAST). Three hundred and forty-two students (69%) completed the questionnaires, of whom 143 indicated that they were current drinkers of alcohol (42% of respondents). Of the 143,16 (11%) reported, through the KAST, experience of problem drinking behavior. A factor analysis of 36 reasons for drinking identified 5 factors: Escapism, Sociability, Tension Reduction, Acting Like a Man, and Enjoyment/Home. A logistic regression analysis showed that drinking because of Escapism, Sociability, and Tension Reduction was significantly related to problem drinking behavior. Also, there was significant correlation between the 3 factors and the number of KAST items experienced by the 143 respondents. Our findings suggest that the factors of Escapism, Sociability, and Tension Reduction lead to problem drinking in Japanese high school students.

Approximately 10-30% of the Japanese population suffer from Japanese cedar (Cryptomeria japonica) pollinosis in the spring. To date, the effects of this pollinosis on lymphocyte subpopulations have not been examined epidemiologically. To examine the effects of smoking and Japanese cedar pollinosis on lymphocyte subpopulations, we used flow cytometry to measure CD4+ and CD8+ T-lymphocyte subpopulations, natural-killer cell subpopulations, B(CD19+) lymphocytes, and total lymphocytes in 61 smokers and 51 nonsmokers. Some of these individuals had histories of pollinosis during November 1993-an off-season for Japanese cedar pollination. Our findings suggested that (a) CD4+ T-lymphocyte subpopulations (i.e., CD4+CD29+, CD4+CD45RA+, and CD4+ CD45RO+ cells) together with total CD4+ T, total T, and total lymphocytes, were increased by the effects of smoking; (b) CD8dim+CD11a+T, and CD8+CD11bt, and CD57+CD16+ natural killer cells, together with total CD8+CD11 a+ T and total CD8+ T lymphocytes, were increased by the effects of pollinosis on smokers, even though no lymphocyte subpopulations were increased by only the pollinosis effects; (c) CD4+CD29+T and CD8dimCD11a+ T lymphocytes were increased by the effects of smoking on pollinosis, and (d) CD4+CD29+ T and CD4+CD45RO+ T lymphocytes, CD8dim+CD11 a+ T, and CD8+CD11b+ T lymphocytes and CD57+CD16+ natural killer cells, together with total CD4+ T, total T (CD3+), total CD8+CD11a+, total CD8+ T, and total lymphocytes, were increased by the combined effects of smoking and pollinosis.

To investigate the effects of weather conditions on outbreaks of Salmonella food poisoning, the relationships of five weather indices, i.e., daily maximum, minimum and mean temperatures and minimum and mean humidity with daily outbreaks of Salmonella (S.Enteritidis) food poisoning by causes (incriminated food), i.e., eggs, non-eggs, and unidentified, were examined by multiple logistic regression analysis, for the years of 1989-95 in Japan, using outbreak of food poisoning as a dependent variable and five weather indices asindependent variables. During this period, the type of Salmonella detected in food poisoning cases was reported to be mainly Salmonella . Enteritidis, whereas Salmonella Typhimurium had been frequently found in the preceding years. The following results were obtained: (1) Salmonella food poisoning caused by eggs had positive relationships to the minimum temperature on the day of its outbreak and of one day before, and to the mean temperatures of two and three days before; (2) poisoning due to non-egg foods had positive relationships to the minimum temperatures of the outbreak day and of one, two, and three days before; (3) poisoning due to unidentified cause had positive relationships to the mean temperatures of the outbreak day and of one day before, and to the minimum temperatures of two and three days before. Increase in 1°C of the mean or minimum temperatures resulted in 7.2-12.2% increase in the risk of outbreak. It is thus suggested that high temperatures lead to outbreaks of Salmonella food poisoning regardless of the causative food for the years of 1989-95 in Japan, possibly due to the change in type of Salmonella.

There is an increased risk of developing colorectal neoplasia in ulcerative colitis (UC) and surveillance colonoscopy is recommended for early detection. We investigated the precise features of UC retrospectively to identify a subgroup with longstanding extensive UC at increased risk of neoplasia. From 1985 to August 1997, we experienced eight UC patients with colorectal cancer and eight with definite dysplasia. All 16 had extensive disease of seven years or more in duration. During the same period, 61 of 334 UC patients without colorectal neoplasia were available for detailed study, allowing evaluation of non-surgical patients with extensive colitis of seven years or more in duration. Basic clinical factors including family history of cancer, expressions of disease activity and durations of pharmacotherapy were investigated. Univariate analysis revealed four significant factors: intractability (P=0.001), periods of inflammation persisting for 3 months or more (P

We conducted a randomized controlled trial (RCT) to examine the effects of mailed advice on reducing psychological distress, blood pressure, serum lipids, and sick leave of workers employed in a manufacturing plant in Japan. Those who indicated higher psychological distress (defined as having GHQ scores of three or greater) in the baseline questionnaire survey (n = 226) were randomly assigned to an intervention group or a control group. Individualized letters were sent to the subjects of the intervention group, informing them of their stress levels and recommending an improvement in daily habits and other behaviors to reduce stress. Eighty-one and 77 subjects in the intervention and control groups, respectively, responded to the one-year follow-up survey. No significant intervention effect was observed for the GHQ scores, blood pressure, serum lipids, or sick leave (p > 0.05). The intervention effect was marginally significant for changes in regular breakfasts and daily alcohol consumption (p = 0.09). The intervention effect was marginally significant for the GHQ scores among those who initially did not eat breakfast regularly (p = 0.06). The study suggests that only sending mailed advice is not an effective measure for worksite stress reduction. Mailed advice which focuses on a particular subgroup (e.g., those who do not eat breakfast regularly) may be more effective.

To examine whether positive and negative components of mental health were differently related to job stressors and life events, correlational analyses were conducted using data for the GHQ-12 and some scales of the NIOSH Generic Job Stress Questionnaire collected from 765 workers in Japan. Six positive items and six negative items of the GHQ-12 were summed up for positive and negative components of mental health (GHQ-POS, GHQ-NEG). The GHQ-POS was significantly correlated with only positively-oriented job stressors. The GHQ-NEG was significantly correlated with only negatively-oriented job stressors. Most correlations were significantly different between GHQ-POS and GHQ-NEG. This correlation pattern resulted in smaller, but significant, correlations between job stressors and the GHQ-12. These results may reflect "measuring similarity" due to item-wording. Detailed inspection suggested that GHQ-POS and GHQ-NEG, as well as positively- and negatively-oriented job stressors, were not attributable only to positive affectively or negative affectivity, respectively. Work-related events showed higher correlations with all mental health variables than their job stressors' counterparts. For females, mental health variables were seldom correlated with job stressors, but significantly correlated with life events. These results might indicate the superiority of "event-type stress measure" as compared to perceived rating scale in assessing job stressors. Further direction was discussed.

To examine the effects of smoking on lymphocyte subpopulations, we measured the following cell subpopulations: CD4+ T-cell subpopulations (i.e., CD4+CD29+, CD4+ CD45RO+, and CD4+CD45RA+ cells); CD8+ T-cell subpopulations (i.e., CD8+CD11a+ and CD8+CD11b+ cells); and natural killer cell subpopulations (i.e., CD16+CD57-, CD16+CD57+, and CD16-CD57+ cells). We measured these subpopulations, together with total CD4+ T, total CD8+ T, total CD3+ T, B (CD19+), and total lymphocytes, in 10 male heavy smokers, 38 male light-to-moderate smokers, and 33 male nonsmokers. The mean ages were 30 y, 31 y, and 32 y, respectively, and ages did not vary significantly among the smokers. CD4+CD29+ and CD4+CD45RO+ (memory T) cells in heavy smokers were significantly more numerous than those in light-to-moderate smokers and nonsmokers. Also, these memory T-cell subpopulations were significantly more numerous in light-to-moderate smokers than in nonsmokers. The number of CD4+CD45RA+ (naive T) cells was significantly larger in heavy smokers than nonsmokers; numbers of CD4+CD45RO+ T and CD4+CD29+ T cells (memory T cells) were significantly correlated with daily cigarette consumption. Numbers of CD3+ T, CD4+ T, CD19+ B, and total lymphocytes in heavy smokers were significantly larger than in nonsmokers. There were significantly more CD3+ T, CD4+ T, and total lymphocytes in light-to-moderate smokers than in nonsmokers. The numbers of CD4+ T lymphocytes in heavy smokers were significantly larger than in light-to-moderate smokers. Perhaps CD4+ T cell subpopulations, especially memory T cells, are most susceptible to the effects of smoking on lymphocyte subpopulations.

To examine if chelated lead was a more predictive indicator of the subclinical effect of lead on conduction velocities of faster or slower nerve fibers as compared with blood lead (BPb).Distribution of conduction velocities (DCV) in large myelinated fibers of the sensory median nerve was measured twice at a 1-year interval in 17 male gun-metal foundry workers with BPb concentrations of 22-59 (mean 40.2) microg/dl and a mobilization yield of lead into urine (MPb) by calcium disodium ethylenediaminetetraacetate of 0.15-2.09 (mean 1.19) mg/24 h for the 1st year and in 20 healthy males (controls).Yearly changes in the conduction velocities of faster fibers were significantly correlated with the corresponding change in MPb (P0.05) but not with that in BPb (P0.05). In ten workers showing an increase in MPb during the 1-year period (0.44 mg/24 h on average) the conduction velocities of faster fibers were decreased significantly, resulting in the values being significantly lower in all the workers combined than in the controls (P0.05). On the other hand, in the remaining workers, who showed a lesser extent of reduction in MPb (0.08 mg/24 h on average), the DCV did not change (P0.05).Chelated lead might be a more predictive indicator of the effect of lead on the conduction velocities of faster fibers than blood lead.

Background No one has previously examined the relation of serum total cholesterol, serum triglycerides and fasting plasma glucose to colorectal carcinoma in situ. Methods A case-control study was performed with 129 cases of colorectal carcinoma in situ and 258 matched controls among examinees undergoing a health check-up in Tokyo from January 1991 to March 1993. Results There was a significant, positive association between serum total cholesterol levels and the risk of colorectal carcinoma in situ after adjustment for age, sex, body mass index, smoking status and alcohol consumption. Serum triglyceride levels were significantly and positively associated with colorectal carcinoma in situ risk regardless of adjustment for the above covariates. Although there was no clear relation between colorectal carcinoma in situ and fasting plasma glucose levels, a modest increase of colorectal carcinoma in situ risk was observed in the highest category (> or =116 mg/dl) of fasting plasma glucose levels. Conclusions The findings suggest a positive association between serum total cholesterol levels and the risk of colorectal cancer, rather than an inverse relation. The strong association with serum triglyceride levels and the weak association with fasting plasma glucose levels support the hypothesis that hyperinsulinaemia may play an important role in colorectal carcinogenesis.

Chronic neurobehavioral effects of acute sarin poisoning were evaluated in 9 male and 9 female patients who were exposed to sarin poisoning in the Tokyo subway incident in Japan. The investigators used nine neurobehavioral tests, as well as a posttraumatic stress disorder checklist, 6-8 mo after the poisoning occurred. Serum cholinesterase activity in patients on the day of poisoning (i.e., March 20, 1995) ranged from 13 to 131 IU/l (mean=72.1 IU/l). The results of analysis covariance, in which age, education level, alcohol consumption, and smoking status (covariates) were controlled in 18 sarin cases and in 18 controls, showed that the score on the digit symbol (psychomotor performance) test was significantly lower in the sarin cases than in controls. Nonetheless, the scores for the General Health Questionnaires, fatigue of Profile of Mood States, and posttraumatic stress disorder checklist were significantly higher in the sarin cases than controls. The investigators added posttraumatic stress disorder to the covariates, and only the score on the digit symbol test was significantly lower in sarin cases. In addition, the results of stepwise multiple regression analysis in 18 sarin cases revealed that scores for the General Health Questionnaires, fatigue of Profile of Mood States (i.e., fatigue, tension-anxiety, depression, and anger-hostility)-together with the paired-associate learning test-were associated significantly with posttraumatic stress disorder. The association did not remain significant for the digit symbol test score. Perhaps a chronic effect on psychomotor performance was caused directly by acute sarin poisoning; on the other hand, the effects on psychiatric symptoms (General Health Questionnaire) and fatigue (Profile of Mood States) appeared to result from posttraumatic stress disorder induced by exposure to sarin.

To evaluate the effects of calcium disodium ethylenediamine tetraacetate (CaEDTA) on the behavior of 8 heavy metals in human urine and blood, CaEDTA was administered for 1 h by intravenous injection to 18 male metal foundry workers, whose blood lead concentrations (PbB) were between 16 and 59 (mean 34) microg/dl. Significant increases were found in urinary excretion of manganese, chromium, lead, zinc, and copper after the start of CaEDTA injection. Urinary chromium excretion reached a maximal level within 1 h after the start of injection, while urinary manganese, lead, and zinc excretion reached their highest concentrations between 1 and 2 h. Urinary copper excretion reached the highest level between 2 and 4 h. The rapid increases in urinary excretion of five metals were different from the "circadian rhythms," which are the normal, daily variations in renal glomerular filtration, reabsorption, and excretory mechanisms. Plasma lead concentrations were highest 1.5 h after the start of the 1-h injection, while plasma zinc concentration became lowest 5 h after the start of CaEDTA injection. Data suggest that manganese and chromium absorbed in human tissues might be mobilized by CaEDTA.

To investigate the effects of lead on the human immune system, we analyzed T cell subpopulations and B (CD19+) cells in peripheral blood in 71 male lead workers. They were engaged in manufacturing lead stearate in a chemical factory, aged 20 to 74 (mean 48) years. Their blood lead concentrations (PbB) were between 7 and 50 (mean 19) μg/dl. The control group consisted of 28 “healthy” male volunteers without a history of occupational exposure to lead or other hazardous substances, aged 33 to 67 (mean 55) years. In comparison with the controls, a significant reduction in the number of CD3+CD45RO+ (memory T) cells and a significant expansion in the percentage of CD8+ cells in the lead workers were found. There was a significant positive correlation between the percentage of CD3+CD45RA+ (naive T) cells and PbB in the lead workers. It is suggested that CD45RO+ memory T cells may be most susceptible to the effects of lead on T cell subpopulations.

Assessment of Peripheral. Central and Autonomic Nervous System Functions in Two Lead Smelters with High Blood Lead Concentrations: A Follow-Up Study: Yasushi FUJIMURA, et al. Department of Public Health. School of Medicine. University of Tokyo-To examine the effects of lead on peripheral, central and autonomic nervous system functions, the median and radial motor and sensory nerve conduction velocities (MCV and SCV), distribution of median nerve conduction velocities (DCV), short-latency somatosensory, brainstem auditory and visual evoked potentials (SSEP, BAEP and VEP, respectively), event-related potential (P300), and electrocardiographic R-R interval variability (CVRR) were measured once a month for 12 and 25 months in two male lead smelters with the first blood lead (BPb) concentrations of 105.6 μg/dl (Lead smelter 1) and 76.5 μg/dl (Lead smelter 2), respectively. The measurements were conducted a day before the workers underwent BPb measurement and lead mobilization test with 1-hr calcium disodium ethylenediamine tetraacetate infusion. The following results were obtained: (1) The delayed values for V 20-V90 velocities of the DCV, MCVs in the median and radial nerves, SCV in the median nerve. N13-N 20 interpeak latency of the SSEP, V Iatency of the BAEP, and P300 Iatency in Lead smelter 1 were significantly more frequent than the expected values in control subjects. (2) Also, the delayed values for V 60-V90 velocities of the DCV, MCV and SCV in the median nerve, and N9 Iatency of the SSEP in Lead smelter 2 were significantly more frequent than the expected values in control subjects. (3) The delayed values for MCVs in the median and radial nerves and N13-N20 interpeak (SSEP), V (BAEP) and P300 latencies in Lead smelter 1 were significantly more frequent than those in Lead smelter 2. (4) In the two lead smelters, the delayed values for V80 and V 90 velocities of the DCV were significantly more frequent than those for V10 and V20 velocities. These data suggest that faster nerve fibres of the peripheral nerve are more sensitive to chronic lead exposure than slower nerve fibres are, and peripheral nerve function is more sensitive to chronic lead exposure than central and autonomic nervous system functions.

To evaluate delayed (long-term) effects of acute sarin poisoning on postural balance, nine male and nine female victims of the Tokyo Subway Sarin Poisoning in Japan (sarin cases) were examined by computerized posturography 6-8 months after the poisoning. Their plasma cholinesterase activities (ChE) on the day of the poisoning (March 20, 1995) were 13-95 (mean 68.2) IU/l for females and 19-131 (mean 75.9) IU/l for males, which were not significantly different between the two sexes. In females, the postural sway of low frequency (0-1 Hz) in the anterior-posterior direction and area of sway with eyes open was significantly larger in the cases than in the controls. Romberg quotients for the low-frequency sway in the anterior-posterior direction for females and low-frequency sway and length of sway in the medio-lateral direction for males were significantly related to log ChE. It is suggested that a delayed effect on the vestibulo-cerebellar system was induced by acute sarin poisoning; females might be more sensitive than males.

Industrial Health (NIIH) and the National Institute of Industrial Safety (NIIS) were amalgamated into a single, comprehensive research facility legislated as the Japan National Institute of Occupational Safety and Health (JNIOSH), a new independent administrative government institution. From its inception as the Silicosis Laboratory, an attached office of the Industrial Health Division, Japan Ministry of Labour, in 1949, the NIIH has since played a leading role in industrial health research, both domestically and internationally. Similarly, the NIIS, which was first established as the Research Institute of Industrial Safety by the Ministry of Welfare in1942, has pursued a wide variety of research topics in the field of industrial safety as a governmental institution within the Ministry of Labour throughout the latter half of last century, since 1947. In 1963, our journal: INDUSTRIAL HEALTH, began publishing peer-reviewed original research papers in the field of industrial hygiene and occupational health. This quarterly journal was open to all international contributors, and by the year 2000 had published a total of 992 papers, of which 755 were original articles, 220 short communications, and 17 in-depth review articles1). During its history, INDUSTRIAL HEALTH was instrumental in the development of advanced occupational health knowledge from a global perspective, especially in Asia. Another significant activity to promote occupational health research in Japan has been made by the National Conference on Promotion of Occupational Health Research Priorities. This national conference was organized by the NIIH in 2001 and has been supported exclusively by the Japan Ministry of Health, Labour and Welfare. The activity of the conference is based on the National Occupational Health Research Agenda (NOHRA), with three key research areas, 18 research priorities and eight implementation measures, proposed in the previous national conference: Conference on Occupational Health Research Strategies in the 21st Century organized by the Japan Ministry of Health, Labour and Welfare from 1998 through to 2001 (Fig. 1, Tables 1, 2)2–4). So far, through a four-year extensive review of literature and a questionnaire survey to all members of three major academic societies on occupational health in Japan, the Conference on Promotion of Occupational Health Research Priorities revealed that the following four research priorities were most intensively investigated in terms of both the number of original papers published in the past five years and the number of research workers directly involved (Table 1, Fig. 2)4): Work stress and mental health, Quality of working life and health promotion, Toxicity assessment of chemicals, and Risk assessment and health effect index (Research priorities 3, 17, 7 & 12, respectively). In contrast, two research priorities, i.e. Industrial Health 2006, 44, 215–217

To evaluate the effects of calcium disodium ethylenediamine tetraacetate (CaEDTA) injection on human immune system in relation to exposure to lead, we administered CaEDTA by intravenous injection for 1 hr three times (three consecutive days) a week to two male lead workers. They had been engaged in recycling lead for 31 and 22 years, aged 61 and 53 years (workers 1 and 2), respectively. Before the treatment of CaEDTA, their blood lead concentrations (PbB) were 81 and 68 μg/dl, respectively. The administration of CaEDTA had been carried out to worker 1 for 10 weeks and to worker 2 for 6 weeks. A significant decrease in PbB between before and after three-times CaEDTA injection was found in both workers. Significant increases in IgG, IgA, IgM, CD8+, and CD57+ cells were found in worker 1. A significant increase in IgD was found in worker 2. During the study period, IgG in worker 1 and CD4+ cells in worker 2 were gradually increasing. There was a significant negative correlation between IgG and PbB in worker 1. It is suggested that the immunological function such as antibody formation in lead workers might be improved by CaEDTA injection. Am. J. Ind. Med. 32:674–680, 1997. © 1997 Wiley-Liss, Inc.

A cohort of 1022 consecutive singleton births was generated during 1986-1987 in the Faroe Islands. Increased methylmercury exposure from maternal consumption of pilot whale meat was indicated by mercury concentrations in cord blood and maternal hair. At approximately 7 years of age, 917 of the children underwent detailed neurobehavioral examination. Neuropsychological tests included Finger Tapping; Hand-Eye Coordination; reaction time on a Continuous Performance Test; Wechsler Intelligence Scale for Children-Revised Digit Spans, Similarities, and Block Designs; Bender Visual Motor Gestalt Test; Boston Naming Test; and California Verbal Learning Test (Children). Clinical examination and neurophysiological testing did not reveal any clear-cut mercury-related abnormalities. However, mercury-related neuropsychological dysfunctions were most pronounced in the domains of language, attention, and memory, and to a lesser extent in visuospatial and motor functions. These associations remained after adjustment for covariates and after exclusion of children with maternal hair mercury concentrations above 10 microgram(s) (50 nmol/g). The effects on brain function associated with prenatal methylmercury exposure therefore appear widespread, and early dysfunction is detectable at exposure levels currently considered safe.

To clarify the effects of organic solvents on the postural balance system, 29 male sandal, shoe, and leather factory workers exposed to n-hexane, xylene, and toluene (solvent workers) were examined by computerized static posturography with sway frequency analysis. Concentrations of metabolites of solvents in urine samples taken from the workers in the morning before work ranged from 0.41 to 3.06 (mean, 1.20) mg/g creatinine (Cn) for 2,5-hexanedione, from 0.10 to 0.43 (mean, 0.19) g/g Cn for methylhippuric acid, and from 0.05 to 2.53 (mean, 0.37) g/g Cn for hippuric acid; estimated concentrations of n-hexane in workplace air ranged from 13 to 100 (mean, 40) ppm. Control subjects were 22 healthy males without exposure to solvents. With eyes open, postural sway with a frequency of 2-4 Hz in solvent workers was significantly larger than that in controls in the anteroposterior direction. With eyes closed, sway with a frequency of 0-1 Hz was significantly larger in solvent workers in the mediolateral and anteroposterior directions. Results of multiple regression analysis showed that with eyes open the 1- to 2-Hz and 2- to 4-Hz sways were related positively to 2,5-hexanedione and inversely with methylhippuric acid. The pattern of changes suggests that the vestibulocerebellar and spinocerebellar afferent systems are asymptomatically affected by n-hexane; the effect of n-hexane on the vestibulocerebellar system is possibly inhibited by xylene.

The objective of this study was to clarify the autonomic, central and peripheral nervous effects of vibrating-tool operation.The ECG R-R interval variability (CVRR), including the C-CVHF, C-CVLF (two component CVs of the CVRR reflecting parasympathetic and sympathetic activities, respectively) and the power spectral densities (PSDHF and PSDLF) after autoregressive analysis, short-latency somatosensory evoked potentials (SSEP), distribution of nerve conduction velocities (DCV), and median and radial nerve conduction velocities (NCVs) were measured in 17 vibrating-tool operators and the same number of age-matched control subjects. Some of the operators complained of white finger even in summer as soon as they arrived at the cold workplace.The significance of the differences in neurophysiological data between the exposed and unexposed groups and the associations between these data in the former were investigated.The CVRR, C-CVHF and PSDHF were significantly lower in the vibrating-tool operators than in the matched controls. The N9-N13 interpeak latency of the SSEP, i.e., conduction time of the cervico-spinobulbar pathway, in the operators was significantly prolonged as compared with the controls; the faster velocities of the DCV and the NCVs were significantly slowed in the operators. The N9-N13 interpeak latency in the operators was significantly correlated with the C-CVHF.Complex stressors of local vibration, cold, noise and heavy work, seem to affect the cervico-spinobulbar, parasympathetic and peripheral nerve functions. Also, parasympathetic hypofunction may imply a consequence in brainstem pathology induced by cold exposure in addition to vibration.

Neurophysiological measurement, a promising technique for assessment of the subclinical effects of occupational and environmental factors, is rapidly progressing following development of computer technology. The methods include measurement of evoked and event-related potentials, nerve conduction velocity, distribution of nerve conduction velocities, electrocardiographic R-R interval variability, and computerized static posturography. This paper provides an overview of these methods, except for evoked and event-related potentials, which have been reviewed previously by the authors, to evaluate the effects of occupational and environmental factors on the peripheral, autonomic, and cerebellar nervous systems. The available data indicate that these methods are sensitive, reliable, and easily applied in a field study. When conducting these measurements, controlling for confounding factors such as age, sex, height, skin temperature, alcohol ingestion, and neurologic diseases is necessary.

The determination of odor recognition threshold values of n- and iso-amyl (pentyl) acetates was carried out by odor panel test (Japanese students 18-22 years old;6 males and a female) using 10-liter Tedlar bag static method. The trace concentrations of n- and iso-amyl acetates in the Tedlar bag were determined by gas chromatography and an odor sensor (SnO 2 type). The odor recognition threshold values of amyl acetates were 7.70 ppm for n-amyl and 1.50 ppm for iso-amyl. The odor quality from several odor panels were evaluated, such as a binder solvent-like, aqueous paint, stimuli, fruity, aromatic, ether-like, gasoline-like, pungent, minty, sour, petroleum-like, respectively.

A case-control study was performed in order to examine the relation of cigarette smoking and alcohol use to colorectal carcinoma in situ and cancer, separately. Study subjects consisted of 129 colorectal carcinoma in situ cases, 66 colorectal cancer cases, and 390 controls recruited from health check-up examinees in Tokyo from January 1991 to March 1993. Smoking status and alcohol habit were ascertained from a self-administered questionnaire. Both cumulative cigarette smoking and current smoking status were associated significantly with an increased risk of carcinoma in situ. A statistically nonsignificant increase in the risk of colorectal cancer was noted only among those with the heaviest exposure category of these measures of smoking. The cumulative exposure to cigarette smoking within recent 20 years was associated significantly with an increased risk of carcinoma in situ, whereas smoking until 20 years before the diagnosis was associated significantly with an increase of cancer risk. A significant and positive association was observed between cumulative alcohol drinking and colorectal cancer. These findings suggest that cigarette smoking may act as an initiator in colorectal carcinogenesis and also provide weak evidence that alcohol drinking is related to an increased risk of colorectal cancer.

Previously, we found a decrease in CD4 + CD45RA + T lymphocytes in workers exposed to the aromatic amines (AAs) [benzidine (BZ) and beta naphthylamine (BNA)]. For further investigation of the effects of AAs on lymphocyte subpopulations, we measured natural killer (NK) cell subpopulations using two-color staining with anti-Leu7 (CD57) and anti-Leu11 (CD16) monoclonal antibodies in peripheral blood in 78 male dyestuff workers. The workers had been exposed to AAs before 1972 at a chemical plant, either in the production of AAs (40 workers, high-exposure group) or in other work that involved handling dyestuffs (38 workers, low-exposure group). The controls were 30 "healthy" male volunteers without a history of occupational exposure to AAs or hazardous chemicals. The number of CD57 + CD16- cells in the high-exposure group was significantly higher than that in the controls (P0.01, analysis of covariance with age as a covariate). No significant differences were found in CD57 + CD16-, CD57 + CD16+ and CD57- CD16 + NK cells between the low-exposure group and the controls. It is suggested that a decrease in the number of CD4+ T lymphocytes following exposure to AAs might be compensated by the increase in CD57 + CD16- cells, i.e. circulating peripheral lymphocytes with poor NK cell activity.

Two male lead workers, aged 57 and 51 y, were studied to compare the urinary flow/creatinine-adjusted values published earlier by Araki et al. and by Greenberg and Levine. We collected 24-h urine samples once a month for 31 mo and 16 mo for workers 1 and 2, respectively. The workers' urinary excretions of lead, delta-aminolevulinic acid, and coproporphyrin were measured. No significant correlations between urine flow rate and urinary flow/creatinine-adjusted values published by Araki et al. for the three substances were found for these two workers. However, urinary flow/creatinine-adjusted values presented by Greenberg and Levine for lead and delta-aminolevulinic acid were correlated positively with urine flow rate in the two workers, and their adjusted value for coproporphyrin was correlated positively with urine flow rate in one of the workers. We concluded that use of the urinary flow/creatinine-adjusted value by Greenberg and Levine for biological monitoring poses a problem because of the theoretical fallacy.