The paper argues for a “new generation” approach to occupational health, laying foundations for future demands. Occupational health deals with issues which are at the heart of the economy and society, and are beginning to attract increasing attention of politicians. Old disciplinary barriers must be crossed, and communication improved so that healthy work is accepted as a mainstream concern. This presents challenges both to occupational health professionals and to those with responsibilities for policy. As a first step, we need to make more effective use of the body of available research, and develop an understanding of how the conclusions from research can inform responsible decision making.
Hypothesis and scenarios of future developments in ORP and ORP research are derived. Based on an analysis of events in the past, on the content and process of research projects in the German “humanization” program, on literature analysis and expert interviews 19 anamnesis to diagnosis relationships are formulated concentrating on the following topics: 1. Innovation potentials and value systems of ORP research, 2. Fields and topics of ORP research of the future, 3. Serviceoriented systems of actors in ORP, 4. Demands and limits for research transfer. So the creative potential of the ORP community in Germany was used to conclude on recommendations for ORP developments.
According to the recent changes of working environments and socio-economical conditions, the proportion of working women are increasing in Japan. Characteristics of occupational workload and stress of Japanese working women are consistent with those in many industrialized countries except man-dominant culture. In this review we describe the history, current issues, and future research directions on occupational health of working women, especially focused on reproductive health, workrelated musculo-skeletal disorders (WMSDs), and mental disorders. In the reproductive health survey, traditionally main concern was about pregnancy outcomes, then fecundity studies, such as time to pregnancy, became topics recently. Future research will be shifted to outcomes not only during pregnancy but also disorders of hormonal balance and climacterium or health conditions after menopause. WMSDs are reviewed on mainly gender difference and its causative factors. Historically, mental health of working women in Japan has focused on the job stress of nurses. We compare results with a lot of recent researches in Europe and U.S.A., where interaction between occupational stress and family roles were studied. It is not easy to predict the prospective status of female workers in Japan, but social, workplace and familial supports will enhance their health promotion.
Recent progress in our knowledge of gene expression systems provides evidence that many industrial chemicals affect the transcriptional machineries directly or indirectly, and gene expression is now recognized as one of the main targets of many chemicals. In view of the increasing number of man-made chemicals, it is therefore necessary to establish a reliable gene expression assay with rapidity and high sensitivity. Among various gene expression assays, the so-called reporter assay is now accepted as a suitable tool to assess hazardous effects of chemicals on gene expression. This article focuses on the principle and applications of the reporter assay in research on endocrine disrupters.
There is a growing trend in re-orientating occupational health research towards risk management. Such a trend is accelerated by the increasing attention to occupational safety and health management systems. The trend, also seen in many Asian countries, is offering new opportunities for strengthening primary prevention. Useful examples are provided from recent work improvement projects dealing with technology transfer, small workplaces and rural areas. Common features of both these work improvement projects and accepted occupational risk management principles are reviewed based on recent experiences in Asian countries. Such features seem highly relevant in examining the occupational health research strategies. These experiences clearly show that locally adjusted procedures for risk assessment and control must be developed. There are new research needs concerning (a) the effective ways to encourage voluntary control at the workplace; (b) practical methods for local risk assessment; and (c) the types of participatory steps leading to continual improvements in the varying local context. Criteria of action-oriented research that can contribute to more effective risk control in different settings are discussed. Six relevant criteria may be mentioned: (a) adaptive risk management; (b) work/risk relationships; (c) action-oriented risk assessment; (d) use of collective expertise; (e) participation of local people; and (f) mutual learning. It appears crucial to stimulate research into the practical risk control procedures adjusted to the local situation.
A questionnaire was sent out to elementary, junior high and high schools in Yokohama and Kawasaki Cities from January to March 1998 regarding the use of personal computers by pupils and students. The survey included the questions that asked how often and in what environment computers are used, whether any instructions are given as to their use, children's working posture, and the effect on health. The results show that most schools are slow to develop instructive programs from the environmental or ergonomic point of view. So far there are not many children who complain of any serious symptoms such as pain in the neck, head or shoulders, but a future increase in the number of classes which involve computing, as well as the widespread popularity of home computers, will surely arouse a legitimate concern about the health of pupils and students, since they will spend more and more time operating the devices. An effective way to anticipate the problem is to provide young students with adequate knowledge of easy-on-body usage and environmental design, and now there is an urgent need for specific guidelines to protect them.
To clarify the relationship between perceived job stress and lymphocyte subpopulations, a cross-sectional study was conducted in 231 male electric power plant workers (aged 40 to 60, mean 46 years). Job stress, i.e., job control, job demands, and social support at work, was assessed by means of the Japanese version of the Job Content Questionnaire. Blood samples were taken from all the workers, and numbers of CD4+ T lymphocyte subpopulations, total CD4+ T, T (CD3+) lymphocytes, CD16CD56+ natural killer (NK) cells, total lymphocytes, and white blood cells were determined. After controlling for age, number of cigarettes smoked per day, alcohol drinking, frequency of regular exercise, job demands, and social support at work by the partial correlation coefficients, numbers of memory (CD4+CD45RO+) T, total CD4+ T, and total T (CD3+) lymphocytes were positively correlated with job control (p<0.05). Neither job demands nor social support at work showed significant correlations with lymphocyte subpopulations. It is suggested that lower job control is associated with a decrease in the number of CD4+CD45RO+ T lymphocytes in male middle-aged workers.
A cross-sectional questionnaire study was carried out on nursery school (NS) teachers in public nursery schools in N city in Japan to determine the magnitude of associations of probable risk factors with neck, shoulder, and arm pain, adjusting for potential confounders in logistic regression models. Of 1438 subjects, responded to the questionnaire, 959 NS teachers in charge of a separate or mixed group of children were subjected to analyses. Prevalence of neck and/or shoulder pain was 33.6%-35.4% in NS teachers in charge of children aged 0, 0-1, 4, and 5 in contrast to 25.0-29.8% in those in charge of children aged 1, 2, and 3. The prevalence of neck/shoulder pain tended to increase with the length of employment in all groups classified according to the age of children under care. In a logistic regression model that simultaneously adjusted demographic and personal variables, length of employment and care for children aged 0 in the workplace were found significantly associated with musculoskeletal pain. In further logistic models, pain in the neck/shoulders and arms had associations with some specific variables: care for children aged 0, holding/lifting a child/material, overwork, and poorly supported job situations. The odds ratios for those variables varied from 1.37 to 2.41. This results suggest that pain in the neck/shoulders and arms is induced by a wide variety of risk factors in NS teachers that include high physical workload, long working hours, job demand-support imbalance, and cumulative influence of workloads.
Cadmium (Cd) is a hazardous heavy metal present in working and living environments. Cd affects many cellular functions, but little is known about the mechanisms of its toxicity and cellular defense against it. Recently, advanced gene expression analysis employing DNA microarrays provided us the means to profile the expression of thousands of genes simultaneously. We describe here a study of Cd-induced gene expression profile. Messenger RNA was prepared from HeLa cells exposed to a non-lethal dose of CdSO4, and analyzed by the use of an array consisting of 7, 075 human cDNAs. Many stress response genes including those coding for metallothioneins and heat shock proteins were observed to be induced by Cd. The cellular metabolism inclined toward the synthesis of cysteine and glutathione after Cd exposure. Anti-oxidant genes also appeared to be induced to protect cell components and to quench reactive oxygen species. Ubiquitin pathway was activated as well probably to degrade proteins which might not be renatured. These data suggest that human cells mobilize every genomic resource (induction of some genes and repression of others) to overcome cytotoxicity caused by Cd.
An important challenge to occupational health services in Japan is the necessary shift from regulation-based occupational health program to health risk-based program. The Occupational Safety and Health Management System (OSHMS) is an effective tool for introducing risk-based activities. To date, the Five Management system has been used to manage occupational health activities. This classification, however, does not show the interactions among the listed activities. Nor is it clear how this system contributes to the PDCA (Plan/Do/Check/Act) cycle for continual improvement. The category in the Five Management system called “Roles of the Occupational Physician” covers most of the occupational health services required in Japan. The items listed in the Five Management system were compared to the guidelines of OSHMS from the International Labour Office and issues that should be solved for occupational health activities with OSHMS were clarified. Seven issues are discussed in this paper; (1) occupational safety and health policy and audit that can drive the PDCA cycle effectively, (2) reclassification of occupational health activities with several different objectives, (3) set up of targets, (4) risk assessment methods that can prioritize health risks compared to safety risks, (5) exposure assessment methods for risk assessment, (6) flexibility of laws and regulations, and (7) development of talented professionals for risk-based occupational health activities.
In our previous study, we found no genetic alteration in exons 1 and 2 of Ha- and Ki-ras oncogenes nor in exons 5 to 9 of the p53 suppressor gene in seven Japanese malignant mesothelioma patients exposed to asbestos. To examine further whether malignant mesothelioma due to asbestos has genetic alterations in the p53 suppressor gene and in Ha- and Ki-ras oncogenes, we analyzed point mutations of these genes in paraffin embedded operative open biopsied samples of the primary tumor of malignant mesothelioma in twelve American patients. The genetic analysis was conducted by the PCR-SSCP (polymerase chain reaction single-strand conformation polymorphism) method in all patients and by sequencing analysis of DNA bases in the two patients with suspected gene mutation. The analysis of the p53 suppressor gene showed an amino acid converting mutation of exon 7 in one patient and a polymorphism of exon 6 in another patient; the former patient was a heavy smoker with a biphasic cell type. No genetic alteration was found in exons 1 and 2 of Ha- and Ki-ras oncogenes in any of the patients. The results suggest that the effects of asbestos on the p53 suppressor gene and Ha- and Ki-ras oncogenes in malignant mesothelioma are negligible. Further studies are needed to examine whether the observed mutation of the p53 suppressor gene is due to the combined effects of asbestos and smoking or to other unknown factors.
The effects of safety behaviours associated with pesticide use on the occurrence of acute organ symptoms in 395 male and 101 female tobacco-growing farmers in Malaysia were studied. We used a 15-questionnaire checklist on safe pesticide-use behaviours and a 25-questionnaire checklist on acute organ symptoms reported shortly after spraying pesticides. Results of stepwise multiple linear regression analysis indicated that no smoking while spraying, good sprayer-condition, and changing clothes immediately after spraying significantly prevented occurrence of acute symptoms just after pesticide spray in male farmers; in female farmers, only wearing a hat while spraying significantly prevented the symptoms. Safety behaviours in pesticide use in male and female tobaccogrowing farmers are discussed in the light of these findings.
Mancozeb, an organocarbamate fungicide, was administered to examine the effect on implantation at doses of 18, 24, 30 and 36mg/kg body weight/d to normal virgin swiss albino mice for 8 days to pregnant mice. The vaginal smear and body weight of the mice were recorded daily and mice were sacrificed on 9th day of pregnancy. There was a complete inhibition of implantation in 36mg mancozeb treated mice with 100% pre-implantation loss. There was a partial inhibition of implantation in 24 and 30mg mancozeb treated mice with 53.44 and 90.16% pre-implantation loss respectively. However, implantation was not affected in 18 mg mancozeb treated mice with 4.92% pre-implantation loss when compared to oil treated controls. To study the temporal effect, the effective dose of 36mg/kg body weight/d mancozeb was administered orally for 3 and 5 days and on day 3 only. There was a complete inhibition of implantation in 5 days treated mice with 100% pre-implantation loss and partial inhibition of implantation of 3 days treated mice with 75% pre-implantation loss. However, implantation was not affected in mice treated on day 3 only with 1.63% pre-implantation loss when compared to control mice. There was a significant decrease in the diestrus phase with the result there was a concomitant increase in the estrus phase and there was a significant decrease in the uterus weight with 24, 30 and 36mg and for 3 and 5 days with 36 mg mancozeb treatment. Inhibition of implantation by mancozeb may be due to hormonal imbalance or its toxic effects.
In order to prevent low back pain during dishwashing, we developed a standing aid for supporting the forward bending posture, and then evaluated the effects of the standing aid on decreasing load on the low back and legs. Eight female volunteers were asked to wash plates for 60 minutes in each of three working postures: (a) without the standing aid, (b) with the standing aid under the thighs, and (c) with the standing aid under the shins. The following were measured: electromyogram (EMG), electrocardiogram (ECG), the force applied to the standing aid, the ground reaction force, the bending angle of the trunk, the bending angle of the knee, and local discomfort in body regions. While using the standing aid under the shins, the muscle load decreased in the low back and legs. While using the standing aid under the thighs, the muscle loads decreased in the low back but increased in the legs. It was suggested that the standing aid under the shins was more effective in decreasing the load on the low back and legs than the standing aid under the thighs.
Our aim was to investigate the adverse effects of occupational exposure to trivalent chromium. We measured chromium and iron levels in serum and urine and hemoglobin levels in tannery workers and unexposed persons. We studied three groups of subjects. Group 1 included 15 non-smoking male tannery workers highly exposed to chromium from tanning and retanning departments. Group 2 included 14 non-smoking male tannery workers with moderate chromium exposure from dying, drying and finishing departments. Group 3 included 11 healthy, non-smoking male subjects without direct chromium exposure. Higher serum chromium levels were observed in groups 1 and 2 with respect to group 3 (mean values respectively: 0.43; 0.25 and 0.13 μg•l-1). Urine chromium levels in group 1 were higher than those in controls (mean values: 1.78 and 1.35 μg•l-1). In group 1 an inverse association was found between serum chromium and urine iron (-0.524), urine chromium and hemoglobin (-0.594) and between the urine chromium to iron ratio and hemoglobin (-0.693, p<0.05). The results suggest a chromium adverse effect on iron metabolism, possibly associated with excessive body chromium accumulation. In conclusion, chromium urine test could be recommended for diagnosis of chromium adverse effect on iron metabolism. Further studies are needed to quantify the relationship between urine chromium and hemoglobin metabolism.
Photocopier toner has been implicated in the etiology of some pulmonary diseases. We examined here the in vitro toxicity of toner particles to alveolar macrophages. Cell magnetometry revealed that relaxation was not delayed in macrophages exposed to toner, which represents a rapid decrease in the remaining magnetism emitted by phagocytosed magnetite. However, relaxation was delayed in macrophages exposed to silica (positive controls). The release of intracellular LDH enzyme activity to the extracellular space was negligible in cells exposed to toner compared with negative and positive controls. Morphological examinations by light and electron microscopy revealed no abnormal findings in the exposed cells. A histochemical study using TUNEL staining and the electrophoretic profile of DNA obtained from cells exposed to toner and to silica were negative for apoptosis. The results of the present and other investigations into animal exposure indicate that photocopier toner is toxicologically inert. However, although the present study examined only effects in vitro, exposure to toner should be minimized because lung overloading in animals has been reported.