Objectives: According to some newspapers, concerns are growing over the health of local government employees in the Great East Japan Earthquake disaster areas. Concerns were consistently present after the Hanshin-Awaji and Niigata-Chuetsu earthquakes but not studied analytically. Methods: Municipal employees responding to the disasters after an earthquake and floods answered a questionnaire about the degrees of workload, fatigue, psychological distress, resilience and personality traits. Results: Two-thirds of the employees suffered fatigue and psychological distress, which were significantly correlated with workload but inversely correlated with emotional stability personality traits and psychological resilience. Conclusions: Together with substantial workload, individual differences in emotional stability and to lesser degree in resilience were found to have an impact on perceived fatigue. These individual factors should be considered as potential mediators of distresses among local government employees responding to disasters.
Background: A nuclear accident occurred at the Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Company (TEPCO) as a result of a mega-earthquake and tsunami in March, 2011. A large number of workers were engaged in response and recovery operations under a complex structure of involved companies. They were exposed not only to radiation but also to other health hazards. TEPCO implemented programs to prevent radiation exposure, but had no effective systems for managing the other health risks and few occupational health (OH) professionals contributed to the health risk management. Activities: The University of Occupational and Environmental Health (UOEH), Japan, dispatched physicians to a quake-proof building at the plant to provide first-aid services from mid-May, 2011, and took a strategic approach to protecting workers from existing health risks. UOEH presented recommendations on OH systems and preventive measures against heat stress to the Government and TEPCO. The Ministry of Health, Labour, and Welfare issued guidelines to TEPCO and contractors. TEPCO implemented a comprehensive program against heat stress according to the guidelines and in cooperation with UOEH. As a result, we successfully prevented severe heat illness during summer 2011. Discussion: From our experiences, we believe that the following recommendations should be considered: 1) the role of OH and the participation of experts should be defined in emergency response plans; 2) regulations should allow the national government and main companies involved to lead safety and health initiatives for all workers at disaster sites; and 3) OH professionals, response manuals and drills should be organized at a national level.
Objectives: The aim of study was to determine the associations of work hours and actual availability of weekly rest days with the onset of lifestyle-related diseases such as obesity, hypertension, hypertriglyceridemia, low levels of high-density lipoprotein (HDL) cholesterol and hyperglycemia. Methods: For this longitudinal study, we used data from checkups conducted in 1999 and 2006 for 30,194 men who worked for a local public institution in Japan. We calculated the cumulative incidence rates of onset of obesity, hypertension, hyperglycemia, hypertriglyceridemia and low HDL cholesterol over this 7-year period and performed a χ2 test to determine the association between the above diseases and work conditions (work hours and actual availability of weekly rest days) at the time of the baseline survey. We then performed multiple logistic regression analysis of the diseases that showed significant associations. Results: The adjusted odds ratio for the onset of hypertriglyceridemia in subjects who worked ≥9 hours was high (1.11 [95% CI: 1.02–1.22], p=0.02) in comparison with those who worked<9 hours. The adjusted odds ratio for the onset of hypertriglyceridemia in subjects who could not often take weekly rest days was high (1.13 [95% CI: 1.01–1.27], p=0.03) in comparison with those who were able to take most of the available weekly rest days off work. Conclusions: These results show that work hours and actual availability of weekly rest days independently predict the onset of hypertriglyceridemia. Working only regular hours and taking advantage of weekly rest days can contribute to the prevention of hypertriglyceridemia.
Objective:This study examined the associations between respiratory symptoms and patterns of pulmonary dysfunction of 115 male roofing cement workers compared with 134 unexposed subjects. Methods: A cross-sectional study was conducted. Environmental samplings and spirometry measurements were also collected. Results: The exposed workers had higher respiratory dust exposure levels (0.65 mg/m3) compared with the unexposed groups (0.32 mg/m3). The exposed group had significantly higher prevalence than the unexposed group for shortness of breath (OR=2.19). The exposed group also had higher but insignificant prevalence of chronic cough (OR=1.34), chest tightness (OR=1.64), and wheezing (OR=1.89). The ventilatory respiratory function values (FEV1 and FVC) were slightly lower for the exposed group. Conclusion: An association between higher cement dust levels and a decline in ventilatory function among roofing fiber cement workers suggests that the respiratory health of roofing cement workers should be protected through policies or work standards.
Objectives: Human cases of 1-bromopropane (1-BP) toxicity showed ataxic gait and cognitive dysfunction, whereas rat studies showed pyknotic shrinkage in cerebellar Purkinje cells and electrophysiological changes in the hippocampus. The present study investigated the effects of 1-BP on astrocytes and oligodendrocytes in the rat cerebellum and hippocampus to find sensitive markers of central nervous system toxicity. Methods: Forty-eight F344 rats were divided into four equal groups and exposed to 1-BP at 0, 400, 800 and 1,000 ppm for 8 h/day; 7 days/week, for 4 weeks. Nine and three rats per group were used for biochemical and histopathological studies, respectively. Results: Kluver-Barrera staining showed pyknotic shrinkage in the cytoplasm of Purkinje cells and nuclei of granular cells in the cerebellum at 1,000 ppm. Immunohistochemical analysis showed increased length of glial fibrillary acidic protein (GFAP)-positive processes of astrocytes in the cerebellum, hippocampus and dentate gyrus at 800 and 1,000 ppm. The myelin basic protein (MBP) level was lower at 1,000 ppm. The numbers of astrocytes and granular cells per tissue volume increased at 400 ppm or higher. Conclusion: The present study showed that elongation of processes of astrocytes accompanies degeneration of granular cells and Purkinje cells in the cerebellum of the rats exposed to 1-BP. The decrease in MBP and number of oligodendrocytes suggest adverse effects on myelination. The increase in astrocyte population per tissue volume in the cerebellum might be a sensitive marker of 1-BP neurotoxicity, but the underlying mechanism for this change remains elusive.
Objectives: CO poisoning has been a serious industrial hazard in Japanese workplaces. Although incomplete combustion is the major cause of CO generation, there is a risk of CO poisoning during some welding operations. The aim of the present study was to evaluate the generation rate of CO from CO2 arc welding under controlled laboratory conditions and estimate the ventilation requirements for the prevention of CO poisoning. Methods: Bead on plate welding was carried out with an automatic welding robot on a rolled steel base metal under several conditions. The concentration of emitted CO from the welding was measured by a real-time CO monitor in a well-ventilated laboratory that was free from ambient CO contamination. The generation rate of CO was obtained from the three measurements–the flow rate of the welding exhaust gas, CO concentration in the exhaust gas and the arcing time. Then the ventilation requirement to prevent CO poisoning was calculated. Results: The generation rate of CO was found to be 386–883 ml/min with a solid wire and 331–1,293 ml/min with a flux cored wire respectively. It was found that the CO concentration in a room would be maintained theoretically below the OSHA PEL (50 ppm) providing the ventilation rate in the room was 6.6–25.9 m3/min. The actual ventilation requirement was then estimated to be 6.6–259 m3/min considering incomplete mixing. Conclusions: In order to prevent CO poisoning, some countermeasures against gaseous emission as well as welding fumes should be taken eagerly.
Objectives: The purpose of this research was to develop a method for the simultaneous determination of p-phenylazoaniline (also called 4-aminoazobenzene, AAB) and 2-methyl-4-(2-tolylazo)aniline (also called o-aminoazotoluene, AAT) in workplace air for risk assessment. Methods: The characteristics of the proposed method, such as recovery, limit of quantitation, reproducibility and storage stability of the samples were examined. Results: An air sampling cassette containing two sulfuric acid-treated glass fiber filters was chosen as the sampler. The AAB and AAT were extracted from the sampler filters by methanol and then analyzed by a high-performance liquid chromatograph equipped with a photo-diode array detector. The overall recoveries from spiked samplers were 77–98 and 85–98% for AAB and AAT, respectively. The recovery after 5 days of storage in a refrigerator exceeded 96%. The overall limits of quantitation were 5.00 and 2.50 μg/sample for AAB and AAT, respectively. The relative standard deviations, which represent the overall reproducibility defined as precision, were 0.6–1.8 and 0.5–2.2% for AAB and AAT, respectively. Conclusions: The proposed method enables 4-h personal exposure monitoring of AAB and AAT at concentrations of 21 to 2,000 μg/m3 for AAB and 10 to 2,000 μg/m3 for AAT, respectively. The proposed method is useful for estimating worker exposure to AAB and AAT.