Sleep-wake rhythm in an irregular shift system

Sleep in shift work has been studied extensively in regular shift systems but to a lesser degree in irregular shifts. Our main aim was to examine the sleep-wake rhythm in shift combinations ending with the night or the morning shift in two irregular shift systems. Three weeks' sleep/work shift diary data, collected from 126 randomly selected train drivers and 104 traffic controllers, were used in statistical analyses including a linear mixed model and a generalized linear model for repeated measurements. The results showed that the sleep-wake rhythm was significantly affected by the shift combinations. The main sleep period before the first night shift shortened by about 2 h when the morning shift immediately preceded the night shift as compared with the combination containing at least 36 h of free time before the night shift (reference combination). The main sleep period before the night shift was most curtailed between two night shifts, on average by 2.9 and 3.5 h among the drivers and the controllers, respectively, as compared with the reference combination. Afternoon napping increased when the morning or the day shift immediately preceded the night shift, the odds being 4.35-4.84 in comparison with the reference combination. The main sleep period before the morning shift became 0.5 h shorter when the evening shift preceded the morning shift in comparison with the sleep period after a free day. The risk for dozing off during the shift was associated only with the shift length, increasing by 17 and 35% for each working hour in the morning and the night shift, respectively. The results demonstrate advantageous and disadvantageous shift combinations in relation to sleep and make it possible to improve the ergonomy of irregular shift systems.     

高速铁路软土地基处理对策及效果分析

介绍了沪宁段铁路沿线的软土分布特征,将沿线软土地基分为4类,并从技术和经济两方面,分别对各类软土地基的处理进行了分析和比较,提出了相应的处理建议。     

青藏高原鼠疫耶尔森菌基因型分布

目的研究青藏高原鼠疫耶尔森菌（鼠疫菌）基因组型分布特征.方法对分离到的青藏高原鼠疫菌297株,根据已经证实的22个差异区段设计引物,每株鼠疫菌的每个基因差异区段都采用PCR技术进行验证.结果在喜马拉雅旱獭鼠疫自然疫源地中,鼠疫菌基因组型有9种,分别为1、5、6、7、8、10、11、新基因组型和Ype-ancestor型,其中以5、8和10型为主,3种基因组型合计所占比例为80.6%（204/253）,而且不同地区鼠疫菌基因组型的分布也不一致.青藏高原青海田鼠鼠疫疫源地鼠疫菌基因组型全部为14型.结论青藏高原鼠疫菌基因组型分布具有明显的地理特征.根据基因组型的分布状况推测出了鼠疫菌在青藏高原的传播路径.     

包虫病自然疫源性的研究——Ⅰ.高原鼠兔作为包虫中间宿主的证实

本文首次报道了青藏高原的野生害鼠——高原鼠兔(Ochotona curzoniae Hodgson)作为包虫中间宿主的结论。采用病理组织学和免疫学的方法,取得了高原鼠兔包虫囊肿的形态结构和包虫囊液特异抗原性的研究资料。初步论述了高原鼠兔在包虫病流行病学和动物流行病学上的意义及其自然疫源性问题。为进一步开展野生动物群体的包虫病调查研究,了解与掌握人、家畜、野生动物三个生物群体间的包虫病内在规律性,提供了重要线索和科学依据。     

Prevalence of musculoskeletal disorders among Indian railway sahayaks

Railway sahayak or also known as coolie is one of the oldest occupations in India. This occupational group is continuously subjected to various musculoskeletal problems due to repetitive load exertion in unnatural postures. The present research aims to examine the prevalence of musculoskeletal disorders (MSDs) among Indian railway sahayaks. A cross-sectional study has been conducted on a sample of 51 male sahayaks. With a modified Nordic questionnaire, data were collected on their demographics, work, and musculoskeletal pain history. Electromyography (EMG) of the upper trapezius muscle of selected 12 healthy sahayaks having no history of neck–shoulder complaints were analyzed under different load lifting and carrying conditions. Additionally, ergonomic risk levels were recorded using Rapid Entire Body Assessment method. The questionnaire revealed that for the past 1 year prevalence, the most affected body regions of railway sahayaks were neck (47%), shoulder (51%), lower back (43%), and knee (47%). The association between age group and MSDs in different body regions were found significant (p = 0.012 for neck, p = 0.017 for shoulder, etc.). Work experience also had a significant relation to the MSDs in different body regions (p = 0.013 for shoulder,p = 0.023 for calf, etc.). Analysis of variance reveals high significance level between EMG values and tasks performed by the sahayaks. In conclusion, railway sahayaks were found to have high rate of MSDs which may be associated with lifting/carrying heavy loads in awkward postures. Ergonomic interventions must be implemented to reduce the risk level on this group of workers.     

太原市城区铁路边界噪声污染状况调查

[目的]了解太原市城区范围内铁路边界噪声的污染状况。[方法]按照GB 12525-90《铁路边界噪声限值及其测量方法》对城区和铁路边界进行噪声监测。[结果]噪声敏感点以铁路住宅区为主,这些住宅区均与铁路边界重合;列车在各敏感点区段均须鸣笛,未采取噪声控制措施;各监测点的昼、夜间噪声值,作为铁路边界噪声合标率达90.91%,作为环境噪声其合标率为0%。[结论]太原市城区范围内铁路边界噪声作为噪声源合标率很高,但对与铁路边界重合的敏感点的环境噪声污染很严重。     

Cancer incidence among male railway engine-drivers and conductors in Sweden, 1976–90

During recent years, the relationship between exposure to magnetic fields and cancer has attracted increasing interest. In Sweden, train personnel are exposed to comparatively strong magnetic fields in their work. The aim of the present study was to investigate cancer incidence, particularly leukemia and brain tumors, among male railway engine drivers and conductors, respectively, and to compare their cancer incidence with that of the general male population. The study population comprised all male railway engine drivers (n=7,466) and conductors (n=2,272) who were ever employed at the Swedish State Railways during the period 1976–90. The study population was observed with regard to cancer incidence by means of the National Cancer Register for the period 1976–90. The total cancer incidence (all tumors included) among railway engine drivers was lower than in the general Swedish population. An increased incidence of lymphocytic leukemia was observed among railway engine drivers and conductors combined (relative risk = 2.3; 95 percent confidence interval = 1.3–3.2), with the same point estimate for both occupational groups. For brain tumor (astrocytoma), the observed relative risk was close to one. The study provides evidence of an excess risk of lymphocytic leukemia in railway engine drivers and conductors, workers with known occupational exposure to magnetic fields.Drs Alfredsson and Hammar are with the Division of Epidemiology, Institute of Environmental Medicine, Karolinska Instituter, Stockholm, Sweden. Dr Alfredsson is also with the Department of Occupational Health, Karolinska Hospital, Stockholm, Sweden. Dr Karlehagen is with the National Occupational Health Services, Örebro, Sweden. Address correspondence to Dr Alfredsson, Division of Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Box 210, S-171 77 Stockholm, Sweden. The study was supported by the Swedish State Railway Company.     

Excavation of the chest due to railway mishap

Injuries sustained due to railway mishaps are well documented. In these mishaps, ascertaining the cause of death is usually not difficult, but frequently circumstances do raise questions as to the manner of death. It is a real challenge for an autopsy surgeon to correlate the alleged history with injuries present on the body, thereby helping the investigating officer to come to a conclusion on the manner of death. Here, we present a case of an unusual excavation injury to the chest due to train impact, and discuss the mechanism of causation of this injury and the manner of death.     

南京铁路游泳馆卫生状况调查

目的调查南京铁路游泳馆卫生状况,探讨游泳馆卫生管理措施。方法游泳馆2010-2012年卫生监测资料:游泳馆水质及微小气候。采用统一调查表进行调查游泳者自觉症状、游泳馆卫生管理情况调查。结果 (1)游泳馆微小气候达标率较高,基本符合国家卫生标准;(2)尿素严重超标,给游泳者健康造成潜在的危害;(3)游离性余氯合格率偏低,游泳者随着游泳时间的延长自感异常症状者普遍增多(x2=101.81,p<0.01);(4)管理力度不够,消毒质量把关不严,无专业消毒剂配置设施及专业保健人员等。结论加强领导,健全组织,全方位监控游泳馆水质,为游泳者提供舒适、卫生的游泳环境。