Research progress of microbes in subway air / 环境与职业医学

Accumulating studies suggest that, as the subway is one of the important means of transport in cities, airborne microorganisms in its system have potential effects on human health, but previous studies have mainly focused on some foreign cities. We reviewed the spatio-temporal distribution characteristics of airborne microorganisms in subway stations in different cities, including diurnal, weekly, and seasonal variations, and the distribution of microorganisms in different regions of the world. The factors affecting airborne microorganisms, such as human activities, temperature and humidity, ventilation, and particulate matter, were presented. The potential health effects were described. Although there was no significant risk of infection from using subway, many pathogens do exist in the air. The influence of microorganisms in subway air on health has become a public health problem that cannot be ignored.

Mediating effect of mental health on psychological capital and work engagement in subway employees / 中国职业医学

OBJECTIVE: To understand the mental health status of subway employees, and to explore the relationship among their mental health, psychological capital and work engagement. METHODS: Using the typical sampling method, a total of 2 758 subway employees from a rail transit group Co., Ltd in a city were selected as the study subjects. The Symptom Check List 90, Psychological Capital Questionnaire, and Utrecht Work Engagement Scale were used to investigate the mental health, psychological capital and work engagement of the study subjects. RESULTS: The screening positive rate of mental disorder of the study subjects was 15.6%(431/2 758), and the median scores of mental health, psychological capital, and work engagement were 108, 109, and 62 points, respectively. The mental health scores of the study subjects were negatively correlated with their psychological capital and work engagement scores [Spearman correlation coefficient(r_S) were-0.55 and-0.57, respectively, P<0.01]. The psychological capital score was positively correlated with the work engagement score(r_S=0.70, P<0.01).Mental health played a partial mediating role in the influence of psychological capital on work engagement(mediating effect was 0.07, 95% correlation coefficient: 0.06-0.08, P<0.01). CONCLUSION: The mental health status of the subway employees is good. Psychological capital of subway employees can not only directly affect work engagement, but also indirectly affect work engagement by influencing mental health.

Mental health status and its influencing factors on subway operators in a city / 中国职业医学

OBJECTIVE: To analyze the mental health status and its influencing factors on subway operators in a city. METHODS: A judgment sampling method was used to select 375 subway operators of a metro operation company in a city as the research subjects. The Symptom Checklist 90(SCL-90) was used to investigate the mental health status of the research subjects, and the influencing factors of mental health levels in the subway operators were analyzed through the multivariate logistic regression analysis. RESULTS: The total score of SCL-90 for the mental health level of the subway operators in this city was higher than the national average scores [(142.9±45.0) vs(130.0±33.6), P<0.01].The positive rate of psychological abnormalibies was 46.9%(176/375). The multivariate logistic regression analysis results showed that the positive rate of psychological abnormalities was lower in the subway operators in the group aged above 18 and secondary college education group(P<0.01). CONCLUSION: The mental health status of subway operators in the city is generally poor. The age and educational level are important factors influencing mental health level.

The Effects of Noise from the Subway Cars on the Preferred Listening Volumes and Noise Exposure Using Earphones / 听力学及言语疾病杂志

Objective To investigate the effects of noise from the subway cars on the preferred listening volumes using different kinds of earphones.Methods A total of 75 subjects with normal hearing were investigated to listen the same song wearing 4 kinds of earphones: insert earphones, intra-concha earphones, supra-concha earphones, and circumaural earphones, in the semi-anechoic background and inside the Line 7 subway-cars of the Beijing subway (the mean of LAeq,1s is 80.3 dB A and then selected personally preferred listening volumes.The effects of noise in the subway cars and earphone types on the preferred listening volumes were then analyzed.Results Inside subway-cars, the preferred listening levels using insert earphones, intra-concha earphones, supra-concha earphones, circumaural earphones were 76.6±4.7, 84.3±5.0, 82.3±4.2, and 80.8±4.2 dB A, respectively.The levels were respectively 65.5±6.8, 71.9±7.1, 69.5±7.5, 67.9±7.3 dB A for those in the semi-anechoic background.The preferred listening levels increase more than 10 dB averagely when stepped into noisy subway-cars background from silent background.According to the threshold levels stipulated in the WHO, to avoid hearing impairment, the daily noise exposure duration should not exceed 134 mins when exposed to subway-cars noise and the duration should not exceed 315, 54, 85, and 120 mins respectively when wearing those 4 kinds of earphones in subway-cars.Conclusion The noise and earphones types have great effects on the preferred listening volumes.The noise exposure levels in the ear canal wearing earphones with good sound insulation and listening at highly increased volume may be lower than that without earphones.

Analysis of Subway Interior Noise at Peak Commuter Time

BACKGROUND AND OBJECTIVES: Although mass transit systems are convenient and efficient for urban people, little attention has been paid to the potential hearing hazard from their noise. The purpose of the current study was to measure and analyze levels of subway interior noise at peak commuter times and to provide information about commuters' daily dose of noise exposure. MATERIALS AND METHODS: To measure the subway interior noise, nine subway lines inside Seoul (i.e., lines 1-9) and six lines surrounding the capital city area (i.e., Central, Bundang, Sinbundang, Incheon, Gyeongui, and Gyeongchun) were chosen. The noise was measured and recorded by a sound level meter for two-hour periods in the morning and evening. RESULTS: 1) In the LZeq analysis, the average noise level of all 15 lines was 72.78 dB; the maximum and minimum noise levels were 78.34 and 62.46 dB, respectively. The average noise level of the nine lines inside Seoul was 73.45 dB, which was 1.68-dB louder than that of the six lines surrounding the capital city area. 2) Based on the LZeq analysis of 33 measured frequencies, 12.5 Hz was the highest frequency and 20,000 Hz was the lowest. 3) There was no remarkable difference in the level of subway interior noise between morning and evening peak commuter times. CONCLUSIONS: We concluded that the level of subway interior noise was not loud enough for commuters to incur noise-induced hearing loss. Regardless, environmental noise control efforts in the subway system might be needed for commuters who take a subway every day.

Factors associated with suicide ideation among subway drivers in Korea

BACKGROUND: There were several suicide events of subway drivers in Korea. The aim of this study is to explore work-related factors associated with suicide ideation among subway drivers. METHODS: We analyzed data from 980 male subway drivers. A section of the Korean version of the Composite International Diagnostic Interview (K-CIDI 2.1) was administered by trained interviewers to judge whether a driver has suicide ideation and to diagnose psychiatric disorders. A questionnaire was also administered to collect data on sociodemographic characteristics, work environments, occupational stress, person under train (PUT) experience, and work-related problems. Occupational stress was examined by using the Korean Occupational Stress Scale (KOSS). Logistic regression was applied to evaluate the association between work-related factors and suicide ideation among subway drivers. RESULTS: Regarding work-related problems, conflict with passengers and sudden stops due to the emergency bell were significantly associated with suicide ideation. MDD, PTSD, and panic disorder were strongly associated with suicide ideation. In the analysis of occupational stress, insufficient job control (OR 2.34) and lack of reward (OR 2.52) were associated with suicide ideation even after being adjusted for psychiatric disorders and other work-related factors. CONCLUSIONS: Insufficient job control and lack of reward were associated with suicide ideation among subway drivers. Strategies for drivers to have autonomy while working and to achieve effort-reward balance should be implemented. Furthermore, drivers who have experienced negative work-related problems should be managed appropriately.

The association between psychiatric disorders and work-related problems among subway drivers in Korea

OBJECTIVES: This study aimed to find the prevalence and occupational risk factors for major psychiatric disorders among subway drivers in South Korea. METHODS: Of all 998 current subway drivers, 995 participated in this study. The Korean version of the Composite International Diagnostic Interview (K-CIDI 2.1) was administered by trained interviewers to diagnose psychiatric disorders in all participants. The questions on socio-demographic characteristics and working conditions included some questions related to a person under train (PUT) experience and work-related problems. One-year prevalence and lifetime prevalence of major depressive disorder (MDD), post-traumatic stress disorder (PTSD), and panic disorder were diagnosed through the interview. The standardized prevalence ratios (SPRs) of these three disorders were calculated in the sample of subway drivers using the 2011 Korean National Epidemiologic Survey data as a basis. Multiple logistic regressions were performed to determine the association between work-related factors and the prevalence of the psychiatric disorders. RESULTS: The standardized prevalence ratios (SPRs) for a 1-year prevalence of MDD and PTSD among subway drivers were 1.1 (95% CI 0.7-1.7) and 5.6 (95% CI 3.1-8.8), respectively. Conflict with passengers was significantly associated with an increased risk for both MDD and PTSD in 1-year and in lifetime prevalence. Experiencing a sudden stop due to an emergency bell increased the risk of the lifetime prevalence of MDD (OR 2.61, 95% CI 1.14-6.97) and PTSD (OR 7.53, 95% CI 1.77-32.02). The risk of PTSD significantly increased among drivers who once experienced a near accident in terms of both the 1-year prevalence (OR 8.81, 95% CI 1.96-39.3) and the lifetime prevalence (OR 6.36, 95% CI 2.40-16.90). CONCLUSIONS: PTSD and panic disorder were more prevalent among subway drivers than in the general population. We found that having a conflict with passengers, a near accident, and a breakdown while driving can be risk factors for psychiatric disorders among subway drivers. Therefore, a prompt and sensitive approach should be introduced for these high risk groups within the subway company.

Technological response measures against subway bioterrorism in the United States:investigation and analysis / 军事医学

Due to the large population and relatively closed space environment , the subway system is vulnerable to bioterrorist attacks.This paper analyzes the technological response measures against subway bioterrorism in the United States, including Detect to Protect program of Department of Homeland Security (DHS) and PROTECTS program of Depart-ment of Energy ( DOE) .We also put forward some proposals on how to improve China′s capability of prevention of and response to subway bioterrorism .

Association of Subway Driver's Depressive Symptoms and Experience of Work-Related Problems / 한국역학회지

OBJECTIVES: Subway drivers experience various types of work-related problems during their driving, and those experiences can act as risk factors for depressive symptoms. This study was conducted to investigate the association between work-related problems and subway driver's depressive symptoms. METHODS: We recruited all of the 961 current subway drivers of a subway company located in Seoul, South Korea and conducted a survey of their socio-demographic and vocational characteristics, hospital visits as an outpatient or inpatient, and work-related problem experiences during the last year. Work-related problems included an accident resulting in death or injury, a conflict with a customer, a sudden stop from an emergency bell, or a near accident. Depressive symptoms were measured with the Center for Epidemiologic Studies-Depression (CES-D) instrument. The survey was performed using a self-report questionnaire from April 16 to July 13, 2007. The data of 827 drivers (86.2%) were analyzed. RESULTS: Experience of a conflict with a passenger (p=0.011), a sudden stop from an emergency bell (p=0.001), or a near accident (p=0.001) increased the prevalence of depressive symptoms among subway drivers. A multiple logistic regression analysis revealed that a sudden stop from an emergency bell increased the risk of depressive symptoms significantly (OR=2.59, p=0.026). Near accidents were marginally associated with a higher risk for depressive symptoms (OR=1.62, p=0.062). CONCLUSION: The experience of a sudden stop from an emergency bell increased subway driver's depressive symptoms, and near accidents may increase the risk of depressive symptoms. Therefore, interventions for the drivers who had experienced these work-related problems are needed.

The Effect of Non-Smoking Campaign for Subway Workers on Their Health Behavior / 산업간호학회지

PURPOSE: This study was done to investigate the effect of non-smoking campaign for subway workers on their health behavior such as smoking, drinking, and exercise. METHOD: The study was done on the subjects of 112 male employees for 3 years from 2003 to 2005 working at the Seoul Metropolitan Rapid Transit Corporation. However, the subjects decreased to 105 in 2004 and 111 in 2005 due to work transfer. The data were obtained through administering questionnaires. The non-smoking campaign was done with health education using various strategies and methods by an administrator-in-charge assisted by the community health center. RESULTS: Smoking rate and cigarette consumption decreased but there was no statistical significance. Smokers' frequency of drinking and exercise were higher than that of non-smokers, but there was no statistical significance. CONCLUSION: The result indicated the program was not effective to change the subjects' health behavior; therefore, tailored program considering the subjects is recommended.

The Effect of Non-Smoking Campaign for Subway Workers on Their Health Behavior / 산업간호학회지

PURPOSE: This study was done to investigate the effect of non-smoking campaign for subway workers on their health behavior such as smoking, drinking, and exercise. METHOD: The study was done on the subjects of 112 male employees for 3 years from 2003 to 2005 working at the Seoul Metropolitan Rapid Transit Corporation. However, the subjects decreased to 105 in 2004 and 111 in 2005 due to work transfer. The data were obtained through administering questionnaires. The non-smoking campaign was done with health education using various strategies and methods by an administrator-in-charge assisted by the community health center. RESULTS: Smoking rate and cigarette consumption decreased but there was no statistical significance. Smokers' frequency of drinking and exercise were higher than that of non-smokers, but there was no statistical significance. CONCLUSION: The result indicated the program was not effective to change the subjects' health behavior; therefore, tailored program considering the subjects is recommended.

Factors Associated with Quality on Sleep of Subway Workers by Shift-Work / 대한산업의학회지

BACKGROUND: The sleep quality of subway drivers who work in the dark underground with an rotating shift system is generally poor, which can degrade the quality of a worker's life. This study examined the relationship between the sleep quality of subway worker and shift work by comparing three shift systems (rotating shift system, a three day shift system, and no-shift system). METHOD: Questionnaires including The short form of the Korean Occupational Stress Scale (KOSS), Pittsburgh Sleep Questionnaire (PSQI), the worker's age, gender, job type, accident, near miss and shift system were given to a total of 1010 workers. The results of 759 qualified questionnaires (75.15 %) were analyzed using the SPSS (ver 12.0) program. RESULT: The highest level of job stress was found among those working a rotating shift system followed by three shift system and no-shift system. The mean sleep quality score in the rotating shift workers was 5.1 (SD+/-3.2), which was greater than the sleep symptom score (5). 34.8% of rotating shift workers suffered from sleep symptoms. The sleep quality score by shift-work was significantly different. High job demand, strong external locus control, the experience of a near miss or an accident in the workplace during previous year has an adverse affect on the sleep quality. The sleep quality improved in case of a change into a no-shift system or a strong internal locus control. CONCLUSION: A rotating shift system is more harmful to the quality of sleep in subway workers than a 3 shift system or no-shift system. In addition, job stress, personality, near miss and the experience of an accident affect the sleep quality of subway workers.

Posttraumatic Stress Disorder of Survivors in Daegu Subway Fire Accident: A Prospective Study on Predictors / 신경정신의학

OBJECTIVES: The purpose of this study was to determine the predictors of PTSD in subway fire accident survivors. METHODS: Subjects consisted of 129 survivors from the Daegu subway fire accident. The 129 subjects were registered at April, 2003, which was 2 months after the accident, and 49 of them were followed up from June to November 2004. Subjects were assessed at 2 months and 18 months after the accident. All participants completed BDI-II, SCL-90-R, MMPI, PCL-C, STAI-S, STAI-T and IES at the two time points, respectively. CAPS was only administered in the follow-up assessment. Statistical analysis was performed using Binary Logistic regression with SPSS 12.01. RESULTS: Only the BDI-II total scores at 2 months significantly predicted PTSD at 18 months. Other measures did not significantly predict PTSD. Conclusions: These findings suggest that high BDI-II total scores at the initial assessment may be regarded as a major predictor of PTSD. Accordingly, early treatment intervention may serve to prevent the chronicity of PTSD among accident survivors.

Job Stressors in Subway Workers and Firemen / 대한산업의학회지

OBJECTIVES: To determine the job stress factors of subway workers and firemen and to develope appropriate stress management systems for the works places. METHODS: The study subjects comprised 1,826 male subway workers and 538 male firemen residing in Daegu metropolitan city. The Korean Occupational Stress Scale (KOSS) questionnaire was used. RESULTS: The median values of the study subjects were lower than the reference values. The categories of physical environment and insufficient job control were more stressful to firemen while the organization system category was stressful to both subway workers and firemen (p<0.05). There was no statistical difference in the stress factor of the interpersonal conflict category. Among the firemen, the physical environment category was more stressful to field work department workers than to desk workers (p<0.05). CONCLUSION: The study results suggested that interpersonal conflict and organization system categories are stressful to male subway workers and firemen. Especially, effective control of firemen's physical environment stress factor is needed.

Increasing Risk of Mental Health Problems Among Subway Drivers Experiencing Accidents on the Track / 대한산업의학회지

OBJECTIVES: This study examined the prevalence of Post traumatic stress disorder(PTSD) and the comorbidity with panic disorder in subway drivers who experienced accidents on the track. In addition, this study examined the differences in panic disorder, stress levels, work-related problems, and sleep disturbances between drivers with and without an accident-experience. METHODS: 628 Seoul metropolitan subway drivers were participated in this study. We assessed mental health status of the subjects using the Clinician-administered PTSD scale (CAPS), panic disorder scale based on the DSM-IV criteria, Worker's Stress Response Inventory, and Sleep Questionnaire. RESULTS: The prevalence of PTSD and comorbid panic disorder was significantly higher among those drivers who had experienced accidents than in those who had not. Drivers with an accident experience showed significantly higher somatic, depressive, anger symptoms in the stress measures, and more sleep problems than those drivers without an accident experience. CONCLUSIONS: The experience of an accident on the track threatens both the work efficiency and the mental health of drivers. In order to reduce the negative effect of an extremely stressful event related to accidents, intervention programs for PTSD and panic disorder need to be developed and utilized.

A Clinical Analysis of Trauma Pattern in Subway Station

PURPOSE: Till now, various circumstances have generated mass casualties. Thus, the government is now concerned about providing a social safety system against disasters. Most of accidents involving mass casualties have broken out in public places like department stores, bridges, and train depots, but there are few little medical reports on accidents in subway station. So the author investigated the types of traumas experienced in cases of mass casualties at subway stations and to searched for ways to prevent injury. METHODS: Thirty-nine patients, who presented at the Emergency Department with traumas incurred at subway stations, except for those who had definite medical diseases, were enrolled in this study, and the medical records of those patients were reviewed retrospectively. The age, gender, mechanism of injury, and other characteristics were collected for analysis. RESULTS: There was no significant relationship between the incidence of trauma and age. In general, most of the accidents occurred on platforms and on escalators. However the older patients were more likely to be injured on escalators rather than on platforms. The opposite was true for younger patients. CONCLUSIONS: In subway stations, platforms and escalators are weak points for trauma. Elderly people are injured much more often on escalators and young people on platforms. Thus age is a serious factor when planning an injury prevention and control system for subway stations.

Characteristics of Personality Factors in Patients with Posttraumatic Stress Disorder : Survivors of Daegu Subway Fire Accident / 신경정신의학

OBJECTIVES: The purpose of this study was to assess the personality factors of posttraumatic stress disorder (PTSD) patients to investigate the contribution of personality to the development of PTSD. METHODS : The PTSD group and Non-PTSD group with no other sympton met DSM-IV Diagnostic Criteria for major psychiatric disorders were selected among 129 survivors of Daegu subway fire accident. Of 129 survivors of the accident, 95 survivors who had faithfully resonded to the psychiatric evaluation were assessed with Catell's 16 Personality Factor Questionnaire (16PF) and Spielberger's State-Trait Anxiety Inventory (STAI). Of 95 survivors, 52 survivors were diagnosed to have PTSD. The results were compared among PTSD group, non-PTSD group and normal group. RESULTS : In 16PF measurement, the scores of Anxiety and Tender-mindedness were significantly higher in PTSD group than normal and Non-PTSD groups. And the scores of Liberalism was significantly higher in PTSD group than normal group. The scores of Warmth, Stableness, Dominance, Surgency were significantly lower in PTSD and Non-PTSD than normal group. The scores of Guilty-proness and Anxiety were significantly higher in PTSD and Non-PTSD groups than normal group. In STAI measurement, PTSD group showed higher scores than Non-PTSD and normal group. CONCLUSION : These results suggested that patients with PTSD group were disposed to tension, anxiety, inpatience, fatigue, dependence, concern and compassion. It indicates that development of PTSD is associated with personality factors such as Anxiety and Tender-mindedness. Further prospective studies are necessary to clarify how personality factors were involved in the development of PTSD.

Health Behavior Practices and Needs for Health Promotion Program According to Shift Work Pattern in Subway Workers / 대한산업의학회지

OBJECTIVES: To determine the health behavior practices and needs for health promotion in shift work pattern in subway workers. METHODS: Among 789 male subway workers divided into four groups, 191 day time workers, 187 station service men (3 groups, 2 turns), 204 rolling stock inspectors (3 groups, 2 turns) and 207 train operators (8 groups, 5 turns), we surveyed the health behavior and needs for health promotion by questionnaire. RESULTS: For obesity, blood pressure and total cholesterol, day time workers had the highest levels, while train operators had higher diseases of the liver and stomach than others. The station service men had the highest smoking rate and daily smoking amount. More than 80% of the respondents consumed alcohol, and the drinking amount was highest among the day time workers and the 8/5 shift train operators. Eighty-two percent of the station service men had irregular eating habits and 17.7% did not have any breakfast. In health promotion activities, exercise and restriction of one's favorite(smoking or drinking) were most preferred in the four groups of respondents. The priority of needs and participation for health promotion program was exercise programs, followed by stress management, cancer prevention program, weight control program, anti-smoking campaign, high blood pressure control program, and abstinence/moderation in drinking. CONCLUSION: As the health behavior practices differed relative to shift work patterns, it was suggested that a comprehensive health promotion program according to shift work pattern should be planned and implemented among subway workers.

A Study on Noise Induced Hearing Loss of Employees Working for Seoul Metropolitan Subway Cooperation

Although some employees working for Seoul Metropolitan Subway Cooperation are working at the noisy workplaces, they has been excluded from Special Periodic Health Examination Program. And some workers complained of hearing loss or tinnitus. So, this study was carried out to investigate the prevalence rate of Noise Induced Hearing Loss of employees(10,792) working for Seoul Metropolitan Subway Cooperation. The number of subjects were total 10,792 with 10,355 men and 437 women. A questionnaire survey, otological examination, Rinne test, pure tone audiometric tests were performed and through the first and second screening audiometric examination, 605 workers were selected after excluding employees with past otologic problems, recent exposure to high level noise, and under medications. and the results were as follow; 1. Among 10,792 workers, 4 workers(0.037%) diagnosed as NIHL and 601 workers(5.56%) as early NIHL. As workers grew older, the prevalence rate of NIHL and early NIHL became more rising. 2. The prevalence rate of NIHL and early NIHL was different between work site. After age adjustment, The prevalence rate of NIHL and early NIHL was 23.74% in Train repairmen{80dB(A)}, 3.1% in Station staffs{below 70dB(A)}, 2.53% in Train crew{below 70dB(A)}, 2.1% in Office workers. 3. The perception rate of necessities of ear plug in NIHL and early NIHL was below 55% and wearing rate of ear plug in NIHL and early NIHL was 1.1% In conclusion, some employees who was under working environment in Seoul Metropolitan Subway Cooperation should be monitored to prevent hearing impairment and would be needed health education.