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PubMed1986

Studies on motion sickness caused by high curve speed railway vehicles. Evaluation of the swing and its effects on passengers and conductors.

The high curve speed railway vehicles (HCSRVs) of the Japanese National Railway have been operating since 1973 with the aim of increasing speed on ordinary routes with many curve track sections. Although the aim of increased speed has been attained, it has been pointed out that the swing of HCSRVs is stronger than that of ordinary-type trains and it may increase motion sickness among the passengers and conductors. In this study, the authors examined motion sickness symptoms among 119 passengers and 100 conductors of both trains with a self-administered questionnaire, and evaluated the vibration acceleration on the floor by using the 1/3 Octave Band Analyzer and the Fast Fourier Transform method (FFT). The results can be summarized as follows: There were more passengers and conductors suffering from motion sickness riding on HCSRVs than those on the control trains. HCSRVs had the peak values of vibration acceleration within the range of 0.5 Hz and 1 Hz at horizontal, although the control train showed them above 1.0 Hz. These results suggest that the high rates of subjective complaints of passengers and conductors riding on HCSRVs were affected by vibration acceleration of frequency lower than 1 Hz.

Acceleration↗
PubMed1988

Mortality among migrant tunnel workers.

To clarify the mortality pattern of migrant tunnel workers, a retrospective cohort study was conducted in the southern part of Oita Prefecture, which is well known as a source area for tunnel workers. This study was made on 1,078 tunnel workers and 943 non-tunnel workers who were observed for 8 years and 6 months from January 1975 to June 1983. The overall SMR of tunnel workers was 162 which was statistically significant. The SMRs for pulmonary tuberculosis (SMR = 3,267), industrial accidents (SMR = 1,000), and pneumoconiosis (SMR = 26,000) which were all closely related to tunnelling work were extraordinarily high and statistically significant. Mortality from lung cancer was considerably higher among tunnel workers than among non-tunnel workers. The results of ratios of observed to expected deaths by age-group showed significant excess mortality in three age-groups: 40 to 49, 50 to 59, and 60 to 69. These findings show that migrant tunnel workers have serious health problems. On the other hand, in non-tunnel workers, the overall SMR was 89. No significant excess mortality was observed for any cause of death or any age-group.

Adult↗
PubMed2006

Public health lessons learned from analysis of New York City subway injuries.

Serious subway injuries are devastating to their young victims and have high rates of mortality and amputation. We identified the urban population at greatest risk for subway injuries and investigated the influence of local economies on injury rates. We propose using changes in social conditions as a "trigger" for increased vigilance and protective measures at times of higher risk.

Accidents↗
PubMed2004

Improving road safety and residential quality of life : evaluating the automated wayside horn system.

The automated wayside horn system is designed to replace the train horn as a means of alerting motorists to danger and thus enhancing safety at highway-rail grade crossings. Furthermore, the wayside horn directionality is such that the warning sound is broadcast over a smaller sector than the train horn, thereby reducing residential noise. This article examines the results of an evaluation comparing train horns with wayside horns in the village of Mundelein, Illinois, USA. The study derived from previous work in Gering, Nebraska, and Ames, Iowa.During the 3 months covering the 'before' (train horn) period and through to 'after' (wayside horn), more than 19 500 crossing gate closures were recorded on videotape at three crossings. Analysis showed motorist violation of level-crossing laws decreased 68%, from an average rate of 3.53 per 100 gate closings when train horns were in use to 1.12 per 100 with the wayside horn. The decrease was statistically significant. Of equal importance was the decrease in residential noise. Sound measurements taken in a sample of residential yards showed a decrease in sound levels by more than 10 decibels (dB) at most locations. When plotted as sound contours, decreases in the area of coverage ranged from 85% at the 90dB level to 65% at the 70dB level.However, there are two issues with the use of wayside horns that need to be resolved. First, and most important, is that the wayside horn starts sounding when the warning lights begin to flash. This startles motorists, and some stop on the rail tracks. A second issue is the frequent unwarranted activation of the system, which encourages people to ignore the gate.

Accidents, Traffic↗
PubMed1979

Untangling the logics of urban service bureaucracies: the strange case of the San Francisco Municipal Railway.

Marxist analysts have developed theoretical propositions concerning the conflicting functions of government in advanced capitalist countries, while public policy analysts have examined the logic of public resource allocation. Through an historical analysis of a typical urban bureaucracy, the San Francisco Municipal Railway, this paper describes how bureaucratic structure and functioning relate to broader conflicts over whom government actions should benefit. It concludes that the apparent shortcomings of the organization can be traced to, and were caused by, this conflict. The argument thus draws from each of these two quite different approaches to the question of what logic motivates the public sector.

California↗
PubMed1993

Sugar and spice and everything nice: health effects of the sexual division of labor among train cleaners.

Attempts have been made to justify the sexual division of labor by referring to women's relative physical weakness, lack of technical competence, and dislike for dirty work. An analysis of the work activity of train cleaners in France showed a rigid sexual division of labor, in which the task of toilet cleaning was exclusively assigned to women. Interviews and observations revealed a number of physical constraints associated with the work, and particularly with toilet cleaning. Women employees suffered from many musculoskeletal problems and were frequently absent from work. Toilet cleaning involved traveling distances of over 20 kilometers per day and maintaining uncomfortable postures. Twenty-five percent of time during the actual cleaning was spent in a crouched position. The work was complex, involving a number of choices and decisions, as well as requiring a variety of techniques adapted to the differences in the nature and location of soil. This "women's job" was dirty and physically demanding, and required technical skill. Among train cleaners, the inability to rotate jobs due to sex-typed job assignment may be associated with specific health and safety risks for both sexes.

Absenteeism↗
PubMedDate not supplied

Mefloquine chemoprophylaxis in Chinese railway workers on contract in Nigeria.

BACKGROUND: Nonimmune Chinese nationals on a 2-year railway contract job were commenced on mefloquine (MQ) chemoprophylaxis 20 weeks after arrival in Nigeria. The objective of the study was to determine the usefulness of mefloquine (MQ) (despite the delay in starting) and its tolerability in this group. METHODS: Ninety-one workers (89 males, 2 females) were commenced on weekly MQ 250 mg doses for 17 weeks. Most of the subjects were followed up to 16 weeks after cessation of chemoprophylaxis. The morbidity pattern before, during, and after cessation of chemoprophylaxis was compared. RESULTS: Of the 91 workers included in the study, 89 were evaluable. Three (3.37%) of these developed clinical illness during the 17-week period of chemoprophylaxis. This protection was highly significant when compared to 23 of 91 people (25.27%) who developed clinical illness before chemoprophylaxis was commenced (RR 0.13, 95% CI 0.04-0.43, p <.001). The risk of developing acute malaria increased more than three times, among 84 members of the group who were followed up to 16 weeks after MQ was discontinued (RR 3.18, 95% CI 0.89-11.34). Two subjects withdrew after the second dose due to adverse reactions, however the remaining 89 subjects tolerated the drug for the 16-week period. CONCLUSIONS: Mefloquine significantly reduced malaria morbidity in the study group. Pretravel counseling and advice is important in preventing unnecessary deaths and morbidity in nonimmune travelers to malarious areas.

Adult↗
PubMed2005

Insomnia as a sequela of sarin toxicity several years after exposure in Tokyo subway trains.

More than 5,000 passengers on Tokyo subway trains were injured with toxic chemicals including the nerve gas "sarin" on March 20, 1995. The purpose of this study was to identify the effect of sarin exposure on insomnia in a cross-sectional study. A self-administered questionnaire concerning sleep-related items was distributed to victims of sarin exposure in October and November, 2003. Questionnaires were completed by 161 of the 163 participants (98.8%), who were selected from 1,500 subjects. Among them, the authors selected 75 women 30 to 69 years of age. Control participants were collected from inhabitants living in Maebachi City, Gunma Prefecture, Japan. For the younger exposed group (under 50 yr. of age), percentages of poor sleep, difficulty falling asleep, intermittent awakening, early morning awakening, a feeling of light overnight sleep, and insomnia were significantly higher than those for the control group. In contrast, the older exposed group (ages 50 to 69 years) had significantly higher prevalence of poor sleep, a feeling of light overnight sleep, and early morning awakening for the exposed group when compared with the control group. The high prevalence of insomnia and insomnia-related factors for victims especially under 50 years of age suggests a need for research on sleep quality after sarin exposure. Although posttraumatic stress disorder is assumed to be a psychological effect of exposure to a toxic substance, a cause-and-effect relationship has not been established.

Adult↗
PubMed1994

Assessment of noise environment in a major railway station in India.

To assess the degree of noise pollution in relation to the health and safety of the employees and commuters, a study on the levels of noise originating from various locomotives and also from different other sources was undertaken at Kalupur railway station of Gujarat State in India. The sound pressure levels (SPL) were measured on platforms. Noise dose count was monitored on a ticket collector on duty for 8 h. The results reflected that the SPLs in the platforms well exceeded the day time noise exposure limit. Further, the SPLs produced by loudspeakers were high and those by train whistles were intensely high pitched. The noise dose count of the ticket collector was also in excess of ACGIH standard. All these suggest that the SPLs in the platforms can endanger the healthful living of the users. Suitable control measures have been suggested.

Humans↗
PubMed1996

Calcutta metro: is it safe from noise pollution hazards?

A modest assessment of noise was made in Calcutta Metro, India's first ever underground tube rail system, to examine if the range of noise levels present could endanger the hearing sensitivity of workers for the Metro. Sound measuring instruments of a sound level meter, an octave band analyzer, and a sound level calibrator were used for measuring the sound pressure levels in platforms of three stations: Esplanade, Kalighat and Tollygunge. The results indicated that the averaged A-weighted SPLs in these stations were in the range of 84-87 dBA. In the coaches of the moving train the Leq values ranged 92-99 dBA and LNP 105-117 dBA, all exceeding the safe limit of day time noise exposure of 55 dBA and 85 dBA of ACGIH. The SPLs at 4,000 Hz in the coaches were also in excess of safe exposure limit of 79 dB. The findings thus posed a potential threat to the workers.

Environmental Monitoring↗
PubMed1998

The influence of the great Hanshin earthquake on human response to environmental vibration due to the Shinkansen.

A severe earthquake of magnitude 7.2 hit the west part of Japan on January 17, 1995. A part of the Shinkansen railway, which is one of the most popular high-speed mass transportation systems in Japan, was seriously damaged by the earthquake. About 80 days later, the Shinkansen service was resumed but complaints about vibration due to the passing Shinkansen increased rapidly among residents near the tracks. This paper reports the results of two investigations that were carried out in both stricken and non-stricken areas to determine the cause of complaint. In the first investigation, the ground vibration propagation induced by passing trains was measured. In the second investigation, questionnaires were distributed to the people living near the Shinkansen tracks. As a result, it was found out that the vibration levels before and after the earthquake were almost the same at most measured points in the stricken area. It was also found that the vibration levels in the stricken area and a non-stricken area were almost the same within 50 m from the Shinkansen tracks. However the results of the questionnaire survey showed that people's nuisance due to the vibration in the stricken area was clearly greater than that in the non-stricken area. This inconsistency was explained using the "category judgment method", which is generally used to determine the relationship between a physical stimulus and psychological reaction. According to the results of this analysis, the vibration level, at which 50% of the inhabitants complained about Shinkansen vibration, was approximately 54 dB in the non-stricken area and 50 dB in the stricken area. This result suggests that the people who experienced the severe earthquake became 4 dB more sensitive to the Shinkansen vibration than the people living in a non-stricken area despite the fact that this investigation was carried out 10 months after the earthquake struck.

Data Interpretation, Statistical↗
PubMed1998

Momentary discomfort caused by vibration of railway vehicle.

When trains pass level crossings or turnouts, they are momentarily subject to relatively strong vibrations. In railway engineering, evaluation of the riding comfort under such occasional vibrations is called the momentary evaluation, which is distinguished from the long-term evaluation. In order to identify the effective vibrational characteristics on the momentary evaluation now controversial in Japan, an experiment was performed with a riding comfort simulator. Twenty adult subjects were exposed to lateral vibration with varying peak acceleration and crest factor. Referring to the vibrations of real trains, the peak acceleration in the range of 0.35-2.00 m/s2 were varied in steps of 0.35 m/s2 and the crest factors in the range of 1.5-5.0 were varied in steps of 0.5. The frequency was set constant at 2 Hz. The task was to rate the degree of discomfort under each vibration which was given them successively. Results indicate that changes in the peak acceleration are most effective, and application of the crest factor in parallel improves the correlation with the perceived discomfort. Whether subjects can perceive changes in the peak or not affects the evaluation. Weights of vibrational characteristics that make a cue to the evaluation by subjects differ from person to person.

Acceleration↗
PubMed2005

The impact of extended leave on sleep and alertness in the Australian rail industry.

In the past, scientific studies have investigated the effects of shift timing and duration on sleep and alertness in the rail industry. To our knowledge no research has been conducted to determine the effects of extended break lengths (>48 h) on these factors. Hence, this study analyses the work and rest schedules of 304 Australian rail employees (mean age 41.3 yr, standard deviation 7.4 yr) to determine the effect of prior break lengths (12-169 h) on sleep and subjective alertness at work after periods of leave. Extended break periods (>48 h) were found to increase the length of the sleep prior to returning to work and reduce the total wake time to the end of the first shift, but did not influence levels of subjective alertness immediately prior to the commencement of the first shift. Research into the influence of longer break periods (>169 h) is needed in order to make definitive conclusions regarding sensible return to work policies after extended leave within the Australian rail industry.

Adult↗
PubMed2005

Sleepiness in various shift combinations of irregular shift systems.

The present study examined the occurrence of sleepiness in various shift combinations ending with a night or morning shift. Three weeks' sleep/work shift diary data, collected from 126 randomly selected train drivers and 104 traffic controllers, were used in statistical analyses. The occurrence of sleepiness at work (i.e., Karolinska Sleepiness Scale 7 or higher) was tested with a generalised linear model with repeated measurements including explanatory factors related to shifts, sleep, and individual characteristics. The prevalence of severe sleepiness varied between 25% and 62% in the combinations ending with a night shift and between 12% and 27% in the combinations ending with a morning shift. The occurrence of sleepiness did not, however, systematically vary between the shift combinations in either case. An increased risk for sleepiness was associated with high sleep need and long shift duration in the night shift and with high sleep need, short main sleep period, long shift duration and an early shift starting time in the morning shift. Also having a child was associated with an increased risk for sleepiness in the night shift. The results suggest that the shift history of 24-36 h prior to the night and the morning shift is not strongly associated with the occurrence of sleepiness at work, but there are other factors, such as shift length and starting time and sleep need, that affect a risk for sleepiness at work.

Adult↗
PubMed2005

Self-report naps in irregular work schedules.

Few studies have examined napping in irregular work schedules such as those experienced by freight locomotive engineers. The current study examined the effect of napping in irregular work schedules on sleep length and three subjective measures: ability to go to sleep, ability to stay asleep, and a feeling of being well-rested upon awakening. One hundred and seventy-nine freight engineers completed a 14-d activity log, providing information on sleep times and subjective evaluations of sleep. The results indicated that days with naps resulted in significantly more total sleep but less sleep in the main sleep period of the day. The days with naps also resulted in somewhat more difficulty with going to sleep, staying asleep and with feeling well-rested upon awakening. It is important to note, however, that when examining the days with naps, nap length was not significantly correlated with main sleep time, ability to go to sleep, ability to stay asleep, or feeling well-rested upon awakening. These results suggest that napping may be useful when working irregular work schedules if the engineer is willing to accept a slight decrease in ability to go to sleep, stay asleep, and feeling rested.

Adult↗