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While many studies estimate medical costs and lost wages from workplace injuries, few have estimated pain and suffering costs. This study develops a wage-risk model for railroad workers and estimates the total cost of on-the-job injuries. On average, the total cost of an on-the-job injury to a railroad worker in 1980 was between $19,500 and $22,500. These estimates are substantially higher than the sum of medical costs plus lost wages.
The maximum train speed of the Tohoku Shinkansen was increased from 210 to 240 km/h in March 1985. In order to determine the effects of the expected increase in noise level on the living environment of school children, a longitudinal study was carried out in an elementary school near the Tohoku Shinkansen line in Saitama prefecture comprising noise measurements and social surveys of the school children and their mothers using a questionnaire. The results were as follows: 1. When measured 25 meters away from the railroad track, the noise level increased from 73 to 76 dB (A)along the inbound track, while it increased from 77 to 78 dB (A)along the outbound track. 2. The maximum noise level in a classroom when an outbound train passed at a speed of 216 km/h was 67 dB(A). 3. In the school environment the most pronounced effects of the Shinkansen noise were annoyance and listening disturbance, with the percentages reporting such significantly increasing after the speed-up. 4. In the home environment the most pronounced effects of the Shinkansen were annoyance, structural vibration, television interference, and listening disturbance. However, the percentages of these complaints did not show any significant change after the speed-up. 5. Among those living near the railroad track there were significant differences between children and their mothers in the percentages reporting annoyance, television and radio listening interference, and structural vibration, with the percentages for the mothers being higher than their children. These results indicate that disturbances in listening has especially increased in the school environment after the speed-up and that the increase in both noise levels and number of train passages have contributed to increasing disturbance.
The immune structure of different professional groups with respect to L. pneumophila has been studied. A wide spread of Legionella infection among subway construction workers, subway personnel and railroad conductors has been established, which makes it possible to regard these professions as high risk groups susceptible to Legionella infection. The risk factors for this group are as follows: work in the atmosphere of high dust content with air supply by means of air conditioners, contact with soil in the process of earthwork. The bacteriological study of water samples obtained in dining cars has resulted in the isolation of two strains of L. pneumophila, serogroup I, which confirms the possibility of cases of Legionella infection among railroad personnel.
The results of the study of the immunological structure of the population at the western section of the Baikal-Amur Railroad in respect to influenza virus at different seasons of the year and with different intensity of the epidemic process are presented. The dynamics of the total level and properties of immunoglobulins of three classes (IgM, IgG and IgA) has been followed. The potential human capacity for immune response to infections under the conditions of the construction of the Baikal-Amur Railroad has been shown to remain unchanged.
BACKGROUND: Diesel exhaust is considered a probable human carcinogen by the International Agency for Research on Cancer (IARC). The epidemiologic evidence rests on studies of lung cancer among truck drivers, bus drivers, shipyard workers, and railroad workers. The general public is exposed to diesel exhaust in ambient air. Two regulatory agencies are now considering regulating levels of diesel exhaust: the California EPA (ambient levels) and the Mine Safety Health Administration (MSHA) (occupational levels). To date, there have been few quantitative exposure-response analyses of diesel and lung cancer based on human data. METHODS: We conducted exposure-response analyses among workers in the trucking industry, adjusted for smoking. Diesel exhaust exposure was estimated based on a 1990 industrial hygiene survey. Past exposures were estimated assuming that they were a function of 1) the number of heavy duty trucks on the road, 2) the particulate emissions (grams/mile) of diesel engines over time, and 3) leaks from trucks' exhaust systems for long-haul drivers. RESULTS: Regardless of assumptions about past exposure, all analyses resulted in significant positive trends in lung cancer risk with increasing cumulative exposure. A male truck driver exposed to 5 micrograms/m3 of elemental carbon (a typical exposure in 1990, approximately five times urban background levels) would have a lifetime excess risk of lung cancer of 1-2% above a background risk of 5%. CONCLUSIONS: We found a lifetime excess risk ten times higher than the 1 per 1,000 excess risk allowed by OSHA in setting regulations. There are about 2.8 million truck drivers in the U.S. Our results depend on estimates about unknown past exposures, and should be viewed as exploratory. They conform reasonably well to recent estimates for diesel-exposed railroad workers done by the California EPA, although those results themselves have been disputed.
The associations between soft tissue sarcoma (STS) and occupational exposures were studied in a case-referent study in the southeast of Sweden. Exposure information was obtained through mailed questionnaires to 96 cases, 450 randomly selected population referents, and 200 cancer referents. Odds ratios (OR), were calculated for various occupational groups, and particularly, for occupations with potential exposure to chlorinated phenoxy herbicides and chlorophenols. In the analyses based on population referents, increased risks for soft tissue sarcoma were seen for especially gardeners (OR = 4.1), but also railroad workers (OR = 3.1); construction workers with exposure to impregnating agents (OR = 2.3), asbestos (OR = 1.8), or pressure impregnating agents (OR = 1.7); and unspecified chemical workers with potential exposure to phenoxy herbicides and/or chlorophenols (OR = 1.6). A similar pattern appeared when cancer referents were used although the numerical values of the odds ratios became different. A grouping of jobs resulted in Mantel-Haensel OR from 1.5 to 1.9 for farmers and forestry workers, dependent on referents used and even more increased OR for railroad workers and unspecified chemical workers with potential exposure to phenoxy herbicides and chlorophenols. The results of the study confirm rather than refute that phenoxy herbicides and chlorophenols could be of etiologic importance for STS; the high risk for gardeners, although based on a small number of individuals, was unexpected and remains unclear. Also, since other cancers were used as referents, no definite problems of recall bias should obtain in this material. None of the exposed groups had a higher proportion of smokers than the unexposed group.
PURPOSE: We assessed the feasibility, efficacy and long-term outcome of neodymium (Nd):YAG laser core-through urethrotomy for posttraumatic urethral stricture. MATERIALS AND METHODS: Between May 1997 and April 2000, 65 patients 5 to 62 years old underwent laser core-through urethrotomy for posttraumatic urethral stricture. Most patients had been involved in a motor vehicle accident but 8 and 3 sustained trauma after tractor injury and a railroad accident, respectively. All patients underwent suprapubic cystostomy formation and 18 had previously undergone anastomotic urethroplasty, railroad or attempted cold knife core-through urethrotomy. Mean stricture length was 2.2 cm. on bi-directional uroradiography and endoscopy. All strictures were in the bulbomembranous urethra except 3, which were prostatic-supraprostatic. The procedure was technically unsuccessful in 4 cases. Core-through urethrotomy was performed using Nd:YAG a 600 mu. contact bare fiber at 15 to 20 W. on an outpatient basis. Catheter removal and voiding cystourethrography were performed at 6 weeks. Uroflowmetry and urethroscopy were done 3 months after urethral catheter removal. Followup was 9 to 44 months. RESULTS: Nd:YAG laser core-through urethrotomy was performed on an outpatient basis successfully in all except 4 cases without any intraoperative or postoperative complications. Blood transfusion was not required. Although most patients were symptom-free, a few underwent initial optical internal urethrotomy and/or endoscopic dilation before the stricture became stable. The urethral lumen was obliterated again in 2 cases. CONCLUSIONS: Nd:YAG laser core-through urethrotomy is feasible and effective with good long-term results for posttraumatic urethral stricture.
A modified laryngeal mask airway was used to facilitate nasotracheal intubation with a fibreoptic laryngoscope. A size 4 laryngeal mask airway was modified by creating a defect at the base of the stem and removing the bars to allow passage of the fibreoptic laryngoscope from the nasopharynx to the larynx. The laryngeal mask airway cuff was split and the cut edges were sealed with silicone. This design allowed the cuff to function normally and allowed removal of the split laryngeal mask airway after the tracheal tube had been 'railroaded' into place. Thirty-four patients were studied. The split laryngeal mask airway was easily inserted with satisfactory airway maintenance in 32 patients. Nasal airway endoscopy and laryngoscopy were successfully achieved with the split laryngeal mask airway in place in 31 of 32 patients. Railroading the tracheal tube over the fibreoptic laryngoscope with the split laryngeal mask airway in place was successful in all 31 of these patients. This prototype split laryngeal mask airway allows good airway maintenance while fibreoptic nasotracheal intubation is performed.
PURPOSE: The purpose of this study was to explain the origin of image patterns demonstrated by conventional epidurography, which is a controversially discussed topic in recent literature. MATERIAL AND METHODS: After introduction of thoracic epidural catheters and iopamidol injection, conventional epidurography and CT-epidurography were performed on 25 preoperative patients. After injection of Gadolinium-DTPA MR-epidurography was performed in two patients treated for chronic pain with already introduced epidural catheters. Three volunteers also underwent identical imaging after introduction of thoracic epidural catheters and in addition helical-CT epidurography using twin-beam technology. RESULTS: 40% of the patients demonstrated the railroad track phenomenon. We were able to prove that it is a sign of a rhythmically variable filling of segments of the lateral epidural space with contrast medium 76% of the patients demonstrated no ventral epidural space at the thoracic level. 56% of the patients showed a medial area of translucence combined with a band-shaped contrasting of the epidural space in the standard ap view. This was proven in all cases to be a plica mediana dorsalis by CT. In all volunteers who underwent helical-CT and MR epidurography we observed the railroad track phenomenon and the filling defect of the anterior thoracic epidural space. CONCLUSION: CT epidurography is well suited for obtaining new insights into the interpretation of findings obtained by conventional epidurography.
While the International Agency for Research on Cancer (IARC) classified diesel exhaust (DE) as a"probable"carcinogen in 1989 based primarily on"sufficient"animal data, other investigators have since concluded that the lung tumors found in the rat studies were a result of particle overloading. Subsequent health risk assessments of DE have not used the rat cancer data. The U.S. Environmental Protection Agency (EPA), in developing its 2002 Health Assessment Document (HAD) for DE, primarily considered the epidemiology studies of railroad workers and truck drivers to develop health risk assessments of DE. However, both sets of epidemiology studies have serious weaknesses that make them unsuitable for cancer risk assessment. Major shortcomings were the lack of contemporaneous measurements of exposures to DE, difficulties with exposure history reconstruction, and adequately accounting for other exposures such as gasoline exhaust and cigarette smoke. To compound these problems, there was not, and there is still not, a specific exposure marker for DE. Interestingly, in the underground mining industry, where diesel exposures are much higher than observed in railroad workers and truck drivers, there was no increase in lung cancer. These problems and concerns led the U.S. EPA to conclude that while DE was a"likely"carcinogen, a unit risk value or range of risk cannot be calculated from existing data and that the risk could be zero. In addition, the DE emissions have changed and continue to change with the implementation of new emission control technologies. The HAD recognized this fact and noted that further studies are needed to assess new diesel engine emissions. Recent chemical characterization studies on low-emitting diesel engines with catalyzed particulate filters have shown emissions rates for several chemicals of concern that are even lower than comparable compressed natural gas (CNG)-fueled engines. With lower emissions, better fire safety, and improved cost-effectiveness of new low-emitting diesels compared to CNG, current efforts to restrict use of low-emitting diesels seems misguided.
A randomised study was carried out in 60 patients to assess the influence of tracheal tube tip design on the ease of railroading a tracheal tube during fibreoptic intubation. A new design of tracheal tube with a tapered tip, without a bevel, was compared with a tracheal tube of standard design. The new design was found to be greatly superior in both oro- and nasotracheal fibreoptic intubation, when compared with the traditional tracheal tube (p < 0.001). The shape of the tip of a tracheal tube is an important determinant of the ease of railroading the tube over an inserted fibrescope.
The ventilation-exchange bougie is a new airway device which can be mounted on a fibreoptic laryngoscope for passage through the larynx into the trachea via a laryngeal mask airway. Subsequent removal of the fibreoptic laryngoscope and laryngeal mask airway allows a tracheal tube to be railroaded into position over the ventilation-exchange bougie. This study described the use of this technique for elective tracheal intubation in two groups of 12 subjects in whom difficulty with intubation was not expected. All the subjects were successfully intubated by one of two anaesthetists, one experienced and the other inexperienced with fibreoptic intubation techniques. Neither had had prior experience with the ventilation-exchange bougie. Because ventilation was maintained throughout the procedure, intubation did not need to be hurried. Cusum analysis confirmed the impression of a learning curve and the technique could be considered learnt after four and six intubations for the experienced and inexperienced fibreoptic laryngoscopists respectively. No difficulty was found either in intubating the larynx with the fibreoptic laryngoscope and ventilation-exchange bougie or when railroading the tracheal tube over the ventilation-exchange bougie. It is suggested that this new device could have an important role in teaching fibreoptic techniques, management of the difficult airway and failed intubations.
We conducted a randomised study in 70 patients to assess the effect of orientation of a standard polyvinyl chloride tracheal tube on the ease of railroading the tube during awake fiberoptic orotracheal intubation. Conventional orientation of the tube (with the bevel of the tube directed to the patient's left) was compared with orientation of the tube with the bevel facing posteriorly. The success rate of intubation at the first attempt was higher with the bevel oriented posteriorly (35/35; 100%) than with the conventional orientation (21/35; 60%; p = 0.0001), and the intubating time was shorter (median (range) 7 (5-11) s and 11 (5-60) s, respectively; p = 0.0001). We recommend that the tracheal tube should be aligned in this manner when railroading it over the fibrescope during awake fibreoptic orotracheal intubation.
There are several countries in the world in which people with severe hearing loss are not eligible for a car driver's license. As a technical approach to solve this problem, an electronic device is developed which detects traffic-alarm-sounds, i.e. horns of cars, sirens of emergency vehicles and alarm signals of railroad crossings, and then displays them as vibration to the driver. The basic operating principle of the device is that those traffic-alarm-sounds have marked regularity in some particular frequency region whereas the traffic noise is a wide-band random noise. The real time detection of the regularity is realized by use of a phase-locked-loop and a simplified lock-in amplifier. The results of simulation experiments and road tests demonstrate that the performance of the device is satisfactory except in the case of the detection of the alarm signals of railroad crossings.
BACKGROUND: Both continuous and impact noise exposures of rail yards and railways have been historically understudied. We summarize noise exposures to rail workers at a large chemical facility in North America. METHODS: Rail workers were surveyed over the course of three 12-hr shifts. Personal noise dosimeters were used to derive a 12-hr time-weighted average (L(AVG)), an 8-hr time-weighted average (L(TWA)), and a percent dose. Peak and maximum sound levels were also recorded during each sampling period. Six workers were sampled on three separate days for a total of 18 full-shift noise samples. RESULTS: Full-shift noise exposures were all below the Occupational Safety and Health Administration's (OSHA) permissible exposure limit (PEL) and action level for a 12-hr workday. Peak impact sound levels exceeded 140 dB in 17 of 18 samples (94%) with a mean peak sound level of 143.9 dB. Maximum continuous sound levels were greater than 115 dBA in 4 of 18 samples (22%) with a mean maximum sound level of 113.1 dBA. The source of peak impact sound levels was a daily exposure to a concussion caused by a sudden break in a freight airline. CONCLUSIONS: Rail workers at this facility are at risk of noise induced hearing loss from high impact noise exposures. Peak impact and maximum continuous sound levels can be attenuated through the use of hearing protection or by increasing distances from railroad noise sources.
The present study examines the association between asbestos-related pleural plaques and lung function in a group of workers with occupational exposure to asbestos. Exposure, smoking, and respiratory histories, chest radiographs, flow-volume loops, and single breath DLCOs were obtained on 383 railroad workers. A score based on the ILO-1980 classification system was used to quantify the extent of plaquelike thickening. In order to eliminate potential confounders, we excluded from final analysis subjects with diffuse pleural thickening (n = 10) or small irregular opacities classified as profusion 0/1 or greater (n = 6) on chest radiograph. Definite pleural plaques were observed in 22.6%. The single breath DLCO was similar in the groups with and without plaques (p = 0.0550). Decrement in FVC and the occurrence of pulmonary restriction were associated with the presence of definite plaques (p = 0.0306 and 0.0431, respectively) and with quantitative pleural score (p = 0.0135 and 0.0126), controlling for duration of asbestos exposure and smoking. A test for trend revealed an association between level of diagnostic certainty (none, suspect, definite) for pleural plaques and these measures of lung function (p less than 0.02). Our findings reveal an association between asbestos-related pleural plaques and decrement in lung function as measured by FVC and criteria for pulmonary restriction.
Studies of Swedish railway employees have indicated that railroad engine drivers have an increased cancer morbidity and incidence of chronic lymphatic leukemia. The drivers are exposed to relatively high magnetic fields (MF), ranging from a few to over a hundred microT. Although the possible genotoxic potential of MF is unclear, some earlier studies have indicated that occupational exposure to MF may increase chromosome aberrations in blood lymphocytes. Since an increased level of chromosomal aberrations has been suggested to predict elevated cancer risk, we performed a cytogenetic analysis on cultured (48 h) peripheral lymphocytes of Swedish train engine drivers. A pilot study of 18 engine drivers indicated a significant difference in the frequency of cells with chromosomal aberrations (gaps included or excluded) in comparison with seven concurrent referents (train dispatchers) and a control group of 16 office workers. The engine drivers had about four times higher frequency of cells with chromosome-type aberrations (excluding gaps) than the office workers (P < 0.01) and the dispatchers (P < 0.05). Seventy-eight percent of the engine drivers showed at least one cell per 100 with chromosome-type aberrations compared with 29% among the dispatchers and 31% among the office workers. In a follow-up study, another 30 engine drivers showed an increase (P < 0.05) in the frequency of cells with chromosome-type aberrations (gaps excluded) as compared with 30 referent policemen. Sixty percent of the engine drivers had one or more cells (per 100 cells) with chromosome-type aberrations compared with 30% among the policemen. In conclusion, the results of the two studies support the hypothesis that exposure to MF at mean intensities of 2-15 microT can induce chromosomal damage.
Forty-seven railroad workers who were exposed to polychlorinated phenols, including dioxin (TCDD), during 1979 while cleaning up the chemical spillage following damage to a tank car filled with these chemicals were followed medically for the subsequent 6 years. Two committed suicide. The initial neurological complaints included a sense of fatigue and muscle aching, both of which have been reported in other individuals following dioxin exposure. On detailed neurological examination in December, 1985, 24 of 45 had dystonic writer's cramp and/or other action dystonias of the hands. None of the involved individuals had a family history of dystonia, and all 24 dated the onset of the dystonia to the first 2 to 3 years subsequent to their toxic exposure. The dystonias varied in severity but were usually mild. No other types of dystonic involvement were recognized. Thirty-five of the 45 individuals also manifested postural and terminal intention tremor which resembled benign essential tremor. None of the involved individuals had a family history of tremor, and all 35 of those affected dated the onset of the tremor to some time subsequent to their toxic exposure. Forty-three of 45 patients had histories and findings suggestive of peripheral neuropathy. This is the first report relating any type of dystonia to prior dioxin exposure and the first report relating action dystonia, such as dystonic writer's cramp, and postural/terminal intention tremor, to toxic exposure of any type.