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PubMed1995

Coronary mortality and its prediction in samples of US and Italian railroad employees in 25 years within the Seven Countries Study of cardiovascular diseases.

BACKGROUND: Samples of railroad male employees aged 40-59 were examined from companies operating in the northwest quadrant of the US in the late 1950s (n = 2571), and in Rome and surroundings. Italy in the early 1960s (n = 768) in an international co-operative study on cardiovascular diseases. METHODS: A number of cardiovascular risk factors (age, blood pressure, serum cholesterol, body mass index, subscapular skinfold, physical activity, smoking habits) were measured at year 0 and year 5, while data on mortality and causes of death were collected for 25 years. RESULTS: Coronary heart disease (CHD) death rates were always higher in the US than in Italy; after 25 years the excess was 51%. Cox proportional hazards models with CHD deaths as endpoint and seven CHD risk factors as covariates showed only the coefficients for age and smoking habits statistically different between the two cohorts. Changes in systolic blood pressure during the first 5-year follow-up were additional predictors of 5- to 25-year CHD mortality in both groups. Cholesterol plus age (greater in the US), subscapular skinfold (greater in the US) and body mass index (greater in Italy) 'explained' 67% of the observed differences in 25-year CHD mortality in the two cohorts. CONCLUSIONS: A large proportion of differential CHD mortality can be attributed to some traditional risk factors.

Adult↗
PubMed2002

Carpal tunnel syndrome in railroad workers.

OBJECTIVE: To determine, within a specific industry, if carpal tunnel syndrome (CTS) is associated with job classification or other personal risk factors. To determine if surgical intervention for the treatment of CTS is indicated on the basis of electrodiagnostic criteria. DESIGN: More than 2500 claimants who screened positive for CTS were subjected to a formal history, physical examination, and electrodiagnostic studies. A total of 900 subjects were randomly selected for this study. The presence of CTS was determined by a method of comparing median minus ulnar nerve distal latency differential (MUD). RESULTS: There was a statistically significant relationship between CTS and body mass index (P < 0.001), wrist index (P < 0.001), and age (P < 0.001). A total of 43.4% of the participants (391/900) and 38.6% of the wrists (694/1800) had either positive or borderline findings for CTS. There was no difference between the left and right hands. There was no association between job classification and the presence of CTS. Using MUD criteria, more than half of the participants presumed to have CTS did not meet the requirements for diagnosis. Applying the same MUD criteria to all surgical cases, the indication for surgery could not be determined in one-third of the cases (33%, 83/248). CONCLUSIONS: In the population claiming CTS caused by railroad occupations, there was a significant association between CTS and body mass index, age, and wrist index, but not job classification. More than half of the study group and one-third of the surgical subset had normal MUD data.

Adult↗
PubMed1993

Optimal spinal strength normalization factors among male railroad workers.

In spite of increasing interest in techniques and devices for quantifying trunk strength and lifting capacity, relatively little research has been done to determine optimal normalizing factors for strength. The isolation of the ideal factors is a critical prerequisite for comparison of patient data to expected physical capacities in the uninjured population. In the present study, 160 incumbent railroad workers from four heavy laboring jobs were tested for isokinetic trunk strength and lumbar/cervical isokinetic lifting capacity as part of a study to establish normative data (Union Pacific RR, Omaha, NE). Three variables relating height and weight were studied to determine optimal normalization: actual body weight (BW), ideal weight (IW) and adjusted weight (AW). "IW" is actually a height/weight variable based on a weight control chart specifying ideal weights for given heights and genders. "AW" represents the lesser of BW or IW. Subjects were tested for isokinetic trunk extension/flexion for lumbar (floor-to-knuckle) and cervical (knuckle-to-shoulder) lifts. Results demonstrated that the isolated trunk strength tests showed the best correlation coefficients with BW for flexion-extension work at 60 and 150 per sec. Moreover, the correlation coefficients between the lumbar isokinetic lifting peak force measures and BW were high (ranging 0.49-0.67, P < 0.001), with much lower correlations for AW or IW. By contrast, cervical correlations between Liftask peak force and the height/weight variables were all lower, and were also better for AW than for BW or IW (ranging 0.37-0.50). It appears that body weight is the best normalizing factor for isokinetic trunk flexor/extensor strength and lumbar (floor-to-knuckle) lifting.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2006

Corpus callosum volume in railroad workers with chronic exposure to solvents.

OBJECTIVE: Changes to cognition and behavior have been reported after long-term exposure to solvents. Solvents are hypothesized to affect brain white matter. To test this, we examined the volume of the corpus callosum in workers with a history of exposure to solvents. METHODS: We manually traced (blind to group membership) the volume of the corpus callosum in 31 railroad workers and 31 matched controls. RESULTS: There was a decrease in the genu of the corpus callosum in the solvent-exposed workers compared with controls. A smaller volume of the genu of the corpus callosum was associated with greater exposure and worse performance on cognitive tasks. CONCLUSIONS: This study supports the hypothesis that occupational exposure to solvents affects the anterior white matter of the brain and is related to extent of exposure and degree of cognitive change.

Brain Diseases↗
PubMed2001

Multi-stage model estimates of lung cancer risk from exposure to diesel exhaust, based on a U.S. railroad worker cohort.

A California Environmental Protection Agency (Cal/EPA) report concluded that a reasonable and likely explanation for the increased lung cancer rates in numerous epidemiological studies is a causal association between diesel exhaust exposure and lung cancer. A version of the present analysis, based on a retrospective study of a U.S. railroad worker cohort, provided the Cal/EPA report with some of its estimates of lung cancer risk associated with diesel exhaust. The individual data for that cohort study furnish information on age, employment, and mortality for 56,000 workers over 22 years. Related studies provide information on exposure concentrations. Other analyses of the original cohort data reported finding no relation between measures of diesel exhaust and lung cancer mortality, while a Health Effects Institute report found the data unsuitable for quantitative risk assessment. None of those three works used multistage models, which this article uses in finding a likely quantitative, positive relations between lung cancer and diesel exhaust. A seven-stage model that has the last or next-to-last stage sensitive to diesel exhaust provides best estimates of increase in annual mortality rate due to each unit of concentration, for bracketing assumptions on exposure. Using relative increases of risk and multiplying by the background lung cancer mortality rates for California, the 95% upper confidence limit of the 70-year unit risks for lung cancer is estimated to be in the range 2.1 x 10(-4) (microg/m3)(-1) to 5.5 x 10(-4) (microg/m3)(-1). These risks constitute the low end of those in the Cal/EPA report and are below those reported by previous investigators whose estimates were positive using human data.

Adult↗
PubMed2005

Squamous cell carcinoma of the skin and coal tar creosote exposure in a railroad worker.

A 50-year-old male railroad worker presented to his primary care physician with an erythematous, tender skin lesion on the right knee; a biopsy of this lesion revealed squamous cell carcinoma in situ. The site of the lesion was sun-protected but had been associated with 30 years of creosote-soaked clothing. In this article, we review dermal and other malignancies associated with creosote, along with creosote occupational exposures and exposure limits. This is a unique case, given the lack of other, potentially confounding, polyaromatic hydrocarbons and the sun-protected location of the lesion.

Carcinoma, Squamous Cell↗
PubMed1997

Public health on the railroad: William Freeman Snow and the California Sanitation Exhibit.

This paper describes the California Sanitation Exhibit, a railroad car outfitted for instruction in public health that toured California in 1909 and 1910. The sanitation exhibit used display models, photographs, and lectures to educate the public about tuberculosis and other infectious diseases, waste contamination, and the dangers of bad milk. The success of the exhibit, which reached 5% of the state's population, resulted in the appointment of its creator, William Freeman Snow, as secretary of the California State Board of Health.

California↗
PubMed1984

Mortality among asbestos-exposed workers in a railroad workshop.

The mortality experience of a cohort of 3 297 railroad maintenance shopworkers exposed to asbestos was investigated. The study period was 1951-1980, and the vital status was assessed for 99.6% of the men. Individual estimates of cumulative asbestos exposure were based on detailed records on work tasks and divisions. Dust measurements were scanty in earlier decades, and estimates of average fiber levels were therefore based on information on the amount and kind of asbestos used, job descriptions, and interviews with older workers. The overall mortality was lower than expected from the national death rates (standardized mortality ratio = 82). The mortality from lung cancer increased as cumulative exposure increased in consistent dose-response relationships. Employment times of less than 30 years in workplaces with moderate levels of mainly chrysotile asbestos was not associated with any apparent increase in the risk of lung cancer. A subgroup exposed for more than 30 years in workplaces repairing steam engines, where amphiboles were used as well, had a standardized mortality ratio of 192 for lung cancer. This figure may be an underestimation due to healthy worker selection and fewer smokers than normal. The "true" standardized mortality ratio was estimated to be about 300. Five cases of mesothelioma were observed.

Aged↗
PubMed1990

Privacy Act of 1974; computer matching program--HCFA. Notice of a matching program--HCFA's Health Insurance (HI) Master Record and information from four Railroad Retirement Board (RRB) systems of records.

The Department of Health and Human Services is providing public notice that the RRB agrees to disclose information concerning Medicare eligible railroad retirees to HCFA. The matching report set forth below is in compliance with the Computer Matching and Privacy Protection Act of 1988 (Pub. L. No. 100-503).

Aged↗
PubMedDate not supplied

[High risk of pleural mesothelioma among the state railroad carriage repair workers].

Exposure to asbestos in a facility for the repair of railroad carriages in Bologna was initially studied in 1980, when the Local Health Unit started a program of primary prevention on request of the Unions. At that time workers employed in jobs with high exposure to asbestos were identified. The mortality experience of these 173 subjects was investigated from 01.01.1979 through 31.12.1997, and compared to that of the population of Emilia Romagna. SMR for all causes was 69, with upper limit of the confidence interval lower than 100; this was largely due to a significant decrease of cardiovascular mortality. Among neoplasms, there was a significant excess of pleural mesothelioma (6 observed, 0.09 expected); one more subject died for peritoneal mesothelioma and one for malignant mesothelioma of unspecified site. About half of the subjects deceased for neoplastic disease (8/17) were affected by mesothelioma.

Humans↗
PubMed2000

Determining disability. Railroad Retirement Board. Final rule.

The Railroad Retirement Board (Board) hereby amends its disability regulations to discontinue the current policy of conducting continuing disability reviews (CDR's) for medical recovery of disability annuitants in medical improvement not expected (MINE) cases. The Board has found that these reviews have not been cost effective and impose an unnecessary burden on the annuitant.

Disability Evaluation↗
PubMedDate not supplied

Expression of the CYP1A1 gene in peripheral lymphocytes as a marker of exposure to creosote in railroad workers.

We have conducted a pilot study to assess levels of cytochrome CYP1A1 gene expression in human peripheral lymphocytes as a molecular biomarker assay for polycyclic hydrocarbon exposure. Basal and 3-methylcholanthrene-induced levels of gene expression were measured by standard slot-blot mRNA analyses in mitogen-stimulated cultures of peripheral blood lymphocytes from creosote-exposed railroad workers and unexposed control subjects. Dermal and inhalation exposure of workers to creosote may vary substantially as a function of working conditions related to temperature. Therefore, blood specimens were collected from separate groups during the winter, fall, and summer. Basal and induced CYP1A1 gene expression levels were not elevated in workers from any of the three seasonal studies. However, induced/basal (inducibility) CYP1A1 mRNA ratios from workers sampled in the summer (when actual exposures were greatest) were significantly higher when compared to those of controls (P < 0.01). These studies demonstrate the potential usefulness of specific gene expression assays in human peripheral lymphocytes for the assessment of carcinogen exposure in human populations.

Adult↗
PubMed1991

[The microfloral wound dynamics of the victims in the railroad disaster in Bashkiria].

The work deals with the microbial composition of burn wounds in the victims of the railroad catastrophe in Bashkiria during their stay in a hospital. The comparison of the microbial spectrum in the wounds of the burn victims of the catastrophe with the results of the monitoring of the causative agents of burn infections in patients treated at the department of thermal lesions over a period of 3 years is presented. The medicinal sensitivity of wound microflora at all stages of the hospital treatment of the patients was studied and compared with the medicinal sensitivity of microorganisms isolated from the wounds of burn patients in 1988.

Accidents, Traffic↗
PubMed1990

Markers of exposure to diesel exhaust in railroad workers.

Diesel exhaust is a known mutagen and a potential human carcinogen. Recent epidemiological studies have demonstrated a small increase in the risk of lung cancer from diesel exhaust exposure. However, many epidemiological studies have used crude estimates of exposure, and even accurate measures of exposure may not be accurate estimates of the internal dose received. Measurement of diesel exhaust exposure also has been limited by the absence of a standard marker. This study was undertaken to evaluate the usefulness of urinary mutagenicity as a biological marker of diesel exhaust exposure in the workplace. We measured the exposure of individual railroad workers to diesel exhaust by using personal air samples taken over two consecutive work shifts. Nicotine in the samples was measured to adjust the respirable particle concentrations for active and passive cigarette smoking. Urine samples were collected at the end of the study work shifts and were analyzed for markers of cigarette smoking (nicotine, cotinine) and for mutagenicity, using a sensitive microsuspension assay (micro preincubation assay; Salmonella strain TA98 with or without S9 enzyme). The number of cigarettes smoked on the study shift was recorded, and subjects completed a questionnaire at the end of the second day on personal habits and exposures at home and work. Multiple regression analyses were used to analyze independent determinants of urinary mutagenicity, including a generalized least-squares analysis that divided residual variation into between- and within-person components. Eighty-seven subjects completed 151 two-day protocols; an additional four subjects provided usable data for a single day (n = 306 samples). Respirable particle concentration was not a good marker of diesel exhaust exposure when contamination by environmental tobacco smoke existed in the work location, but respirable particle concentration that was adjusted for environmental tobacco smoke correlated with a priori assessments of diesel exhaust exposure by job grouping. Phenanthrene concentration, as a potential marker, was measured in a subset of personal samples, and correlated with known diesel exhaust exposure by job grouping. A constant ratio of phenanthrene to respirable particles in area samples from diesel exhaust-exposed work locations suggested that phenanthrene is promising as a marker for diesel exhaust. Mutagenic activity was also measured from extracts of respirable particles in a few personal filter samples, and this technique may be useful for further investigation in epidemiological studies.(ABSTRACT TRUNCATED AT 400 WORDS)

Air Pollutants, Occupational↗
PubMed1994

Deaths associated with exposure to fumigants in railroad cars--United States.

Multiple incidents of illness and death following exposure to fumigated agricultural products in railroad cars have been reported by several states along the U.S.-Mexico border. From 1989 through 1993, the Texas Department of Health identified three incidents involving 11 exposed persons, resulting in two deaths. The California Environmental Protection Agency, Department of Pesticide Regulation, recorded two deaths in fumigated boxcars in 1989. This report summarizes the two most recent fatal incidents.

Adult↗
PubMed2004

Assessing lung cancer risk in railroad workers using a first hitting time regression model.

This article examines the application of a first hitting time (FHT) model, using an operational time scale, to assess mortality risk differentials of the work environment. A major case application is presented that applies the model to three job categories of railroad workers. The data set involves a study of more than 50 000 workers with mortality assessed from 1959 to 1996. Lung cancer mortality was assessed because of a suspected link to diesel exhaust exposure. Based on a model that stipulates that death occurs when the disease state of a subject first hits a threshold value, the FHT model provides insights into factors influencing disease progression. In this application, in particular, the findings suggest that a job category in 1959 alters the risk of death from lung cancer.

Journal Article↗
PubMed1991

Anthropometric predictors of coronary heart disease and total mortality: findings from the US Railroad Study.

Prospective data from the US Railroad Study were used to investigate the relations of several anthropometric variables to coronary heart disease and all-cause mortality in males initially free of cardiovascular disease. Middle-aged men were examined in 1957-1960 and followed until 1977 or death. Anthropometric indicators of total body fat (body mass index and the sum of the subscapular and triceps skinfolds) and central body fat (the ratios chest circumference/biacromial (shoulder) diameter, and chest circumference/standing height) were significantly and directly associated with age-adjusted coronary heart disease mortality. When systolic blood pressure, serum cholesterol, cigarette smoking, and vital capacity were also taken into account, the ratio chest circumference/biacromial diameter remained significantly associated with coronary heart disease mortality. Total, central, and peripheral body fat had a "U"-shaped relation with all-cause mortality. Measures of the ratio of central to peripheral body fat were inconsistently related to mortality. These results indicate that certain anthropometric measurements, especially those that may indicate central adiposity, are positively related to the development of fatal coronary heart disease and quadratically related to all-causes death rates.

Adult↗
PubMed2004

An in vivo dual-reporter system of cyanobacteria using two railroad-worm luciferases with different color emissions.

In vivo genetic reporter systems using luciferase enzymes enable the real-time monitoring of gene expression in living cells. We have challenged concurrent monitoring of two independent promoter activities within the same cells to precisely compare their characteristics in vivo. In this report, we describe a simple dual-reporter system capable of simultaneously monitoring two promoter activities in living cyanobacterial cells. Two railroad-worm luciferases catalyzing the bioluminescent emissions of different colors served as the dual reporters; each emission was successfully separated by interference filters to estimate the individual bioluminescence signals using photomultiplier tubes. Using this system, we clearly demonstrated the difference in the expression profiles between promoters in the same cells.

Animals↗