Research gaps and needs for preventing worker fatigue in the transportation and utilities industries

BACKGROUND

The transportation and utilities industries include establishments engaged in the movement of passengers and freight, or the provision of public power, water, and other services. Along with the warehousing industry, they make up the US National Occupational Research Agenda's Transportation, Warehousing and Utilities (TWU) industry sector. In 2018 the sector composed 5% of the US workforce, with approximately 8 million workers. TWU workers experienced 19% of all fatalities among U.S. workers in 2018 and 7% of total occupational injuries and illnesses.

METHODS

Around-the-clock operations, heavy workloads, long and irregular shifts, complicated schedules, and time pressures characterize work across the US TWU sector. However, there are considerable differences in worker priorities and concerns between TWU industries. Major areas of concern within the sector include disparities in work schedules; required training for employee fatigue awareness and prevention; physical and mental job demands; and safety culture.

RESULTS

Strategies for fatigue mitigation are critical to reduce the prevalence of injuries, safety-critical events, and crashes in TWU workers. Further research on the incidence and characterization of fatigue among TWU workers will guide the development of effective mitigation strategies. The influence of work scheduling on missed sleep opportunities and disrupted circadian rhythms should be determined. Evaluation of fatigue mitigation strategies can lead to the adoption of the most effective ones for each TWU industry.

CONCLUSION

Implementation of effective strategies is critical for the health, safety, wellbeing, and productivity of workers in the TWU sector.

A Descriptive Study of Musculoskeletal Injuries in Long-Haul Truck Drivers: A NIOSH National Survey

Long-haul truck drivers are significantly affected by musculoskeletal injuries with incidence rates 3.5 times higher than the national average. Yet, little is known about injuries that affect long-haul trucks drivers. In 2010, interviewers collected data from 1,265 long-haul truck drivers at 32 truck stops across the United States. These surveys were analyzed to describe all self-reported musculoskeletal injuries. Injuries to the arm (26.3%) and back (21.1%) were the two areas most reported in the survey. Musculoskeletal injuries were most often caused by falls (38.9%) and contact with an object or equipment (33.7%) resulting most commonly in sprains/strains (60%). This large scale survey highlights the significance of musculoskeletal injuries in long-haul truck drivers and suggests the need to develop interventions to prevent injuries and improve recovery once injuries occur.

A Pilot Study of Healthy Living Options at 16 Truck Stops Across the United States

PURPOSE

There is a growing body of evidence that the built environment influences diet and exercise and, as a consequence, community health status. Since long-haul truck drivers spend long periods of time at truck stops, it is important to know if this built environment includes resources that contribute to the emotional and physical well-being of drivers.

SETTING

The truck stop environment was defined as the truck stop itself, grocery stores, and medical clinics near the truck stop that could be accessed by a large truck or safely on foot.

DESIGN

Researchers at the National Institute for Occupational Safety and Health (NIOSH) developed and utilized a checklist to record the availability of resources for personal hygiene and comfort, communication and mental stimulation, health care, safety, physical activity, and nutrition at truck stops.

SUBJECTS

The NIOSH checklist was used to collect data at a convenience sample of 16 truck stops throughout the United States along both high-flow and low-flow truck traffic routes.

MEASURES

The checklist was completed by observation within and around the truck stops.

RESULTS

No truck stops offered exercise facilities, 94% lacked access to health care, 81% lacked a walking path, 50% lacked fresh fruit, and 37% lacked fresh vegetables in their restaurant or convenience store.

CONCLUSION

The NIOSH found that most truck stops did not provide an overall healthy living environment.

NIOSH national survey of long-haul truck drivers: Injury and safety

Approximately 1,701,500 people were employed as heavy and tractor-trailer truck drivers in the United States in 2012. The majority of them were long-haul truck drivers (LHTDs). There are limited data on occupational injury and safety in LHTDs, which prompted a targeted national survey. The National Institute of Occupational Safety and Health conducted a nationally representative survey of 1265 LHTDs at 32 truck stops across the contiguous United States in 2010. Data were collected on truck crashes, near misses, moving violations, work-related injuries, work environment, safety climate, driver training, job satisfaction, and driving behaviors. Results suggested that an estimated 2.6% of LHTDs reported a truck crash in 2010, 35% reported at least one crash while working as an LHTD, 24% reported at least one near miss in the previous 7 days, 17% reported at least one moving violation ticket and 4.7% reported a non-crash injury involving days away from work in the previous 12 months. The majority (68%) of non-crash injuries among company drivers were not reported to employers. An estimate of 73% of LHTDs (16% often and 58% sometimes) perceived their delivery schedules unrealistically tight; 24% often continued driving despite fatigue, bad weather, or heavy traffic because they needed to deliver or pick up a load at a given time; 4.5% often drove 10miles per hours or more over the speed limit; 6.0% never wore a seatbelt; 36% were often frustrated by other drivers on the road; 35% often had to wait for access to a loading dock; 37% reported being noncompliant with hours-of-service rules (10% often and 27% sometimes); 38% of LHTDs perceived their entry-level training inadequate; and 15% did not feel that safety of workers was a high priority with their management. This survey brings to light a number of important safety issues for further research and interventions, e.g., high prevalence of truck crashes, injury underreporting, unrealistically tight delivery schedules, noncompliance with hours-of-service rules, and inadequate entry-level training.

National Survey of US Long-Haul Truck Driver Health and Injury: health behaviors

OBJECTIVE

To compare selected health behaviors and body mass index (modifiable risk factors) of US long-haul truck drivers to the US working population by sex.

METHODS

The National Survey of US Long-Haul Truck Driver Health and Injury interviewed a nationally representative sample of long-haul truck drivers (n = 1265) at truck stops. Age-adjusted results were compared with national health surveys.

RESULTS

Compared with US workers, drivers had significantly higher body mass index, current cigarette use, and pack-years of smoking; lower prevalence of annual influenza vaccination; and generally lower alcohol consumption. Physical activity level was low for most drivers, and 25% had never had their cholesterol levels tested.

CONCLUSIONS

Working conditions common to long-haul trucking may create significant barriers to certain healthy behaviors; thus, transportation and health professionals should address the unique work environment when developing interventions for long-haul drivers.

Vital signs: seat belt use among long-haul truck drivers--United States, 2010

BACKGROUND

Motor vehicle crashes were the leading cause of occupational fatalities in the United States in 2012, accounting for 25% of deaths. Truck drivers accounted for 46% of these deaths. This study estimates the prevalence of seat belt use and identifies factors associated with nonuse of seat belts among long-haul truck drivers (LHTDs), a group of workers at high risk for fatalities resulting from truck crashes.

METHODS

CDC analyzed data from its 2010 national survey of LHTD health and injury. A total of 1,265 drivers completed the survey interview. Logistic regression was used to examine the association between seat belt nonuse and risk factors.

RESULTS

An estimated 86.1% of LHTDs reported often using a seat belt, 7.8% used it sometimes, and 6.0% never. Reporting never using a belt was associated with often driving ≥10 mph (16 kph) over the speed limit (adjusted odds ratio [AOR] = 2.9), working for a company with no written safety program (AOR = 2.8), receiving two or more tickets for moving violations in the preceding 12 months (AOR = 2.2), living in a state without a primary belt law (AOR = 2.1); and being female (AOR = 2.3).

CONCLUSIONS

Approximately 14% of LHTDs are at increased risk for injury and death because they do not use a seat belt on every trip. Safety programs and other management interventions, engineering changes, and design changes might increase seat belt use among LHTDs.

IMPLICATIONS FOR PUBLIC HEALTH

Primary state belt laws can help increase belt use among LHTDs. Manufacturers can use recently collected anthropometric data to design better-fitting and more comfortable seat belt systems.

Obesity and other risk factors: the national survey of U.S. long-haul truck driver health and injury

BACKGROUND

Drivers of heavy and tractor-trailer trucks accounted for 56% of all production and nonsupervisory employees in the truck transportation industry in 2011. There are limited data for illness and injury in long-haul truck drivers, which prompted a targeted national survey.

METHODS

Interviewers collected data during 2010 from 1,670 long-haul truck drivers at 32 truck stops across the 48 contiguous United States that were used to compute prevalence estimates for self-reported health conditions and risk factors.

RESULTS

Obesity (69% vs. 31%, P < 0.01) and current smoking (51% vs. 19%, P < 0.01) were twice as prevalent in long-haul truck drivers as in the 2010 U.S. adult working population. Sixty-one percent reported having two or more of the risk factors: hypertension, obesity, smoking, high cholesterol, no physical activity, 6 or fewer hours of sleep per 24-hr period.

CONCLUSION

Survey findings suggest a need for targeted interventions and continued surveillance for long-haul truck drivers.

Occupational exposures to respirable crystalline silica during hydraulic fracturing

This report describes a previously uncharacterized occupational health hazard: work crew exposures to respirable crystalline silica during hydraulic fracturing. Hydraulic fracturing involves high pressure injection of large volumes of water and sand, and smaller quantities of well treatment chemicals, into a gas or oil well to fracture shale or other rock formations, allowing more efficient recovery of hydrocarbons from a petroleum-bearing reservoir. Crystalline silica ("frac sand") is commonly used as a proppant to hold open cracks and fissures created by hydraulic pressure. Each stage of the process requires hundreds of thousands of pounds of quartz-containing sand; millions of pounds may be needed for all zones of a well. Mechanical handling of frac sand creates respirable crystalline silica dust, a potential exposure hazard for workers. Researchers at the National Institute for Occupational Safety and Health collected 111 personal breathing zone samples at 11 sites in five states to evaluate worker exposures to respirable crystalline silica during hydraulic fracturing. At each of the 11 sites, full-shift samples exceeded occupational health criteria (e.g., the Occupational Safety and Health Administration calculated permissible exposure limit, the NIOSH recommended exposure limit, or the ACGIH threshold limit value), in some cases, by 10 or more times the occupational health criteria. Based on these evaluations, an occupational health hazard was determined to exist for workplace exposures to crystalline silica. Seven points of dust generation were identified, including sand handling machinery and dust generated from the work site itself. Recommendations to control exposures include product substitution (when feasible), engineering controls or modifications to sand handling machinery, administrative controls, and use of personal protective equipment. To our knowledge, this represents the first systematic study of work crew exposures to crystalline silica during hydraulic fracturing. Companies that conduct hydraulic fracturing using silica sand should evaluate their operations to determine the potential for worker exposure to respirable crystalline silica and implement controls as necessary to protect workers.

Occupational exposures to respirable crystalline silica during hydraulic fracturing

This report describes a previously uncharacterized occupational health hazard: work crew exposures to respirable crystalline silica during hydraulic fracturing. Hydraulic fracturing involves high pressure injection of large volumes of water and sand, and smaller quantities of well treatment chemicals, into a gas or oil well to fracture shale or other rock formations, allowing more efficient recovery of hydrocarbons from a petroleum-bearing reservoir. Crystalline silica ("frac sand") is commonly used as a proppant to hold open cracks and fissures created by hydraulic pressure. Each stage of the process requires hundreds of thousands of pounds of quartz-containing sand; millions of pounds may be needed for all zones of a well. Mechanical handling of frac sand creates respirable crystalline silica dust, a potential exposure hazard for workers. Researchers at the National Institute for Occupational Safety and Health collected 111 personal breathing zone samples at 11 sites in five states to evaluate worker exposures to respirable crystalline silica during hydraulic fracturing. At each of the 11 sites, full-shift samples exceeded occupational health criteria (e.g., the Occupational Safety and Health Administration calculated permissible exposure limit, the NIOSH recommended exposure limit, or the ACGIH threshold limit value), in some cases, by 10 or more times the occupational health criteria. Based on these evaluations, an occupational health hazard was determined to exist for workplace exposures to crystalline silica. Seven points of dust generation were identified, including sand handling machinery and dust generated from the work site itself. Recommendations to control exposures include product substitution (when feasible), engineering controls or modifications to sand handling machinery, administrative controls, and use of personal protective equipment. To our knowledge, this represents the first systematic study of work crew exposures to crystalline silica during hydraulic fracturing. Companies that conduct hydraulic fracturing using silica sand should evaluate their operations to determine the potential for worker exposure to respirable crystalline silica and implement controls as necessary to protect workers.

Environmental risk factors and work-related lower respiratory symptoms in 80 office buildings: an exploratory analysis of NIOSH data

BACKGROUND

We evaluated relationships between lower respiratory symptoms and risk factors for microbiological contamination in office buildings.

METHODS

The National Institute for Occupational Safety and Health collected data from 80 office buildings during standardized indoor environmental health hazard evaluations. Present analyses included lower respiratory symptom-based outcome definitions and risk factors for potential microbiologic contamination. Multivariate logistic regression models for selected outcomes identified key risk factors.

RESULTS

Adjusted odds ratios (95% confidence intervals) for "at least three of four work-related lower respiratory symptoms" were, for debris in ventilation air intake, 2.0 (1.0-3.9), and for poor drainage in air-conditioning drip pans, 2.6 (1.3-5.2). Adjusted associations with risk factors were consistently stronger for outcomes requiring both multiple symptoms and improvement away from work, and somewhat stronger among diagnosed asthmatics.

CONCLUSIONS

Moisture and debris in ventilation systems, possibly by supporting microbiologic growth, may increase adverse respiratory effects, particularly among asthmatics. Data from more representative buildings are needed to confirm these findings.

Hearing protector use in noise-exposed workers: a retrospective look at 1983

Although hearing protectors have been available for more than 60 years, little field surveillance has been done to assess their appropriate wear in noisy occupational environments. This study examined historical field survey data to determine whether workers use hearing protection when exposed to loud noise. Data from the 1981-83 NIOSH National Occupational Exposure Survey were analyzed to determine whether workers in noise greater than or equal to 85 dBA were using hearing protection. The study also looked at the effect of company personal protective equipment (PPE) policies on hearing protector compliance. This study found that, in 1981-83, an estimated 4.1 million industrial workers were exposed to noise greater than or equal to 85 dBA. Of these, 41% were wearing some form of hearing protection. This percentage varied from 79% of workers exposed in SIC 76 (Miscellaneous Repair Service) to less than 1% in Communications (SIC 48), Wholesale Trade Nondurable Goods (SIC 51), and Automotive Dealers & Service Stations (SIC 55). Whether an establishment had a written policy on wearing PPE seemed to make no difference, because there appeared to be no tie between the percentage of workers wearing of hearing protection and presence of a PPE policy.

Metalworking fluid exposures in small machine shops: an overview

Sampling was conducted in 79 small machine shops to assess airborne exposures to metalworking fluids (MWFs). Measured exposures were compared with data from the literature and exposure criteria currently recommended by the National Institute for Occupational Safety and Health and the Occupational Safety and Health Administration MWF Standards Advisory Committee. Sixty-two percent of 942 personal samples collected were less than the recommended exposure limit (REL) of 0.50 mg/m3 for total particulate. However, at least 1 sample exceeded the REL in 61 of the 79 facilities studied; 100% of the samples collected in 10 shops were greater than the REL. Similar trends were found for thoracic particulate exposures where 75% of 238 samples were below the thoracic particulate REL of 0.40 mg/m3. The ratio between thoracic and total particulate for 238 paired samples was 0.55 (r2=0.73). Workers exposed to straight fluids had the highest exposures (GM=0.67 mg/m3) when compared with workers exposed to other classes of MWFs. The highest exposures were measured for grinding and hobbing (GM=0.67 and 0.60 mg/m3, respectively). Measurements using personal impactors indicated that particle size distributions of MWF aerosols had an average mass median aerodynamic diameter of 5.3 microm. Straight oils and soluble fluids tended to be associated with larger particles than were other fluid types; grinding and turning produced the largest particles, whereas hobbing resulted in the smallest. In general, exposures were similar in magnitude and particle size to those previously reported in large automotive plants. Therefore, workers in these small shops may have risks of adverse health effects similar to those demonstrated in the automotive industry.

An evaluation of short-term exposures to metalworking fluids in small machine shops

In a study of 23 small machining shops using metalworking fluids (MWFs), real-time air monitoring using an aerosol photometer was performed to investigate the temporal nature of the exposure and to examine the relationship between the instrumental measurements and traditional sampling methods. Time-weighted averages were calculated from the aerosol photometer data and the results were compared to collocated thoracic and 37-mm closed face cassette samplers. The filter samples were analyzed for total mass and the solvent extractable fraction. Depending on the averaging period used, short-term MWF concentrations exceeded 2.0 mg/m3 in 13 to 39% of the plants studied. High short-term exposures were as likely to be found in plants with average concentrations below 0.4 mg/m3 (thoracic-gravimetric) as those above. Regression analyses indicated that the aerosol photometer most closely matched the data obtained from the thoracic fraction of the total mass. In general, the aerosol photometer overestimated the levels determined using the thoracic cyclone and filter, especially when measuring concentrations of water-based fluids. Use of a calibration factor of 0.7 for straight oils or 0.5 for water-based fluids may assist in the interpretation of aerosol photometer measurements if field calibration data are not readily available. Several approaches to determining the calibration factor from field data were evaluated; more complex calibration techniques improved the accuracy of the measurements.

Comparison of three sampling and analytical methods for the determination of airborne hexavalent chromium

A field study was conducted with the goal of comparing the performance of three recently developed or modified sampling and analytical methods for the determination of airborne hexavalent chromium (Cr(VI)). The study was carried out in a hard chrome electroplating facility and in a jet engine manufacturing facility where airborne Cr(VI) was expected to be present. The analytical methods evaluated included two laboratory-based procedures (OSHA Method ID-215 and NIOSH Method 7605) and a field-portable method (NIOSH Method 7703). These three methods employ an identical sampling methodology: collection of Cr(VI)-containing aerosol on a polyvinyl chloride (PVC) filter housed in a sampling cassette, which is connected to a personal sampling pump calibrated at an appropriate flow rate. The basis of the analytical methods for all three methods involves extraction of the PVC filter in alkaline buffer solution, chemical isolation of the Cr(VI) ion, complexation of the Cr(VI) ion with 1,5-diphenylcarbazide, and spectrometric measurement of the violet chromium diphenylcarbazone complex at 540 nm. However, there are notable specific differences within the sample preparation procedures used in three methods. To assess the comparability of the three measurement protocols, a total of 20 side-by-side air samples were collected, equally divided between a chromic acid electroplating operation and a spray paint operation where water soluble forms of Cr(VI) were used. A range of Cr(VI) concentrations from 0.6 to 960 microg m(-3), with Cr(VI) mass loadings ranging from 0.4 to 32 microg, was measured at the two operations. The equivalence of the means of the log-transformed Cr(VI) concentrations obtained from the different analytical methods was compared. Based on analysis of variance (ANOVA) results, no statistically significant differences were observed between mean values measured using each of the three methods. Small but statistically significant differences were observed between results obtained from performance evaluation samples for the NIOSH field method and the OSHA laboratory method.

Trends in hearing protector usage in American manufacturing from 1972 to 1989

This study investigated the trends in hearing protector use in United States manufacturing industries. Using data from the National Institute for Occupational Safety and Health-sponsored National Occupational Hazard Survey (1972), the National Occupational Exposure Survey (1983), and the Occupational Safety and Health Administration-sponsored National Survey of Personal Protective Equipment Usage (1989), estimates were made of numbers of workers using hearing protection in various industries. Unique to this study is discussion of the impact of enactment of hearing conservation regulations during the same time frame as the two earlier surveys. In general, higher percentages of workers utilized hearing protection in 1989 than in 1972. Increased hearing protection use over time was also found when size of facility (number of employees) was taken into account. Differences in the use of hearing protection over the period 1972-1989 varied in individual industries, ranging from less than 10 to more than 30%.

Elevated lead contamination in homes of construction workers

National Institute for Occupational Safety and Health investigators studied lead exposures among 37 families of construction workers; 22 neighborhood families with no known lead exposures were included for comparison. Workers were identified as having blood lead levels at or above 25 micrograms/dL. This article reports the levels of lead contamination on hands and interior surfaces of homes and automobiles of study participants. Results indicate that the hands of lead-exposed workers were seven times more contaminated with lead compared with control workers; no difference was found between exposed and control family members' hands. Surface lead contamination was significantly higher in automobiles driven by the lead-exposed workers; some locations, such as armrests, were 10 times more contaminated for the exposed group. High lead loadings in lead workers' automobiles were found on the driver's floor (geometric mean [GM] = 1100 micrograms/m2), driver's armrest (2000 micrograms/m2), and passenger's armrest (1200 micrograms/m2). Surface lead concentrations were significantly higher for exposed homes compared with control homes in rooms where work clothing was changed (GM = 370 versus 120 ppm; p = 0.005). While environmental sources of lead were also evaluated, study results strongly suggest that construction workers' occupational exposures together with poor hygiene practices were the primary causes of lead contamination. Requirements intended to prevent "take-home" lead exposures were reported by workers in this study to be infrequently followed by employers. These findings may be limited in representativeness since only highly exposed workers were selected from a specific geographic area. Regardless, targeted education and enforcement efforts are necessary to help ensure that preventive measures are adequately practiced throughout the construction industry.

Mortality of Carpenters' Union members employed in the U.S. construction or wood products industries, 1987-1990

This study evaluated the mortality of 27,362 members of the U.S. Carpenters' Union who died in 1987-1990. Age-adjusted proportionate mortality ratios (PMRs) and proportionate cancer mortality ratios (PCMRs) were computed using the U.S. age-, gender-, and race-specific proportional mortality for the years of the study. For white male carpenters who were last employed while in construction industry locals, raised mortality was observed for lung cancer (PCMR = 107, CI = 103, 111), bone cancer (PMR = 181, CI = 107, 286), asbestosis (PMR = 283, CI = 158, 457), emphysema (PMR = 115, CI = 102, 130), transportation injuries (PMR = 121, CI = 109, 135), and falls (PMR = 122, CI = 104, 142). For white male carpenters who were last employed while in industrial wood products locals, significantly raised mortality occurred for stomach cancer (PMR = 187, CI = 136, 250), male breast cancer (PCMR = 469, CI = 128, 720), and transportation injuries (PMR = 136, CI = 110, 173). Excess breast cancer was associated with last employment inn wood machining trades. Nasal cancer mortality was not elevated. A total of 121 mesotheliomas were observed. Contributing cause of death analyses revealed raised mortality for these and additional causes; 4,594 (18%) death certificates mentioned occupational and other lung disease as a contributing factor, resulting in significantly elevated mortality. These data show that construction carpenters have moderately elevated mortality for the diseases caused by asbestos (lung cancer and malignant mesothelioma) and from traumatic injuries. The finding of elevated mortality for stomach, bone, and breast cancer was unexpected and requires further evaluation of possible occupational factors. This study confirms that construction carpentry is an extremely hazardous trade. The data suggest that additional preventive action guarding against asbestos exposure and occupational injury is urgently needed in this occupation.

Breast Cancer Screening among Employed American Women

From the 1990 National Health Interview Survey Health Promotion and Disease Prevention supplement, the authors estimated the 1990 baseline prevalence of breast cancer screening among employed U.S. women aged 50-70 years. Proportions of women screened for breast cancer were calculated by occupational category and demographic characteristics, and were compared with the Healthy People 2000 objective that 60% of women aged 50 and older have had mammography and a clinical breast examination within the preceding two years. The objective was exceeded for white-collar workers (61.8%) and workers with some college (64.1%), but was not met by any blue-collar/service workers (40.8%); or any workers with only a high school diploma (54.7%) or less than a high school diploma (38.5%). Identification of occupational categories and demographic subgroups among working women will be helpful to those planning breast cancer screening programs, in both the public and the private sectors.

Occupational exposure to noise and ototoxic organic solvents

The objectives of this study were to review the literature on the effects of occupational exposure to organic solvents on the auditory system and to identify work settings in which exposure to these agents and to noise might occur. The criteria for selecting the chemicals were (a) evidence available that indicated that the chemicals may affect the auditory system and enhance noise effects, and (b) the ubiquity of their use. References to ototoxicity were noted for three proven neurotoxicants, i.e., carbon disulfide, toluene, and trichloroethylene, and for two probable human neurotoxicants--styrene and xylene. The percentages of workers (estimated by NIOSH National Occupational Exposure Survey) exposed to these solvents in each economic sector are shown. Work settings are identified where multiple exposures occur to solvents and noise. The need for future research is discussed.

Job tasks, potential exposures, and health risks of laborers employed in the construction industry

Construction laborers have some of the highest death rates of any occupation in the United States. There has been very little systematic research focused exclusively on "laborers" as opposed to other workers in the construction industry. We reviewed the English language literature and various data bases describing the occupational tasks, exposures, and work-related health risks of construction laborers. The sources of information included 1) occupational mortality surveillance data collected by the states of California and Washington and the National Institute for Occupational Safety and Health (NIOSH); 2) National Occupational Exposure Survey; 3) national fatality data; 4) cancer registry data; and 5) case reports of specific causes of morbidity. While the literature reported that construction laborers have increased risk for mesothelioma, on-the-job trauma, acute lead poisoning, musculoskeletal injury, and dermatitis, the work relatedness of excess risks for all-cause mortality, cirrhosis, cerebrovascular disease, chronic obstructive pulmonary disease, ischemic heart disease, and leukemia is less clear. Furthermore, while laborers are known to be potentially exposed to asbestos, noise, and lead, and the NIOSH Job Exposure Matrix describes other potential hazardous exposures, little research has characterized other possible exposures and no research has been found that describes the exposures associated with specific job tasks. More advanced study designs are needed that include a better understanding of the job tasks and exposures to construction laborers, in order to evaluate specific exposure-disease relationships and to develop intervention programs aimed at reducing the rate of work-related diseases.

Development, use, and availability of a job exposure matrix based on national occupational hazard survey data

A job exposure matrix has been developed based on potential exposure data collected during the 1972-1974 National Occupational Hazard Survey (NOHS). The survey sample was representative of all U.S. non-agricultural businesses covered under the Occupational Safety and Health Act of 1970 and employing eight or more employees. Potential worker exposure to all chemical, physical, or biological agents was recorded during the field survey if certain minimum guidelines for exposure were met. The job exposure matrix (JEM) itself is a computerized database that assists the user in determining potential chemical or physical exposures in occupational settings. We describe the structure and possible uses of the job exposure matrix. In one example, potential occupational exposures to elemental lead were grouped by industry and occupation. In a second example, the matrix was used to determine exposure classifications in a hypothetical case-control study. Present availability as well as future enhancements of the job exposure matrix are described.

An examination of occupational medicine practices

The traditional occupational health on-site utilization of physicians as part of an overall occupational health program has been in decline in recent times. The on-site practitioner is increasingly being replaced by physicians who practice at an off-site location. The effects of this change on the health care delivered to the work force are largely unknown. By utilizing data from the 4490 facilities surveyed during the National Occupational Exposure Survey, it was possible to perform analyses of the association between the on- and off-site practice of medicine and several industrial facility characteristics and services usually associated with occupational medicine. Examination of the data indicated that, in comparison with on-site activity, the off-site practice of occupational medicine appears to result in diminished provision of the screening tests and medical examinations for which data were available.

A genetic study of Hirschsprung disease

Hirschsprung disease, or congenital aganglionic megacolon, is commonly assumed to be a sex-modified multifactorial trait. To test this hypothesis, complex segregation analysis was performed on data on 487 probands and their families. Demographic information on probands and the recurrence risk to relatives of probands are presented. An increased sex ratio (3.9 male:female) and an elevated risk to sibs (4%), as compared with the population incidence (0.02%), are observed, with the sex ratio decreasing and the recurrence risk to sibs increasing as the aganglionosis becomes more extensive. Down syndrome was found at an increased frequency among affected individuals but not among their unaffected sibs, and the increase was not associated with maternal age. Complex segregation analysis was performed on these family data. The families were classified into separate categories by extent of aganglionosis. For cases with aganglionosis beyond the sigmoid colon, the mode of inheritance is compatible with a dominant gene with incomplete penetrance, while for cases with aganglionosis extending no farther than the sigmoid colon, the inheritance pattern is equally likely to be either multifactorial or due to a recessive gene with very low penetrance. A model of gene action with random effects during morphogenesis is compatible with our observations.

Some trends in worker access to health care in the United States (1974-1983)

As a result of national surveys of occupational health and safety conditions in the American workplace, the National Institute for Occupational Safety and Health (NIOSH) has collected data on the provision of health care to workers as a consequence of their employment. Two of these surveys, initiated in 1972 and 1981, permit a preliminary examination of the trends in worker access to such care. This paper presents data on the provision of some aspects of medical care to workers in manufacturing and nonmanufacturing facilities as a result of employment. Among the principal findings are increases in general health care provided to workers, increased use of off-site physicians, and increased use of screening examinations or tests. Other analyses indicate a decreased use of on-site physicians and pre-employment examinations and decreased industrial retention of health information on new employees.

Compliance with OSHA record-keeping requirements

The Occupational Safety and Health Act of 1970 requires employers to maintain records of workplace injuries and illnesses. To assess compliance with the law, data from the National Occupational Exposure Survey (NOES) were examined. Of the 4,185 companies with 11 or more employees, 75 per cent maintained OSHA Form 200 designed for recording illnesses and injuries. The number of employees and the presence of a union were positive determinants in the record maintenance. Of companies with 500 or more employees, 95 per cent kept records compared with 60 per cent of companies with between 11 and 99 employees.

Reconstruction of penile agenesis by a posterior sagittal approach

Penile agenesis is a rare condition requiring gender reassignment and staged perineal reconstruction. This report describes two children reconstructed by taking advantage of the posterior sagittal approach. This approach allows a precise anatomic dissection, construction of a neovagina and accurate positioning of all perineal orifices. We think that this is the preferred approach for this rare condition.

Gastric heterotopia in rectum complicated by rectovesical fistula

Heterotopic gastric mucosa in the rectum produced a rare complication of rectovesical fistula. Diagnosis was made by direct biopsy and 99mTc scanning. Excision of ectopic gastric mucosa, diverting colostomy, and repair did not result in closure of the fistula. Endorectal pull-through constituted definitive treatment.

Does zonal aganglionosis really exist? Report of a rare variety of Hirschsprung's disease and review of the literature

The aganglionic segment of intestine in Hirschsprung's disease begins at the anus and extends proximally for a distance that varies from case to case. Occasional reports describe patients in whom the aganglionosis is segmental, with normal distal innervation or a skip area of normal innervation within an area of aganglionosis. This paper describes 4 patients with Hirschsprung's disease wherein a segment of normally innervated colon was found in an otherwise aganglionic colon. Two of these patients were siblings with different fathers. Problems encountered in the management of these patients are detailed. In a critical review of the literature, 2 additional male patients with well-documented zonal aganglionosis were identified. Although variations from the usual morphology or Hirschsprung's disease do exist, they are so rare that they merit clinical consideration only when the anatomic record and the clinical course are in obvious disagreement. Rectal biopsy remains the best method for the diagnosis of Hirschsprung's disease.

Megacystis-microcolon-intestinal hypoperistalsis syndrome: additional clinical, radiologic, surgical, and histopathologic aspects

Four newborn infants with megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) were identified at Children's Hospital of Pittsburgh. These cases provide additional insight into the syndrome and broaden its spectrum. This report includes MMIHS in an infant boy, one long-term survivor, an apparently related complication of neonatal obstructive volvulus, evidence of small intestinal hypoperistalsis, and histopathologic findings as follows: (1) apparently increased numbers of ganglion cells in early biopsies and normal or even decreased numbers of ganglion cells in later biopsies probably due to bowel dilatation; and (2) in two of three infants at autopsy, there were many nerve trunks (a neuromalike layer in one), and there was elastosis of the urinary bladder.

Double choledochus with ectopic drainage into the stomach-a rare congenital anomaly of the biliary ductal system

A patient with an accessory bile duct originating from the left common hepatic duct and emptying into the stomach along the lesser curvature presented with periodic symptomatic bile gastritis. Reimplantation of the accessory duct into the duodenum relieved his symptoms.

The effect of maternal responder status on the genetic control of the antibody response

Various genetic models were examined with regard to the control of the antibody response in rats. Distributions of the response to poly(Glu52Lys33Tyr15) were determined in the inbred ACI (high responder) and F344 (low responder) strains and in the F1, F2 and backcross generations. Falconer's test for the effective number of genes showed that there was a larger number of genes involved if the maternal parent were the high responder strain. Studies in mating combinations involving high and moderate responders showed that the effective number of genes influencing the antibody response was much lower than in the mating between the high and low responders. Theoretical distributions of antibody response levels were generated using Monte Carlo techniques. The Kolmogorov-Smirnov goodness-of-fit test indicated that a three-gene model best fitted the matings involving the ACI female and that a two-gene model best fitted the matings involving the F344 female. These calculations indicate that the antibody response is a complex, multifactorial trait whose expression is significantly affected by the responder status of the maternal strain.

Vesicointestinal fissure revisited

This complicated anomaly of bladder exstrophy, intestinal fistula, and various degrees of colonic atresia with imperforate anus is readily recognizable. The long-term result of conventional management has been disappointing. Fecal and urinary incontinence have been unavoidable and a source of disappointment to patients and parents. An alternative method of total management is detailed. This variation of management may result in earlier and more complete social acceptability of the child so afflicted. At as young an age as possible, the vesicointestinal connection is detached and the bladder defect as well as the intestinal opening closed. The short colon is freed and transected at its midpoint. The right half of the colon is brought out through a separate wound as a colostomy. The distal half of the divided colon is brought out as mucous fistula on the left. This distal colonic segment is the proposed future colonic loop for urinary diversion to be fashioned in the first year of life. The exstrophied bladder is removed at a later date. Epispadias in the male may be repaired later. A Pediatric Ostomy Club has been organized to include a pediatric stomal therapist and involved nurses and physicians. The group gives the parents advice and moral support. We believe that this approach will permit the child to go to school and carry on relatively normal activity and to be socially acceptable. An overview of our total experience in the management of 25 patients with vesicointestinal fistula details the result in 9 surviving patients.

Alimentary tract duplications in children

This report reviews the experience with 78 alimentary tract duplications found in 64 patients over a 40 year period at the Children's Hospital of Pittsburgh. Ten patients had the duplication discovered at autopsy. Multiple duplications were found in 15% of patients. The symptoms and physical findings of a duplication varied with location, size and mucosal pattern. About one-fifth of the duplications contained ectopic mucosa, usually gastric. Two-thirds of the patients were diagnosed prior to one year of age. Vertebral anomalies, as a clue to the presence of the lesion, were present in 15% of the patients. The most common indications for surgery included a mediastinal or abdominal mass, intestinal obstruction, and gastrointestinal bleeding. The results of surgery were favorable, with a mortality of 20%. Surgical complications accounted for six deaths, while four children died of severe associated anomalies. Three others died without surgical treatment, but with symptoms from the duplication.

Congenital cricopharyngeal achalasia

Fifteen infants with congenital cricopharyngeal achalasia are reviewed. Although most of the patients had symptoms at birth, the diagnosis was frequently not confirmed until later in the first year of life. While four of the infants had only cricopharyngeal achalasia, 11 had associated diseases related to the central nervous system. Those patients without associated diseases improved spontaneously with conservative management; most of the infants with other abnormalities also improved, although their clinical progress was slower and more complicated. In three of the patients, the symptoms were persistent and there were two deaths related to associated diseases. Cricopharyngeal myotomy was performed on two children with only moderate improvement in symptoms. Congenital cricopharyngeal achalasia is more common than formerly recognized. When suspected, an esophagram with tele- or cineradiography is essential to confirm the diagnosis. Esophageal motility studies will quantify changes and also evaluate lower esophageal dysfunction not easily identified on esophagrams.