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Coal mining has been, and continues to be, a hazardous occupation with some of the highest rates of death and injury. The authors conducted a study of former and current coal miners from the western United States to identify the prevalence of acute injuries as well as arthritis and hearing impairment. Of the 102 randomly selected miners, 69 (67.6%) had experienced one or more injuries during their mining careers, with back injuries the most often identified. Thirty‐eight (37.3%) reported currently suffering health‐related quality of life effects from one or more injuries, including pain and activity restrictions. Forty‐four (43.1%) identified arthritis and 60 (58.8%) reported hearing impairment. These results were higher than national data for the general population of the United States when controlling for age. Based upon respondent‐reported health status, the miners identified themselves as being in poorer overall health compared with national data and a control group from the same study area. The need ...

A case study of 102 surface and underground coal miners in the western United States randomly selected from a telephone survey of two mining communities was conducted, examining their perceptions of working conditions and health both before and after the Federal Coal Mine Health and Safety Act of 1969. Miners working since 1970 reported lower amounts of dust breathed in, increased dust‐mask use, and better mine ventilation. Respiratory illnesses, including coal workers’ pneumoconiosis (CWP), were most often reported by those who worked largely prior to the Act; respiratory symptoms, such as persistent cough and shortness of breath, were reported by miners who worked primarily after the act. Miners’ perceptions of the federal black‐lung compensation process and concerns about diesel equipment are presented. These data are further discussed within the environmental‐justice and risk‐perception frameworks. Recommendations are suggested regarding regulations and public policy.

The route of breathing, oral or nasal, is a determinant of the doses of inhaled pollutants delivered to target sites in the upper and lower respiratory tracts. We measured partitioning of ventilation, using a divided oronasal mask during a submaximal exercise test, in 37 male and female subjects who ranged in age from 7 to 72 y. The following four patterns of breathing were evident during exercise: (1) nasal only (13.5%), nasal shifting to oronasal (40.5%), oronasal only (40.5%), and oral only (5.4%). Children (i.e., 7-16 y of age) displayed more variability than adults with respect to their patterns of ventilation with exercise. Young adults (i.e., 17-30 y of age) who initially breathed nasally with exercise switched to oral ventilation at a lower percentage of the previously measured maximum ventilation (10.8%) than older subjects (31.8%). The partitioning of ventilation between the nasal and oral routes follows complex patterns that cannot be predicted readily by the age, gender, or nasal airway resistance of the subject.

Sources of variability in nasal airway resistance measured by posterior rhinomanometry were studied in 5 subjects tested on 5 different days and 56 subjects tested on 2 different days. On each day, a questionnaire on upper airway health and nasal symptoms was completed. The mean individual difference in nasal airway resistance between the 2 test days in the group of 56 subjects was 5.3% (SD 52.7%). Between-subject variability accounted for 74.9% and 72.5% of the total variability in the group of 5 and the group of 56 subjects, respectively. For the 5 subjects, by accounting for a change in upper airway symptoms or upper respiratory tract infection that occurred over the 5 test days, there was a significant decrease in the between-subject variability. The difference in sources of variation due to a change in upper airway symptoms was not seen in the group of 56 subjects. We conclude that the largest source of variability in nasal airway resistance is due to between-subject differences.

A Computer-assisted Chest Radiograph Reader System (CARRS) was developed for the detection of pathological features in lungs presenting with pneumoconioses. CARRS applies novel techniques in automatic image segmentation, incorporates neural network-based pattern classification, and integrates these into a graphical user interface. The three aspects of CARRS are described: Chest radiograph digitization and display, rib and parenchyma characterization, and classification. The quantization of the chest radiograph film was optimized to maximize the information content of the digital images. Entropy was used as the benchmark for optimizing the quantization. From the rib-segmented images, regions of interest were selected by the pulmonologist. A feature vector composed of image characteristics such as entropy, textural statistics, etc. was calculated. A laterally primed adaptive resonance theory (LAPART) neural network was used as the classifier. LAPART classification accuracy averaged 86.8 %. Truth was determined by the two pulmonologists. The CARRS has demonstrated potential as a screening device. Today, 90% or more of the chest radiographs seen by the pulmonologist are normal. A computer-based system that can screen 50% or more of the chest radiographs represents a large savings in time and dollars.

Working in mines is associated with acute and chronic occupational disorders. Most of the uranium mining in the United States took place in the Four Corners region of the Southwest (Arizona, Colorado, New Mexico, and Utah) and on Native American lands. Although the uranium industry collapsed in the late 1980s, the industry employed several thousand individuals who continue to be at increased risk for developing lung cancers. We present the case of a 72-year-old Navajo male who worked for 17 years as an underground uranium miner and who developed lung cancer 22 years after leaving the industry. His total occupational exposure to radon progeny was estimated at 506 working level months. The miner was a life-long nonsmoker and had no other significant occupational or environmental exposures. On the chest X-ray taken at admission into the hospital, a right lower lung zone infiltrate was detected. The patient was treated for community-acquired pneumonia and developed respiratory failure requiring mechanical ventilation. Respiratory failure worsened and the patient died 19 days after presenting. On autopsy, a 2.5 cm squamous cell carcinoma of the right lung arising from the lower lobe bronchus, a right broncho-esophageal fistula, and a right lower lung abscess were found. Malignant respiratory disease in uranium miners may be from several occupational exposures; for example, radon decay products, silica, and possibly diesel exhaust are respiratory carcinogens that were commonly encountered. In response to a growing number of affected uranium miners, the Radiation Exposure Compensation Act (RECA) was passed by the U.S. Congress in 1990 to make partial restitution to individuals harmed by radiation exposure resulting from underground uranium mining and above-ground nuclear tests in Nevada.

To describe the clinical characteristics of a group of patients infected with the newly recognized hantavirus in the Southwestern United States.Case series.Tertiary referral center.All patients with confirmed hantavirus infection admitted to the University of New Mexico Hospital between May 1, 1993 and January 1, 1994.Records of patients with hantavirus infection were reviewed to collect all pertinent clinical data.Pulmonary disease in these patients was characterized by hypoxemia covering a wide range of severity. The cause of hypoxemia was an increased permeability (noncardiac) pulmonary edema which could be differentiated from hydrostatic (cardiac) pulmonary edema by its association with low pulmonary artery occlusion pressures and increased protein content of edema fluid. Hemodynamic measurements in severe cases showed a shock state characterized by a low cardiac index (range 1.6 to 3.0 L/min/min2), a low stroke volume index (range 10.5 to 29 mL/m2), and high systemic vascular resistance index (range 1,653 to 2,997 dyne.sec/cm5.m2). Progression to death was associated with worsening cardiac dysfunction unresponsive to treatment and causing oxygen debt and lactic acidosis.The two major life-threatening pathophysiologic changes in Hantavirus Pulmonary Syndrome are increased permeability pulmonary edema, and an atypical form of septic shock caused by myocardial depression and hypovolemia.

The presence of radiographic silicosis as a risk factor for lung cancer was assessed in a case-control study conducted within a study cohort of New Mexico underground uranium miners. Chest radiographs were interpreted for the presence of silicosis for 65 lung cancer cases and 216 controls. The presence of silicosis on the chest radiograph taken closest to the start of employment or on the latest radiograph available was not associated with lung cancer risk after adjustment for cumulative exposure to radon progeny. The odds ratio associated with the presence of any type of opacity indicative of pneumoconiosis on the chest x ray closest to the start of employment was 1.33 (95% confidence interval, 0.31-5.72). For the most recent available chest x ray, the corresponding odds ratio was 1.16 (95% confidence interval, 0.35-3.84). Although the findings are limited by the relatively small number of subjects, the lack of association of silicosis with lung cancer suggests that silica exposure should not be regarded as a major uncertainty in extrapolating radon risk estimates from miners to the general population.

The clinical utility of nonsteroidal anti-inflammatory drugs (NSAlDs) to manage pain and inflammation is limited by adverse side effects. Although effective analgesic and anti-inflammatory agents, NSAlDs are associated with side effects that are a consequence of nonspecific inhibition of both cyclooxygenase-1 (COX-1) and 1 cyclooxygenase-2 (COX-2).The primary adverse events associated with NSAID therapy are upper gastrointestinal (GI) ulceration, perforation, or bleeding, all of which involve mucosal damage of varying severity and can be asymptomatic and I occur with little warning. Clinicians who prescribe NSAIDs should be able to identify patients who are at risk of an NSAID-induced GI adverse event and to detect and manage the event should one occur. The use of COX-2-specific inhibitors to manage pain and inflammation may minimize the risks of NSAID-associated toxicities.

The prescribing patterns for hypnotic medications were surveyed in 765 patients of three skilled-nursing facilities and two intermediate-care facilities. Seven per cent of the patients received a hypnotic routinely; an additional 3 per cent had as-needed orders for a hypnotic medication. Temazepam, flurazepam, and triazolam were, in descending order, the three most commonly prescribed hypnotics and accounted for 79 per cent of the hypnotic prescriptions. The average duration of use for triazolam, temazepam, and flurazepam was 11 weeks, 24 weeks, and 82 weeks, respectively. Seventy-six per cent of the flurazepam prescriptions were given seven days a week; 31 per cent of these prescriptions were for 30 mg doses. Medications that were not hypnotics but did have sedative side-effects were prescribed with bedtime orders for 11 per cent of the patients. The three most commonly prescribed drugs in this class were diphenhydramine, thioridazine, and haloperidol. Possible explanations for the lower frequency of hypnotic use observed in this study as compared to the frequencies reported in the literature are discussed, as are possible hazards of high-dose and long-term use of hypnotics.