(33/7118) Functional and high-resolution computed tomographic studies of divers' lungs.
OBJECTIVES: Several cross-sectional studies have described a decrease in the expiratory flow rates of divers. The objective of this study was to determine whether the combined application of high-resolution computed tomography (HRCT) and lung function testing supports the reported development of small airway obstruction in divers. METHODS: Thirty-two navy divers, 27 commercial divers, and 48 referents matched for age and smoking history underwent pulmonary function testing and HRCT of the lungs supplemented by a limited number of expiratory scans. The commercial divers were older and dived longer than the navy divers. Multivariate regression analysis was used to assess the relevant correlations of age, height, pack-years of cigarette smoking, and indices of diving exposure with lung function parameters. RESULTS: The inspiratory vital capacity and forced vital capacity (FVC) were greater, while the FEV% [(100 x FEV10)FVC] and maximum expiratory flow (MEF) at 25% (MEF25) of the FVC were lower for the navy divers than for the referents. The lung volumes and expiratory airflow pattern did not differ between the commercial divers and the corresponding referents. The forced expiratory volume in 1 second (FEV10), FEV%, MEF75, and MEF25 correlated negatively with the years of diving experience. This association was independent of age, height, and pack-years of cigarette smoking. For the majority of the divers and referents the expiratory HRCT revealed minor lobular air trapping without any difference between the groups. The HRCT did not show relevant morphologic abnormalities of small or large airways. CONCLUSIONS: The data confirm that diving may affect pulmonary function. However, there is no radiologic evidence for the development of small airway disease in these 2 subgroups of divers. (+info)
(34/7118) Petroleum distillate solvents as risk factors for undifferentiated connective tissue disease (UCTD).
Occupational solvent exposure may increase the risk of connective tissue disease (CTD). The objective of this case-control study was to investigate the relation between undifferentiated connective tissue disease (UCTD) and solvent exposure in Michigan and Ohio. Women were considered to have UCTD if they did not meet the American College of Rheumatology classification criteria for any CTD but had at least two documented signs, symptoms, or laboratory abnormalities suggestive of a CTD. Detailed information on solvent exposure was ascertained from 205 cases, diagnosed between 1980 and 1992, and 2,095 population-based controls. Age-adjusted odds ratios (OR) and 95 percent confidence intervals (CI) were calculated for all exposures. Among 16 self-reported occupational activities with potential solvent exposure, furniture refinishing (OR = 9.73, 95 percent CI 1.48-63.90), perfume, cosmetic, or drug manufacturing (OR = 7.71, 95 percent CI 2.24-26.56), rubber product manufacturing (OR = 4.70, 95 percent CI 1.75-12.61), work in a medical diagnostic or pathology laboratory (OR = 4.52, 95 percent CI 2.27-8.97), and painting or paint manufacturing (OR = 2.87, 95 percent CI 1.06-7.76) were significantly associated with UCTD. After expert review of self-reported exposure to ten specific solvents, paint thinners or removers (OR = 2.73, 95 percent CI 1.80-4.16) and mineral spirits (OR = 1.81, 95 percent CI 1.09-3.02) were associated with UCTD. These results suggest that exposure to petroleum distillates increases the risk of developing UCTD. (+info)
(35/7118) Chronic toxic encephalopathy in a painter exposed to mixed solvents.
This paper describes symptoms and findings in a 57-year-old painter who had been exposed to various organic solvents for over 30 years. He began to work as a painter at 16 years of age, frequently working in poorly ventilated areas; he used solvents to remove paint from the skin of his arms and hands at the end of each work shift. The patient and his family noticed impaired short-term memory function and changes in affect in his early forties, which progressed until after he stopped working and was thus no longer exposed to paints and solvents. After the patient's exposures had ended, serial neuropsychological testing revealed persistent cognitive deficits without evidence of further progression, and improvement in some domains. Magnetic resonance imaging revealed global and symmetrical volume loss, involving more white than gray matter. The findings in this patient are consistent with chronic toxic encephalopathy and are differentiated from other dementing processes such as Alzheimer's disease, multi-infarct (vascular) dementia, and alcoholic dementia. Previous descriptions in the literature of persistent neurobehavioral effects associated with chronic exposure to organic solvents corroborate the findings in this case. (+info)
(36/7118) In vivo finger flexor tendon force while tapping on a keyswitch.
Force may be a risk factor for musculoskeletal disorders of the upper extremity associated with typing and keying. However, the internal finger flexor tendon forces and their relationship to fingertip forces during rapid tapping on a keyswitch have not yet been measured in vivo. During the open carpal tunnel release surgery of five human subjects, a tendon-force transducer was inserted on the flexor digitorum superficialis of the long finger. During surgery, subjects tapped with the long finger on a computer keyswitch, instrumented with a keycap load cell. The average tendon maximum forces during a keystroke ranged from 8.3 to 16.6 N (mean = 12.9 N, SD = 3.3 N) for the subjects, four to seven times larger than the maximum forces observed at the fingertip. Tendon forces estimated from an isometric tendon-force model were only one to two times larger than tip force, significantly less than the observed tendon forces (p = 0.001). The force histories of the tendon during a keystroke were not proportional to fingertip force. First, the tendon-force histories did not contain the high-frequency fingertip force components observed as the tip impacts with the end of key travel. Instead, tendon tension during a keystroke continued to increase throughout the impact. Second, following the maximum keycap force, tendon tension during a keystroke decreased more slowly than fingertip force, remaining elevated approximately twice as long as the fingertip force. The prolonged elevation of tendon forces may be the result of residual eccentric muscle contraction or passive muscle forces, or both, which are additive to increasing extensor activity during the release phase of the keystroke. (+info)
(37/7118) Mycobacterium sp. as a possible cause of hypersensitivity pneumonitis in machine workers.
Hypersensitivity pneumonitis (HP) in workers exposed to metal removal fluids (MRFs) is increasing. This study supports the hypothesis that aerosolized mycobacteria colonizing the MRFs likely cause the disease. Three case studies of HP outbreaks among metal workers showed potentially high exposures to a rare and newly proposed Mycobacterium species. Retrospective review of samples submitted to our laboratory showed an association between presence of mycobacteria and HP. (+info)
(38/7118) Back pain among persons working on small or family farms--eight Colorado counties, 1993-1996.
In the United States, work-related back pain often results in lost wages, reduced productivity, and increased medical costs. However, national surveillance data about these injuries, such as occupationally acquired back pain among workers on small or family farms, are limited. To characterize back pain in a farming population, researchers at Colorado State University interviewed adult farmers residing in eight northeastern Colorado counties (Larimer, Logan, Morgan, Phillips, Sedgewick, Washington, Weld, and Yuma) during 1993-1996, using the Colorado Farm Family Health and Hazard Survey (CFFHHS). This report summarizes the findings of CFFHHS, which indicate that back pain is common among farmers and most frequently attributed to repeated activities (RAs) (e.g. lifting, pushing, pulling, bending, twisting, and reaching). (+info)
(39/7118) Outbreak of Hendra-like virus--Malaysia and Singapore, 1998-1999.
During September 29, 1998-April 4, 1999, 229 cases of febrile encephalitis (111 [48%] fatal) were reported to the Malaysian Ministry of Health (MOH). During March 13-19, 1999, nine cases of similar encephalitic illnesses (one fatal) and two cases of respiratory illness occurred among abattoir workers in Singapore. Tissue culture isolation identified a previously unknown infectious agent from ill patients. This report summarizes the preliminary epidemiologic and laboratory investigations of these cases, which indicate that a previously unrecognized paramyxovirus related to, but distinct from, the Australian Hendra virus is associated with this outbreak. (+info)
(40/7118) Diagnosing occupational asthma: use of induced sputum.
The diagnosis of occupational asthma (OA) needs to be made with as much objective evidence as possible. If there is airway inflammation, measurement of this should be an asset. The objective of this study was to investigate whether there is an increase in induced sputum and blood eosinophils and eosinophil cationic protein (ECP) in OA after work exposure. Patients were assessed after a 2-4 week period at work and away from work with cell counts and ECP assays performed blind to the clinical data. They were considered to have OA if symptoms were worse at work and there was a fall in forced expiratory volume in one second (FEV1) > or =20% or in the provocative concentration of methacholine causing a 20% fall in FEV1 (PC20) of four-fold or more compared with away from work. Patients whose symptoms were worse at work but had a change in FEV1 of <20% and in methacholine PC20 of less than four-fold were considered as controls. Sixteen patients were studied. Ten had OA and six were controls. Patients with OA had a significant increase in median (interquartile range) sputum eosinophils and ECP when at work compared with the periods out of work, 10.0 (17.05) versus 0.8 (1.6)% (p=0.007) and 3,840 (6,076) versus 116 (180) microg x L(-1) (p=0.01). They also had a higher blood eosinophil count, 0.3 (0.5) x 10(9) versus 0.2 (0.1) x 10(9) x L(-1) (p=0.013), and a trend towards higher serum ECP levels, 44.0 (20.0) versus 32.0 (18.5) microg x L(-1) (p=0.07). In conclusion, the proportion of eosinophils and levels of eosinophil cationic protein in sputum are particularly high at work in patients with occupational asthma, suggesting that the measurement of these factors can supplement other physiological outcomes in establishing the diagnosis of occupational asthma. (+info)