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Biomedical subjects

K H Kilburn

Publications and source records attributed to K H Kilburn.

At least 19 recordsLinked to original sources
PubMed1992

Irregular opacities in the lung, occupational asthma, and airways dysfunction in aluminum workers.

We examined chest X-rays, measured expiratory flows and FVC by spirometry and TLC by projected lung area, ascertained respiratory data by questionnaires, and performed chest examinations in 670 Southeastern aluminum workers and 659 unexposed regional controls. Both groups were asbestos exposed. More aluminum workers had irregular opacities and fewer had pleural abnormalities than did regional pipefitter referents. The pulmonary function tests were expressed as percentage of predicted to adjust for height, age and duration of smoking based on a randomly selected U.S. reference population. Data from aluminum workers were compared to regional controls with students "t" tests run for unequal size groups. Aluminum workers had significant reductions in FEV1 of 3.2% predicted (p less than .003), FEF25-75 of 11.3% predicted (p less than .0001), FEF75-85 of 22.5% predicted (p less than .0001), and an increased TLC of 2.0% predicted (p less than .005). The 145 who had never smoked (NS) were compared with 124 NS controls and showed this same pattern of differences; but in smokers, the differences were significant for mid and terminal flows, but not for FEV1. In aluminum workers who never smoked, asthma prevalence by history was 7.6% vs. 4.0% in controls, and wheezes were heard in 21.4% vs. 2.4% in controls. In aluminum workers who were current smokers, asthma prevalence was 16.4% vs. 9.4% in controls, and wheezes were heard in 43.7% vs. 21.1% in controls. Aluminum workers had significantly more asthma, wheezing, airways obstruction, and pulmonary parenchymal abnormalities similar to asbestosis than did regional blue collar controls not melting and casting aluminum.

Aluminum↗
PubMed1992

Prevalence of symptoms of systemic lupus erythematosus (SLE) and of fluorescent antinuclear antibodies associated with chronic exposure to trichloroethylene and other chemicals in well water.

Criteria for the recognition of systemic lupus erythematosus (SLE) were applied to 362 subjects exposed to trichloroethylene, trichloroethane, inorganic chromium, and other chemicals in water obtained from wells in an industrially contaminated aquifer in Tucson, Arizona. Their antinuclear autoantibodies were measured by fluorescence (FANA) in serum. Ten patients with clinical SLE and/or other collagen-vascular diseases were considered separately. Results were compared to an Arizona control group, to published series, and to laboratory controls. Frequencies of each of 10 ARA symptoms were higher in exposed subjects than in any comparison group except those with clinical SLE. The number of subjects than in any comparison group except those with clinical SLE. The number of subjects with 4 or more symptoms was 2.3 times higher compared to referent women and men. FANA titers greater than 1:80 was approximately 2.3 times higher in women but equally frequent in men as in laboratory controls. ARA score and FANA rank were correlated with a coefficient (cc) of .1251, r2 = .0205 (p less than 0.036) in women and this correlation was almost statistically significant in men cc = .1282, r2 = .0253 (p less than 0.059). In control men and women neither correlation was significant. Long-term low-dose exposure to TCE and other chemicals in contaminated well water significantly increased symptoms of lupus erythematosus as perceived by the ARA score and the increased FANA titers.

Antibodies, Antinuclear↗
PubMed1992

Neurobehavioral effects of formaldehyde and solvents on histology technicians: repeated testing across time.

Neurobehavioral functions were studied by periodic testing of 318 histology technicians and by a single session testing 494 of such technicians from 1982 through 1986. Tests included immediate recall of stories, of drawings, and of number series from the Wechsler Memory Scale, block designs from the Wechsler Adult Intelligence Scale (WAIS), slotted pegboard, trail making A and B, embedded figures, number writing on the fingers, visual simple and two-choice reaction times, balance (speed of body sway), and the profile of mood state (POMS) score. Mean test scores of four initial "first test" groups were not different from 1982 to 1986. Immediate recall of stories and drawings improved on the first retest as did the block design score. Other test scores showed insignificant variation over the 4 years, including memory for numbers forward and backward, trails A and B, number writing on fingers, radius of body sway, and choice reaction time. Only placing of pegs in the pegboard took longer. POMS score was lower in the second year in naive subjects and decreased from 39 to 13 in those retested. Variations in results of neurobehavioral tests given at intervals across 4 years were small. No cumulative effects of occupational exposures or of aging were found. However, small decreases may have been offset by increases due to test familiarity or learning.

Adult↗
PubMed1992

Expiratory flows decreased in Los Angeles children from 1984 to 1987: is this evidence of effects of air pollution?

To estimate the effects of air pollution we measured expiratory flows and vital capacities in 556 Mexican-American Los Angeles children in 1984 and 251 in 1987. They included 106 who were measured in 1984 and 1987 and 145 measured only in 1987. Pulmonary function values were standardized for growth be expressing them as percentages of predicted (% pred) based on sex and height. In 1987 mean values for FEV1 and FEF25-75 were lower by 4.5% pred and 13.6% pred respectively (P < 0.001), while vital capacities were not different in 213 children tested as fifth graders in 1984 and 251 fifth grade children in 1987. For the 106 children tested at both sessions (in second grade in 1984 and in fifth grade in 1987) FVC was also not different but FEV1 was 2.0% pred lower (P < 0.06) and FEF25-75 was 7.0% pred lower (P < 0.001). For the 450 children tested only in 1984 and the 106 retested in 1987 there were no significant differences in mean values for FVC, FEV1, and FEF 25-75. Similarly there were no significant differences between the 1987 mean values for 145 children who were studied longitudinally were not different from the 1984 and 1987 cross-sectional cohorts. Across this interval FEV1 and midflows diminished but vital capacities did not. Airways obstruction worsened during children's residence in Los Angeles from 1984 to 1987 and this is probably due to air pollution.

Air Pollutants↗
PubMed1992

Pulmonary effects of exposure to fine fibreglass: irregular opacities and small airways obstruction.

OBJECTIVE: Man made mineral fibres imitate asbestos and produce tumours of the pleura in animals. To answer the question, Does prolonged exposure to fibreglass adversely affect pulmonary function or produce radiographic abnormalities in human subjects? we studied workers in a midwestern appliance plant where refrigerator doors and previously entire cabinets were insulated with fibreglass sheeting and loose rotary spun fibreglass. METHODS: Spirometry and lung volumes were measured, respiratory and occupational questionnaires were administered, and chest x-ray films were read for pneumoconiosis using International Labour Office (ILO) 1980 criteria in 284 workers with exposure of 20 years or more. RESULTS: Expiratory flows were reduced including FEV1 (mean 90.3% of predicted (pr), FEF25-75 (85.5% pr), and FEF75-85 (76.2% pr). Forced vital capacity was significantly reduced (92.8% pr) and total lung capacity was significantly increased (109.2% pr). In white male smokers, a group large enough for comparisons, parameters of pulmonary function were reduced further in the presence of irregular opacities. Forty three workers (15.1%) had evidence of pneumoconiosis on chest radiographs: 26 of these (9.1%), had no known exposure to asbestos and 17 (6.0%) had some exposure. The best judgement was that in 36 (13.0%), pulmonary opacities or pleural abnormalities were due to fibreglass. CONCLUSION: Commercial rotary spun fibreglass used for insulating appliances appears to produce human disease that is similar to asbestosis.

Asthma↗
PubMed1992

Are hearing loss and balance dysfunction linked in construction iron workers?

The objective was to determine whether an association existed between hearing loss and balance dysfunction in construction workers exposed to noise. Screening pure tone audiometry and balance testing were performed using a sound emitter and dual microphone system to evaluate 78 iron workers who were compared with 128 histology technicians. Most iron workers showed hearing loss at frequencies below 3000 Hz. Their sway speeds were significantly faster both with the eyes open (1.05 (SD 0.39) v 0.91 (SD 0.22) cm/s) and with eyes closed (1.66 (SD 0.82) v 1.31 (SD 0.51) cm/s) than those of histology technicians. Coefficients for sway speed with the eyes closed and hearing loss in the left ear were significantly correlated at 500 to 8000 Hz. They were also correlated with the sway speed, eyes open, at low and high Hz. It is concluded that the use of air impact power tools in an inordinately noisy work environment makes iron workers prematurely deaf and impairs their balance. Falls may be related to balance dysfunction and impaired equilibrium. Falls from height injure and kill iron workers. Further investigations will determine whether injuries from falls are linked to these impairments.

Accidental Falls↗
PubMed1992

Predictive equations for total lung capacity and residual volume calculated from radiographs in a random sample of the Michigan population.

BACKGROUND: Published predicted values for total lung capacity and residual volume are often based on a small number of subjects and derive from different populations from predicted spirometric values. Equations from the only two large studies gave smaller predicted values for total lung capacity than the smaller studies. A large number of subjects have been studied from a population which has already provided predicted values for spirometry and transfer factor for carbon monoxide. METHODS: Total lung capacity was measured from standard posteroanterior and lateral chest radiographs and forced vital capacity by spirometry in a population sample of 771 subjects. Prediction equations were developed for total lung capacity (TLC), residual volume (RV) and RV/TLC in two groups--normal and total. Subjects with signs or symptoms of cardiopulmonary disease were combined with the normal subjects and equations for all subjects were also modelled. RESULTS: Prediction equations for TLC and RV in non-smoking normal men and women were square root transformations which included height and weight but not age. They included a coefficient for duration of smoking in current smokers. The predictive equation for RV/TLC included weight, age, age and duration of smoking for current smokers and ex-smokers of both sexes. For the total population the equations took the same form but the height coefficients and constants were slightly different. CONCLUSION: These population based prediction equations for TLC, RV and RV/TLC provide reference standards in a population that has provided reference standards for spirometry and single breath transfer factor for carbon monoxide.

Adult↗
PubMed1992

Severity of pulmonary asbestosis as classified by International Labour Organisation profusion of irregular opacities in 8749 asbestos-exposed American workers. Those who never smoked compared with those who ever smoked.

The profusion of irregular opacities on chest roentgenograms by International Labour Organisation pneumoconiosis criteria was used to assess the severity of asbestosis in 8749 asbestos-exposed active and retired American workers. Seventy-eight percent had no asbestosis (category 0/0 or 0/1), 18.6% had slight asbestosis (1/0 to 1/2), 3% had moderate asbestosis (2/1 to 2/3), and 0.3% had advanced disease (3/2 or greater). Significantly more current smokers had asbestosis than did those who had never smoked, and their average profusion of opacities was higher. The mean age of current smokers with asbestosis was 60 years, whereas subjects with the disease who had never smoked had a mean age of 64 years, a significant difference. Cigarette smoking and asbestosis appear to act synergistically to produce irregular opacities on chest roentgenograms of asbestos-exposed American workers.

Asbestosis↗
PubMed1991

Difficulties of attribution of effect in workers exposed to fiberglass and asbestos.

Man-made mineral fibers have many properties of asbestos that raise concern about their safety. We studied 175 fiberglass production workers, using chest radiographs, measurement of total lung capacity, chest examinations, and occupational and medical histories. Pulmonary volumes and flows were calculated as percent of predicted, adjusted for height, age, ethnicity, and cigarette smoking. Thirty-one men with radiographically evident small irregular opacities of profusion of 1/0 or greater and/or pleural abnormalities were observed. Eight of 38 men with such changes said they had been exposed only to fiberglass; the other 23 with radiologically detectable pleural and/or pulmonary changes were among the 137 whose histories indicated that they had been exposed to asbestos and to fiberglass. Pulmonary function measurements as group means were reduced in the 175: FVC was 94.8% predicted, FEV1 was 91.3% predicted, FEF25-75 was 80.7% predicted, FEF75-85 was 73.1% predicted and FEV1/FVC was 0.73. Total lung capacity (TLC) was elevated to 114.2% predicted (mean) and RV/TLC (mean 0.46) was also elevated. Although only 78% of fiberglass production workers gave histories of asbestos exposure, all had shared the air in a manufacturing plant where ovens insulated with asbestos were continuously cleaned, repaired, dismantled, and rebuilt. It appears that attribution of the effects of their exposure to fiberglass could not be estimated independently of the effects of asbestos exposure.

Adult↗
PubMed1991

Abnormal lung function associated with asbestos disease of the pleura, the lung, and both: a comparative analysis.

The impairment of lung function associated with different types of asbestos related disease was examined in 1298 men. The 310 men with circumscribed pleural lesions (plaques) or diffuse pleural thickening without asbestosis were compared with 596 men with asbestosis only and with 322 men with pleural abnormalities and asbestosis, as classified from chest radiographs by ILO pneumoconiosis criteria. Spirometric indices and total lung capacity (TLC; determined by planimetry) were measured and expressed as percentages of predicted values. Non-smoking men with pleural disease only had reduced values of mid and terminal expiratory flows (80.6 and 69.9% predicted) and a reduced FEV1 (89% predicted) with a forced vital capacity (FVC) of 94% predicted. TLC was 104% predicted. Thus they had airways obstruction with-out restriction. Non-smoking men with pulmonary asbestosis (ILO profusion of opacities mostly 1/0 and 1/1) had pulmonary function similar to that of men with pleural disease. FEV1 and FVC and flow rates at other lung volumes were lower in smokers with asbestosis (after adjustment for duration of smoking) than in the non-smokers with asbestosis. Airflow limitation was worse in the men with both pleural abnormalities and pulmonary asbestosis with lower values for mid expiratory flow, FEV1 and FVC (but not TLC) than those with either abnormality alone, in both non-smokers and current smokers. Men with diffuse pleural thickening that included the costophrenic angles had more airways obstruction and air trapping and lower FVC values than those with circumscribed pleural disease.

Aged↗
PubMed1990

Cross-shift and chronic effects of stainless-steel welding related to internal dosimetry of chromium and nickel.

Ninety welders from a stainless-steel fabricating plant were studied by pulmonary function tests and serum and urine chromium and nickel levels, cross-sectionally, and 31 were compared across a Monday shift. They had welded for a mean of 11 years, mean age was 44 years, and mean smoking duration was 20 years in 62 current smokers. Baseline spirometric tests were significantly reduced: FVC to 95.4 mean percentage of predicted (pop), FEV1 to 94.5 pop, FEF25-75 to 85.9 pop, and FEFR75-85 to 74.8 pop. Current smokers had greater reductions in flow rates and FVC than nonsmokers even after adjustment of their predicted values for the effects of duration of smoking. Neither alveolar volume at 104.3 pop nor diffusing capacity for carbon monoxide (single breath) at 98.5 pop was reduced. There were no significant changes in pulmonary function measurements across a Monday workshift in 31 welders, but in seven men who welded stainless steel, levels of serum chromium (Cr) rose 66% from 1.9 +/- 2.1 micrograms/liter and urinary Cr increased 22%. Serum nickel levels rose only 7%, although they were elevated before shift, 1.1 +/- 0.4 micrograms/liter (compared with 0.21 +/- 0.20 micrograms/liter in controls), and urinary nickel levels did not increase. Eleven years of welding had reduced vital capacities and expiratory flows. Monday stainless-steel welding raised the serum and urine chromium levels (measures of internal dosimetry for exposure) but did not decrease pulmonary function values.

Adult↗
PubMed1990

Airway obstruction in asbestos-exposed shipyard workers: with and without irregular opacities.

Airway obstruction was measured by spirometry in 296 boilermakers with 15 or more years shipyard exposure to asbestos. Percent of predicted was used to adjust each worker's pulmonary function values for height (mean 174 cm), age (mean 52.5 years) and cigarette smoking (mean 23.3 years). Mean values were significantly (P less than 0.05) below predicted for FVC 4.23 l 94.2% FEV1 3.06 l 89.3%, FEF25-75 2.51 l sec-1 82.3% and FEF75-85 0.574 l sec-1 77.8%. Corresponding values for the 106 men with pulmonary asbestosis (ILO profusion of opacities 1/0 or greater), were below these levels. Those without radiographic signs of asbestosis had intermediate values significantly below predicted. Correlation coefficients for pulmonary functions with ILO categories of asbestosis (profusion of irregular opacities) were: FVC -0.2381, FEV1 -0.2494, FEF25-75 -0.2403 and FEF75-85 -0.1629. All were significant P less than 0.05. The subgroup with radiographic asbestosis (ILO 1/0 or greater), had more functional loss. Data on this large cohort of asbestos-exposed workers establish that airway obstruction occurs after 15 years of exposure and before the slightest profusion of asbestosis scarring in the lungs of shipyard workers, and worsens progressively with greater profusions of irregular opacities.

Airway Obstruction↗
PubMed1990

Abnormal pulmonary function associated with diaphragmatic pleural plaques due to exposure to asbestos.

Pulmonary function was measured in 79 men with diaphragmatic pleural plaques (DPP) as the only abnormality characteristic of asbestos disease on chest radiographs. They were selected from 4572 construction and shipyard workers exposed to asbestos. Abnormalities of pulmonary function in 21 non-smokers and 43 current smokers were compared with referent values adjusted for height, age, and duration of cigarette smoking. In the non-smokers, flows (FEV1) FEF75-85 and FEV1/FVC) were reduced and TGV and RV/TGV were raised. Current smokers had similar significant reductions. Thus by contrast with some current opinion that plaques are "an index only of past asbestos exposure," workers with plaques, even limited to the diaphragm, have functional impairment typical of pulmonary asbestosis. This suggests that they have pulmonary asbestosis, which is below the threshold of radiographic recognition.

Aged↗
PubMed1990

Pulmonary functional impairment associated with pleural asbestos disease. Circumscribed and diffuse thickening.

To define the pulmonary functional impairment associated with pleural asbestos signs (PAS), we compared 738 men with only circumscribed (plaques) or diffuse pleural thickening on chest roentgenograms but no irregular opacities by ILO pneumoconiosis criteria (1980) with 738 age-matched asbestos-exposed men without any roentgenographic signs and with 228 men unexposed to asbestos. All men were white. Spirometry and total thoracic gas volumes (TGV) were measured and expressed as percentage of predicted of white Michigan men who have been modeled for spirometric values thereby adjusting for height, age, and in current and ex-smokers for duration of smoking. Asbestos-exposed men who never smoked had reduced FEF75-85 (p less than 0.01) and increased TGV (p less than .0001) as compared with unexposed men. The 155 men with PAS who had never smoked had reduced flows (p less than .0001), FVC (p less than 0.0056), and TGV (p less than .0001) when compared with 155 age-matched asbestos-exposed men. The 325 asbestos-exposed current smokers with normal chest roentgenograms compared with unexposed smokers had reduced expiratory airflows (p less than 0.0001), reduced FEV1 (p less than 0.004), and increased TGV (p less than 0.0001). The 325 current smokers with PAS had additional air trapping that further reduced vital capacity. Thus, PAS were associated with significant pulmonary dysfunction in men who never smoked, and current and ex-smokers had additional dysfunction even after adjustment for duration of smoking.

Asbestosis↗
PubMed1990

Effects of individually motivating smoking cessation in male blue collar workers.

Adverse demonstrable health effects linked to the individual's smoking were shown to 2,689 American workers to motivate cessation during routine examinations to detect asbestosis. This intervention was evaluated six to 25 months later by a mailed questionnaire and by telephone to non-responders. Results were compared to yearly quit rates of 2.5 percent to 5 percent for 736 workers who were ex-smokers at the initial examination. Of the 504 men who responded by mail, 29.8 percent had quit smoking, 35.9 percent had cut down from a mean of 28 to 13 cigarettes per day, and 34.3 percent were smoking as before. Subsequent follow-up at one year showed that 25.6 percent remained quit, and that 23 percent of those who cut down had quit, for an overall quit rate of 34 percent. Of 101 non-responders contacted by telephone, 17 percent had quit and 53 percent had reduced smoking. In both samples, those who quit were more likely to have had lower alveolar carbon monoxide (COa) levels, to be older, and to have had asbestosis. Responders by mail were the same age as non-responders but had smoked longer, had higher prevalences of asbestosis, emphysema, chronic bronchitis and higher COa. Demonstration of the adverse personal effects of smoking appear to have contributed to the quit rates or reduced smoking rates in 65 percent of the responding workers.

Adult↗
PubMed1989

An examination of factors that could affect choice reaction time in histology technicians.

Histology technicians exposed to formaldehyde and solvents have symptoms and objective evidence of neurobehavioral impairment of memory, judgment, and equilibrium. Because reaction time has been prolonged in many groups of workers exposed to toxicants, choice reaction time was measured in 385 female formaldehyde and solvent-exposed histology technicians, and 79 unexposed female laboratory workers. Choice reaction time to a visual stimulus (CRT) is defined, for the purpose of this study, as the time required for discriminated cancellation of two different letters on a microcomputer screen by pressing the matching keys. Initial analysis showed that increases in age, years of cigarette smoking, and hours per day of formaldehyde exposure significantly lengthened CRT, but xylene-toluene exposure had no effect. Since duration of smoking and length of daily formaldehyde exposure were age related, multiple linear regression analysis of CRT was performed using them as independent variables. Increasing age was the only significant factor in lengthening CRT. However, in these female histology technicians, the second measurement one year later was 44 msec faster (p less than .04). The reason for improved performance is unclear, but it may be an effect of training encompassing familiarity, improved attention, or learning.

Environmental Exposure↗
PubMed1989

Choice (CRT) and simple reaction times (SRT) compared in laboratory technicians: factors influencing reaction times and a predictive model.

Choice reaction time (CRT) and simple reaction time (SRT) tests were administered to 151 female histology laboratory technicians to determine if occupational exposure to organic solvents and formaldehyde delayed either or both. The relationships between CRT and SRT latencies were evaluated using different testers, sequences of administration, and microcomputers. Formaldehyde exposure, cigarette smoking history, ethnicity, and alveolar CO levels did not significantly influence CRT and SRT. However, slightly different protocols did significantly affect SRT. A linear model demonstrated that logSRT (LSRT) and LogCRT (LCRT) were longer with increasing age, promising further clinical applications. It is concluded that both CRT and SRT measure some overlapping and some different neurologic pathways. Reaction times in large "normal" populations are needed to compare with groups exposed to potential neurotoxins.

Adult↗