Biomedical subjects

R Warshaw

Publications and source records attributed to R Warshaw.

18 recordsLinked to original sources

PubMed1991

Prevalence of spirometric abnormalities in a representative sample of the population of Michigan.

A random sample of a large industrial state in the United States (Michigan) was studied via respiratory questionnaire, medical history, physical examination, and spirometry: 976 white adults performed a battery of spirometric tests (FVC, FEV1, FEV1/FVC and FEF25-75%). Using predictive equations derived from normal subjects in the survey and defining spirometric abnormality by the lower 95% confidence interval, prevalences of abnormality were greater in those who had a smoking history. When equations derived from normal non-smokers were used, as has been the general practice, 21.3% of men and 18.5% of women with a positive smoking history had an abnormal FEV1 and 26.7% and 17.8% an abnormal FEF25-75%, respectively. Although FVC is thought to be affected little by smoking, mean values were lower and prevalences of abnormal values higher in smokers. Prevalences are also shown using an adjustment for the effect of smoking and using conventional (percent of predicted value) definitions of spirometric abnormality. The prevalences of spirometric impairments in this cross section of a large state should be useful for comparison with other populations under study in North America.

Adult↗

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

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↗

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↗

PubMed1989

Pulmonary function in histology technicians compared with women from Michigan: effects of chronic low dose formaldehyde on a national sample of women.

Chronic workplace exposure to formaldehyde and solvents at low doses reduced pulmonary function in 280 non-smoker white women working as histology technicians. They were studied during national workshops at four United States cities for four years. Height and age adjusted comparisons of pulmonary function were made with women in a stratified random population sample of Michigan and with a selected subset of the population that was used to model predictive pulmonary equations for function. The major functional change in histology technicians was a steeper decrement in vital capacity and flows from age 20 to 60 by regression analysis than occurred in the modelled Michigan population. Furthermore non-smoking and currently smoking women studied at two sites had significantly lower flows than were found in the sample of Michigan women. There was no consistent effect of an aerosol bronchodilator on flows of women at the four sites. Diffusing capacity for carbon monoxide single breath and alveolar volume were below the comparison group of Michigan women only when tested at Washington DC.

Adult↗

PubMed1986

Asbestos diseases and pulmonary symptoms and signs in shipyard workers and their families in Los Angeles.

Families of 338 male and 81 female shipyard workers (SYW), including 280 wives, 144 daughters, and 81 sons, were examined for diseases resulting from asbestos. The workers were initially exposed to asbestos at least 20 years prior to the study date. Radiographic signs of asbestosis (using standard criteria international Labor Office 1980) were found in 64% of 288 male SYW and 21% of 71 female SYW. After excluding those with any occupational exposure to asbestos, asbestosis prevalence was 11% in wives, 8% in sons, and 2% in daughters. Asbestos disease prevalence in workers and in wives increased with the number of years from initial exposure. Male SYW who had smoked had airway obstruction without volume loss. Nonsmokers had normal pulmonary functions. In SYW households prevalences of respiratory diseases, wheezing on physical examination, and symptoms of asthma and chronic bronchitis, exceeded those in the comparison (Michigan) population, even for the younger daughters and sons. These differences, and airway obstruction and distribution defects reported earlier were not explained by cigarette smoking or by asbestos exposure. Instead, they are tentatively ascribed to long-term exposure to ambient air pollution in Los Angeles.

Age Factors↗

PubMed1985

Signs of asbestosis and impaired pulmonary function in women who worked in shipyards.

Fifteen of 71 women (21.1%) who had worked in shipyards before May, 1961 had radiographic signs of asbestos disease. There were irregular opacities in the lung parenchyma in seven and pleural disease in eight, two of whom had pleural calcifications. The 71 women who volunteered to be studied had a mean age of 61.5 years. Chronic bronchitis was diagnosed in 21%, 71% had dyspnea on climbing two flights of stairs, and 42% had wheezing. These prevalences were 50% higher than in wives of shipyard workers. In 50 white women, mean values for expiratory flow rates, log (FEF25-75) and log (FEF75-85), were decreased for non-, ex- and current smokers as compared to normal nonsmokers. Ex-smokers and current smokers showed the greater effects. Diffusing capacity (DLCOsb) and alveolar volume (ALV) were also reduced in all three smoking categories. Comparison to a reference population without asbestos exposure showed that for current, ex- and nonsmoking subgroups, there were significant reductions in log (FEF25-75), DLCOsb, and ALV for nonsmokers, reductions in FEV1, log (FEV25-75), and log (FEF75-85) in ex-smokers, and reduced ALV in current smokers. These decreases may reflect a locality effect. Further studies are recommended.

Age Factors↗

PubMed1985

Pulmonary functional impairment and symptoms in women in the Los Angeles Harbor area.

Spirometric measurements of vital capacity and flow rates, thoracic gas volume, and single-breath diffusing capacity for carbon monoxide were obtained in 360 white women, 238 wives age 58 years and 122 daughters age 32 years of shipyard workers from the Long Beach area of southern California. The values for nonsmokers, exsmokers, and current smokers were compared with smoking-specific mean values, age- and height-adjusted, from a reference population in Michigan. The wives from Long Beach had significantly lower mid and terminal flows, single-breath diffusing capacity for carbon monoxide, and alveolar volume, except that single-breath diffusing capacity for carbon monoxide was not significantly lower in current smokers. Nonsmokers and ex-smokers showed significantly different values for one-second forced expiratory volume in addition to flow rates and single-breath diffusing capacity for carbon monoxide. Daughters showed significant reductions in single-breath diffusing capacity for carbon monoxide and alveolar volume, which are attributable to maldistribution of inspired gas. These data showed that a powerful factor has affected expiratory air flow and distribution of gas, resulting in altered single-breath diffusing capacity for carbon monoxide and alveolar volume in this population. The factor is additive with and resembles the effect of cigarette smoking, and it is postulated that this factor is oxidant air pollution.

Adult↗

PubMed1985

Asbestosis, pulmonary symptoms and functional impairment in shipyard workers.

A group of 339 male shipyard workers responded to an invitation via shipyards, unions, and news media to be studied for the presence of asbestosis and its functional effects. Of these, 288 were white or black, had begun working in shipyards at least 20 years earlier, and had satisfactory chest x-ray film findings; 257 underwent spirometric testing, and 199 had single-breath diffusing capacities for carbon monoxide (Dsb) determined. There were radiographic signs of asbestosis in 64 percent. Of these, 28 percent had parenchymal disease only, 37 percent had pleural disease only, and 35 percent had both. There was pleural calcification in 9 percent. In only 14 (8 percent) was the profusion of opacities greater than 1/1 by the International Labour Organization's criteria. Age was closely related to the duration of exposure to asbestos. Thus, 87 percent of the workers who had asbestosis were born from before 1900 to 1910, 70 percent of those born in 1911 to 1920 had asbestosis, 62 percent of those born in 1921 to 1930 had the disease, and 31 percent of those born in 1931 to 1940 had signs of asbestosis. Function in nonsmokers was not significantly different from the reference population except for alveolar volume; ex-smokers had significantly reduced forced expiratory volume in one second, flow rates, Dsb, and alveolar volume. The forced vital capacity and thoracic gas volume were normal. Shipyard workers who smoked resembled reference smokers except for significantly reduced alveolar volume. These shipyard workers had minimal to moderate asbestosis with much pleural disease and little functional impairment when compared to a smoking-specific reference population.

Adolescent↗

PubMed1985

Asbestos disease in family contacts of shipyard workers.

Radiologic signs of pulmonary asbestos disease were found in 11.3 per cent of 274 wives of shipyard workers who were 20 or more years from initial hiring-on in shipyards in Los Angeles County. Asbestosis was also found in 7.6 per cent of 79 sons and 2.1 per cent of 140 daughters of these workers. The wives, sons, and daughters were without occupational exposure. Comparable radiographic signs were not found in comparison groups. It is probable that asbestos exposure in the household places these family members at risk for mesothelioma and lung cancer.

Adolescent↗

PubMed1979

Decrease in vital capacity in PCB-exposed workers in a capacitor manufacturing facility.

Pulmonary function was evaluated in 243 workers exposed to PCB in the manufacture of capacitors. Mean employment was greater than 15 years. Thirty-four of the workers (14%) were found to have a reduced Forced Vital Capacity (FVC less than 80% of Morris' predicted). Of the 34 with reduced FVC, 27 (80%) demonstrated a restrictive pattern of impairment (FEV1/FVC greater than 0.7). Only one of these 27 workers had an abnormal chest roentgenogram (greater than or equal to 1/0 by ILO UC Classification of Radiographs of Pneumoconioses). These findings are of interest in view of recent experimental data indicating the accumulation of PCBs and PCB metabolites in lung tissue (Brandt and Jansson). Restrictive spirometric impairment with no radiographic change is unusual in occupational exposure.

Adult↗

PubMed1975

Changes in pulmonary function in workers exposed to vinyl chloride and polyvinyl chloride.

To determine whether occupational exposure to vinyl chloride gas and polyvinyl chloride dust is associated with changes in pulmonary function, spirometry and maximum expiratory flow-volume curves were obtained in 348 workers in a VC polymerization plant. The major finding was diminution in air flow in 200 workers (57.5 percent). This abnormality correlated with age and duration of exposure. A relationship with smoking was noted only in younger workers with exposures of less than 10 years. When age exceeded 40 years or exposure 20 years, prevalence of this impairment was similar in smokers and nonsmokers, suggesting that occupational or other environmental factors were operative.

Adult↗

PubMedDate not supplied

Clinical validation of automated spirometry used in surveys of large occupational groups: comparison with conventional water spirometry.

An accurate, rugged automated spirometer which provides immediate data is useful both clinically and for screening large groups with various environmental exposures. Because the need for such surveys has been increasing, we compared a computerized mass flow-meter with a conventional water spirometer. The same forced expiration was measured by both instruments in the laboratory and during an occupational survey. Mean values for forced vital capacity (FVC) were 96 cc greater by the automated technique in the laboratory (this equals 2.2% of the value by the conventional method, with a correlation, r, of 0.998) and 97 cc greater in the field (2.3% of the conventional method; r = 0.995). Differences between the two methods in the laboratory and field for forced expiratory volume in one second (FEV 1.0) were +24 cc (0.68%; r = 0.996) and +47 cc (1.6%; r = 0.996) and for forced expiratory flow (FEF)25-75--179cc/sec (4.18%; r = 0.968) and -63 cc/sec (2.1%; r = 0.992), respectively. For FVC and FEV1.0, the differences between paired values were less than or equal to 10% of the value by water spirometry in all instances and less than or equal to 5% in 95.5% and 96% of comparisons, respectively. For FEF 25-75 the differences between paired values were less than or equal to 20% in 97.2% and less than or equal to 10% in 84.7% of comparisons. These findings confirm the validity of the measurements provided by the automated spirometer.

Autoanalysis↗

PubMedDate not supplied

Neurobehavioral and respiratory symptoms of formaldehyde and xylene exposure in histology technicians.

Disturbances of memory, mood, equilibrium, and sleep that occurred simultaneously with headache and indigestion, were experienced more frequently among women working in histology who had daily exposure to formaldehyde, xylene, and toluene than in unexposed female clerical workers working in the same hospitals. Neurobehavioral symptoms were accompanied by irritation of eyes, upper airways, and trachea. Formaldehyde exposure correlated better with neurobehavioral symptoms and with respiratory and mucous membrane symptoms than did exposure to xylene/toluene or to other agents.

Adult↗

PubMedDate not supplied

Pulmonary and neurobehavioral effects of formaldehyde exposure.

Two groups of male workers who were exposed to formaldehyde, the first group in phenol-formaldehyde-plastic foam matrix embedding of fiberglass (batt making), and the second in the fixation of tissues for histology, were studied for work-related neuro-behavioral, respiratory, and dermatological symptoms; and for pulmonary functional impairment. Forty-five male fiberglass batt makers who were studied across the initial work-shift after a holiday had average frequencies of combined neurobehavioral, respiratory, and dermatological symptoms of 17.3 for the hot areas and 14.7 for the cold areas of the process. Their symptom counts were significantly greater than those for 18 male histology technicians who averaged 7.3, and for 26 unexposed male hospital workers who averaged 4.8. During their first workshift after holidays, 58% of the batt makers had a decrease in one or more tests of pulmonary function. Nine nonsmokers had decreases more frequently than did 35 smokers; forced expiratory volume in one second FEV1.0 decreased in 16%, diffusing capacity for carbon monoxide (sb) decreased in 30%, forced expiratory flow 25-75 decreased in 16%, and forced expiratory flow) 75-85 decreased in 36%. Thirty-five percent of all 44 men had drops in FEV1.0, forced vital capacity, or in diffusing capacity (sb).

Adult↗

PubMedDate not supplied

Formaldehyde impairs memory, equilibrium, and dexterity in histology technicians: effects which persist for days after exposure.

Results of neurobehavioral testing in 305 histology technicians were studied by regression analysis with age, years of cigarette smoking, and hours per day of exposure to formaldehyde and to solvents as major independent variables. Increasing age was associated with poorer performance on visual memory, block design, trails, dexterity by pegboard, sharpened-Romberg, finger writing, as well as with longer choice reaction time. Increased daily hours of exposure to formaldehyde were correlated with reduced performance on story memory, visual memory, digit span, pegboard and sharpened-Romberg, as well as with errors on trails. Exposure to solvents was associated only with diminished recall of story.

Adult↗

PubMedDate not supplied

Mean and instantaneous expiratory flows, FVC and FEV1: prediction equations from a probability sample of Michigan, a large industrial state.

Prediction equations for FVC, FEV1, FEV1/FVC, FEF25-75%, FEF75-85%, FEF50% and FEF75% were modelled for 396 normal non-obese adult lifetime nonsmokers and continuing smokers. Subjects came from a random cross-section of the white population of Michigan, a large industrial state. In both sexes, linear models utilizing age and height were appropriate for FVC, FEV1/FVC and FEV1; flows were better described by logarithmic transformation. These regression equations provided similar predicted values for FVC and FEV1 in nonsmokers to other models in wide use. Previous equations for instantaneous flows have yielded inconsistent predicted values. It is hoped that the present equations will be useful for these measurements. Duration of cigarette smoking was a significant prediction variable for FEV1, FEV1/FVC and mean and instantaneous flows in these normal men, but not in normal women. For FEV1, the effect of each year of smoking was 40% of the effect of ageing.

Adult↗