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Biomedical subjects

W K Morgan

Publications and source records attributed to W K Morgan.

At least 127 records · Page 7Linked to original sources

Closing volume in coal miners.

Closing volume and closing capacity were determined in 82 working Appalachian coal miners and in a comparable group of control subjects. Abnormalities of closing volume and closing capacity were related to other measurements of pulmonary function. The relationship of smoking history, dust exposure, and presence of pneumoconiosis and bronchitis to elevations of closing volume and closing capacity was determined. It was shown that nonsmoking miners had elevated closing volume and closing capacity when compared to control subjects. Miners who were smokers or ex-smokers also had elevated closing capacity when compared to control subjects. Neither bronchitic symptoms nor the radiographic presence of pneumoconiosis were associated with an elevation of closing volume or closing capacity.

Bronchitis↗

Severe airway disease due to inhalation of fumes from cleansing agents.

A subject had severe airway obstruction and evidence of small-airway disease resulting from inhalation of "fumes" liberated during the course of mixing several drain-cleansing agents. The evidence in favor of the airways as the predominant site of damage was severe reduction of maximal expiratory flow in the presence of normal lung-recoil pressure in a nonsmoker who had no other known industrial exposures or predisposing respiratory conditions.

Acids↗

Pilot study of closing volume in byssinosis.

A study of the relative sensitivities of forced expiratory volume in one second (FEV1), maximal mid-expiratory flow (MMF), and closing volume (CV) in the detection of subjects with byssinosis was carried out in a North Carolina cotton mill. Altogether 35 workers participated in the study. Of these, nine showed a decline in FEV1 of 10% or more during the first work shift that followed the weekend break. Twelve subjects showed a decrease in MMF of 15% or more. In contrast only six workers exhibited a 10% increase in closing capacity, while ten showed a 10% increase in CV. Recent evidence of the magnitude of variability in closing volume manoeuvres suggests that our chosen level of change was too low, A 40% change in CV would have identified only five subjects. CV is a more complex manoeuvre for the subject being tested and for the technician to perform, is more time consuming, and is subject to greater variation. To have any advantage over spirometry, CV would have to be appreciably more sensitive. Our study suggests that it is not. However, the MMF may prove to be more sensitive than the FEV1 in the detection of byssinosis.

Byssinosis↗

Mortality from heart disease in coal miners.

A study of 3,726 Appalachian coal miners was undertaken to determine the standard mortality ratio (SMR) for heart disease and to ascertain the effect of smoking, excess weight, and the level of physical activity on deaths due to this cause, SMR's were calculated for all forms of heart disease and also separately for ischemic heart disease. For heart disease as a whole, SMR's of 73 for working and 104 for nonworking miners were obtained. It was found in both working and nonworking miners that obese smokers had the greatest risk of dying of heart disease (SMR's of 142 and 144, respectively). In the nonsupervisory underground work categories of face, transportation, and maintenance, an increase of SMR was observed, with face having the lowest and maintenance workers having the highest SMR. Use of all men from seven Appalachian states vs all US men as a standard population tended to slightly reduce the calculated SMR's.

Adolescent↗