A STATISTICAL INVESTIGATION OF THE PULMONARY EFFECTS OF EXPOSURE TO ASBESTOS
ATKINSON, EDWARD NEELY
Doctor of Philosophy
In this study, data collected on a group of 1112 workers formerly employed in the production of insulation containing amosite asbestos at a plant in Tyler, Texas are examined and a subset of continuously employed workers with no other known exposure to asbestos is selected for detailed analysis. The response variables examined are scores for tests of pulmonary mechanics and the explanatory variables are age, height, weight, race, employment history and smoking behavior; the method of analysis is linear least squares regression. The numerical problems associated with presence of strong correlations in the data matrix are considered, and a method for the choice of a subset regression which attempts to alleviate these problems is proposed. Equations for each lung function test are selected and examined in detail. Regression techniques are used to attempt to detect an interactive effect between smoking and asbestos exposure with respect to lung function; such an effect has been reported with respect to carcinoma of the lung. No interactive effect is detected. Finally, maximum likelihood estimation is used to identify a subset of workers who seem particularly susceptible to the effects of asbestos.