Document NGy6z5M44qnqzdDbab4vevZ3D

70 circumstance in which a statistically significant greater percentage of abnormalities is found is for abnormal lymph glands among the popu lation serving as an unexposed control. With the number of subcate gories established in Table 42, such a finding would be expected on the basis of chance alone. We attribute no significance to it. Table 43 shows the number and percentage of individuals with rales or finger clubbing according to their X-ray reading. A greater percentage of individuals with abnormal X-rays have dry rales than do individuals with normal X-rays. The numbers, however, are so small that the data do not achieve significance. There was no correlation of finger club bing with X-ray findings. Overall, rales were observed in 4.8% of the entire study group and clubbing in 2.6% compared to 25.2% with abnormal X-rays [or 13.1% if more stringent X-ray reading criteria were utilized (c.f. Table 11)]. Thus, in contrast to earlier data from Great Britain (British Occupational Hygiene Committee, 1968), it would appear that the presence of X-ray abnormalities is a considerably more sensitive parameter than rales (or restrictive pulmonary function deficits) for the categorization of asbestos disease. This has also been seen in several other asbestos-exposed groups, including shipyard workers (to be published) and chemical or oil refinery maintenance employees (Lilis et al., 19S0). Data for the blood pressures are shown in Table 44 according to age, job category, and race. As can be seen, the systolic and diastolic blood pressures of the blacks are significantly above those of the whites. Systolic pressures increase from 5 to 7 percent per decade and diastolic from 2 to 3 percent each decade with the rates of increase being greater for blacks than whites. The analyses of the age stand ardized blood pressures according to smoking history or job category are shown in Table 45. White cigarette smokers appear to have somewhat lower blood pressures, but this could be artifactual as it is not reflected in blacks. No significant differences are seen in the analy sis of blood pressures according to work activity.