Document KRr8oa9maeb9d8ZvkkrjXV4RQ

utilized >als are ulation e same linic at eligible 75 and ^st 326 of the viewed * were ions or d resiptonits, eroan- rs and Ige of tilized at and Red as ibined >leural of the on the a later jure is sehold i e/she as the >sure" ;r was jsure" jrker. were ibarit. ity of es.4 Anderson et al.\ Household Asbestosis 389 Results In the six-year period 1973-1978, over 3100 household contacts of the 1664 amosite asbestos factory workers were identified. Of that group, 756 are known to be deceased, and of the remaining 2300+, 771 have been examined in our clinics. During 1975-1976, 326 controls were identified. Ninety-two individuals did not meet the criteria set for inclusion in this analysis. Five household contacts and one control are not included in this report because of current medical conditions which are known to cause the types of x-ray abnormalities seen on their radiographs. The use of the ILO U/C Classification would thus be misleading. These included three pleural mesotheliomas, one lymphosarcoma (post radiation and surgical therapy), two cases of sarcoidosis (one in a control). In addition, there were two unreadable, under-exposed films and one examinee refused a chest x-ray. Residence histories were carefully reviewed and individuals who were not actually in residence with the index worker at the time he was actively employed, were placed in a separate category. Thirty-three individuals were placed into this sub group. They resided in the household only after the worker had ceased active employment. Occupational histories taken at the time of examination revealed that 51 Table 1 Occupational Exposures to Asbestos among 756 Household Contacts Occupation Direct asbestos trade Brake repair work Dry wall construction Shipyard work Indirect asbestos exposure Other fibrogenic dust exposure Total Number 19 8 1 6 16 1 51 Abnormal X-ray 7 (37%) 4 (50%) 0 4 (67%) 8 (50%) 0 23 (45%) individuals had potential personal past occupational exposure to asbestos. The distribution of occupations of these individuals and the prevalence of radiographic abnormality is shown in Table 1. Thus, 92 of the 771 examined did not meet the criteria for inclusion in the study, which is limited to the 679 household contacts who had lived in the household of an actively employed amosite asbestos factory worker and who themselves had not had an occupational exposure to asbestos or other fibrogenic dust. The age distribution for the study subjects and the control population showed that the controls were slightly older than the household contacts (mean age 48 compared to 45 in the contacts) (Table 2). The distribution of examined household contacts by the duration of their exposure in the home of an actively employed index worker and by the year that they were first exposed is shown in Table 3. Duration of active employment and presumably concomitant active daily household contamination was less than one year for 28% of those examined. In only 5% was index worker employment, with increasing household contamination, 10 or more years. At the time of their examination, all study participants were more than 20 years from onset of their first asbestos exposure.