Document vQykzjYmXJNMmv3qL3809B4w

PART 12. ASBESTOS EXPOSURE OF NONOCCUPATIONAL GROUPS Mortality Experience of Family Contacts of Asbestos Factory Workers LOU JOUBERT," HERBERT SEIDMAN,* AND IRVING J. SELIKOFF4 "Research Department American Cancer Society New York, New York bDepartment of Community Medicine Ml. Sinai Medical Center New York. New York 10029-6574 Studies linking asbestos to disease began in the early 1900s. Direct exposure to asbestos has been implicated in various diseases, principally mesothelioma, lung cancer, asbestosis, and lung scarring. The risks in all four diseases are closely influenced by dose and duration of asbestos exposure, and they involve long and variable latent periods after initial exposure (20-40 years). Only limited epidemiologic investigations have been undertaken to assess the risks of nonmalignant and malignant disease associated with low levels of expo sure to asbestos dust from living in the same house with an asbestos worker; we refer to those secondarily exposed persons as household contacts. In such cases the worker would typically come home with his clothes covered with asbestos dust, which would then constitute the exposure for the contact person. Since 1975 we have been observing a group of 878 household contacts of workers at UN ARCO Industries, an amosite asbestos factory in New Jersey that was in operation from 1941-1954. The plant produced thermal insulation. All workers still alive in 1978-1980 were contacted and questioned about the persons who lived in his or her household at the time of the exposure. The next of kin of deceased workers were also contacted and questioned about the persons living in the household at the time of his exposure. Street directories were also consulted to verify information. The composition of the subjects in the study was as follows: Number of workers Number of household contacts Number of contacts examined (1973-1976) Alive Dead Traced through January 1990 = 1664 = 4044 = 878 763 115 870 (22%) (99.1%) For all of the household contacts more than 20 years had elapsed from onset of exposure to the time of initial examination. This paper reports the mortality experience of the 115 persons who died among these household contacts examined (Tables 1, 2, and 3). None of the 878 contacts had personal occupational exposure to asbestos. The source of home contamination in individual exposure resulted from dust adhering 416 JOUBERT et al.: MORTALITY OF FAMILY CONTACTS table l. Total Cohort by Length of Exposure of Worker" Length of Exposure No. of Persons Percentage of Cohort No. of Deaths Less than 1 yr 1 yr-5 yr 5+ yr Totals 129 369 64 562 23 66 11 100% 47 55 13 115 For this report we do not have exposure on 201 cases. 417 Percentage of Deaths 41 48 11 100% .table 2 Cancer Deaths (115) by Length of Worker's Exposure Length of Exposure No. of Persons Percentage of Cancer Deaths Percentage of Total Deaths Less than 1 yr 1 yr-5 yr 5+ yr Total 20 16 7 43 47 37 16 100% 17 14 6 37 to workclothes, hair, and shoes. Household exposure started at a relatively early age in this group: Most were 10 to 15 years old. Their deaths occurred between the ages of 70 and 80 (Figs. 1 and 2). The actual intensity of household asbestos contamination and length of expo sure for each family contact is not known, but the data of first employment and duration of employment of the worker are known. Length of employment ranged from one day to 13 years. We observed 115 total deaths, of which 43 were cancer deaths. Death certifi cates were obtained on all cases and coded by death certificate cause only. We NO. OF CASES 763 300 |---------------------------- NO, OF CASES 115 35]--------------------------- 0 10 20 SO 40 SO 60 70 AGE FIGURE 1. Alive householders' fre quency distribution by age at first expo* sure of workers* AGE FIGURE 2. Householder's frequency distribution at age of death. 418 ANNALS NEW YORK ACADEMY OF SCIENCES table 3. Number and Percentage of Deaths for Cancer Sites among Male and Female Household Contacts of Asbestos Factory Workers to January I, 1990 Cancer Site Total Observed Percent All Sites Lung Total digestive organs including stomach, pancreas, esophagus, and colon and rectum Non-Hodgkin's lymphoma Breast Reproductive organs Other kinds of cancer (nonspecified) Pleural mesothelioma 43 12 10 7 4 2 4 4 100 28 23 16 9 5 9 9 have observed that 38% of the deaths to January 1, 1990 were of cancer: mesothe lioma, non-Hodgkin's lymphoma, and cancer of the lung and gastrointestinal tract among others. The national estimated overall percentage is about 22%. Our fig ures were about double that. Therefore, since there is no known safe level of asbestos exposure, we urge that studies of other groups of family contacts be undertaken so that additional data be available to confirm whether such limited asbestos contact is as dangerous as it appears, and whether many more people may be at risk of asbestos-induced cancer than is now anticipated.