Document 3b1BpLxRMjX0gk09vgY86y3E

l J\.' >1 .-I M \ r. > . nir.K.r, response rule, even in those exposed to the hcaviest closes. In addition, the response is usually the result of oust, rather than current, expo sures. This poor correlation has led to the current interest in "susceptibility," i.e,, factors account ing for between-subject differences in response. The concept of the dose-response relation ship. insofar as it applies to exposed workers, can be explored only by studies that use epi demiologic techniques and consider all of those at risk. Of what relevance is the concept of doseresponse to a physician dealing with the health problems of an individual patient? In the first place, knowledge of dose-response relationships may provide the answer to why a particular pa tient was-at risk; second, this information may alert the physician to the potential risk to other workers; third, it may have importance in establishing prognosis and determining man agement. Thus, in the detailed descriptions of the various asbestos-related lung diseases that fol low, their relationship to exposure dose, and possible differences in the dose-response rela tionships of the various fiber types will be dis cussed and sututnaii/ed in the final section in terms of the implications to the physician. Significance of Coated and Uncoated Fibers in Clinical Material The presence of ferruginous bodies (so called in this section because positive identification of the fiber core has been undertaken in only a few' of the mote recent studies) or coated fibers in biologic material derived from persons who are occupationally exposed to asbestos has long been recognized as a hallmark of exposure (55). Their presence in routine autopsy material, first reported from Cape Town, South Africa (99), has subsequently been confirmed in many countries, in urban and rural communities, in alt parts of the svorld, in fact, whenever sought (table 5). Prevalence tends to increase with the vigor of the search and depends on the amount TABLE 4 LISTING OF STUDIES* THAT SHOW A DOSE RELATIONSHIP BETWEEN ESTIMATED EXPOSURE * TO ASBESTOS AND BIOLOGIC RESPONSE ^NNsRe*pon*e Measured Years of exposure Years since first exposure Occupation Occupation and duration Fibrosis Lung Bader et at (65) Sluis-Cremer (66) Zedda et at (72) Pleura Selikoff et at (64) Regan et at (70) Harries ef at (75) Sheers and Templeton (76) Selikoff et at (641 Harries et at (75) Sheers and Templeton (76) Meurmart et at (77) Balaam and McCullagh (78) Cumulative dust exposure Jodoin et at (84) McDonald et at (86) Becklake et at (87) Rossiter at at (88) Weill et at (94. 95) Fiber count in pathologic material (electron microscopy) Rossiter et at (88) Cancer Lung Knox et at (67) Don (68) Meurman et at (77) Selikoff er at (6a) Selikoff et at (64) Pleura Newhouse et at (30) Newhouse (29, 71) Berry et at (73J Maneuto and El-Attar (741 Meurman et at (77) Enterline end Kendrick (79) Enterline (80) Enterline and Henderson (81) Newhouse (71) Enterline et at (82, 83) McDonald et at (86) Pooley, F O. (7), p. 222 * Identified by reference number In parentheses. tMinina (66), mining and milling (84-88, 92), manufacturing (29, 30, 64, 94. 95), and secon dary use including removal of old asbestos insulation (64, 65. 75, 76). ( ; i 1 ( 'i *i