SILICA AND PROGRESSIVE SYSTEMIC-SCLEROSIS (SCLERODERMA) - EVIDENCE FOR WORKERS COMPENSATION POLICY

The occurrence of several confirmed cases of progressive systemic scle rosis (scleroderma) among male miners prompted a request by a member o f the provincial parliament (MPP) of Ontario that the industrial Disea se Standards Panel (IDSP) evaluate the evidence for an occupational co nnection. A number of publications in reputable peer-reviewed medical journals offer case-control evidence gathered over four decades on thr ee continents showing a rather clear-cut relationship between occupati onal exposure to crystalline silica and scleroderma. This article summ arizes the evidence for a causal relationship and describes the proces s by which the members of the panel, using the criteria developed by S ir Austin Bradford Hill as a guide, made a finding of probable connect ion, the term mandated by the Workers' Compensation Act of Ontario. It provides insight into the difficulties encountered by those setting o ccupational disease policy when scientific certainty is unobtainable. (C) 1996 Wiley-Liss, Inc.