Risk Analysis and Public Policy in Relation to Silica Exposure

Abstract

Abstract Crystalline silica, when inhaled occupationally in sufficient concentration of fine particles (respirable size) and duration, was widely identified as a hazard early in this century; some would say much earlier. In spite of the long-term general recognition of lung fibrosis (silicosis) resulting from such exposures in a wide variety of industries, increasingly accurate measurement of airborne crystalline silica, and the establishment of potential for human adverse biological effects by cytotoxicity and animal studies, epidemiologic results from studies of occupationally exposed workers have yielded only limited and variable information on dose–response relationships for silicosis. Adequate risk characterization has, therefore, been slow in evolving, and epidemics of silicosis continue to occur. Workplace standards have been set on the basis of these limited available data, which were reviewed at this conference. In spite of the indicated deficiencies of quantitative estimates of silicosis risk, i...