A report on silica exposure levels in United States foundries.

Is silicosis still a serious threat to foundry workers? Medical and epidemiological information has been scant for the past 30 years. However, several recent surveys of silica dust levels in United States foundries give substantial indication of a continuing exposure hazard. The present research effort was aimed at collecting silica dust exposure data in the foundry environment. OSHA industrial hygiene records were collected from foundry inspections in which air sampling of silica-bearing dusts had been conducted. Two hundred and five foundries supplied 1743 personal air samples. The results present a detailed exposure profile of specific work areas, job titles, type and size of foundry. Based on the results of this and other similar studies reported in the past decade, it appears that silica dust continues to be a serious health hazard to foundry workers. If such is the case, then an epidemiological investigation of the industry should be undertaken to determine a prevalence rate of silicosis. Such a study could provide much needed information on the dose-response relation of silica exposure and silicosis, as well as information with which to reevaluate the adequacy of the current TLV for crystalline-free silica.