Silicosis surveillance in Ontario from 1979 to 1992.

This paper reports the detection rates of silicosis among silica-exposed persons first exposed to dust in 1950 or later and still employed in 1979 or later in the province of Ontario. The rate varied strongly with latency, being less than two new cases per 10 000 examinations during the first two decades from first exposure, reaching two new cases per 1000 examinations at 27 years from first exposure, and averaging between two and four new …