Standard chest ILO radiograph of small "s" irregular opacities

This is a standard International Labour Organization (ILO) radiograph demonstrating small irregular opacities of the profusion and type, "3/3" and "s/s", typical for asbestosis. The scale for the concentration of opacities ranges from "0", meaning no opacities, to "3", meaning profuse. The degree of profusion of the irregular opacities in this radiograph is designated "3/3", as the profusion is exactly consistent with "3". If the reader thought the profusion looked mostly like a standard "3", but also considered the possibility that it was consistent with a standard radiograph with a profusion of "2", the profusion would be designated "3/2". The "s" designation refers to opacities with a width of ≤1.5 mm. The ILO description of "s/s" means that all or virtually all of the opacities are width "s".