Deposition of airborne particles onto the human eye: wind tunnel studies of the deposition velocity onto the eyes of a mannequin

Abstract

In the field of occupational hygiene much consideration is devoted to the uptake through the human airways, but there are also reports of irritations, complaints and hazards or potential hazards due to particle deposition onto the eyes. There is a need for data regarding the dependence of the deposition rate on particle size and environmental parameters in order to formulate sampling criteria and to find dose-response relations. The deposition of airborne particles onto the human eye was studied by making use of a dummy, the eyes of which were covered with pieces of transparent sticky foil. The dummy was exposed to airborne particles in a wind tunnel. The airborne particle concentration was simultaneously measured using an Aerodynamic Particle Sizer (APS, TSI Inc., U.S.A.). The deposited particles were counted using an optical microscope equipped with an image analyser. For the particle sizes (2–30 μm), wind velocities (0.5 and 1.0 m s −1), wind directions (0, 90 and 180°) and turbulence intensities (1.3 and 19%) employed in this study, deposition velocities onto the eyes were determined to be in the range of 0.001–1 cm s −1.