Abstract
When construction workers use handheld grinders to smooth poured concrete surfaces after forms are stripped, they risk overexposure to respirable dust and crystalline silica. This article examines the performance of a local exhaust ventiliation system for handheld grinders. The system consisted of the grinder (equipped with a ventilated shroud), a length of flexible corrugated hose, and a portable electric vacuum cleaner that acted as the fan and dust collector for the ventilation system (see Figures 1 and 2). Personal breathing zone air samples for respirable dust and crystalline silica were collected during five days of grinding.