Real-Time, Integrated, and Ergonomic Analysis of Dust Exposure During Manual Materials Handling

Abstract

Past studies have shown that ventilation does not always provide complete dust control during the manual weigh-out and transfer of powders. However, these studies have not shown where the dust emission sources are located. A field study was conducted in a plastics manufacturing plant to evaluate factors affecting worker dust exposure at a ventilated booth which was used for the weigh-out and transfer of powdered materials. A unique study plan was formulated utilizing real-time air sampling and short-term air sampling in conjunction with an ergonomic evaluation to determine activities or factors associated with dust exposure. The factors and activities evaluated were depth of scooping, cleanliness of the workers' clothing, worker anthropometry, and work practices. Realtime air sampling and work cycle evaluation showed that dust concentrations were highest when the worker was scooping material out of the drum, and these levels increased dramatically when the worker placed his breathing zone inside the drum to scoop the powder from the bottom. Short-term dust sampling showed that worker and level of material in the drum significantly affected dust concentrations. Soiled clothing had no effect upon worker dust exposure. Anthropometry and work practices may have significantly affected the worker's dust exposure. This study plan proved to be quite useful and, with some modifications, may be helpful in identifying other types of exposure sources.