Environmental factors and work performance of foundry workers

Environmental factors such as atmospheric conditions, lighting, noise, and dust in foundry factories of different sizes were evaluated by direct physical measurements and a subjective rating method using an ergonomic checklist. Working postures and subjective feelings of fatigue of the workers were analyzed in various types of foundry shops. The results showed that work load was highly connected with poor working postures and unfavorable arrangement of work space as well as with poor workplace environment, particularly in terms of dust and noise. Forward bending and squatting positions, which were attributable to the manual working height on or just above the floor level, occupied 70--90% of the actual working time handling large-sized casts, while the work using a table allowed workers more frequent erect standing postures. It seemed essential to redesign the fundamental working processes and to improve the work surface height. A comparison was then made as to performance patterns and electromyographic activities of main muscles between the traditional molding work on the floor and the work at a newly developed hydraulic lift-table operated by foot pedals. The new table assured the worker of an optimal standing position and proved to be an effective means of redesigning the work space.