Control strategies to reduce occupational dust exposure at a mechanical grinding workshop

In this research, real-time changes in dust concentration were monitored at a typical grinding and sealing workshop during actual operation. Results indicated that particle size was between 10.0 and 50.0 µm, and the most abundant elements were Si and Al. The average daily dust exposure value (ADD) was taken as basis when performing the occupational risk assessment. The largest ADD values for the workshop were obtained at heights between 1.5 and 3.0 m. In order to reduce workers exposure to dust, a new type of circulating ventilation and dust removal system was designed. Operation of the new system showed that the shortest response time occurred a ratio of 60.0% of circulating air and 40.0% of fresh air. These data was compared with the ADD obtained under the conventional displacement ventilation system. The results indicated that the new system designed in the present research might significantly improve the environmental quality of the whole workshop (reducing the PM10 concentration in the breathing zone by nearly 9 times) and provide a fast response (reducing the response time to half). The system could provide an efficient measure in reducing hazards in industrial grinding workshops in the future.