Abstract

The objective of the study was to assess employees’ exposure to coal fly ash dust during the replacement of fabric bag filters in bag houses at a power station. Personal and environmental sampling were conducted on a random sample of workers. Samples that were in excess of occupational exposure limits (OEL) for respirable fly ash were analysed for toxic metals. Physical observations and a questionnaire were used to determine awareness of employees on the health effects of coal fly ash dust exposure. The results from personal dust sampling ranged from 20.7 to 477.2 mg/m³ with an average of 101.2 mg/m³. All the results were above the 5.0 mg/m³ legal threshhold specified in the applicable South African legislation. Static dust sampling results ranged from 2.2 to 28.7 mg/m³ with an average of 13.5 mg/m³. Only 8% of the static dust samples were below the OEL for respirable dust (≥ 5mg/m³). Results that were obtained from toxic metal analysis were far below the OEL.  Good awareness by employees regarding the health effects of exposure to coal fly ash and awareness of respiratory zones was also reflected. Control measures are recommended to reduce the exposure risk to fly ash.

Key words: Workers exposure, coal  fly ash, occupational hazards, fabric bag filters.