Diesel particulate filters: Do they work? A study on the efficacy of diesel particulate filters in reducing personal exposure to diesel particulate matter on underground diamond drillers
CCH Australia Limited
School of Medical and Health Sciences
This project was undertaken to assess the effectiveness of diesel particulate filters (DPF) fitted to selected underground heavy vehicles on the exposure of underground diamond drillers and drillers offsiders to diesel particulate matter (DPM) during normal working situations.
Historical data analysed prior to beginning the study demonstrated that the similar exposure group (SEG) at the mine site at the greatest potential risk of exposure to DPM was the underground diamond drillers and drillers offsiders. Data analysed for this project included personal DPM exposure results data collected one year prior to the installation of the DPF and one year post-installation of DPF. The intent of the study was to show a measurable and statistically significant decrease in personal DPM exposure on the workgroup using the Upper Confidence Limit (UCL 1, 95% ) as the indicator.
Pre-filter installation, the UCL 1, 95% of the workgroup was 235% of the occupational exposure limit (OEL), which demonstrates gross non-conformance to the OEL. There was also a demonstrated and significant exposure risk in the workgroup with 85% of all samples collected pre-filter installation above the OEL.
Post-filter installation, the UCL 1, 95% for the workgroup were reduced to 84% of the OEL, which demonstrates conformance to the OEL. Twenty-five per cent of the post-filter readings remained above the OEL, which shows further work is needed, however, a significant shift in the exposure profile of the workgroup has been achieved.
Results of the study have demonstrated a positive relationship between the installation of DPF and a reduction in DPM exposure on the workgroup. Both workgroup exposures and recorded OEL exceedances have reduced as a result of DPF installation.