Measurement of fine and ultrafine dusts exposure in an iron foundry in South Australia

Abstract

Exposure to airborne crystalline silica and other atmospheric contaminants in foundries is a well recognised hazard. However, the ultrafine dust component in foundry environments has been poorly characterised and there is increasing concern regarding cardio-respiratory disease risks. At present, no generic exposure criteria exist for ultrafine particles which may arise from hot processes, grinding and combustion. Fine and ultrafine airborne particle concentrations in a large ferrous foundry were measured over a period of four days using a contour mapping approach, as well as some personal sampling. Number and gravimetric concentrations in various regions were assessed with direct reading instrumentation on a trolley (P-Trak, DustTrak and HandiLaz multichannel particle counter). There was considerable variability in daily results probably reflecting process conditions and sources (such as core shop, furnace area pouring line, barrel line and fettling shop). The highest five-minuted average ultrafine concentration was recorded in the core shop (GM = 2.11×105 pt/cc), with lower values recorded in the pouring line, shakeout and fettling areas. Similar trends were seen for PM2.5 with highest values again in the core shop (GM = 0.3 mg/m3). The highest respirable quartz concentration was found in the shakeout area (0.1 mg/m3). In general, airborne dust was well controlled by enclosure and LEV. These results are generally consistent with the literature and suggest that contour mapping for ultrafine particles is an appropriate strategy for more specific evaluation of sources and dust control systems.