Ultrafine particle emissions and exposure measurement in South Australian workplaces - a pilot study

Abstract

Airborne ultrafine particles (UFPs) are encountered in many working environments and have been associated with a range of potential health risks, including cardio-respiratory disease. However, there are no generic occupational exposure standards for ambient UFPs (less than < 100 nm in diameter) and generally there is a shortage of relevant exposure data. The aim of this pilot study was to assess UFP air concentrations in a range of industrial and commercial workplaces in South Australia. A TSI P-Trak® Ultrafine Particle Counter was used to measure background UFP (range 20 nm ~ 1 μm) levels as well as breathing zone concentrations during selected tasks. Number concentrations in excess of maximum 100,000 particles/cubic centimetre were observed during foundry operations (i.e. furnace operations, coremaking, metal pouring and fettling), office environments (i.e. printing/photocopying with some HP Series colour printers), heavy diesel vehicle maintenance work and welding/grinding processes. Our results demonstrate elevated exposures with certain tasks/equipment compared with background levels. However, background levels in one CBD building appeared to follow peak vehicle traffic patterns, suggesting limited air conditioner filtration performance for UFPs. Where elimination of the UFP source is not feasible, it is recommended that industrial exposure be controlled with local exhaust ventilation. More detailed exposure studies, coupled with health surveys are recommended. Owing to the increasing evidence for health impact, there is a need to develop suitable regulatory guidelines and exposure standards for UFPs based on toxicological information and preventive strategies including evidence from measurements and demonstrated effectiveness engineering and administrative controls.