Monitoring surface and airborne inorganic contamination in the workplace by a field portable X-ray fluorescence spectrometer

Abstract

Assessment of a field-portable energy dispersive X-ray fluorescence spectrometer (PXRFS) was carried out to determine its performance characteristics for direct analysis of surface deposits and airborne inorganic contamination collected on millipore filters. Lower limits of detection (LLDs) determined for 18 elements were found to be below the required sensitivity of analysis, one-tenth of the occupational exposure limit, with the exception of Pb and Cd. Precision of determinations above the LLD indicated that the standard deviation in analysis was less than 10%. Results of PXRFS analyses of millipore filters used in sampling airborne contamination agree well with results obtained by a laboratory-based XRF method. Results of monitoring Pb, Cd, As, Hg, Fe, Mn and Ni contamination on workplace surfaces show good correlation between direct monitoring and surface wipe sampling. Levels of contaminants on workplace surfaces were found to vary between 0 and 1200 μg cm −2 on non-textile surfaces; in office areas up to 1458 μg Cd cm −2 , 862 μg Pb cm −2 and 46 μg Hg cm −2 were found on carpets. The findings indicate that the portable XRF monitor can provide rapid on-site analyses of surfaces, filters and powders and thus play a key role in a cost-effective sampling and analysis strategy.