k0-INAA performance in the measurement of filters sampled in an industry with high loadings of metals

Foundry industry has important environmental and occupational health impacts. More information is needed to properly assess occupational health risks presented by this industrial sector. This works aims at (1) characterizing the workers exposure to particulate matter in the foundry industry using k0-Instrumental Neutron Activation Analysis (k0-INAA) and Particle-Induced X-Ray Emission (PIXE) and (2) identifying some weakness of the k0-INAA technique when high concentrations of particulate matter and metals are involved. Filters were collected in a foundry industry which processes Pb and were analysed by k0-INAA and PIXE. In INAA, the incomplete deposition of gamma-rays in the germanium crystal due to Compton scattering elevated the spectra baseline, thus increased the background, and hindered the identification of some photopeaks. The problem was particularly important due to the high Sb contents existing in the sampled filters. The application of the Compton Suppression System for the analysis of these filters was successfully used in order to ascertain potential improvements on the detection limits for Zn and Fe. Results obtained showed that in this foundry industry workers were exposed to high concentrations of Pb, Sb, Fe, Sn, As, Ni, Br, Na and Cl.