Investigation of skin-deposited particulate matter from smelting operations via tape stripping and SEM-EDS

This study investigated the elemental composition and particle size of particulate matter (PM) deposited on the skin from industrial exposure during work in a ferro-silicon smelter using scanning electron microscopy (SEM) analysis combined with energy-dispersive X-ray spectroscopy (EDS). Tape stripping and interception sampling methods were trialed with different tape types. D-squame tape, together with the D-squame applicator instrument, was chosen because it represented a replicable and standardized method allowing SEM analyses to be performed, enabled analyses of deeper skin layers, and had no negative attributes compared to carbon tape when a protocol for imaging non-conductive specimens was used. The underside of the wrist was selected as the sampling site. The observed particle sizes varied from approximately 200 µm to 200 nm. The backscattered electron mode was best adapted to detect particles inside the stratum corneum (SC) due to all detected inorganic compounds giving stronger backscattering than skin. Elemental analysis was obtained by energy-dispersive X-ray spectroscopy. Using the results of 10 repetitive samples from the worker with the most PM exposure, the elemental concentration profiles for Si, Fe, and S in the SC were measured. The elemental concentration showed an exponential decrease during the first four strips, suggesting that most particle penetration is hindered by the first few layers of the SC.