Use of SEM/EDX methods for the analysis of ambient particulate matter adhering to the skin surface

Abstract

Background The skin is exposed to numerous particulate and gaseous air pollutants. The ones that need particular attention are the particles that adhere to the skin surface, which can later cause direct skin damage. This study aimed to characterize air pollution (AP) particles adhered to the human skin by using scanning electron microscopy (SEM) combined with X‐ray dispersive energy spectrometry (EDX). Methods Tape stripping was performed from six healthy volunteers exposed to urban AP to collect stratum corneum samples from the cheeks and forehead. The samples were analysed using SEM equipped with EDX system with a silicon drift detector at an accelerating voltage of 20 keV. After the preliminary examination, the particles were located and counted using 1000× magnification. Each particle was analysed, increasing magnification up to 5000× for precise dimension measurement and elemental composition analysis. At least 100 fields or a surface of approximately 1 mm2 were examined. Results Particles adhered to the skin were identified in all samples, with a particle load ranging from 729 to 4525. The average area and perimeter of all particles identified were 302 ± 260 μm2 and 51 ± 23 μm subsequently, while the equivalent circular diameter was, on average, 14 ± 6 μm. The particles were classified into ten groups based on morphology and elemental composition. Chlorides were the most numerous particle group (21.9%), followed by carbonaceous organic particles (20.3%), silicates (18%), carbonates (16.4%), metal‐rich particles (14%), and a minor number of bioaerosols, quartz‐like, and fly ash particles. Conclusion The SEM–EDX analysis provides evidence of the contamination of exposed skin to various airborne PM of natural or anthropogenic origin. This method may provide new insights into the link between exposure to AP and AP‐induced skin damage.

Tear Fluid as a Matrix for Biomonitoring Environmental and Chemical Exposures

“…Nonetheless, SEM/EDX can be used to identify and quantify PM 10 in the tear uid. Quantifying particulate matter on Schirmer strips with SEM/EDX may be comparable to methods utilizing skin wipes, which has been used to assess dermal exposure to particulate matter deposition and to estimate air pollution exposure 38 . Biological markers of particulate matter exposure have yet to be reported in human tear uid; however, a study using rat models found that ocular exposure to titanium oxide nanoparticles (a surrogate for particulate matter exposure) induced a signi cant increase in lactate dehydrogenase (p = 0.039) and mucin protein MUC5AC (p = 0.028) in the tear uid 39 .…”

Study of the Hair Matrix in EDX for the Detection of Heavy Metals in Patients with Cancer and Belonging to the Campania Geographical Area

“…Energy dispersive X-ray spectroscopy (EDX) is a technique used for the elemental analysis or chemical characterization of a sample [4]. As a type of spectroscopy, it is based on the investigation of a sample through the interactions between electromagnetic radiation and matter, analyzing the Xrays emitted by matter in response to impact with charged particles.…”