Mobilisation of toxic elements in the human respiratory system

• Published in: NUCL INSTRUM METHODS PHYS RES SECT B Vol. 181; no. 1; pp. 499 - 505
• Main Authors: Pinheiro, T., Alves, L.C., Palhano, M.J., Bugalho de Almeida, A.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Elsevier B.V 01.07.2001
• Subjects: Chemical analysis; Mobilisation of elements; Nuclear microprobe; Particles (particulate matter); Particulate matter; Respiratory system; Toxicity; Mobilisation of elements; Nuclear microprobe; Toxicity; Respiratory system; Particulate matter
• ISSN: 0168-583X; 1872-9584
• DOI: 10.1016/S0168-583X(01)00479-7

The fate of respired particles in the respiratory system is inferred through the chemical characterisation of individual particles at the tracheal and bronchial mucosas, and the accumulation of toxic elements in lung alveoli and lymph nodes. The particles and tissue elemental distributions were identified and characterised using micro-PIXE elemental mapping of thin frozen sections using the ITN Nuclear Microprobe facility. Significant particle deposits are found at the distal respiratory tract. Al, Si, Ti, V, Cr, Fe, Ni, Cu and Zn are elements detected at these accumulation areas. The elemental distributions in the different cellular environments of lymph nodes vary. The major compartments for Al, Si, Ti, Fe and Cr are the phagocytic cells and capsule of lymph nodes, while V and Ni are in the cortex and paracortex medullar areas which retain more than 70% of these two elements, suggesting high solubility of the latter in the cellular milieu. The elemental mobilisation from particles or deposits to surrounding tissues at the respiratory ducts evidences patterns of diffusion and removal that are different than those for elements in the respiratory tract. Mobilisation of elements such as V, Cr and Ni is more relevant at alveoli areas where gaseous exchange takes place. The apparent high solubility of V and Ni in the respiratory tract tissue points towards a deviation of the lymphatic system filtering efficiency for these elements when compared to others.