Toxicity of Vanadium Compounds: Pulmonary and Immune System Targets

Abstract

Inhalation is the most prevalent route of human exposure to insoluble pentavalent vanadium(V) oxides and soluble salts in urban/occupational settings. While initial pulmonary clearance of both soluble and insoluble forms of V is fairly rapid, complete clearance/degree of absorption of any V agent is ultimately a function of its solubility. Nevertheless, there are still several general toxicologic outcomes that arise from lung deposition of various V agents (as pure compounds or Vcontaminated dusts). Workers exposed to V-bearing dusts or fumes display an increased incidence of several lung diseases (e.g., asthma, bronchitis, pneumonia). Similarly, after deposi tion of urban particulate matter (PM) or residual oil fly ash (ROFA), animals develop states of immunomodulation (inflammation, neutrophilic alveolitis, modified resistance to infection) that correlate with the levels of V in the particles. This presentation focused on how general (and in some cases agent-specific) mechanisms have been formulated to explain how entrained V agents induce toxicity and immunomodula tion in the lungs.

Potential mechanisms of some selected heavy metals in the induction of inflammation and autoimmunity

“…2 Several studies reported an incidence increase of innate and adaptive immune cells in numerous lung diseases (such as bronchitis, pneumonia, asthma). 85,86 Grabowski et al 87 reported that exposure of a much higher concentration of rat alveolar macrophages to a vanadium compound (sodium metavanadate) resulted in a general, increased dose-dependent (from 50 μ m ) intracellular ROS generation. This resulted in further activation of NADPH oxidase, sequel to tyrosine phosphorylation of cellular proteins.…”

Harmful Interactions of Non-Essential Heavy Metals with Cells of the Innate Immune System

“…Inhalation is the most prevalent route of human exposure to insoluble pentavalent V oxides and soluble salts in urban/occupational settings. Workers exposed to V-bearing dusts or fumes display an increased incidence of several lung diseases (e.g., asthma, bronchitis, pneumonia) [85]. Exposure to V can also take place through the smoking of cigarettes.…”