Role of metal oxide nanoparticles in histopathological changes observed in the lung of welders

Abstract

BackgroundAlthough major concerns exist regarding the potential consequences of human exposure to nanoparticles (NP), no human toxicological data is currently available. To address this issue, we took welders, who present various adverse respiratory outcomes, as a model population of occupational exposure to NP.The aim of this study was to evaluate if welding fume-issued NP could be responsible, at least partially, in the lung alterations observed in welders.MethodsA combination of imaging and material science techniques including ((scanning) transmission electron microscopy ((S)TEM), energy dispersive X-ray (EDX), and X-ray microfluorescence (μXRF)), was used to characterize NP content in lung tissue from 21 welders and 21 matched control patients. Representative NP were synthesized, and their effects on macrophage inflammatory secretome and migration were evaluated, together with the effect of this macrophage inflammatory secretome on human lung primary fibroblasts differentiation.ResultsWelding-related NP (Fe, Mn, Cr oxides essentially) were identified in lung tissue sections from welders, in macrophages present in the alveolar lumen and in fibrous regions. In vitro macrophage exposure to representative NP (Fe2O3, Fe3O4, MnFe2O4 and CrOOH) induced the production of a pro-inflammatory secretome (increased production of CXCL-8, IL-1ß, TNF-α, CCL-2, −3, −4, and to a lesser extent IL-6, CCL-7 and −22), and all but Fe3O4 NP induce an increased migration of macrophages (Boyden chamber). There was no effect of NP-exposed macrophage secretome on human primary lung fibroblasts differentiation.ConclusionsAltogether, the data reported here strongly suggest that welding-related NP could be responsible, at least in part, for the pulmonary inflammation observed in welders. These results provide therefore the first evidence of a link between human exposure to NP and long-term pulmonary effects.

Assessment of the Lung Toxicity of Copper Oxide Nanoparticles: Current Status

“…However, these broad applications of CuO NPs increase human exposure and, thus, the potential risk related to their short-and long-term toxicity. Andujar et al [84] provided the first evidence of a link between human exposure to metal NPs and long-term pulmonary effects in occupationally exposed welders. However, human pulmonary toxicity or metal fume fever after inhalation exposure to CuO NPs has not been reported in the literature.…”

Airborne Nanoparticle Pollution in a Wire Electrical Discharge Machining Workshop and Potential Health Risks

“…Similarly, it has been proven that welding, with similar local high temperature as in the operation of EDM, generates nanoparticles in high concentrations especially close to the sources (Lee et al, 2007;Pfefferkorn et al, 2010;Gomes et al, 2012;Gomes et al, 2014). However, health risks associated with EDM air pollution are not yet clearly understood (Andujar et al, 2014). Jose et al (2010) evaluated the aerosol exposure of DEDM and showed that the aerosol concentration at breathing zone of the operator was above the permissible limit for repairable particulates (5 mg/m 3 ).…”

Human macrophage responses to metal-oxide nanoparticles: a review

“…In situ studies performed by Andujar et al [55] showed that the chemical ingredient of metal-oxide nanoparticles detected in macrophages presented in the lung tissue of welders, workers commonly exposed to metal fumes, were mainly Fe, Cr and Mn. By analysing THP-1 macrophages (PMA-differentiated cells) in vitro the authors demonstrated that Fe 2 O 3 and alloyed metal oxide MnFe 2 O 4 nanoparticles induce mainly the secretion of pro-inflammatory cytokines TNF-a, IL-1b, CCL-2, CCL-3, CCL-4 and CXCL-9.…”