Three-Year Study of Markers of Oxidative Stress in Exhaled Breath Condensate in Workers Producing Nanocomposites, Extended by Plasma and Urine Analysis in Last Two Years

Our plain-English summary of Three-Year Study of Markers of Oxidative Stress in Exhaled Breath Condensate in Workers Producing Nanocomposites, Extended by Plasma and Urine Analysis in Last Two Years, by D. Pelclova, V. Zdimal, M. Komarc, et al (Nanomaterials, 2020).

The study

• Authors: D. Pelclova, V. Zdimal, M. Komarc, J. Schwarz, J. Ondracek, L. Ondrackova, M. Kostejn, S. Vlckova, Z. Fenclova, S. Dvorackova, L. Lischkova, P. Klusackova, V. Kolesnikova, A. Rossnerova, T. Navratil
• Journal: Nanomaterials
• Published: 2020;10(12)
• Cited by: 23 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Human data concerning exposure to nanoparticles are very limited, and biomarkers for monitoring exposure are urgently needed. In a follow-up of a 2016 study in a nanocomposites plant, in which only exhaled breath condensate (EBC) was examined, eight markers of oxidative stress were analyzed in three bodily fluids, i.e., EBC, plasma and urine, in both pre-shift and post-shift samples in 2017 and 2018. Aerosol exposures were monitored. Mass concentration in 2017 was 0.351 mg/m3 during machining, and 0.179 and 0.217 mg/m3 during machining and welding, respectively, in 2018. In number concentrations, nanoparticles formed 96%, 90% and 59%, respectively. In both years, pre-shift elevations of 50.0% in EBC, 37.5% in plasma and 6.25% in urine biomarkers were observed. Post-shift elevation reached 62.5% in EBC, 68.8% in plasma and 18.8% in urine samples. The same trend was observed in all biological fluids. Individual factors were responsible for the elevation of control subjects' afternoon vs. morning markers in 2018; all were significantly lower compared to those of workers. Malondialdehyde levels were always acutely shifted, and 8-hydroxy-2-deoxyguanosine levels best showed chronic exposure effect. EBC and plasma analysis appear to be the ideal fluids for bio-monitoring of oxidative stress arising from engineered nanomaterials. Potential late effects need to be targeted and prevented, as there is a similarity of EBC findings in patients with silicosis and asbestosis.

In plain English

This follow-up study of research workers at a plant producing nanocomposite materials did not study asbestos. In 2017 and 2018 the authors measured eight markers of oxidative stress (chemical damage to body molecules) in exhaled breath condensate, blood plasma and urine. Workers were sampled before and after a 2.5 to 3.5 hour workshop session. Control subjects not employed in dusty workplaces were also sampled. There were 20 workers and 20 controls in 2017, and 21 workers and 18 controls in 2018. Most airborne particles counted during work were nanoparticles, and workers used no respiratory protection. Markers in breath condensate and plasma were often higher in workers than in controls and often rose after the shift. Urine showed fewer significant differences. In 2018, some control markers in breath condensate and plasma also rose in the afternoon but stayed significantly lower than workers' post-shift levels. Lung function did not differ between groups. The authors concluded that the marker elevation stayed roughly stable over three years. Asbestos appears only as a comparison: the authors noted that breath condensate findings resemble those in patients with silicosis and asbestosis, citing earlier work.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Follow-up study of exposed workers and control subjects, with biological samples taken before and after a work shift in 2017 and 2018, building on a 2016 study of the same plant
• Who was studied: Research workers at a nanocomposites research plant and control subjects from the same location who were not employed in dusty workplaces. In 2017 there were 20 workers and 20 controls; in 2018 there were 21 workers and 18 controls; 17 workers took part in both years.
• Exposure: Workplace aerosols from machining nanocomposites (epoxide resin with nanoSiO2 filler, and in 2017 also recycled carbon fiber filler) and from welding. Total mass concentration was 0.351 mg/m3 during machining in 2017, and 0.179 mg/m3 (machining) and 0.217 mg/m3 (welding) in 2018. No asbestos exposure was studied.
• Main results:
  • Nanoparticles made up 96% of particles by number during machining in 2017, and 90% (machining) and 59% (welding) in 2018
  • Workers used no personal respiratory protection in the workshops
  • In 2017, all eight post-shift breath condensate markers in the workers were higher than in the control subjects
  • In 2018, all eight breath condensate markers in the workers increased after the shift compared with before the shift
  • In 2018, four afternoon breath condensate markers rose in the control subjects, but they remained significantly lower than the workers' post-shift levels
  • In 2018, all post-shift plasma marker levels in the workers were significantly higher than the control subjects' afternoon plasma samples
  • Urine samples showed fewer significant differences than the other fluids; in 2018, worker urine levels were mostly higher than control levels, but the difference was not significant
  • The post-shift effect in the workers was reported as most pronounced in breath condensate (81.3%), less in plasma (68.8%) and least in urine (18.8%)
  • Combining all three years (29 workers pre-shift, 39 controls), seven of eight breath condensate markers differed significantly between workers and controls; 3-nitrotyrosine was the exception
  • In 2017 and 2018 lung function did not differ between workers and controls, and no post-shift decrease was found
• The authors' conclusion: The authors concluded that the elevation of oxidative stress markers in the nanocomposite workers stayed more or less stable over three years in breath condensate, showing neither a cumulative effect nor adaptation, and that plasma and urine results supported this
• Limitations the authors state:
  • Small number of workers and control subjects, which may explain why some differences were not significant
  • Static air measurements may not reflect each worker's actual exposure
  • An unexplained rise in half of the markers in control subjects in 2018
  • Effects of time of day could not be fully excluded

Topics

Medical terms in this study, explained in our Lexicon: Oxidative Stress, Biomarker, Silicosis.

Related studies

• Increased 8-isoprostane, a marker of oxidative stress in exhaled breath condensate in subjects with asbestos exposure — D. Pelclová, Z. Fenclová, et al. (2008)
• Oxidative stress markers in exhaled breath condensate in lung fibroses are not significantly affected by systemic diseases — D. Pelclová, Z. Fenclová, et al. (2011)
• Leukotrienes B4, C4, D4 and E4 in the exhaled breath condensate (EBC), blood and urine in patients with pneumoconiosis — D. Pelclová, Z. Fenclová, et al. (2012)
• Increased alveolar nitric oxide concentration and high levels of leukotriene B(4) and 8-isoprostane in exhaled breath condensate in patients with asbestosis — H. Lehtonen, P. Oksa, et al. (2007)
• Use of exhaled breath condensate to investigate occupational lung diseases — M. Corradi, P. Gergelova, et al. (2010)
• Next Generation Sequencing for miRNA Detection on the Exhaled Breath Condensate: A Pilot Study — R. Cherchi, R. Cusano, et al. (2023)

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