Lipid peroxidation metabolites associated with biomarkers of inflammation and oxidation stress in workers handling carbon nanotubes and metal oxide nanoparticles

Abstract

The purpose of this study was to assess the effects of lipid peroxidation with occupational exposure to different types of nanomaterials (NMs). In this cross-sectional study, urine and exhaled breath condensate (EBC) samples were collected from 80 NM-handling workers [30 workers handling nano-titanium oxide (nano-TiO₂), 28 handling nano-silicon dioxide (nano-SiO₂), 22 handling carbon nanotubes (CNTs)], and 69 controls (office workers) from 2010 to 2012. Urinary 8-isoPGF_2α, 2,3 dinor-8-isoPGF_2α, PGF_2α, and EBC 8-iso PGF_2α were measured as lipid peroxidation biomarkers in 2013. A significant positive correlation was found between 8-isoPGF_2α, 2,3 dinor-8-isoPGF_2α, PGF_2α, and total isoprostane in urine. Furthermore, significant positive correlations were noted between EBC 8-iso PGF_2α and urinary 2,3 dinor-8-isoPGF_2α (Spearman correlation r = 0.173, p = 0.035). Exposure to nano-TiO₂ resulted in significantly higher levels of urinary 8-isoPGF_2α, 2,3 dinor-8-isoPGF_2α and PGF_2α, even after controlling for confounding factors. Moreover, significant associations and exposure intensity–response relationships between EBC 8-iso PGF_2α and NMs were observed in workers, whether handling nano-TiO₂, nano-SiO₂, or CNTs. Among them, the significant trends were identified based on the intensity of risk levels. These results provided evidence that exposure to nano-TiO₂, nano-SiO₂, and CNTs may lead to lipid peroxidation in EBC. For routine biomonitoring purposes, this finding, which came through noninvasive methods, may be useful for workers exposed to NMs.

Highlights

1. Data regarding the effects of nano-titanium oxide (nano-TiO₂), nano-silicon dioxide (nano-SiO₂), and carbon nanotubes (CNTs) on lipid peroxidation in workers are limited.

2. 8-Iso PGF_2α in exhaled breath condensate of workers exposed to nanoparticles was higher than that of office workers.

3. Exposure to titanium oxide (TiO₂) and silica (SiO₂) may lead to lipid peroxidation, as indicated by 8-isoPGF_2α, 2,3 dinor-8-isoPGF_2α, and PGF_2α.

4. Examination of lipid peroxidation in EBC has seems to be a useful technique for noninvasive monitoring of workers exposed to nanoparticles.

Keywords:

• Carbon nanotubes
• metal oxide nanomaterials
• 8-iso-prostaglandin F2α
• biomarkers
• LC-MS/MS

Acknowledgments

The authors thank the late Professor Saou-Hsing Liou for initial support and materials, and lab members for feedback and assistance.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Additional information

Funding

This work was supported by two research grants: MOST 109-2113-M-030-003 from the Ministry of Science and Technology, Taiwan, and 01A1-EOSP03-014 from the National Health Research Institutes, Taiwan.