The genotoxic effects in the leukocytes of workers handling nanocomposite materials

Abstract

The extensive development of nanotechnologies and nanomaterials poses a number of questions to toxicologists about the potential health risks of exposure to nanoparticles (NP). In this study, we analysed DNA damage in the leukocytes of 20 workers who were long-term exposed (18 ± 10 years) to NP in their working environment. Blood samples were collected in September 2016, before and after a shift, to assess (i) the chronic effects of NP on DNA (pre-shift samples) and (ii) the acute effects of exposure during the shift (the difference between pre- and post-shift samples). The samples from matched controls were taken in parallel with workers before the shift. Leukocytes were isolated from heparinised blood on a Ficoll gradient. The enzyme-modified comet assay (DNA formamido-pyrimidine-glycosylase and endonuclease III) demonstrated a considerable increase of both single- and double-strand breaks in DNA (DNA-SB) and oxidised bases when compared with the controls (2.4× and 2×, respectively). Acute exposure induced a further increase of DNA-SB. The welding and smelting of nanocomposites represented a higher genotoxic risk than milling and grinding of nanocomposite surfaces. Obesity appeared to be a factor contributing to an increased risk of oxidative damage to DNA. The data also indicated a higher susceptibility of males vs. females to NP exposure. The study was repeated in September 2017. The results exhibited similar trend, but the levels of DNA damage in the exposed subjects were lower compared to previous year. This was probably associated with lower exposure to NP in consequence of changes in nanomaterial composition and working operations. The further study involving also monitoring of personal exposures to NP is necessary to identify (i) the main aerosol components responsible for genotoxic effects in workers handling nanocomposites and (ii) the primary cause of gender differences in response to NP action.

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

“…In the year 2018, all eight samples consisted of epoxide resin with nanoSiO 2 filler. As in previous years, the grinders used pink corundum discs containing Al 2 O 3 , Cr 2 O 3 , and Fe 2 O 3 [13,17,18]. The technology of welding on metal surfaces used in the plant did not change during the three years.…”

“…The workers would usually perform the following operations: welding of metal materials, smelting of mixtures containing nano-additives (both in workshop 1), and machining of the produced nanocomposite (workshop 2). These procedures and workplace aerosol measurements have already been documented in detail in our previous papers, evaluating studies carried out in 2016 [13,17,18].…”

“…The measurement of aerosol exposure at the workplace was described in detail in previous reports [13,17,18]. Therefore, only a short summary of our approach is given here.…”

Testing Strategies of the In Vitro Micronucleus Assay for the Genotoxicity Assessment of Nanomaterials in BEAS-2B Cells

“…Studies investigating the biological impacts of occupational exposure to titanium dioxide, iron oxide or multi-walled carbon nanotubes, observed elevated oxidative damage to DNA, lipids and proteins in exhaled breath condensate [ 9 , 10 ] or elevated inflammatory cytokines in sputum samples [ 11 ]. Most recently, differences in DNA methylation pattern, as well as DNA damage after acute and chronic occupational exposure to NMs, were reported [ 12 , 13 ]. Interestingly, the application of cytogenetic methods that allow the detection of DNA breaks, losses and/or rearrangements is rare in the human biomonitoring of NMs exposure.…”

The BlueScreen HC assay to predict the genotoxic potential of fragrance materials

“…The EpiDerm model is a multilayered, differentiated tissue consisting of basal, spinous, granular, and cornified layers resembling the normal human epidermis [ 28 ]. This system has been successfully validated and demonstrated to be sensitive to the genotoxic activity of a large variety of chemicals [ 35 ].…”