Department of Nanotoxicology and Molecular Epidemiology, Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska, Prague, Czech Republic.
Department of Occupational Medicine, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Na Bojisti, Prague, Czech Republic.
Mutagenesis. 2020 Sep 12;35(4):331-340. doi: 10.1093/mutage/geaa016.
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.
纳米技术和纳米材料的广泛发展给毒理学家提出了许多问题，即纳米颗粒（NP）暴露的潜在健康风险。在这项研究中，我们分析了 20 名长期暴露于工作环境中 NP（18 ± 10 年）的工人的白细胞 DNA 损伤。在轮班前和轮班后采集血样，以评估（i）NP 对 DNA 的慢性影响（预轮班前样本）和（ii）轮班期间暴露的急性影响（预轮班前和轮班后样本之间的差异）。工人的匹配对照样本在轮班前与工人同时采集。肝素化血液在 Ficoll 梯度上分离白细胞。酶修饰彗星试验（DNA 糖基化酶和内切酶 III）表明，与对照组相比，DNA 单链和双链断裂（DNA-SB）以及氧化碱基均显著增加（分别为 2.4×和 2×）。急性暴露进一步增加了 DNA-SB。纳米复合材料的焊接和熔炼比纳米复合材料表面的铣削和研磨具有更高的遗传毒性风险。肥胖似乎是导致 DNA 氧化损伤风险增加的一个因素。该研究于 2017 年 9 月再次进行。结果显示出类似的趋势，但与前一年相比，暴露组的 DNA 损伤水平较低。这可能与纳米材料成分和工作操作变化导致的 NP 暴露降低有关。有必要进一步进行包括个人 NP 暴露监测在内的研究，以确定（i）负责处理纳米复合材料的工人遗传毒性效应的主要气溶胶成分，以及（ii）对 NP 作用反应的性别差异的主要原因。
