The application of nanomaterials has been rapidly increasing during recent years. Inhalation exposure to nanoparticles (NP) may result in negative toxic effects but there is a critical lack of human studies, especially those related to possible DNA alterations. We analyzed pre-shift and post-shift a group of nanocomposite researchers with a long-term working background (17.8 ± 10.0 years) and matched controls. The study group consisted of 73.2% males and 26.8% females. Aerosol exposure monitoring during a working shift (involving welding, smelting, machining) to assess the differences in exposure to particulate matter (PM) including nanosized fractions <25-100 nm, and their chemical analysis, was carried out. A micronucleus assay using Human Pan Centromeric probes, was applied to distinguish between the frequency of centromere positive (CEN+) and centromere negative (CEN-) micronuclei (MN) in the binucleated cells. This approach allowed recognition of the types of chromosomal damage: losses and breaks. The monitoring data revealed differences in the exposure to NP related to individual working processes, and in the chemical composition of nanofraction. The cytogenetic results of this pilot study demonstrated a lack of effect of long-term (years) exposure to NP (total frequency of MN, P = 0.743), although this exposure may be responsible for DNA damage pattern changes (12% increase of chromosomal breaks-clastogenic effect). Moreover, short-term (daily shift) exposure could be a reason for the increase of chromosomal breaks in a subgroup of researchers involved in welding and smelting processes (clastogenic effect, P = 0.037). The gender and/or gender ratio of the study participants was also an important factor for the interpretation of the results. As this type of human study is unique, further research is needed to understand the effects of long-term and short-term exposure to NP.

中文翻译：

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对职业性接触纳米颗粒的受试者进行的重复细胞遗传学分析：一项初步研究。

近年来，纳米材料的应用正在迅速增加。吸入暴露于纳米颗粒（NP）可能会产生负面的毒性作用，但目前尚缺乏人类研究，尤其是那些与可能的DNA改变有关的研究。我们分析了一组具有长期工作背景（17.8±10.0年）并匹配对照的纳米复合材料研究人员的班前和班后。研究组由73.2％的男性和26.8％的女性组成。在工作班次（包括焊接，熔炼，机械加工）中进行气溶胶暴露监测，以评估暴露于包括<25-100 nm的纳米级颗粒在内的颗粒物（PM）的差异，并对其化学分析进行评估。使用Human Pan Centromeric探针进行微核分析，用来区分双核细胞中着丝粒阳性（CEN +）和着丝粒阴性（CEN-）微核（MN）的频率。这种方法可以识别染色体损伤的类型：损失和断裂。监测数据显示，与个体工作过程相关的NP暴露量和纳米级分的化学组成存在差异。该初步研究的细胞遗传学结果表明，长期（年）暴露于NP缺乏影响（MN的总频率，P = 0.743），尽管这种暴露可能是DNA损伤模式改变的原因（染色体增加了12％）破坏成虫作用）。此外，短期（每日移位）暴露可能是参与焊接和冶炼过程的一组研究人员中染色体断裂增加的原因（生发作用，P = 0.037）。研究参与者的性别和/或性别比也是解释结果的重要因素。由于这种类型的人体研究是独特的，因此需要进一步的研究以了解长期和短期暴露于NP的影响。