At present, little is known about the health effects of nanocomposite processing in the workers. In our study, 20 researchers (41.8±11.4 y/o), handling nanocomposites for 17.8±10.0 years were examined pre-shift and post-shift, together with 21 controls (42.7±11.5 y/o). Panels of oxidative stress biomarkers derived from lipids, nucleic acids, and proteins, and markers of inflammation were analyzed in the exhaled breath condensate (EBC). Aerosol exposures were monitored during three nanoparticle generation operations: smelting, welding and nanocomposites machining. Mass concentrations during these operations ranged from 0.120 to 1.840 mg/m3, and median particle number concentrations from 4.8x104 to 5.4x105 #/cm3. Nanoparticles accounted for 40 to 95%, with prevailing Fe and Mn.
Significant elevations were seen in most oxidative stress markers and in several inflammation markers already in the pre-shift samples relative to controls. Significant associations were found between working in nanocomposite synthesis and a majority of EBC biomarkers. Chronic bronchitis was more frequent in researchers and post-shift decrease of lung functions parameters was found.
Conclusion: Researchers in nanocomposite synthesis may be at risk of developing airway disorders with time. From all markers analyzed in EBC, following markers were most robust and could be recommended for preventive examinations: 8-hydroxy-2-deoxyguanosine (8-OHdG) and 5-hydroxymethyl uracil (5-OHMeU) from nucleic acids; o-tyrosine (o-Tyr) and 3-nitrotyrosine (3-NOTyr) from proteins; and malondialdehyde and aldehydes C6-C13 from lipids. Among markers of inflammation, tumor necrosis factor (TNF) and leukotriene B4 appeared to be the most useful.
ACKNOWLEDGEMENTS: GACR 18-02079S, Project 43/17/RPZP, and Progres Q25 and Q29 of the Charles University.
Copper oxide nanoparticles (CuO NP) are commonly used in industry, chemistry, electronic devices and as an antimicrobial agent. Although in vitro tests indicate high potency of this nanomaterial to induce oxidative stress, apoptosis, cell cycle arrest or DNA damage, exact mechanisms of its biological impact are not well understood. In this study we investigated transcriptomic response in mice exposed by inhalation to CuO NP. Female ICR mice (6 animals/group) were exposed to 8x105 CuO NP/m3 for 3 days, 2 weeks, 6 weeks and 3 months; the control animals inhaled clean air. Total RNA was extracted from lungs and whole genome transcriptome analysis was performed using next generation sequencing. The CuO NP inhalation resulted in deregulation of a number of transcripts that tended to increase with the exposure time. We detected 170 (100 upregulated, 70 downregulated), 590 (432 upregulated, 158 downregulated), 534 (409 upregulated, 125 downregulated) and 1551 (898 upregulated, 653 downregulated) deregulated transcripts after 3 days, 2 weeks, 6 weeks and 3 months of inhalation, respectively. Biological processes and pathways affected by CuO NP inhalation differed between 3 days exposure (collagen formation) and longer treatments (immune response). Two weeks exposure further induced apoptotic processes, 6 weeks inhalation affected cell cycle and 3 months treatment impacted processes related to cell adhesion. In summary, inhalation of CuO NP induced significant transcriptomic response already after 3 days exposure. Longer treatment affected a greater number of transcripts and processes mostly related to immunity. ACKNOWLEDGEMENTS: Supported by the Ministry of Education, Youth and Sports CR (LO1508) and the Czech Science Foundation (P503/12/G147).
Many experimental studies have demonstrated the ability of nanoparticles to induce DNA damage and oxidative stress in a number of organs, probably due to the formation of reactive oxygen species. Our knowledge, however, is still limited, especially as regards the persistence of genotoxic effects after long-term exposure to nanoparticles and their health risks.
We decided, therefore, to analyze DNA damage in lymphocytes of workers long-term exposed to nanoparticles due to processing of nanocomposite materials. Exposed group involved 20 employees examined pre-shift and post-shift, samples from 20 controls were taken in the morning. Lymphocytes were isolated from heparinized blood on a ficoll gradient and frozen until further processing. An alkaline comet assay with enzymes of excision DNA repair (Fpg and Endo III) was used to detect DNA damage.
Within the exposed group, the values of total DNA damage in post-shift samples slightly exceed those in pre-shift ones, but the difference was not statistically significant (% tail DNA 4.47 ± 1.43 vs 3.95 ± 1.23, respectively). Compared to controls, however, the workers showed significantly higher levels of genotoxic damage, both in terms of DNA breakage (% tail DNA 3.08 ± 1.04 vs 1.63 ± 0.50, respectively; p<0.0001), and oxidized bases (% tail DNA 0.88 ± 0.41 vs. 0.57 ± 0.25, respectively; p <0.01). Our preliminary results thus indicate that long term occupational exposure to nanoparticles is associated with an increased risk of DNA damage.
ACKNOWLEDGEMENTS: Supported by GA ČR (18-020795) and MŠMT ČR (LO1508).
Nanoparticles are very common materials for many different industries nowadays, because of their special functional properties which are related to specific size, large surface area, shape and ratio of nanoparticles. In this study were chosen three frequently used nanoparticle oxides: ZnO, TiO2, CeO2 and their interactions with bovine serum albumin were studied. All these nanoparticles can easily come in contact with human body and penetrate to circulation system. Bovine serum albumin (BSA) is often used as an ideal model of serum carrier protein. Serum proteins are abundant in the circulatory system and constitutes the majority of the plasma fluid. The interactions of BSA with ZnO, TiO2 and CeO2 were studied by change of zeta potential, and conformational changes by UV-vis spectroscopy and circular dichroism. Nanoparticles were interacted with different concentrations of BSA and resultant zeta potential was observed in different pHs. The best pH for adsorption of each nanoparticle oxide to BSA was determined from these measurements. Measured zeta potential decreased with increasing concentration of BSA in constant concentration of nanoparticle oxides. For BSA + ZnO zeta potential was altered from 23.9 to -11.8 mV, BSA + TiO2 from 10.2 to -16.0 mV and for CeO2 from 26.6 to -23.6 mV. The adsorption of BSA on nanoparticles was complicated for measurements of adsorbed protein amount due to conformational changes in BSA structure. Next measurements were done at circular dichroism where the secondary structure of BSA was observed. There were determined changes of α-helical content in samples in dependence of nanoparticle oxide concentration: BSA + ZnO (23 - 76%), BSA + TiO2 (18 - 75%) and BSA + CeO2 (13 - 71%).
The application of nanopesticides would represent the first intentional diffusive input of engineered nanoparticles into the environment. Yet, knowledge on their environmental fate, behaviour, bioavailability and effects is lacking. Thus, there is an urgent need to increase the fundamental scientific understanding of nanopesticides in the environment. This research is a priority from the perspective of ecosystem and human health and preservation of soil and water quality. On one side, formulation scientists need data how different carrier systems behave in the environment and how they can help designing better pesticide products and optimising the use of pesticides. On other side, risk assessors and regulators need this knowledge to judge between pros and contras of nanoformulated pesticides. Such research is a basis on which nanopesticide regulation and possible commercialization may later be established. This contribution will present new ongoing research project of RECETOX MU which general goal is to increase understanding of the fate, bioavailability, effects and risks of nanopesticides in environmental matrices. For this goal, specific aims will be achieved: 1) to adapt, optimize and verify current methods for the study of nanopesticide fate and effects; 2) to increase understanding of factors and mechanisms of nanopesticide fate, behaviour and bioavailability in soil and water; 3) to elucidate the impact of nanoformulation on pesticide toxicity and risks. After introducing this ongoing research and planned activities, our results of several case studies with nanopesticides will be presented.
This presentation aims to shortly discuss the difference between real risk of nanomaterials and nanotechnologies based on the existing extensive scientific literature and the risk perceived by general population affected by mostly incompetent interpretations of the scientific results by press and other social media. Nanoparticles are not new in our daily life. It is estimated that number of naturally occurring nanoparticles is (NPs) is by orders of magnitude higher than number of those manmade. This indicates that our bodies are to certain extent adapted to NPs exposure. However, engineered NPs, as they possess specific physicochemical properties and are specifically designed, can represent different hazard. For people working in nanotechnologies it is mostly difficult to extract the relevant information on the specific nanomaterial of interest from published toxicity studies. To avoid inadequate conclusions, it is crucial to study the information not only from the Results section of toxicological papers, but first of all from the Methods section. In most cases, mechanistic in vitro toxicity studies are performed at very high doses of NPs. Some adverse effects demonstrated in these studies are misinterpreted by media (press) as real risk for general population, although it will never be exposed to NP doses reported in such studies. There are examples of intentional misuse of published toxicity data for commercial goals. Several examples demonstrating the difference between real and perceived risk will be given. Simultaneously, some suggestions how to minimize this difference will be shown.