Suchergebnisse

Abstract
Throughout their whole life cycle from production to waste disposal, nanomaterials (NMs) and nano-enabled products (NEPs) are in contact with humans by different exposure routes and may induce adverse health effects. After oral exposure they may give rise to local or even systemic toxic effects associated to their dissolution behaviour, intestinal absorption or by being trapped into the gastrointestinal barrier Safe and sustainable-by-design (SSbD) interventions to reduce or mitigate NM/NEP risks along their life cycle have been suggested in the last years. However, no clear physico-chemical (PC) properties modulating the hazard by the oral route have been identified. Based on published practical examples of successful SSbD strategies, key PC properties determining the technical function of the NM in the NEP as well as those modified by the SSbD intervention are identified. In addition, oral IATAs from the GRACIOUS project are used to identify which PC properties could be relevant to determine the fate of NMs/NEPs after oral exposure. A further literature search on the specific NM/NEP may help to unravel the relationships among key PC properties and associated mechanisms of hazards.
This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 862419.

| openaire: EC/H2020/788489/EU//BioELCell Funding Information: The work in this manuscript was supported by the Finnish Work Environment Fund [Project No. 117146]. OJR and MI acknowledge funding support from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant agreement No 788489, "BioElCell"). Funding Information: The authors would like to thank UPM Kymmene Oy for supplying the bleached sulfite birch dissolving pulp. The processing of cell samples for TEM analyses was outsourced to the Electron Microscopy Core Unit of the University of Helsinki. Publisher Copyright: © 2022, The Author(s). ; Background : Cellulose nanofibrils (CNFs) have emerged as a sustainable and environmentally friendly option for a broad range of applications. The fibrous nature and high biopersistence of CNFs call for a thorough toxicity assessment, but it is presently unclear which physico-chemical properties could play a role in determining the potential toxic response to CNF. Here, we assessed whether surface composition and size could modulate the genotoxicity of CNFs in human bronchial epithelial BEAS-2B cells. We examined three size fractions (fine, medium and coarse) of four CNFs with different surface chemistry: unmodified (U-CNF) and functionalized with 2,2,6,6-tetramethyl-piperidin-1-oxyl (TEMPO) (T-CNF), carboxymethyl (C-CNF) and epoxypropyltrimethylammonium chloride (EPTMAC) (E-CNF). In addition, the source fibre was also evaluated as a non-nanosized material. Results : The presence of the surface charged groups in the functionalized CNF samples resulted in higher amounts of individual nanofibrils and less aggregation compared with the U-CNF. T-CNF was the most homogenous, in agreement with its high surface group density. However, the colloidal stability of all the CNF samples dropped when dispersed in cell culture medium, especially in the case of T-CNF. CNF was internalized by a minority of BEAS-2B cells. No remarkable cytotoxic effects were induced by any of the cellulosic materials. All cellulosic materials, except the medium fraction of U-CNF, induced a dose-dependent intracellular formation of reactive oxygen species (ROS). The fine fraction of E-CNF, which induced DNA damage (measured by the comet assay) and chromosome damage (measured by the micronucleus assay), and the coarse fraction of C-CNF, which produced chromosome damage, also showed the most effective induction of ROS in their respective size fractions. Conclusions : Surface chemistry and size modulate the in vitro intracellular ROS formation and the induction of genotoxic effects by fibrillated celluloses. One cationic (fine E-CNF) and one anionic (coarse C-CNF) CNF showed primary genotoxic effects, possibly partly through ROS generation. However, the conclusions cannot be generalized to all types of CNFs, as the synthesis process and the dispersion method used for testing affect their physico-chemical properties and, hence, their toxic effects. ; Peer reviewed

Abstract
Airborne micro and nano-plastics (MNPs) have been detected in both indoor and outdoor settings, raising concerns about potential adverse effects upon inhalation. Yet, their potential pulmonary toxicity has not been studied extensively.
Herein, we evaluated the pulmonary toxicity and clearance of nanometric Poly-Ethylene Terephthalate (PET; ~50-200 nm) fragments from plastic bottles and two nanometric polystyrene (PS; 50 and 200 nm) beads. Adult mice were exposed to a unique dose of 50 ug in 30uL/mouse of PET, PS-50, PS-200, or vehicle by pharyngeal aspiration. The lungs, broncho-alveolar lavage fluids (BALF) and lymph nodes were collected at 1, 7 and 28 days after exposure. MNPs presence in lung tissue, accumulation in alveolar cells, and clearance from the alveolar cavity and lungs were assessed using confocal Raman microscopy (CRM). Inflammation and tissue damages were evaluated by histology, immunostaining and ELISA. PET and PS nanoplastics were detected by CRM in lungs and alveolar phagocytes. Evaluation of MNPs elimination and translocation to lymph nodes is underway. Pulmonary exposure to MNPs induced immune cell infiltration respective of MNP type or size. Recruitment of neutrophils at day 1 and eosinophils at day 7 was more pronounced for the PS-50 than for the other two MNPs. Recruitment of lymphocytes was noted at day 7, yet only for PS-50 nm. Potential long-term impact (genotoxicity, fibrosis) is under investigation. These results will inform the design of future chronic low-dose exposure studies, and path the way to new policies about the impact of MNPs on human health.

Air force ground crew personnel are potentially exposed to fuels and lubricants, as raw materials, vapours and combustion exhaust emissions, during operation and maintenance of aircrafts. This study investigated exposure levels and biomarkers of effects for employees at a Danish air force military base. We enrolled self-reported healthy and non-smoking employees (n = 79) and grouped them by exposure based on job function, considered to be potentially exposed (aircraft engineers, crew chiefs, fuel operators and munition specialists) or as reference group with minimal occupational exposure (avionics and office workers). We measured exposure levels to polycyclic aromatic hydrocarbons (PAHs) and organophosphate esters (OPEs) by silicone bands and skin wipes (PAHs only) as well as urinary excretion of PAH metabolites (OH-PAHs). Additionally, we assessed exposure levels of ultrafine particles (UFPs) in the breathing zone for specific job functions. As biomarkers of effect, we assessed lung function, plasma levels of acute phase inflammatory markers, and genetic damage levels in peripheral blood cells. Exposure levels of total PAHs, OPEs and OH-PAHs did not differ between exposure groups or job functions, with low correlations between PAHs in different matrices. Among the measured job functions, the UFP levels were higher for the crew chiefs. The exposure level of the PAH fluorene was significantly higher for the exposed group than the reference group (15.9 ± 23.7 ng/g per 24 h vs 5.28 ± 7.87 ng/g per 24 h, p = 0.007), as was the OPE triphenyl phosphate (305 ± 606 vs 19.7 ± 33.8 ng/g per 24 h, p = 0.011). The OPE tris(1,3-dichlor-2-propyl)phosphate had a higher mean in the exposed group (60.7 ± 135 ng/g per 24 h) compared to the reference group (8.89 ± 15.7 ng/g per 24 h) but did not reach significance. No evidence of effects for biomarkers of systemic inflammation, genetic damage or lung function was found. Overall, our biomonitoring study show limited evidence of occupational exposure of air force ground crew ...

Air force ground crew personnel are potentially exposed to fuels and lubricants, as raw materials, vapours and combustion exhaust emissions, during operation and maintenance of aircrafts. This study investigated exposure levels and biomarkers of effects for employees at a Danish air force military base. We enrolled self-reported healthy and non-smoking employees (n = 79) and grouped them by exposure based on job function, considered to be potentially exposed (aircraft engineers, crew chiefs, fuel operators and munition specialists) or as reference group with minimal occupational exposure (avionics and office workers). We measured exposure levels to polycyclic aromatic hydrocarbons (PAHs) and organophosphate esters (OPEs) by silicone bands and skin wipes (PAHs only) as well as urinary excretion of PAH metabolites (OH-PAHs). Additionally, we assessed exposure levels of ultrafine particles (UFPs) in the breathing zone for specific job functions. As biomarkers of effect, we assessed lung function, plasma levels of acute phase inflammatory markers, and genetic damage levels in peripheral blood cells. Exposure levels of total PAHs, OPEs and OH-PAHs did not differ between exposure groups or job functions, with low correlations between PAHs in different matrices. Among the measured job functions, the UFP levels were higher for the crew chiefs. The exposure level of the PAH fluorene was significantly higher for the exposed group than the reference group (15.9 ± 23.7 ng/g per 24 h vs 5.28 ± 7.87 ng/g per 24 h, p = 0.007), as was the OPE triphenyl phosphate (305 ± 606 vs 19.7 ± 33.8 ng/g per 24 h, p = 0.011). The OPE tris(1,3-dichlor-2-propyl)phosphate had a higher mean in the exposed group (60.7 ± 135 ng/g per 24 h) compared to the reference group (8.89 ± 15.7 ng/g per 24 h) but did not reach significance. No evidence of effects for biomarkers of systemic inflammation, genetic damage or lung function was found. Overall, our biomonitoring study show limited evidence of occupational exposure of air force ground crew personnel to UFPs, PAHs and OPEs. Furthermore, the OH-PAHs and the assessed biomarkers of early biological effects did not differ between exposed and reference groups.