DSA - Apresentações orais em encontros nacionais
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- Comparative assessment of the acute toxicity of commonly used metal nanoparticles in two in vitro models of human barriersPublication . Pires, J.; Moreira, L.; Teixeira, João; Fraga, SóniaMetal nanoparticles (M-NP) have application in several areas such as industry, environment, agriculture, and biomedicine. Consequently, human exposure to these nanosized materials is increasing, which raises serious concerns regarding their safety to the human health and the environment. Biological barriers are important lines of defence to xenobiotics, thus expected targets for M-NP. The present study investigated the in vitro toxicity of different types of M-NP in two cell models of biological barriers: human intestinal (Caco-2) and trophoblastic (BeWo clone b30) epithelial cells. Cells were exposed for 24 h to varied concentrations (0.8-48 µg/cm2) of M NP of different chemical composition (Au, Ag, TiO2), primary size (10, 30 and 60 nm), capping (citrate, PEG) and crystal structure (rutile, anatase) and toxicity assessed by determining changes in cell morphology, metabolic activity, plasma membrane integrity, generation of intracellular reactive oxygen species (ROS) and intracellular ATP levels. Our data show that the potential toxicity of the tested M-NPs is similar for both cell lines with AgNPs > AuNPs > TiO2NPs, being the effects more visible at higher concentrations. The influence of the size in the cytotoxic-induced effects was more evident for AgNP than for AuNP, with the smaller NP causing more toxicity, being the BeWo cells more sensitive to these M-NP. In addition, PEG-capping effectively attenuated AuNP-induced toxicity both in Caco-2 and BeWo cells. Only cells exposed to AgNP exhibited significant increased levels of ROS. Thus, our data support that the physicochemical properties of the nanomaterials, in this particular case of M-NP, is an important determinant of their cytotoxicity and that intestinal and trophoblastic cells exhibit different sensitivity to the tested M-NP. Future studies would be useful to further explore the effects of M-NP in the human barriers
- In vitro toxicity of ceramic nanoparticles in 3D human airway epithelial culturesPublication . Bessa, Maria João; Brandão, Fátima; Salmatonidis, Apostolos; Vulpoi, Adriana; Viana, Mar; Cassee, Flemming; Fraga, Sónia; Teixeira, João PauloThis study aimed to investigate the in vitro toxicity of engineered (ENP) and airborne ceramic NP in a 3D human bronchial epithelial model (MucilAir™) under air-liquid interface conditions.
- Multiparametric In Vitro Toxicity Assessment of Consumer-relevant Nanomaterials in a Human Placental ModelPublication . Pires, Joana; Moreira, Luciana; Teixeira, João Paulo; Fraga, SóniaThe increasing number of consumer products containing nanomaterials (NM) has raised serious concerns regarding their environmental and human safety. Among the categories of NM of large market volume are metal nanoparticles (M-NP), inorganic non-metallic and carbon-based NM [1]. So far, little is known about the impact of NM exposure on placental development and function. Thus, our study aimed at evaluating the in vitro toxicity of NM of consumer relevance in human trophoblastic BeWo clone b30 epithelial cells, a widely used human placental model. BeWo b30 cells were exposed for 24 h to varied concentrations (0.8-48 µg/cm2) of NM of different chemical composition [Au, Ag, TiO2, SiO2 and graphene oxide (nano_GO)], primary size (10, 30 and 60 nm Au- and AgNP), capping (citrate- and PEGylated AuNP) and crystal structure (TiO2 NP rutile and anatase forms). In vitro cytotoxicity was assessed by determining changes in cell morphology (optical microscopy), metabolic activity (AlamarBlue assay), plasma membrane integrity (LDH release) and intracellular reactive oxygen species (ROS; DCFH-DA assay) and ATP levels (luminescent assay). In vitro genotoxicity (DNA strand breaks and oxidative damage) was assessed by the comet assay. No evident changes in cell morphology were observed after exposure to any tested NM. Overall, NM can be ranked for cytotoxicity as AgNP > nano_GO > AuNP ~TiO2 NP ~ SiO2 NP, being the effects more visible at higher concentrations. Regarding M-NP, the influence of the size in the cytotoxic-induced effects was more evident for AgNP than for AuNP, with the smaller NP causing more cytotoxicity in BeWo b30 cells. PEG capping was an effective protection, preventing the cytotoxic effects that were visible in cells exposed to the tested citrate-capped AuNP. No significant differences between rutile-anatase and anatase TiO2 NP-induced cytotoxicity were observed. Exposure to AgNP and nano_GO significantly increased ROS levels of the exposed cells suggesting that oxidative stress is a possible mechanism underlying their cytotoxicity in BeWo b30 cells. All tested NM significantly increased intracellular ATP levels compared to control cells, except for 10 nm AuNP. No significant changes in both DNA strand-breaks levels and DNA oxidative damage were detected for all tested NM. Our findings highlight the potential hazard associated with human placental exposure to NM, where the physicochemical properties are important determinants of their toxicity. Additional research is needed for a deeper understanding of NM impact on human placental barrier, to unravel their mechanisms of action and the properties responsible for NM-mediated toxicity, and thus support regulatory decisions that protect consumers and ultimately assist in the development of safer NM.
- EQA in Air Microbiology - PNAEQ 2019Publication . Cano, Manuela; Correia, Helena; Pereira da Silva, Susana; Faria, Ana PaulaEQA implemented in 2010; Evaluation of the air sampling and analysis for the quantification of airborne bacteria and fungi: Sampling equipment used; Culture media (2012); Incubation temperature; Evaluation at 2 different sampling points (different 2 rounds per year (summer and winter).
- The Usefulness of Early Effect Biomarkers in Monitoring Occupational Exposure to Hexavalent ChromiumPublication . Afonso, Catarina; Gomes, Bruno Costa; Louro, Henriqueta; Nogueira, Ana; Pinhal, Hermínia; Reis, S.; Ventura, Célia; Ladeira, Carina; Ribeiro, Edna; Santonen, Tiina; Viegas, Susana; Silva, Maria JoãoIntroduction: In the frame of the Project HBM4EU (https://www.hbm4eu.eu/) a biomonitoring study is being conducted across Europe to characterize occupational exposure to hexavalent chromium [Cr(VI)], a recognized human lung carcinogen. Herein we present the results of biomarkers of exposure and effect characterized in a group of workers from a Portuguese aircraft maintenance company, where Cr(VI) replacement is not expected in the near future. Methods: All participants signed an informed consent and responded to a questionnaire to collect contextual information. Cr(VI) exposure was assessed by the analysis of personal air samples; total Cr was measured in urine and blood samples from 50 workers and 26 controls. The effects biomarkers included the alkaline comet assay and the cytokinesis-block micronucleus assay in blood in leukocytes. Results: The concentrations of Cr in the air samples were variable, depending on the activities performed. Noteworthy, workers engaged in painting exterior surfaces with Cr(VI)-reach paints were exposed to the highest Cr(VI) levels. Results from biomonitoring confirmed the occurrence of internal exposure. Furthermore, significantly increased micronuclei frequencies (p < 0.001, Fisher’s exact test) and DNA damage levels were identified in leukocytes from workers comparatively to controls. Interestingly, among the painters showed up a group of 6 workers who were exposed to a mixture of Cr, organic solvents, silica, and other chemicals and who displayed an elevated level of micronucleated cells comparatively to matched controls. Conclusions: An association between Cr(VI) exposure and genotoxicity biomarkers was found, raising concern about a potentially increased cancer risk. Furthermore, these results suggest that the effect biomarkers selected are useful to strengthen the exposure data, in that more exposed or vulnerable groups can be more reliably detected. This is relevant to allow the prioritization of occupational hygiene and risk management measures implementation in the workplace.
- Auditorias à Qualidade do Ar InteriorPublication . Cano, ManuelaA Qualidade do Ar Interior teve avanços significativos durante as décadas anteriores a 2006 e que levaram ao reconhecimento da QAI como um determinante da saúde. Assim, os legisladores entenderam que deveria ser assegurada a Qualidade do Ar Interior: Como garante da saúde e produtividade dos ocupantes; Sem recurso a elevados consumos de energia; Criando condições objetivas de implementação e monitorização.
- Intoxicação por cianobactérias em bovinos: caracterização de um surtoPublication . Menezes, Carina; Nova, Rita; Azevedo, Joana; Vasconcelos, Vítor; Pinto, CarlosSuspeita de hepatoxicidade provocada por cianotoxinas, num surto de morte súbita em 25 bovinos numa exploração com 54 vacas de carne em Almodôvar, Alentejo.
- Risco Químico: Avaliação de Risco e Monitorização AmbientalPublication . Pires, Ana FilipaA presença de agentes químicos no ambiente dos locais de trabalho é uma realidade incontornável, independentemente das áreas de atividade.
- Risco Biológico: Avaliação de Risco e Monitorização AmbientalPublication . Cano, ManuelaComunicação sobre a Avaliação de Risco e Monitorização Ambiental numa perspectiva de gerir as Substâncias Perigosas para Locais de Trabalho Saudáveis.
- Areia da praia e qualidade da água: qual a relação?Publication . Brandão, JoãoComunicação sobre a relação entre a areia da praia e qualidade da água numa perspectiva de promover a saúde pública.