Browsing by Author "Teixeira, João Paulo"
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- Acid mine drainage from the Panasqueira mine and its influence on Zêzere River (Central Portugal)Publication . Candeias, C.; Freire Ávila, P.; Silva, E. F; Ferreira, A.; Salgueiro, A. R.; Teixeira, João PauloThe Panasqueira hydrothermal mineralization, located in central Portugal, is the biggest Sn–W deposit of the Western Europe. The main evidences of the mining exploitation and ore treatment operations are testified with huge tailings, mainly, in the Rio and Barroca Grande areas. The mining and benefi- ciation processes, at the site, produces metal rich mine wastes. Oxidation of sulfides tailings and flow from open impoundments are responsible for the mobilization and migration of metals from the mine wastes into the environment. Acid mine drainage (AMD) discharged from Rio tailing has a pH around 3 and high metal concentrations. In Zêzere river, Fe and As are the most rapidly depleted downstream from AMD once As adsorbs, coprecipitate and form compounds with iron oxyhydroxides. The Zêzere river waters are oversaturated with respect to kaolinite and goethite and ferrihydrite can precipitate on stream with a near-neutral pH. At sites having low pH the dissolved Fe species in the water, mainly, occur as sulfate complexes due to a high SO4 concentration. Melanterite (Fe2+(SO4)7(H2O)) and minor amounts of rozenite (Fe2+(SO4)4(H2O)) and szomolnokite (Fe2+(SO4)(H2O)) were observed on Rio tailing basement.
- Adequacy of the standardised in vitro mammalian cell Micronucleus (MN) test for nanomaterials genotoxicity testingPublication . Fernández-Bertólez, Natalia; Rodríguez-Fernández, R.; Lema-Arranz, C.; Pásaro, E.; Brandão, Fátima; Teixeira, João Paulo; Costa, Carla; Valdiglesias, Vanessa; Laffon, BlancaAbout adequacy of the standardised in vitro mammalian cell Micronucleus (MN) test for nanomaterials genotoxicity testing.
- Age-related dose deposition of particulate matter in human respiratory tract: findings from a birth cross-sectional study in PortugalPublication . Madureira, Joana; Slezakova, Klara; Costa, Carla; Silva, Ana Inês; Mendes, Ana; Pereira, Maria do Carmo; Teixeira, João PauloIndoor air pollution remains a great global concern. Particulate matter (PM), namely ultrafine particles (aerodynamic diameter smaller than 0.1 μm; UFP), is considered as one of the most health-relevant air pollutant for various subpopulations, one of which is children. Knowledge on the specific dose deposition of PM may provide a critical link for better understanding of the relationship between individual exposure and the respective health effects. Mathematical models have proven to be important tools for analysing PM dose deposition in the respiratory tract providing relevant data for health risk assessment, source apportionment of human lung burdens and control strategies purposes. This work aimed to estimate the deposition dose of different PM sizes at different age categories. Inhalation dosimetry estimations were carried out using the multiple-path particle dosimetry model (MPPD, v3.04). Age specific 5-lobe model with uniform expansion was adopted in the present study
- Air pollution in urban environments: implications for citizens´healthPublication . Slezakova, Klara; Madureira, Joana; Teixeira, João Paulo; Pereira, Maria do CarmoCurrently, 54% of worldwide population lives in urban areas. While growing urbanization causes environmental pollution and energy demand, it has also adverse implications on health, living conditions and lifestyle habits of the respective citizens. To protect human health, numerous organizations have implemented guidelines to limit environmental pollution, or even proposed recommendation on human activity, but how do these translate to the exposure and risks of the respective population? This work aimed to explore how urban development, using time series data from 2015 to 2018, might influence air quality and potential health risks of citizens living in these zones.
- Air pollution: a public health approach for PortugalPublication . Torres, Pedro; Ferreira, Joana; Monteiro, Alexandra; Costa, Solange; Pereira, Maria Carmo; Madureira, Joana; Mendes, Ana; Teixeira, João PauloAt the global level, several epidemiological studies have conclusively pointed out the associations between short-term exposure to air pollution and acute health effects, and long-term exposure with adverse health effects such as premature mortality from severe respiratory and cardiovascular diseases. This study intended to characterize exposures and their adverse health effects. Three independent sets of vectors were analyzed on a nationwide level and annual basis: air pollutant emissions, ambient air concentrations and health indicators of the period 2009 to 2015. The emissions analysis, for the studied pollutants, pointed out the main findings: (i) Lisbon Metropolitan Area presents the most problematic region with regard to the emissions of all the pollutants under study; (ii) the regions of the Alentejo and Algarve showed reduced emissions of the studied pollutants compared to other parts of the country; (iii) Northern regions PM10 concentrations decreased during the two years in analysis. Regarding the analysis of air quality, it was concluded that: (i) regarding ozone, concentration shown a decreasing trend throughout the country; (ii) nitrogen dioxide and particulate matter, concentrations demonstrated an increasing trend in most of the northern part of the country; (iii) the regions of Alentejo and Lisbon Metropolitan Area showed increasing trends for sulfur dioxide and fine particles for the evaluated period. Decreasing trends in mortality associated with cardiovascular and respiratory causes are found mainly in the Alentejo and Algarve regions. In comparison, the North, Central regions, as well as, Lisbon Metropolitan Area exhibited higher mortality values related to this health indicators.
- Airborne bacteria and fungi in different indoor environments: levels and dose ratesPublication . Paciência, I.; Madureira, J.; Cavaleiro Rufo, J.; Aguiar, L.; Teixeira, João Paulo; Pinto, M.; Moreira, A.; de Oliveira Fernandes, E.The study aimed to: (i) quantify bacteria and fungi concentrations in 4 indoor environments; (ii) identify the recovered fungi; (iii) assess the impact of outdoor bacteria and fungi indoors; and (iv) estimate bacterial and fungal inhalation dose rates in children and elderly. Air samples were collected from 20 primary schools, 68 homes, 9 child day-care centres and 22 elderly care centres, with a microbiological air sampler using TSA and MEA culture media.
- An ECVAG inter-laboratory validation study of the comet assay: inter-laboratory and intra-laboratory variation of DNA strand breaks and FPG-sensitive sites in human mononuclear cellsPublication . Ersson, C.; Møller, P.; Forchhammer, L.; Loft, S.; Azqueta, A.; Godschalk, R.W.; van Schooten, F.J.; Jones, G.D.; Higgins, J.A.; Cooke, M.S.; Mistry, V.; Karbaschi, M.; Phillips, D.H.; Sozeri, O.; Routledge, M.N.; Nelson-Smith, K.; Riso, P.; Porrini, M.; Matullo, G.; Allione, A.; Stepnik, M.; Ferlińska, M.; Teixeira, João Paulo; Costa, S.; Corcuera, L.A.; López de Cerain, A.; Laffon, B.; Valdiglesias, V.; Collins, A.R.; Möller, L.The alkaline comet assay is an established, sensitive method extensively used in biomonitoring studies. This method can be modified to measure a range of different types of DNA damage. However, considerable differences in the protocols used by different research groups affect the inter-laboratory comparisons of results. The aim of this study was to assess the inter-laboratory, intra-laboratory, sample and residual (unexplained) variations in DNA strand breaks and formamidopyrimidine DNA glycosylase (FPG)-sensitive sites measured by the comet assay by using a balanced Latin square design. Fourteen participating laboratories used their own comet assay protocols to measure the level of DNA strand breaks and FPG-sensitive sites in coded samples containing peripheral blood mononuclear cells (PBMC) and the level of DNA strand breaks in coded calibration curve samples (cells exposed to different doses of ionising radiation) on three different days of analysis. Eleven laboratories found dose-response relationships in the coded calibration curve samples on two or three days of analysis, whereas three laboratories had technical problems in their assay. In the coded calibration curve samples, the dose of ionising radiation, inter-laboratory variation, intra-laboratory variation and residual variation contributed to 60.9, 19.4, 0.1 and 19.5%, respectively, of the total variation. In the coded PBMC samples, the inter-laboratory variation explained the largest fraction of the overall variation of DNA strand breaks (79.2%) and the residual variation (19.9%) was much larger than the intra-laboratory (0.3%) and inter-subject (0.5%) variation. The same partitioning of the overall variation of FPG-sensitive sites in the PBMC samples indicated that the inter-laboratory variation was the strongest contributor (56.7%), whereas the residual (42.9%), intra-laboratory (0.2%) and inter-subject (0.3%) variations again contributed less to the overall variation. The results suggest that the variation in DNA damage, measured by comet assay, in PBMC from healthy subjects is assay variation rather than variation between subjects.
- Análise do conforto térmico em estruturas residenciais para idosos em clima atlânticoPublication . Torres, Pedro; Aguiar, Lívia; Pereira, Cristiana; Forcada, Nuria; Tejedor, Blanca; Neves, Maria Paula; Teixeira, João Paulo; Mendes, AnaA esperança média de vida da população mundial tem vindo a aumentar, incrementando a faixa etária acima dos 65 anos. Nesse sentido, determinados ser viços experimentam maior demanda em resposta às necessidades crescentes desta população, como é o caso dos ser viços de cuidados a longo prazo, nomeadamente, centros de dia (CD) e estruturas residenciais para idosos (ERPI). Neste âmbito de ser viços para a comunidade idosa, os parâmetros de qualidade e confor to são apresentados como fatores cruciais para o bem-estar dos utentes/residentes, sendo que o confor to térmico (CT) é um fator determinante na monitorização do bem-estar desta população. Para que os valores ótimos de CT sejam alcançados e mantidos nos edificados com esta tipologia de ser viços, elevados gastos energéticos são despendidos para retificar as condições estruturais dos edifícios. A fim de estruturar um modelo matemático viável que permita definir as características estruturais otimizadas na fase de construção e reabilitação dos edifícios para CD ou ERPI, torna-se necessário analisar o CT dos utentes e prever quais as condições térmicas aceitáveis ou preferenciais para esta população. Este estudo, ainda em curso e integrante do programa ConTerMa, analisa as variáveis de CT na zona climática continental atlântica, monitorizando 8 ERPI e CD situados em 5 concelhos da área metropolitana do Por to, e 5 ERPI e CD na área metropolitana de Barcelona, representativas do clima mediterrânico.
- Are iron oxide nanoparticles safe? Current knowledge and future perspectivesPublication . Valdiglesias, Vanessa; Fernández-Bertólez, Natalia; Kiliç, Gözde; Costa, Carla; Costa, Solange; Fraga, Sonia; Bessa, Maria Joao; Pásaro, Eduardo; Teixeira, João Paulo; Laffon, BlancaDue to their unique physicochemical properties, including superparamagnetism, iron oxide nanoparticles (ION) have a number of interesting applications, especially in the biomedical field, that make them one of the most fascinating nanomaterials. They are used as contrast agents for magnetic resonance imaging, in targeted drug delivery, and for induced hyperthermia cancer treatments. Together with these valuable uses, concerns regarding the onset of unexpected adverse health effects following exposure have been also raised. Nevertheless, despite the numerous ION purposes being explored, currently available information on their potential toxicity is still scarce and controversial data have been reported. Although ION have traditionally been considered as biocompatible - mainly on the basis of viability tests results - influence of nanoparticle surface coating, size, or dose, and of other experimental factors such as treatment time or cell type, has been demonstrated to be important for ION in vitro toxicity manifestation. In vivo studies have shown distribution of ION to different tissues and organs, including brain after passing the blood-brain barrier; nevertheless results from acute toxicity, genotoxicity, immunotoxicity, neurotoxicity and reproductive toxicity investigations in different animal models do not provide a clear overview on ION safety yet, and epidemiological studies are almost inexistent. Much work has still to be done to fully understand how these nanomaterials interact with cellular systems and what, if any, potential adverse health consequences can derive from ION exposure.
- Assessing the in vitro toxicity of airborne (nano)particles to the human respiratory system: from basic to advanced modelsPublication . Bessa, Maria João; Brandão, Fátima; Rosário, Fernanda; Moreira, Luciana; Reis, Ana Teresa; Valdiglesias, Vanessa; Laffon, Blanca; Fraga, Sónia; Teixeira, João PauloSeveral studies have been conducted to address the potential adverse health risks attributed to exposure to nanoscale materials. While in vivo studies are fundamental for identifying the relation-ship between dose and occurrence of adverse effects, in vitro model systems provide important information regarding the mechanism(s) of action at the molecular level. With a special focus on exposure to inhaled (nano)particulate material toxicity assessment, this review provides an over-view of the available human respiratory models and exposure systems for in vitro testing, advan-tages, limitations, and existing investigations using models of different complexity. A brief overview of the human respiratory system, pathway and fate of inhaled (nano)particles is also presented.