Browsing by Author "Rocha, Fernando"
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- Characterization of saline waters from Ria de Aveiro (Portugal) for potential use in SPA treatmentsPublication . Almeida, Lara; Rocha, Fernando; Candeias, CarlaABSTRACT: This study aims to characterize the properties of the saline waters from an old saltpan at the Ria de Aveiro, and assess its potential use in skin treatments. Eight water samples were collected from two different areas of an open-air salt SPA, during four different climatic seasons between 2020 and 2021. Physichochemical parameters of the waters revealed an alkaline pH and high electrical conductivity (EC), mainly in the area where salt production takes place (Area 2). Chemical analysis revealead an enrichment in potentially toxic elements (PTEs), namely Cu and Cr6+, in samples of Area 2, collected in the summer. MEV-EDE analysis of the total suspended matter (TSM) showed the presence of NaCl cubic particles, microorganisms (e.g., diatoms) and particles enriched in PTEs. The low concentrations of PTEs does not pose a risk to SPA users, allowing these waters to be used as a liquid phase in SPA treatments for skin diseases.
- Diferenças na intensidade de alteração química de sedimentos Pliocénicos a norte e sul do MondegoPublication . Oliveira, Álvaro; Dinis, Pedro A.; Rocha, FernandoProcede-se a uma análise comparativa de características mineralógicas e geoquímicas (elementos maiores), usadas na definição de intensidade de altyeração química, de sedimentos pliocénicos colhidos na margem Atlântica a norte e sul do rio Mondego. Ainda que se note alguma influência da granulometria dos sedimentos nas características composicionais, as unidades a norte do Mondego revelam sempre alteração química menos intensa que as unidades a sul do Mondego. Estas diferenças justificam-se por proveniência distinta e não devem ter qualquer significado climático.
- Dust Characterization and Its Potential Impact during the 2014-2015 Fogo Volcano Eruption (Cape Verde)Publication . Candeias, Carla; Ávila, Paula Freire; Alves, Célia; Gama, Carla; Sequeira, Cristina; Silva, E. Ferreira da; Rocha, FernandoABSTRACT: Fogo (Fogo Island) is the youngest and most active volcano of Cape Verde. The last eruption occurred in 2014-2015. Aiming to assess the dust sources that impacted the air quality during the present study period, fresh lava samples were collected, while Saharan dust intrusions and transport were modeled. Rooftop dust was also collected on the island dwellings and a mineralogical and chemical characterization was undertaken. Air quality monitors were used to obtain concentrations of atmospheric particulate matter (PM) and gaseous pollutants. The mineralogical constitution was assessed by XRD and Electron Microprobe. The pseudototal chemical concentration was performed by XRF, ICP-MS and SEM; the latter includes particles morphology. During the study, WRF-CHIMERE results showed the intrusion of desert dust which affected the air quality. Lava was classified as tephritic to basanitic, with high potassium content. The Pollution Load Index for rooftop dust was > 1 in all samples, suggesting an enrichment. Higher values were found in dust size fraction < 63 mu m, with contamination factor pointing to high enrichment of As, Ni and Pb, and very high enrichment of Cd. The non-carcinogenic hazard estimated for children suggested that health problems may arise. The carcinogenic risk was above the target risk, mostly due to As > Pb > Co. Ingestion was the main exposure route. PM10 concentrations exceeded the 24-h mean of 50 mu g/m(3) recommended by WHO. Nevertheless, TVOCs displayed levels lower than guidelines. The highest levels of CO2 were recorded in more populated villages and farthest from the volcano.
- Geochemical, mineralogical and morphological characterisation of road dust and associated health risksPublication . Candeias, Carla; Vicente, Estela; Tomé, Mário; Rocha, Fernando; Ávila, Paula Freire; Alves, CéliaABSTRACT: Road dust resuspension, especially the particulate matter fraction below 10 mu m (PM10), is one of the main air quality management challenges in Europe. Road dust samples were collected from representative streets (suburban and urban) of the city of Viana do Castelo, Portugal. PM10 emission factors (mg veh(-1) km(-1)) ranging from 49 (asphalt) to 330 (cobble stone) were estimated by means of the United Stated Environmental Protection Agency method. Two road dust fractions (<0.074 mm and from 0.0074 to 1 mm) were characterised for their geochemical, mineralogical and morphological properties. In urban streets, road dusts reveal the contribution from traffic emissions, with higher concentrations of, for example, Cu, Zn and Pb. In the suburban area, agriculture practices likely contributed to As concentrations of 180 mg kg(-1) in the finest road dust fraction. Samples are primarily composed of quartz, but also of muscovite, albite, kaolinite, microcline, Fe-enstatite, graphite and amorphous content. Particle morphology clearly shows the link with natural and traffic related materials, with well-formed minerals and irregular aggregates. The hazard quotient suggests a probability to induce non-carcinogenic adverse health effects in children by ingestion of Zr. Arsenic in the suburban street represents a human health risk of 1.58 x 10(-4).
- Geochemistry and mineralogy of Pliocene clay deposits from West Portugal : provenance signals?Publication . Oliveira, Álvaro; Dinis, Pedro A.; Rocha, Fernando
- Geosciences research mapping for Portugal in the year 2023: standing and future challengesTavares, Alexandre; Rocha, Fernando; Dinis, Pedro; Pereira, AlcidesABSTRACT: This study carries out a mapping of research topics in geosciences within the context of Portugal for the year 2023. The data for this analysis are sourced from 11 Research Centres and 4 other entities whose missions include research as their main objective. A bibliometric analysis is performed using the SCOPUS database for a sample of 103 researchers, with data collected in May 2023. A focus group is used, qualitatively assessing advanced or specialized knowledge about geoscience research in Portugal. Future constraints and challenges were highlighted, particularly with regard to changing research priorities and access to research funding. Guidelines for research in geosciences are presented from an ex-post point of view and in accordance with the instruments and research focuses in the European Union, namely those foreseen for Horizon 2030. The discussion raises ex-ante questions for the consolidation of geosciences in research centers and the expansion of knowledge to be produced by researchers.
- House dusts of a volcanic island: potential impacts on human healthPublication . Candeias, Carla; Ávila, Paula Freire; Cunha, Leandro; Sequeira, Cristina; Rocha, FernandoABSTRACT: Fogo island (Cape Verde), has an active volcano that last erupted in 2014-15, with melts mainly alkaline, of basanitic to tephritic composition. Dwellings dust composition is the result of natural and anthropogenic interactions. Nineteen house dusts were collected, in representative dwellings all over the island. Fractions < 2 mm was analyzed by ICP-MS, XRF and XRD and SEM for chemical, mineralogical, and morphological characterization. Mineral phases revealed several minerals linked to the volcanic origin. Iron mean concentration in soils, is above the 2014-105 eruption lava mean. Potentially toxic elements were below Acceptable Values (AV), e.g., As 0.6 to 3.3 mg/kg, except once sample 111 mg/kg (AV = 20 mg/kg); Cd, 0,5-3.6 mg/kg (AV = 3 mg/kg). Elements Ni and V presented concentrations above AV in all samples. But is Ti with concentrations much above AV. Risk assessment (USEPA) found As and Ni over the car cinogenic target Risk in most samples, while systemic toxicity in children is mostly due to Fe, V and Zr concentrations. Higher particles concentration is > 50 µm in diameter, suggesting that bioaccessible fraction might not be high, thus, reducing risk.
- Introducing "UrbanEnviron@Lisbon 2008" a GIS-platform for environmental and human health data managementPublication . Patinha, Carla; Reis, Amélia; Silva, Eduardo Ferreira da; Dias, Ana; Bartolomeu, Sofia; Sousa, António; Cachada, Anabela; Batista, Maria Joao; Prazeres, Cátia; Rocha, Fernando; Costa, Cristiana; Sequeira, Cristina; Terroso, Denise; Figueira, Rui; Sérgio, Cecília; Salgueiro, Rita; Neves, Orquídea; Duarte, Armando
- Investigating the hydrothermal activity at Fogo volcano (Cape Verde) using geochemical analyses of soil samplesCandeias, Carla; Rocha, Fernando; Dumont, Stéphanie; Maineult, Alexis; Ramalho, Ricardo; Madeira, José; Antunes, JoãoABSTRACT: Characterizing hydrothermal systems at volcanoes is particularly important as they play a crucial role in controlling eruptive dynamics. On the long term, hydrothermal systems participate in the geochemical alteration of both rocks and soils, through hydrolysis, dissolution, mineral precipitation, and secondary mineralization contributing in the gradual destabilization of volcanic structures. Fogo volcano (Cape Verde) is the most active volcano in he eastern Atlantic. It features a fumarolic field and passive degassing in its summit crater. A total of 65 soil samples were collected and analyzed, 4 years after the 2014-2015 eruption, in the area surrounding the volcanic edifice including the last eruptive vent with the main objective of detecting and identifying the geochemical and mineralogical signature of hydrothermal activity. Preliminary results show that soil samples were enriched in Ca, Cu, Co, Fe, Na, P, and Ti, when compared to 2014-2015 lava flows, which is confirmed by principal component analysis. Distribution of geochemical elements clearly reflects the mineral phases and is discussed together with geophysical data to shed the light on hydrothermal processes taking place at Pico do Fogo.
- Metal(loids) bioaccessibility in road dust from the surrounding villages of an active minePublication . Candeias, Carla; Ávila, Paula Freire; Silva, Ferreira Da; Rocha, FernandoABSTRACT: Human activities, in general, cause a significant impact on the environment and human health. The present study aims to characterize the road dust of villages located near an active mine and to assess metal(loids) bioaccessible fractions. From the collected road dust samples (<250 µm fraction), the pseudo total, gastric (G) and gastrointestinal (GI) phase (UBM assay) concentrations, mineralogical composition, enrichment factor (EF), and risk for humans were determined. The obtained results revealed that arsenic represents the highest risk to humans, with mean pseudototal values higher than the maximum reference value range. The enrichment factor pointed to As as having significant to very high enrichment in all of the villages. In addition, Cd presented the maximum EF values in all of the villages, and was thus classified as having a very high enrichment. Particles enriched in As, Ca, Fe, Cu, Al, and Ti were identified by SEM-EDS in weathered agglomerates, and were linked to mine wastes and long-distance transport through both wind and/or traffic. The arsenic bioaccessibility fraction (%BAF) presented low values in the studied samples, possibly because of the low complex solubility of Fe with adsorbed As, limiting the release of arsenic and reducing its bioaccessibility. The concentrations of bioaccessible Cd for the G and GI phases were within the reference range, while for Cu, they were above and for Pb they were lower than the reference value range. The results show that the pseudototal fraction risk is overestimated when compared with BAF%; nevertheless, the total G and GI risks were above the carcinogenic target risk (1 × 10−6) in most of the samples. The carcinogenic risk of the bioaccessible contaminants showed that As represented the higher risk for developing cancer over a lifetime, with ingestion being the main risk route.