Paula F . Avila - Academia.edu (original) (raw)

Papers by Paula F . Avila

Aiming the characterization of road dusts on the surrounding villages of an active mine and to as... more Aiming the characterization of road dusts on the surrounding villages of an active mine and to assess metal(loids) bioaccessible fractions, a dust samples survey was undertaken. To achieve these objectives, pseudototal element concentration, mineralogical composition, Enrichment factor and in vitro extraction UBM assay for both gastric (G) and gastrointestinal (GI) phases, were determined. Results obtained revealed that arsenic represents the higher risk to humans, with mean pseudototal values higher than the maximum reference value range. Enrichment factor points to As significant to very high enrichment in all villages. Particles enriched in As, Ca, Fe, Cu, Al, Ti were identified by SEM-EDS in weathered agglomerates, linked to mine wastes and long-distance transport, both by wind and/or traffic. Arsenic bioaccessibility fraction (%BAF) presents low values in the studied samples, possibly due to low Fe complexes solubility with adsorbed As, limiting arsenic release and reducing its...

Geochemical evaluation for the site characterization of the Cunha Baixa uranium mine in central Portugal

The Sn-W Panasqueira mine, in activity since the mid-1890s, is one of the most important economic... more The Sn-W Panasqueira mine, in activity since the mid-1890s, is one of the most important economic deposits in the world. Arsenopyrite is the main mineral present as well as rejected waste sulphide. The long history is testified by the presence of a huge amount of tailings, which release considerable quantities of heavy metal(loid)s into the environment. This work assesses soil contamination and evaluates the ecological and human health risks due to exposure to hazardous materials. The metal assemblage identified in soil (Ag-As-Bi-Cd-Cu-W-Zn; potentially toxic elements (PTEs)) reflects the influence of the tailings, due to several agents including aerial dispersion. PTEs and pH display a positive correlation confirming that heavy metal mobility is directly related to pH and, therefore, affects their availability. The estimated contamination factor classified 92.6% of soil samples as moderately to ultra-highly polluted. The spatial distribution of the potential ecological risk index classified the topsoil as being of a very high ecological risk, consistent with wind direction. Non-carcinogenic hazard of topsoil, for children (1-6 years),

Fogo (Fogo island, Cape Verde Republic) is the youngest and most active volcano of the archipelag... more Fogo (Fogo island, Cape Verde Republic) is the youngest and most active volcano of the archipelago. The last eruption occurred in 2014–2015. Aiming at studying dust emissions and transport during the eruption period and assessing their impact on air quality and human health, a mineralogical and chemical characterization was undertaken in outdoor dust from all over the island, as well as in the lava resulting from this event. Air quality monitors were used to obtain concentrations of atmospheric particulate matter (PM) and gaseous pollutants. The mineralogical constitution of the samples was analysed by X-ray diffraction and Electron Microprobe, while the chemical characterization was performed through X-ray Fluorescence Spectrometry and ICP-MS. The volcanic rock was found to be tephritic to basanitic, with high potassium content. Several minerals were identified, such as titanian augite with ilmenite, basaltic hornblendes, pyrrhotites, apatites, pyroxenes, basaltic hornblendes and h...

The fogo volcano (Cape Verde) 2014 eruption: impacts on human health

Volcanic eruptions disturb directly and indirectly the ecosystems and the health of the exposed p... more Volcanic eruptions disturb directly and indirectly the ecosystems and the health of the exposed populations. Hazards include, among others, toxic volcanic ashes with diameters <10 μm (PM10). During volcanic eruptions and their immediate aftermath, increased respiratory system morbidity has been observed as well as mortality among those affected by volcanic eruptions. Unfavorable health effects could partly be prevented by timely application of safety measures.N/

Freixeda Mine is part of the Gold-Silver Metalogenetic Province of Iberian Peninsula. These gold ... more Freixeda Mine is part of the Gold-Silver Metalogenetic Province of Iberian Peninsula. These gold and silver deposits are usually associated with Paleozoic quartzits (Ordovician age) and with black schists (Ordovician and Silurian age) and not so often they can be intragranite. Gold ocurrences are associated with veins, stockwerks and silicified masses in metamorphic metasediments, afected by shear zones, thrusts and latter fractures and faults from Variscan Orogeny.

Bulletin of Volcanology, 2019

The last eruption of the Fogo volcano, in the Cape Verde Archipelago, occurred in 2014-2015. A mi... more The last eruption of the Fogo volcano, in the Cape Verde Archipelago, occurred in 2014-2015. A mineralogical and chemical study was undertaken on fumarole incrustations resulting from this event and compared with results obtained from the previous 1995 eruption. The mineralogical constitution of the fumarole deposits was assessed by X-ray diffraction and the chemical characterization was performed through X-ray fluorescence spectrometry with a wavelength dispersive system and by energy dispersive X-ray fluorescence at the European Synchrotron Radiation Facility. The most common compounds/minerals in solid deposits were sulfur, sodium chloride, and calcium sulphates with variable degrees of hydration, sodium sulphate, hydrated sulphates of sodium aluminum, potassium magnesium, or sodium magnesium and a fluorine-bearing mineral. Thenardite (Na 2 SO 4) and its polymorph (phase III) were found simultaneously for the first time in incrustations, to the best of our knowledge. A large span of minor and trace elements present in incrustations (Na,

Atmospheric Research, 2018

An air quality monitoring campaign by passive sampling techniques was carried out, for the first ... more An air quality monitoring campaign by passive sampling techniques was carried out, for the first time, between November 2016 and January 2017 on the Cape Verdean island of Fogo, whose volcanic mountain rises up to 2829 m. Levels of SO 2 and acid gases (HF, HCl, HNO 3 , H 2 SO 4 and H 3 PO 4) were, in most cases, below the detection limits. Alkylpentanes, hexane, cycloalkanes and toluene were the dominant volatile organic compounds. The m,p-xylene/ethylbenzene ratios revealed that air masses arriving at Cape Verde have been subjected to significant aging processes. High toluene/benzene ratios suggested extra sources of toluene in addition to vehicle emissions. Deposition rates of total settleable dust ranged from 23 to 155 mg/m 2 /day. On average, organic carbon accounted for 15.6% of the dust mass, whereas elemental carbon was generally undetected. Minerals comprised the dominant mass fraction. The dust levels were mostly affected by two main airflows: the westerlies and the Saharan Air Layer. These air masses contributed to the transport of mineral dust from desert regions, secondary inorganic constituents (SO 4 2− , NO 3 − and NH 4 +) and tracers of biomass burning emissions, such as potassium. Sea salt represented 12% of the mass of settleable dust. Scanning electron microscope observations of several particles with different compositions, shapes and sizes revealed high silica mass fractions in all samples, as well as variable contents of carbonates, sulphates, aluminosilicates, Fe, Ti, F and NaCl, suggesting that, in addition to the already mentioned sources, dust is likely linked to industrial emissions in the northern and northwestern coast of the African continent. Although some atmospheric constituents presented higher concentrations near the crater, the small fumarolic activity still present after cessation of the eruption in February 2015 has a limited impact on air quality, which is most affected by long range transport and some local sources at specific locations.

Applied Geochemistry, May 1, 2014

The active Panasqueira mine is a tin-tungsten (Sn-W) mineralization hosted by metasediments with ... more The active Panasqueira mine is a tin-tungsten (Sn-W) mineralization hosted by metasediments with quartz veins rich in ferberite. The economic exploitation has been focused on wolframite, cassiterite and chalcopyrite. The mineralization also comprises several sulphides, carbonates and silver sulphosalts. The mining and beneficiation processes produces arsenic-rich mine wastes laid up in huge tailings and open air impoundments that are the main source of pollution in the surrounding area, once the oxidation of sulphides can result in the mobilization and migration of trace metals/metalloids from the mining wastes into the environment, releasing contaminants into the ecosystem. A geochemical survey was undertaken, in order to investigate the environmental contamination impact on agricultural and residential soils in S. Francisco de Assis village due to the mining activities. Rhizosphere samples, vegetables (Solanum tubersum sava and Brassica olerácea L.) which constitute an important part of the local human diet), irrigation waters and road dusts were collected in private residences in S. Francisco de Assis village. According to the Ontario guidelines (Ministry of Environment, 2011), the Arsenic contents in the rhizosphere soils exceed 20 times the reference value for agricultural soils (11 mg kg À1). The result obtained showed that some edible plants frequently used in the region could be enriched in these metals/metalloids and may represent a serious hazard if consumed. The potatoes tend to have a preferential accumulation in the leaves and roots while in cabbages most elements have a preferential accumulation in the roots. An index of the risk for residents, due to ingesting of these metals/metalloids, by consuming vegetables grown around the sampling area, was calculated and the result indicates that the inhabitants of S. Francisco de Assis village are probably exposed to some potential health risks through the intake of arsenic, cadmium and also lead via consuming their vegetables.

Minerals, 2021

Fogo (Fogo Island) is the youngest and most active volcano of Cape Verde. The last eruption occur... more 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, sugges...

Potentially toxic elements dynamics in the soil rhizospheric-plant system in the active volcano of Fogo (Cape Verde) and interactions with human health

CATENA, 2022

Volcanic eruptions disturb directly and indirectly the ecosystems. Direct impact occurs on the so... more Volcanic eruptions disturb directly and indirectly the ecosystems. Direct impact occurs on the soil-plant system with an input of new elements and indirect hazard occurs by consumption of these plants. Fogo island (Cape Verde Republic) has an active volcano and the last eruption occurred in 2014-15, expelling large amounts of materials that spread all over the island. Soils and edible plants were collected all over the island. Pollution indexes reveal contamination in all samples, mostly due to Hg and Ni and with moderate contribution of Co, Cr, Cu and Pb. Mercury is the PTE with higher contribution to the non-carcinogenic hazard quotient, both by soil ingestion and inhalation. Carcinogenic risk exceeds the target risk in all samples with the higher contribution of Ni. Transfer factor from soils to plants decreasing order is Mn > As > Zn > Cr > Cu > Cd > Pb > Ni > Co > Hg, being < 1 except for As and Mn (TF > 1 point to a significant accumulation of elements in edible plants). The hazard risk index and targeted hazard quotient shows that potential negative health outcomes can be induced by As, Cr, Cu, and Zn by consumption of edible plants.

Atmosphere, 2021

Human activities, in general, cause a significant impact on the environment and human health. The... more 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...

Road dust resuspension, especially the particulate matter fraction below 10 µm (PM10), is one of ... more Road dust resuspension, especially the particulate matter fraction below 10 µm (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 e.g. 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 conten...

Environmental monitoring and assessment, 2015

Through the years, mining and beneficiation processes in Panasqueira Sn-W mine (Central Portugal)... more Through the years, mining and beneficiation processes in Panasqueira Sn-W mine (Central Portugal) produced large amounts of As-rich mine wastes laid up in huge tailings and open-air impoundments (Barroca Grande and Rio tailings) that are the main source of pollution in the surrounding area once they are exposed to the weathering conditions leading to the formation of acid mine drainage (AMD) and consequently to the contamination of the surrounding environments, particularly soils. The active mine started the exploration during the nineteenth century. This study aims to look at the extension of the soil pollution due to mining activities and tailing erosion by combining data on the degree of soil contamination that allows a better understanding of the dynamics inherent to leaching, transport, and accumulation of some potential toxic elements in soil and their environmental relevance. Soil samples were collected in the surrounding soils of the mine, were digested in aqua regia, and we...

Mining Activities: Health Impacts

Encyclopedia of Environmental Health, 2011

ABSTRACT Mining is one of the oldest activities in human civilization. Mining industry is a vital... more ABSTRACT Mining is one of the oldest activities in human civilization. Mining industry is a vital economic sector for many countries, but it is also one of the most hazardous activities, both occupationally and environmentally. Mining operations comprise a series of stages involving the discovery and extraction of mineral lying under the surface of the earth. During these processes several toxic wastes are produced and released into the surrounding environment causing pollution of air, drinking water, rivers and soils, changes in topography, hydrogeology, and chemistry of terrestrial and aquatic ecosystems. Mining activities cause several health impacts in miners and communities living near the mine site that may continue to be experienced even when the mine has gone. Abandoned mines are one of the most important issues as they pose a real or potential threat to human safety and health, and an environmental hazard. Numerous initiatives have been made to reduce risk and maximize benefits but much more needs to be done. Laws and regulations need to be improved to better protect the health and safety of people working in, living near, and those otherwise impacted by historic, current, and proposed mines.

Water–Rock Interaction and Geochemical Processes in Surface Waters Influenced by Tailings Impoundments: Impact and Threats to the Ecosystems and Human Health in Rural Communities (Panasqueira Mine, Central Portugal)

Water, Air, & Soil Pollution, 2015

ABSTRACT The present and past mining activity left several abandoned tailings and dams in the Pan... more ABSTRACT The present and past mining activity left several abandoned tailings and dams in the Panasqueira tin-tungsten mining area. Seasonal water samples and stream sediments were collected during two different periods (rainy and dry seasons) and analyzed for a wide range of major and trace elements, in order to define the present hydrochemical situation. Rain waters interact with the altered sulfides stored in the tailings which generate runoff waters with high metal concentrations. The waste material derived from the exploitation enhanced acidification and metal-releasing processes, due to the increase in the specific surface, which favors the oxidation of sulfide minerals. Acid drainage and high metal(loid)s (Cd, Fe, Mn, Zn, Cu, As) concentrations in solution were observed in waters leaching the Panasqueira tailing deposits. In dry season, generally the acidic waters, enriched in metals, evaporate progressively depositing sulfate efflorescences characteristic of acidic environments. The elements distribution in precipitated minerals helps in the interpretation of aqueous geochemical data. Aqueous concentrations may be attenuated by goethite, gibbsite, and/or ferrihydrite precipitation in the oxidation zone through adsorption processes. The use of these waters for human consumption and for irrigation represents a threat to humans as they have a potential carcinogenic risk, especially due to the As concentrations. The acid water precipitation is present on the stream sediments, with concentrations exceeding the toxicity limits. Stream sediments are good receptors of metals and metalloids transported by waters. The enrichment factor values, of heavy metal(loid)s from Casinhas stream and Zêzere river sediments, are extremely high in Ag, As, Cd, and Cu revealing enrichments for these potential toxic elements. I geo values shows that samples are strongly to very strongly polluted for Ag, As, Bi, Cd, and Cu. According to the consensus-based SQGs, 80 % of the samples were classified at the level of great concern and adverse biological effects are to be expected frequently in this area.

Applied Geochemistry, 2014

Procedia Earth and Planetary Science, 2014

Fractionation of Rare Earth Elements (REE) and the accumulation and translocation indexes were me... more Fractionation of Rare Earth Elements (REE) and the accumulation and translocation indexes were measured and determined in the native vegetation [Halimium lasianthum (Lam.) Spach subsp. alyssoides (Lam.) Greuter; Cytisus multiflorus (L'Hér.) Sweet; and Cistus monspeliensis L.; Cistus ladanifer subsp. ladanifer; Lavandula stoechas L.] from the iron mining area of Moncorvo (NE Portugal). There is no correlation between the amounts of REE in rhizosphere and in plants. The REE concentration as the fractionation follows roots>leaves>stems in plants. A slightly enrichment in HREE were found in rhizosphere and plants (roots and stems), whereas the leaves are enriched in LREE. The accumulation and translocation depend of internal complexes ligands. The redox and pH conditions of the rhizosphere conditioned the REE uptake. Greatest bioaccumulation ability of heavy REE (HREE) was found in C. monspeliensis, followed by H. lasianthum that also, has a high capacity of the REE translocation to the aerial parts, contrary to C. monspeliensis. An M-type tetrad effect was determined mainly for HREE (Gd-Ho series) indicating a complexation of REE. The greatest differences in the REE fractionation patterns (mainly for HREE) are observed in stems, as a consequence of the transport function of this organ. Cerium anomaly indicates that the pH and redox conditions affected the uptake of Ce by plants, where the free ionic species are dominated in roots and leaves (positive anomaly), and stems (negative anomaly). Also the Eu-anomaly is greater in roots and leaves than in steams probably by participation in metabolic functions due to similarity with calcium.

Land Degradation & Development, 2010

Land pollution due to past mining activities is a major environmental issue in many European coun... more Land pollution due to past mining activities is a major environmental issue in many European countries. The Aljustrel mine (SW Portugal), located in the western sector of the Iberian Pyrite Belt (IBP) presents a negative visual and environmental impact as a consequence of the mining activity that has developed since the Roman era. Its impacts are also a restraint on the life quality of the population. The exposure of pyrite and other sulphides to air are responsible for the pollution observed in soils, surface water and stream sediments. This paper investigates the pollution load of potential toxic elements in soil samples collected around the Aljustrel mining area. The aim is to assess the levels of soil contamination with respect to average concentrations of toxic elements in the region and to understand the partitioning and availability of pollutants in the area. The results showed severe soil contamination (mainly As, Cd, Cu, Pb and Zn). The concentrations of As (up to 3936 mg kg À1 ) and certain heavy metals (up to 5414 mg kg À1 Cu, 61Á6 mg kg À1 Cd, 20 000 mg kg À1 Pb and 20 000 mg kg À1 Zn) are two orders of magnitude above the regional South Portuguese Zone (SPZ) background values. The median concentrations of As, Cd, Cu, Pb and Zn exceed the values established for world soils, the European Union, Portugal and Andalusia. The results suggest that the distribution patterns of Co, Cr and Ni element concentrations in the Aljustrel area are primarily influenced by the lithology and geochemistry nature of bedrock. The soil background of this geological domain is characterized by relatively high heavy metal contents, essentially derived from the parent rocks.

Journal of African Earth Sciences, 2014

The Panasqueira hydrothermal mineralization, located in central Portugal, is the biggest Sn-W dep... more The 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 beneficiation 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 SO 4 concentration. Melanterite (Fe 2+ (SO 4)Á7(H 2 O)) and minor amounts of rozenite (Fe 2+ (SO 4)Á4(H 2 O)) and szomolnokite (Fe 2+ (SO 4)Á(H 2 O)) were observed on Rio tailing basement.