80 research outputs found
Geochemical mapping of Santiago island with a medium/low sampling density
Doutoramento em GeociênciasA ilha de Santiago é a maior do arquipélago de Cabo Verde, apresenta uma área de 991 km2, com um comprimento e largura máximos de 54,9 km e 29 km, respectivamente, e 1392 m de maior altitude. As condições climáticas e a erosão são alguns dos problemas naturais do arquipélago de Cabo Verde. Além disso, a intervenção humana no ambiente superficial revela-se muitas vezes inadequada e com forte impacto. A construção em solos com aptidão agrícola ou florestal, as actividades industriais, a deposição de materiais sólidos ou líquidos de forma inadequada, as práticas agrícolas incorrectas e intensivas, o uso abusivo de pesticidas e fertilizantes, a rega com água contaminada, a sobreexploração de aquíferos que levam muitas vezes à salinização, etc. têm enorme impacto em termos de contaminação de solos, águas superficiais e subterrâneas nas áreas envolventes. Por conseguinte, o conhecimento da variabilidade geoquímica natural é fundamental para a resolução de questões de índole económica, ambiental e de ordenamento do território, médica, e jurídica.
A necessidade de construir uma base de dados de geoquímica georeferenciada que caracterize o ambiente superficial da ilha de Santiago foi a principal motivação para a realização deste estudo. Realizou-se um levantamento geoquímico de 337 amostras de sedimentos de corrente e 249 amostras de solos na ilha de Santiago, tendo sido seguidas as recomendações do Projecto Internacional IGCP 259 não só na fase de amostragem, mas também nas fases seguintes de preparação, análise, tratamento dos dados e elaboração de mapas. Determinaram-se os teores, na fracção < 2 mm, para 36 elementos – 9 elementos maiores (Al, Ca, Fe, K, Mg, Mn, Na, P, Ti) e 27 elementos vestigiais (Ag, As, Au, B, Ba, Bi, Cd, Co, Cr, Cu, Ga, Hg, La, Mo, Ni, Pb, S, Sb, Sc, Se, Sr, Th, Tl, U, V, W, Zn). Efectuou-se ainda a análise textural e estudou-se a composição mineralógica de cerca de 25% das amostras. Analisaram-se, também, 103 amostras de rochas, colhidas nas várias formações da ilha de Santiago, tendo sido determinados os teores de K2O, Na2O, Fe2O3(T), MnO, Sc, Cr, Co, Zn, Ga, As, Br, Rb, Zr, Sb, Cs, Ba, Hf, Ta, W, Th e U e REE, a fim de se fazer uma comparação com os teores destes elementos encontrados nos solos e sedimentos de corrente, averiguando se a sua variação é ou não essencialmente condicionada pela geoquímica da rocha-mãe. Os padrões geoquímicos obtidos através dos mapas de distribuição espacial foram correlacionados com a natureza da rocha mãe, o tipo de solo, e ainda com algumas fontes de contaminação.
A interpretação dos resultados foi realizada não só pela observação dos mapas geoquímicos, mas também após análise estatística dos conjuntos de dados obtidos, e apoiada em informação diversa disponível.
A utilização da Análise de Componentes Principais permitiu distinguir associações entre elementos químicos, quer de origem geogénica quer antropogénica. Foram ainda elaborados mapas de distribuição espacial de vários índices multielementares de importância ambiental, como o Índice de Acidificação Al/(Ca+Mg+K), Índice de Combi, Índice de Avaliação de Risco Ambiental e Índices de Enriquecimento/Contaminação para vários grupos de elementos considerados como “primary pollutant metals”.The island of Santiago is the largest of the Cape Verde archipelago, covering an area of 991 km2 , with a length and width of 54.9 km and 29 km respectively, and reaching an altitude of 1392 m. Climatic conditions and erosion are some of the natural problems of the Cape Verde archipelago. Furthermore, human influence on the surficial environment has often proven to be inappropriate and with a strong impact. The construction on soil fit for agriculture or forestry, the dumping of solid or liquid materials in an inadequate manner, the incorrect and intensive farming practices, the abuse of pesticides and fertilizers, the watering with contaminated water, the over-exploitation of aquifers in a manner that often leads to salinization, and so on, are the cause for countless consequences in terms of contamination of soil and both surface and subterranean water. So the knowledge of the natural geochemical variability is essential for the suitable resolution of economic, environmental, planning, medical and legal issues.
The need for building a database of georeferenced geochemical information that comprises the surficial environment of the island of Santiago was the main motivation for carrying out this study. A geochemical survey of 339 of stream sediment samples and 249 soil samples from the island of Santiago was conducted, following the guidelines of the International Project IGCP 259 not only at the sampling stage, but also in the subsequent stages of preparation, analysis, data treatment and mapping. Levels were determined, in the fraction < 2mm, of 36 elements: 9 major elements (Al, Ca, Fe, K, Mg, Mn, Na, P, Ti) and 27 trace elements (Ag, As, Au, B, Ba, Bi, Cd, Co, Cr, Cu, Ga, Hg, La, Mo, Ni, Pb, S, Sb, Sc, Se, Sr, Th, Tl, U, V, W, Zn). A textural analysis was also carried out, and the mineralogical composition of about 25% of the samples was studied.
A total of 83 rock samples were also from various formations on the island of Santiago were also collected. In order to make a comparison with the element concentrations found in soils and stream sediments, the K2O, Na2O, Fe2O3(T), MnO, Sc, Cr, Co, Zn, Ga, As, Br, Rb, Zr, Sb, Cs, Ba, Hf, Ta, W, Th and U and REE concentrations having been determined in the rock samples.
The geochemical patterns obtained from spatial distribution maps were correlated with the nature of the parent rock, the soil type and also some sources of contamination. The interpretation of the results was carried out not only by analyses of the geochemical maps, but also after statistical analysis of the data gathered, and supported by a wide range of available information. The use of Principal Component Analysis allowed identify associations between chemical elements to be perceived, whether geogenic or anthropogenic in origin.
Spatial distribution maps of various multi-element indices of environmental importance were also drawn up, such as the Al/(Ca+Mg+K) Acidification Index, the Combi Index, the Environmental Risk Assessment Index, and the Enrichment/Comtamination Indices for several groups of elements considered primary pollutant metals.FCT; FSE - SFRH/BD/24791/200
Using elemental concentrations and dust loadings as metrics of human exposure to potentially toxic elements in kindergarten indoor dust
Due to the hand-to-mouth activities frequently observed among the
youngest children, they are likely to ingest higher amounts of indoor dust than
adults. Since pre-schoolers are prone to exposure to potentially toxic elements
(PTEs) through the ingestion route, characterising human exposure within
kindergarten microenvironments is paramount for children who spend
considerable time in school. Ergo, a study encompassing five kindergartens in an
industrial city was performed. Indoor dust samples were collected from the
kindergartens. The present study reports dust metal concentrations and metal
loadings to estimate indoor exposure to PTEs. Total concentrations of chromium
(Cr), cobalt (Co), nickel (Ni), cadmium (Cd), arsenic (As) and lead (Pb) were
determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) in the
of the <63 μm and <250 μm particle size fractions of the indoor dust. The results
show that the elemental loadings vary widely among the different kindergartens
but are consistently higher in the finer dust size fraction. Non-parametric analysis
(Spearman's rank-order correlation) shows strong and significant (p<0.001)
positive correlations between total dust loading - dust elemental loading.
Relatively strong correlations were also obtained between elemental loadings
and elemental concentrations, but the relationship is only significant for Ni and
Pb. The strong correlation (rs= 0.73) between Pb concentration and dust Pb
loading suggests that total dust loading has a greater influence on dust Pb
loading. The results suggest a negligible influence of dust mass over the dust
elemental loading for elements such as Cd, Co, Cr and As
Estimated Background Values of Some Harmful Metals in Stream Sediments of Santiago Island (Cape Verde)
Environmental Risk Assessment Based on High-Resolution Spatial Maps of Potentially Toxic Elements Sampled on Stream Sediments of Santiago, Cape Verde
Geochemical mapping is the base knowledge to identify the regions of the planet
with critical contents of potentially toxic elements from either natural or anthropogenic
sources. Sediments, soils and waters are the vehicles which link the inorganic environment
to life through the supply of essential macro and micro nutrients. The chemical composition
of surface geological materials may cause metabolic changes which may favor the
occurrence of endemic diseases in humans. In order to better understand the relationships
between environmental geochemistry and public health, we present environmental risk maps
of some harmful elements (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, V, and Zn) in the stream
sediments of Santiago, Cape Verde, identifying the potentially harmful areas in this island.
The Estimated Background Values (EBV) of Cd, Co, Cr, Ni and V were found to be above
the Canadian guidelines for any type of use of stream sediments and also above the target values of the Dutch and United States guidelines. The Probably Effect Concentrations (PEC),
above which harmful effects are likely in sediment dwelling organisms, were found for Cr
and Ni. Some associations between the geological formations of the island and the
composition of stream sediments were identified and confirmed by descriptive statistics and
by Principal Component Analysis (PCA). The EBV spatial distribution of the metals and the
results of PCA allowed us to establish relationships between the EBV maps and the
geological formations. The first two PCA modes indicate that heavy metals in Santiago
stream sediments are mainly originated from weathering of underlying bedrocks. The first
metal association (Co, V, Cr, and Mn; first PCA mode) consists of elements enriched in basic
rocks and compatible elements. The second association of variables (Zn and Cd as opposed
to Ni; second PCA mode) appears to be strongly controlled by the composition of alkaline
volcanic rocks and pyroclastic rocks. So, the second PCA mode is also considered as a
natural lithogenic mode. The third association (Cu and Pb; third PCA mode) consists of
elements of anthropogenic origin
Associations between trace elements and cognitive decline: an exploratory 5-year follow-up study of an elderly cohort
Trace elements (TE) homeostasis is crucial in normal brain functioning. Although imbalances have the potential to exacerbate events leading neurodegenerative diseases, few studies have directly addressed the eventual relationships between TE levels in the human body and future cognitive status. The present study aimed to assess how different TE body-levels relate to cognitive decline. This exploratory research included a study-group (RES) of 20 elderly individuals living in two Portuguese geographical areas of interest (Estarreja; Mértola), as well as a 20 subjects neuropsychological control-group (CTR). Participants were neuropsychologically assessed through the Mini Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA) and the RES group was biomonitored for TE through fingernail analysis. After 5 years, the cognitive assessments were repeated. Analyses of the RES neuropsychological data showed an average decrease of 6.5 and 5.27 points in MMSE and MoCA, respectively, but TE contents in fingernails were generally within the referenced values for non-exposed individuals. Higher levels of Nickel and Selenium significantly predicted lesser cognitive decline within 5 years. Such preliminary results evidence an association between higher contents of these TE and higher cognitive scores at follow-up, suggesting their contribution to the maintenance of cognitive abilities. Future expansion of the present study is needed in order to comprehensively assess the potential benefits of these TE.This research was supported by the Portuguese Foundation for Science and Technology (Fundação para a Ciência e a Tecnologia (FCT)) — grants SFRH/BPD/71030/2010, IF/01325/2015, SFRH/BD/146680/2019, and UIDB/04035/2020. Funding for this research was also provided by the Labex DRIIHM, French programme “Investissements d’Avenir” (ANR-11-LABX-0010), which is managed by the ANR
Deposição atmosférica de poeira e níveis de elementos traço numa cidade industrial com clima mediterrânico
This study was performed to examine the influence of an industrial complex, and the high traffic volume associated with it, on the atmospheric dust deposition in a Mediterranean setting. The most frequently used device for collecting total atmospheric wet and dry deposition consists of a funnel connected to a receiving bottle. Two deposition collectors were placed in exterior areas of two schools (Escola Básica Visconde de Salreu and Escola Secundária de Estarreja) located a few km south from the industrial complex of Estarreja. Sample collection was performed from May 2018 to September 2018 on a monthly basis. Soluble untreated samples were analysed for electrical conductivity and anions by ion chromatography.The pseudo-total trace elements content in soluble and insoluble fractions of atmospheric dust deposition were determined by inductively coupled plasma - mass spectrometry (ICPMS). The results obtained suggest similar temporal variation patterns for the deposition flux of soluble copper and zinc and a distinct variation pattern for the atmospheric deposition of insoluble zinc.Este estudo foi realizado para examinar a influência de um complexo industrial, e o elevado volume de tráfego associado, na deposição de poeira atmosférica numa cidade com clima mediterrâneo. O dispositivo comumente utilizado para recolher a deposição atmosférica total consiste num sistema composto por um funil ligado a uma garrafa coletora. Dois sistemas foram colocados nas áreas exteriores de duas escolas (Escola Básica Visconde de Salreu e Escola Secundária de Estarreja) localizadas poucos quilómetros a sul do complexo industrial de Estarreja. A recolha de amostras foi realizada mensalmente de maio de 2018 a setembro de 2018. Nas amostras solúveis não tratadas foi determinada a condutividade elétrica bem como a concentração de alguns aniões por cromatografia iónica. O teor de elementos traço nas frações solúvel e insolúvel da deposição atmosférica de poeiras
foi determinado por ICP-MS. Os resultados sugerem padrões de variação temporal semelhantes para o fluxo de deposição de cobre e zinco solúvel, e um padrão de variação distinto para fluxo de deposição do zinco insolúvel.publishe
Recent Advances on Properties and Utility of Nanomaterials Generated from Industrial and Biological Activities
Today is the era of nanoscience and nanotechnology, which find applications in the field
of medicine, electronics, and environmental remediation. Even though nanotechnology is in its
emerging phase, it continues to provide solutions to numerous challenges. Nanotechnology and
nanoparticles are found to be very effective because of their unique chemical and physical properties
and high surface area, but their high cost is one of the major hurdles to its wider application. So,
the synthesis of nanomaterials, especially 2D nanomaterials from industrial, agricultural, and other
biological activities, could provide a cost-effective technique. The nanomaterials synthesized from
such waste not only minimize pollution, but also provide an eco-friendly approach towards the
utilization of the waste. In the present review work, emphasis has been given to the types of
nanomaterials, different methods for the synthesis of 2D nanomaterials from the waste generated
from industries, agriculture, and their application in electronics, medicine, and catalysis
MAMMALS IN PORTUGAL : A data set of terrestrial, volant, and marine mammal occurrences in P ortugal
Mammals are threatened worldwide, with 26% of all species being includedin the IUCN threatened categories. This overall pattern is primarily associatedwith habitat loss or degradation, and human persecution for terrestrial mam-mals, and pollution, open net fishing, climate change, and prey depletion formarine mammals. Mammals play a key role in maintaining ecosystems func-tionality and resilience, and therefore information on their distribution is cru-cial to delineate and support conservation actions. MAMMALS INPORTUGAL is a publicly available data set compiling unpublishedgeoreferenced occurrence records of 92 terrestrial, volant, and marine mam-mals in mainland Portugal and archipelagos of the Azores and Madeira thatincludes 105,026 data entries between 1873 and 2021 (72% of the data occur-ring in 2000 and 2021). The methods used to collect the data were: live obser-vations/captures (43%), sign surveys (35%), camera trapping (16%),bioacoustics surveys (4%) and radiotracking, and inquiries that represent lessthan 1% of the records. The data set includes 13 types of records: (1) burrowsjsoil moundsjtunnel, (2) capture, (3) colony, (4) dead animaljhairjskullsjjaws, (5) genetic confirmation, (6) inquiries, (7) observation of live animal (8),observation in shelters, (9) photo trappingjvideo, (10) predators dietjpelletsjpine cones/nuts, (11) scatjtrackjditch, (12) telemetry and (13) vocalizationjecholocation. The spatial uncertainty of most records ranges between 0 and100 m (76%). Rodentia (n=31,573) has the highest number of records followedby Chiroptera (n=18,857), Carnivora (n=18,594), Lagomorpha (n=17,496),Cetartiodactyla (n=11,568) and Eulipotyphla (n=7008). The data setincludes records of species classified by the IUCN as threatened(e.g.,Oryctolagus cuniculus[n=12,159],Monachus monachus[n=1,512],andLynx pardinus[n=197]). We believe that this data set may stimulate thepublication of other European countries data sets that would certainly contrib-ute to ecology and conservation-related research, and therefore assisting onthe development of more accurate and tailored conservation managementstrategies for each species. There are no copyright restrictions; please cite thisdata paper when the data are used in publications.info:eu-repo/semantics/publishedVersio
Mammals in Portugal: a data set of terrestrial, volant, and marine mammal occurrences in Portugal
Mammals are threatened worldwide, with ~26% of all species being included in the IUCN threatened categories. This overall pattern is primarily associated with habitat loss or degradation, and human persecution for terrestrial mammals, and pollution, open net fishing, climate change, and prey depletion for marine mammals. Mammals play a key role in maintaining ecosystems functionality and resilience, and therefore information on their distribution is crucial to delineate and support conservation actions. MAMMALS IN PORTUGAL is a publicly available data set compiling unpublished georeferenced occurrence records of 92 terrestrial, volant, and marine mammals in mainland Portugal and archipelagos of the Azores and Madeira that includes 105,026 data entries between 1873 and 2021 (72% of the data occurring in 2000 and 2021). The methods used to collect the data were: live observations/captures (43%), sign surveys (35%), camera trapping (16%), bioacoustics surveys (4%) and radiotracking, and inquiries that represent less than 1% of the records. The data set includes 13 types of records: (1) burrows | soil mounds | tunnel, (2) capture, (3) colony, (4) dead animal | hair | skulls | jaws, (5) genetic confirmation, (6) inquiries, (7) observation of live animal (8), observation in shelters, (9) photo trapping | video, (10) predators diet | pellets | pine cones/nuts, (11) scat | track | ditch, (12) telemetry and (13) vocalization | echolocation. The spatial uncertainty of most records ranges between 0 and 100 m (76%). Rodentia (n =31,573) has the highest number of records followed by Chiroptera (n = 18,857), Carnivora (n = 18,594), Lagomorpha (n = 17,496), Cetartiodactyla (n = 11,568) and Eulipotyphla (n = 7008). The data set includes records of species classified by the IUCN as threatened (e.g., Oryctolagus cuniculus [n = 12,159], Monachus monachus [n = 1,512], and Lynx pardinus [n = 197]). We believe that this data set may stimulate the publication of other European countries data sets that would certainly contribute to ecology and conservation-related research, and therefore assisting on the development of more accurate and tailored conservation management strategies for each species. There are no copyright restrictions; please cite this data paper when the data are used in publications
Educomunicação e suas áreas de intervenção: Novos paradigmas para o diálogo intercultural
oai:omp.abpeducom.org.br:publicationFormat/1O material aqui divulgado representa, em essência, a contribuição do VII Encontro Brasileiro de Educomunicação ao V Global MIL Week, da UNESCO, ocorrido na ECA/USP, entre 3 e 5 de novembro de 2016. Estamos diante de um conjunto de 104 papers executivos, com uma média de entre 7 e 10 páginas, cada um.
Com este rico e abundante material, chegamos ao sétimo e-book publicado pela ABPEducom, em seus seis primeiros anos de existência. A especificidade desta obra é a de trazer as “Áreas de Intervenção” do campo da Educomunicação, colocando-as a serviço de uma meta essencial ao agir educomunicativo: o diálogo intercultural, trabalhado na linha do tema geral do evento internacional: Media and Information Literacy: New Paradigms for Intercultural Dialogue
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