Geoquímica e qualidade ambiental de solos urbanos

Mestrado em GeoquímicaOs ecossistemas urbanos representam um elevado consumo de recursos, tendo um efeito insustentável no meio ambiente. Os solos urbanos são utilizados durante o desenvolvimento urbano e necessitam de ser geridos para serem preservados e deste modo manter o seu papel de suporte e aumentar a qualidade de vida. Sendo os solos considerados fontes e acumuladores de poluição é importante desenvolver metodologias para avaliação da qualidade ambiental de solos urbanos como ferramenta de gestão sustentável dos recursos. As zonas urbanas são afectadas por uma enorme variedade de actividades antropogénicas, sendo as mais importantes o tráfego e a indústria. Estarreja é uma importante área industrial situada no noroeste de Portugal, estando o complexo químico localizado apenas aproximadamente a 1 km do centro urbano. Assim, e de modo a obter uma caracterização geral da área de estudo, foram recolhidas informações acerca do clima, topografia, geologia, tipo de solo, dados ambientais (emissões para atmosfera, poluição da água, etc.), planeamento local, população, uso do solo e caracterização da indústria. Os pontos de amostragem foram depois seleccionados com base em fotografias aéreas, mapas de solo e observação no campo. De seguida foram seleccionados alguns indicadores da qualidade de solos urbanos, tendo em conta que um indicador útil para uma gestão sustentável dos solos deve ser sensível a mudanças na gestão. Finalmente, e com ajuda de instrumentos de SIG, foi possível obter uma visualização da variabilidade espacial dos parametros estudados. O estudo de indicadores de qualidade, aliado à informação recolhida inicialmente é essencial como apoio a processos de decisão, permitindo uma melhor sustentabilidade na gestão dos recursos urbanos. Permite ainda uma monitorização das mudanças na qualidade ambiental que ocorrem e definir quais as principais fontes de poluição que afectam os centros urbanos. ABSTRACT: Urban systems represent high turnover of resources, having an effect on the environment in an unsustainable manner. Urban soils are used during urban development and needs to be managed if it is to be preserved and maintained its role in supporting and enhancing the quality of life. Since soil can be considered both as a source and as a sink of pollution, it is important to develop and validate a methodology for the assessment of environmental quality in urban soils, as a tool for sustainable resource management. The urban areas are affected by a wide variety of anthropogenic activities, such as traffic and industry. Estarreja is a very important industrial area ofNorthwest Portugal, being the chemical complex located near (1 km away) the town centre of the urban area also called Estarreja. Therefore, data about the climate, topography, geology, soil type, other environmental data (air emissions, water pollution, etc.), local planning, population (type and distribution), industry characterisation and distribution, land use, transports and energy inputs, were collected in order to have a general characterization of the study area. The sampling sites were chosen based on aerial photographs, soil maps and field observation. Indicators of urban soil quality were then chosen taking into account that as a useful indicator of land management practices sustainability, a soil parameter must respond sensitively to changes in management. Finally GIS tool were used to show spatial variability of contaminant. The main usefulness of this study is the important information for decision-making, allowing a better sustainable resource management in very industrialized urban areas. These results of urban indicators, allied with data collected are essential for sustainable urban planning allowing a more efficient management of resources available as well as an effective control of state changes occurring in the environmental quality of urban ecosystems, particularly in what concerns urban soils. They also allow defining the main causes of pollution affecting urban areas

Organic contaminants in urban soils: major inputs and potential risks

Doutoramento em QuímicaUrban soil quality may be severely affected by hydrophobic organic contaminants (HOCs), impairing environmental quality and human health. A comprehensive study was conducted in two contrasting Portuguese urban areas (Lisbon and Viseu) in order to assess the levels and potential risks of these contaminants, to identify sources and study their behaviour in soils. The concentrations of HOCs were related to the size of the city, with much higher contamination levels observed in Lisbon urban area. Source apportionment was performed by studying the HOCs profiles, their relationship with potentially toxic elements and general characteristics of soil using multivariate statistical methods. Lisbon seems to be affected by nearby sources (traffic, industry and incineration processes) whereas in Viseu the atmospheric transport may be playing an important role. In a first tier of risk assessment (RA) it was possible to identify polycyclic aromatic hydrocarbons (PAHs) in Lisbon soils as a potential hazard. The levels of PAHs in street dusts were further studied and allowed to clarify that traffic, tire and pavement debris can be an important source of PAHs to urban soils. Street dusts were also identified as being a potential concern regarding human and environmental health, especially if reaching the nearby aquatic bodies. Geostatistical tools were also used and their usefulness in a RA analysis and urban planning was discussed. In order to obtain a more realistic assessment of risks of HOCs to environment and human health it is important to evaluate their available fraction, which is also the most accessible for organisms. Therefore, a review of the processes involved on the availability of PAHs was performed and the outputs produced by the different chemical methods were evaluated. The suitability of chemical methods to predict bioavailability of PAHs in dissimilar naturally contaminated soils has not been demonstrated, being especially difficult for high molecular weight compounds. No clear relationship between chemical and biological availability was found in this work. Yet, in spite of the very high total concentrations found in some Lisbon soils, both the water soluble fraction and the body residues resulting from bioaccumulation assays were generally very low, which may be due to aging phenomena. It was observed that the percentage of soluble fraction of PAHs in soils was found to be different among compounds and mostly regulated by soil properties. Regarding bioaccumulation assays, although no significant relationship was found between soil properties and bioavailability, it was verified that biota-to-soil bioaccumulation factors were sample dependent rather than compound dependent. In conclusion, once the compounds of potential concern are targeted, then performing a chemical screening as a first tier can be a simple and effective approach to start a RA. However, reliable data is still required to improve the existing models for risk characterization.A qualidade dos solos urbanos pode ser afetada por contaminantes orgânicos hidrofóbicos (HOCs), prejudicando a saúde ambiental e humana. Este trabalho consistiu em estudar duas áreas urbanas contrastantes (Lisboa e Viseu), com o objetivo de avaliar os níveis de HOCs nos solos e os seus potenciais riscos para a saúde humana e para o ambiente. Pretendia-se ainda identificar as fontes e estudar o comportamento destes contaminantes no solo. Foi possível relacionar as concentrações de HOCs com o tamanho da cidade, sendo os níveis de contaminação muito mais elevados em Lisboa. A identificação das fontes destes contaminantes foi feita através do estudo dos respetivos perfis e da relação com elementos potencialmente tóxicos, utilizando métodos estatísticos multivariados. Lisboa parece ser afetada por fontes próximas (tráfego, indústria e incineração) enquanto em Viseu o transporte atmosférico aparenta ter um papel mais importante. Num primeiro nível da avaliação de risco (RA), foi possível identificar os hidrocarbonetos aromáticos policíclicos (PAHs) nos solos de Lisboa como um perigo potencial. Os níveis de PAHs em poeiras das ruas de Lisboa foram também estudados e permitiram clarificar que o tráfego e os detritos de pneus e de pavimento podem também ser uma importante fonte destes compostos. Utilizaram-se e discutiram-se ferramentas de geoestatística assim como a respetiva utilidade em RA e em planeamento urbano. De modo a obter uma avaliação mais realista dos riscos de HOCs é importante avaliar a fração disponível, que é também a mais acessível para os organismos. Deste modo, foi feita uma avaliação dos processos envolvidos na disponibilidade de PAHs e também dos resultados obtidos pelos diferentes métodos químicos. A adequação dos métodos químicos para prever a biodisponibilidade de PAHs em solos naturalmente contaminados ainda não foi demonstrada, sendo especialmente difícil para os compostos de elevado peso molecular. No presente trabalho também não foi possível estabelecer uma relação significativa entre a disponibilidade química e a biodisponibilidade. No entanto, apesar das elevadas concentrações totais encontradas em alguns solos de Lisboa, tanto a fração solúvel em água como os resíduos acumulados nos ensaios de bioacumulação foram, em geral, muito baixos, o que estará relacionado com os fenómenos de envelhecimento destes contaminantes nos solos. Observou-se que a fração solúvel de PAHs depende do composto em causa e é regulada pelas propriedades do solo. Apesar de não se terem observado correlações entre as propriedades do solo e a biodisponibilidade, observou-se que os fatores de bioacumulação dependem mais da amostra do que do composto. Em conclusão: após a identificação dos contaminantes de interesse uma avaliação química baseada nos teores totais pode ser uma abordagem eficaz no primeiro nível da RA, mas no entanto é necessário melhorar os modelos existentes para a caracterização do risco

THE ENVIRONMENTAL IMPACT OF USING COPPER SULPHATE TO AVOID GRAPEVINE POWDERY MILDEW IN THREE VINEYARDS OF THE DOURO REGION, PORTUGAL

Copper-based fungicides have been used in vineyards throughout the world, for many decades to protect against downy mildew. However, their use results in an accumulation of Cu in surface soils which can potentially impact on the biological health of the soil and could be transported and stored in the sediments deposited close to valley bottoms. In Douro region, northern of Portugal, vineyards are located on steep slopes and are susceptible to accelerated soil erosion. In this study, 50 soils samples were collected in 3 vineyards of different ages, one with more of 50 years, other with more 15 years and one recently planted. Two rivers converge into a water reservoir located close to vineyards. Five samples of stream sediment, pore water and superficial water were collected in the rivers and reservoir. The total Cu (CuT) content in the soils varies between 17.8 and 211 mg/Kg (mean = 79.4 mg/Kg). However in the old vineyard the Cu concentration is higher than in the others (mean value of 144.8 mg/kg). The total Cu content in stream sediments ranges from 19.4 to 35 mg/Kg (mean = 26.1). The average Cu concentration in soils is 3 times higher than in sediments. The solid phase distribution of copper in stream sediments shows that the metal is associated with Fe-Oxyhydroxides and silicates, indicating that most Cu in the sediment has a geogenic source. In sediment pore water the Cu content is always below 2µg/L, with the exception of the sample collected in the reservoir. For superficial waters no Cu was detected. These results suggest that the rate of erosion is low and the contribution of soils Cu in stream sediments is irrelevant. The sediment core was divided in 31 sub-samples and a pore-water sample was extracted when possible. The distribution of CuTalong the profile seems shows a slight increase with depth, with values ranging from 55.3 (surface) to 73.8 mg/Kg. In the pore water, Cu distribution shows an antipathetic patter

Multivariate analysis for assessing sources, and potential risks of polycyclic aromatic hydrocarbons in Lisbon urban soils

Urban soils quality may be severely affected by polycyclic aromatic hydrocarbons (PAHs) contamination, as is the case of Lisbon (Portugal). However, to conduct a risk assessment analysis in an urban area can be a very difficult task due to the patchy nature and heterogeneity of these soils. Thus, the present study aims to provide an example on how to perform the first tier of a risk assessment plan in the case of urban soils using a simpler, cost effective, and reliable framework. Thus, a study was conducted in Lisbon to assess the levels of PAH, their potential risks to the environment and human health, and to identify their major sources. Source apportionment was performed by studying PAHs profiles, their relationship with potentially toxic elements, and general characteristics of soil using multivariate statistical methods. Results showed that geostatistical tools are useful for evaluating the spatial distribution and major inputs of PAHs in urban soils, as well as to identify areas of potential concern, showing their usefulness in risk assessment analysis and urban planning. Particularly, the prediction maps obtained allowed for a clear identification of areas with the highest levels of PAHs (close to the airport and in the city center). The high concentrations found in soils from the city center should be a result of long-term accumulation due to diffuse pollution mostly from traffic (through atmospheric emissions, tire debris and fuel exhaust, as well as pavement debris). Indeed, most of the sites sampled in the city center were historical gardens and parks. The calculation of potential risks based on different models showed that there is a high discrepancy among guidelines, and that risks will be extremely associated with the endpoint or parameters used in the different models. Nevertheless, this initial approach based on total levels was useful for identifying areas where a more detailed risk assessment is needed (close to the airport and in the city center). Therefore, the use of prediction maps can be very useful for urban planning, for example, by crossing information obtained with land uses, it is possible to define the most problematic areas (e.g., playgrounds and schools).This research was funded by FCT (Foundation for Science and Technology), through an individual research grant attributed to A. Cachada (SFRH/BPD/100429/2014), and through the research project URBSOIL-LISBON (PTDC/CTE-GEX/68523/2006). This work was also supported by the Strategic Funding UID/Multi/04423/2013 (CIIMAR), UID/GEO/04035/2013 (GEOBIOTEC), and UID/AMB/50017/2013 (CESAM RU), through national funds provided by FCT (Foundation for Science and Technology), and the European Regional Development Fund (ERDF), in the framework of the PT2020 Partnership Agreement

GRAPEVINE CULTIVATION AND THE GEOCHEMISTRY OF ZINC: IMPACT ON THE ENVIRONMENTAL EQUILIBRIUM OF A VULNERABLE SITE WITHIN THE ALTO DOURO WINE REGION

This study presents preliminary results of a research project that aims assessing the environmental impact of intensive grapevine cultivation in the Alto Douro wine region, a World Heritage Site. A total of 50 soil samples were collected from three nearby vineyards of different ages. Surface drainage of these vineyards discharges into an important water reservoir, the Varosa Dam. The dam collects water from two rivers, the Varosa and the Balsemão Rivers. At the dam, 5 sites were selected to collect water, sediment and sediment pore-water. One sediment core was collected in the middle of the dam as representative of the entire reservoir. The depth of the water column is 80 m and the sediment core has a length of 50 cm. The core was divided and sampled in 31 sections. Core sediment pore-water was extracted at several depths. Anthropogenic zinc is introduced in the vineyard soils through the use of a fungicidal spray. Near total concentrations of zinc in the soils range from 73 to 195 mg kg-1 and the highest values occur in the oldest vineyard. In the sediment samples the concentrations of zinc range from 91 to 120 mg kg-1 and the highest value occurs in the sample collected at the confluence with the Balsemão River. The correspondent pore-water sample has a zinc concentration that is 10 times higher (2210 µg l-1) than that of the other pore water samples. This result indicates that the sediment is probably supplying zinc to the water. The solid-phase distribution study shows that four of the sediment samples have most of the zinc bounded to Fe-oxyhydroxides phases and to the residue. However, the sediment collected in the confluence with the Balsemão River has an important fraction of zinc associated to more labile phases, which may explain why the pore water has such an elevated concentration. Zinc concentration increases with depth in the core sediments but is highly erratic in the correspondent pore-water samples

Long-term application of the organic and inorganic pesticides in vineyards: Environmental record of past use

Areas such as Douro Demarcated Region (Portugal), where vineyards are frequently located on steep slopes of narrow valleys, can be particularly sensitive to runoff and erosion processes. These particular conditions are expected to enhance the transport of pollutants, acting as a potential source of contamination to freshwater systems. The intense vine cultivation in this region includes decades of pesticides application, that have resulted in the accumulation of these chemicals and its degradation products in the vineyards soils and sediments. Residues of several pesticides related to agricultural activities were found in soils, with older vineyards showing higher levels of Cu and banned insecticides (such as DDT). The metabolite 4,4-DDE was the compound found at higher levels in soils and in sediments. The relatively high levels in more recent sediments suggest that soils are still a source of contamination. Levels of currently used pesticides were low, which is related with their physicochemical properties, the application period, and climacteric conditions

OHMi Estarreja: an ecosystem highly anthropized where contamination is the unifying element towards interdisciplinarity

The Estarreja area (North of Portugal) has been subject to intense industrial pollution and host the second largest chemical industry complex in the country, which produced mainly ammonium sulphate, nitric acid and ammonium nitrate, but also synthetic resins. The CNRS’ Human–Environment International Observatory of Estarreja (OHMi Estarreja) aims to study the multiple effects of this industrial activity on the man-environment relationship, considering the temporal dimension, marked by changes in industrial practices. Another OHMi Estarreja originality is that human health projects are being carried out at the local level, under a double geochemical and socio-behavioral approach. Lastly, the Estarreja region is also part of one of the most important wetland ecosystems from Portugal, the Baixo Vouga Lagunar. This area is highly vulnerable and currently faces a set of natural and anthropogenic pressures. The overall interdisciplinary understanding of the risk induced by the chemical complex was possible by several complementary approaches: (a) spatial-temporal evolution of the contamination level, (b) health studies of the Estarreja population, and (c) societal changes in Estarreja area. The results showed a complex relationship between industrial pollution and health risks. During these first 10 years of OHMi existence, the bibliographic research as well as the study of the titles of the funded projects clearly show the interdisciplinarity in place to address this complex issue of human–environment interactions

Alternatives to CU Applications in Viticulture. How R&D Projects Can Provide Applied Solutions, Helping to Establish Legislation Limits

Copper (Cu) and its based preparations have been used for over 200 years to control fungi and bacterial diseases in cultivated plants. Downy mildew caused by the obligate biotrophic oomycete Plasmopara viticola is one of the most relevant and recurrent diseases of grapevines. Recently, the use of Cu is being limited by some regulations because of its high impact at different levels (health and environmental problems). Due to its accumulation in soil, this metal causes a little controversy with the principles of sustainable production. Therefore, international legislation and initiatives have recently been arisen to start limiting its use, with the main goal to replace it. In this framework, some alternatives have been tested and others are recently being developed to replace, at least partially, the use of Cu in viticulture. Many of them, are being developed and tested under the scope of research and development EU funded projects. To not compromise sustainability targets in viticulture, results from these R&D projects need to be considered to assess the present risks of using Cu in viticulture and to better support establishing limits for its applications, considering soils vulnerability, while no sustainable alternatives are available in the market