Human lifeways in Late Roman and Medieval Europe

The investigation of past human lifeways, which include subsistence practices, infant feeding strategies, small regional movements, and/or broader migrations, leads to obtaining a palimpsest of information on multiple and interconnected historical variables that engage with ancient societies. Even in modern times, how people behave in quotidian aspects can be associated with a shared system of values that is influenced by economic organisation, political agenda, social status, technological level, cultural views, ethics and religion. For example, nutrition is a biological necessity that grants the organism to grow, survive, and reproduce, but the varying consumption of different foods is, in most cases, driven by complex human choices. Also infant feeding practices are a particular aspect of nutrition. Infants cannot provide nourishment for themselves but they have to rely on their parents' choices, including how and when being breastfed. Breastmilk is a safe and easily digestible source of calories and macronutrients for neonates but when this is lacking or reduced to a short time, neonates may face serious health issues. Weaning is the process that involves breastmilk paired with complementary food. Breastfeeding and weaning timings are nowadays an important research topic in archaeology, considering that these may vary significantly across sites or even families, following a mixture of cultural norms, economic affordability and medical knowledge. Human and animal spatial mobility at different geographic scales may also impact human subsistence practices plus other lifeway aspects that are shared in a given community. Smaller regional movements at individual level may be associated with socio-economic phenomena, whereas broader mass migrations may instead affect local cultural traditions, bring in new technologies, religions and political systems, and adapt to novel farming economies. This cumulative dissertation includes multiple scientific publications with the aim of exploring spatiotemporal shifts in human lifeways across late Roman and medieval Europe. Given the existence of multiple historical variables, a higher resolution in reconstructing past human lifeways can be obtained through a transdisciplinary multi-proxy approach. Whenever disparate proxies are available, these can be compared and contrasted. This is particularly applicable to Roman and medieval Europe, given that a high level of archaeological preservation is often paired with a large number of written documents and treaties. In addition, archaeobotanical, zooarchaeological, and bioarchaeological studies for these periods are increasing and this provides hence the possibility of exploring high-resolution diachronic and synchronic changes in diet, resource management, and spatial mobility. During the period interested by this dissertation, i.e. Late Roman to late Medieval (c. third-fifteenth centuries), several historical events affected European regions at different rates and scales. Political transitions can be observed in reunification attempts made after the fall of the western part of the Roman Empire, such as the Carolingian (751-919 CE) and Holy Roman (962-1806 CE) empires. Moreover, new ‘proto-national’ kingdoms were established. The migration of several Germanic and Slavic tribes interested Europe at least for the whole Late Antique and Early Middle Ages (broadly 300-1000 CE). This created a combination of socio-cultural and legislative systems based on the previous Roman substrate and adapted to shared traditions from these incoming populations. Religions, their denominations and multiple dogmatic aspects (e.g. fasting rules) also had a central role in Late Roman and Medieval society. From Charlemagne’s coronation on Christmas night in 800 CE, the most effective temporal power expressed by a religious head was that of the Pope, who played a role of balance and sometimes of leadership among Christian states. Other particular dynamics involved climatic events on a limited temporal range (e.g. the volcanic winter of 536) or on a broader scale (e.g. the Medieval Warm Period). Finally, pandemics such as the ‘Justinian Plague’ (541-544 CE) or the ‘Black Death’ (1346-1353 CE) also are well documented historical events that impacted European societies. All of the above historical developments marked this age as an extremely heterogeneous period in European history and, for this reason, synchronic and diachronic shifts in past human diets, infant feeding practices, animal and crop management strategies, and spatial mobility are expected to reflect these events. A large array of archaeological methods can nowadays be employed to detect these shifts. In this dissertation, stable isotope analysis is used as the main research proxy and combined with other sources of evidence to obtain the highest resolution available. Stable isotope ratios measured on osteological human or animal remains, and on charred plant organic samples, have been used in archaeology to answer multiple archaeological questions. These include, but are not limited to, the reconstruction of human diets, the investigation of animal and crop management practices, the recognition of probable dwelling places for given individuals, and/or the inspection of breastfeeding and weaning timings in past populations. As such, human lifeways were here approached through ‘Big Data’ collections, meta-analyses, Bayesian modelling, and newly generated measurements. Also non-isotopic proxies were employed, as several forms of archaeological evidence can be included in a model to increase the accuracy and precision of the reconstruction. Using this transdisciplinary, multi-proxy, and multi-scale approach, changes in human subsistence practices, infant feeding strategies, and spatial mobility were detected both at regional level (e.g. archaeological sites) and following broader spatiotemporal coordinates. An important point within this work is hence the multi-scale approach. Depending on the research question, an analysis can be carried out at different scales. ‘Big Data’ meta-analyses can in fact attest shifts and/or the spread of given archaeological data that are otherwise invisible or underestimated at site level. Different scales can provide for different resolutions and interpretative limitations. In particular, the wider the scale, the higher is the possibility of observing how human lifeways shifted (or did not) across a more restricted number of historical variables. A ‘Big Data’ meta-analysis reduces in fact the impact of diverging behaviours on the final interpretation, hence allowing the detection of main trends. Novel statistical models have been recently proposed to investigate these. Developing machine learning programs and artificial intelligence implementations will also likely allow refining historical correlations. However, this is valid whenever a chosen scale is adequate to the amount and typology of data that is available. In this dissertation, some of the ‘Big Data’ spatio-temporal Bayesian options available from https://isomemoapp.com/ (IsoMemo) were presented here for the first time. Moreover, the use of the latest version of FRUITS (now ReSources), a Bayesian dietary mixing model, was also introduced as a potential high-resolution application of Bayesian softwares on different scales. In addition, the model OsteoBioR was employed on a selected case study to compare infant feeding practices on a local scale. Publications composing this cumulative dissertation are preceded by an extensive introduction on human lifeways, stable isotopes, Bayesian modelling tools, database production and brief summary of the articles. Conclusive thoughts, constraints of the project, and future research directions are also included. This dissertation consists of six articles. Three of these relate to database production and these are: 1) Amalthea, a database for incremental dentine stable isotope analysis; 2) the Tooth formation age dataset for early childhood bioarchaeological and medical studies, a non-isotopic database that can be used as a reference for addressing early childhood diets; 3) the Compendium Isotoporum Medii Aevi (CIMA), a database collecting all isotopic measurements on human, faunal and plant samples from medieval Europe (more than 50000). As a general rule, data collections can highlight research gaps and provide for large data archives that can be used to compare new measurements. However, as mentioned, these compilations can provide for large scale spatiotemporal data meta-analyses concerning diet, farming economies, spatial mobility and infant feeding practices. Preliminary results have shown potential links between shifts in human lifeways trends and historical developments during the late Roman and medieval ages. This is also enhanced by the designing of a well-characterised metadata structure that includes several archaeological, historical, and biological variables. For example, shifting human dietary practices compared across imperial, late antique, and early medieval Rome were associated with demographic decrease, collapse of the political and economic Roman structure, and new adaptative farming economies. A large regional dietary variability was also observed on an European scale, suggesting that different climates, environments, political agenda, socio-economic systems, and cultural traditions had different impacts on human communities. An additional ‘Big Data’ meta-analysis using Bayesian modelling of pollen variables on a continental scale was also included in this dissertation. This showed how mortality rates of the Black Death were overestimated in the historiographic reconstruction. Two selected case studies also compose this dissertation. These allowed observing shifting human lifeways on a local scale. Here, stable isotopes and Bayesian modelling options could be employed to explore past infant feeding practices in the Roman site of Bainesse (UK), and human diets, farming economies, and spatial mobility in southern Italy. These case-studies revealed smaller intra- and inter-site variations that suggested the existence of multiple local variables influencing human lifeways. For example, in Roman Bainesse (UK), some striking correlation between ancient medical recommendations and infant feeding practices as revealed through isotopes, suggested that the former could have been known, even at the northern frontier of the Roman empire. This is likely linked to military and commercial mobility in the area. However, the completion age of weaning varied across individuals and this still indicates that given choices could be influenced by other factors. This was associated with family traditions and/or socio-economic status. In Tertiveri (Italy), a moderate consumption of C4 plants (likely millet) detected through isotopes is an interesting anomaly in respect to what is observed from other archaeological indicators in the region. This was connected to a local economy based on transhumance routes. Moreover, historical developments, likely linked with military expeditions, were associated with mobile individuals found in Tertiveri, who appear to have travelled from outside the region. Overall, this dissertation proved that, at different scales and using multiple proxies, human lifeways in late Roman and medieval Europe were extremely heterogeneous. This was expected at site level, as many local variables and single human choices can influence subsistence practices, farming economies, infant feeding strategies, and mobility patterns. However, preliminary ‘Big Data’ Bayesian meta-analyses carried out on large volumes of isotopic data and combined with known evidence obtained from zooarchaeology, archaeobotany, anthropology, and written sources have revealed this point as valid even on a wider scale. This is not necessarily an a priori consequence of differences in the local scale, given that large human trends would overshadow smaller local differences. More likely, this instead confirms that human societies are impacted as a whole by main historical developments and environmental differences. This indicates hence that human lifeways do not only respond to biological inputs. At the state of the arts, it is hard to estimate which historical and/or environmental variables impacted late Roman and Medieval human lifeways the most. A direction to follow will be that of including into the analysis machine learning softwares applied to ‘Big Data’. Future research concerning Roman and Medieval Europe and its margins is therefore suggested to employ a similar multi-scale and multi-proxy transdisciplinary approach to investigate human lifeways.Die Untersuchung vergangener menschlicher Lebensweisen, zu denen Subsistenzpraktiken, Ernährungsstrategien für Kleinkinder, kleine regionale Bewegungen und/oder größere Migrationen gehören, führt zu einem Palimpsest von Informationen über vielfältige und miteinander verknüpfte historische Variablen, die sich mit alten Gesellschaften befassen. Selbst in der Neuzeit kann das alltägliche Verhalten der Menschen mit einem gemeinsamen Wertesystem in Verbindung gebracht werden, das von wirtschaftlicher Organisation, politischer Agenda, sozialem Status, technologischem Niveau, kulturellen Ansichten, Ethik und Religion beeinflusst wird. So ist zum Beispiel die Ernährung eine biologische Notwendigkeit, die dem Organismus Wachstum, Überleben und Fortpflanzung ermöglicht. Der unterschiedliche Verzehr verschiedener Nahrungsmittel wird aber in den meisten Fällen durch komplexe menschliche Entscheidungen bestimmt. Auch die Ernährung von Säuglingen ist ein besonderer Aspekt der Ernährung. Säuglinge können sich nicht selbst ernähren, sondern sind auf die Entscheidungen ihrer Eltern angewiesen, unter anderem darauf, wie und wann sie gestillt werden. Muttermilch ist eine sichere und leicht verdauliche Kalorien- und Makronährstoffquelle für Neugeborene. Doch wenn sie fehlt oder auf eine kurze Zeit reduziert wird, können Neugeborene ernsthafte gesundheitliche Probleme bekommen. Bei der Entwöhnung wird die Muttermilch mit Beikost kombiniert. Die Still- und Entwöhnungszeiten sind heutzutage ein wichtiges Forschungsthema in der Archäologie, da sie von Fundort zu Fundort und sogar von Familie zu Familie stark variieren können. Dies ist auf eine Mischung aus kulturellen Normen, wirtschaftlicher Erschwinglichkeit und medizinischem Wissen zurückzuführen. Die räumliche Mobilität von Menschen und Tieren auf verschiedenen geografischen Ebenen kann sich auch auf die menschlichen Subsistenzpraktiken und andere Aspekte der Lebensweise auswirken, die in einer bestimmten Gemeinschaft geteilt werden. Kleinere regionale Bewegungen auf individueller Ebene können mit sozioökonomischen Phänomenen in Verbindung gebracht werden, während breitere Massenmigrationen stattdessen lokale kulturelle Traditionen beeinflussen, neue Technologien, Religionen und politische Systeme einführen und sich an neue landwirtschaftliche Wirtschaftsformen anpassen können. Diese und weitere Fragestellungen können u. a. mit Hilfe der Analyse stabiler Isotope beantwortet werden. Die vorliegende kumulative Dissertation umfasst insgesamt sechs wissenschaftliche Veröffentlichungen sowie in der Einleitung weitere bislang unpublizierte Daten. Ziel der Arbeit ist es, raum-zeitliche Verschiebungen in der menschlichen Lebensweise im spätrömischen und mittelalterlichen Europa zu untersuchen. Dabei fokusiert diese Dissertation auf einen grundlegenden Aspekt der Lebensweise - die Ernährungsweise der Menschen. Außerdem wird auch die Mobilität im Raum angesprochen. Angesichts der Existenz zahlreicher historischer Variablen kann eine höhere Auflösung bei der Rekonstruktion vergangener menschlicher Lebensweisen durch einen transdisziplinären Multi-Proxy-Ansatz erreicht werden. Wann immer unterschiedliche Proxies verfügbar sind, können diese verglichen und gegenübergestellt werden. Dies gilt insbesondere für das römische und mittelalterliche Europa, da ein hohes Maß an archäologischer Erhaltung oft mit einer großen Menge an schriftlichen Dokumenten und Verträgen einhergeht. Darüber hinaus nehmen archäobotanische, zooarchäologische und bioarchäologische Studien für diese Zeiträume zu, was die Möglichkeit bietet, hochauflösende diachrone und synchrone Veränderungen der Ernährung, des Ressourcenmanagements und der räumlichen Mobilität zu untersuchen. Während des Zeitraums, der für diese Dissertation von Interesse ist, d. h. von der spätrömischen Zeit bis zum späten Mittelalter (ca. viertes bis fünfzehntes Jahrhundert), wirkten sich mehrere historische Ereignisse in unterschiedlichem Tempo und Ausmaß auf europäische Regionen aus. Politische Übergänge lassen sich an den Wiedervereinigungsversuchen nach dem Untergang des westlichen Teils des Römischen Reiches beobachten, wie z. B. das Karolingerreich (751-919 n. Chr.) und das Heilige Römische Reich (962-1806 n. Chr.). Darüber hinaus wurden neue „proto-nationale“ Königreiche gegründet. Die Einwanderung verschiedener germanischer und – später – slawischer Stämme prägte Europa zumindest in der gesamten Spätantike und im frühen Mittelalter (im Wesentlichen 300-1000 n. Chr.). Dies führte zu einer Kombination aus soziokulturellen und rechtlichen Systemen, die auf dem früheren römischen Substrat basierten und an die gemeinsamen Traditionen dieser neuen Völker angepasst wurden. Auch die Religionen, ihre Konfessionen und zahlreiche dogmatische Aspekte (z. B. Fastenregeln) spielten in der spätrömischen und mittelalterlichen Gesellschaft eine zentrale Rolle. Seit der Krönung Karls des Großen in der Weihnachtsnacht des Jahres 800 war die wirksamste weltliche Macht, die von einem religiösen Oberhaupt ausgeübt wurde, die des Papstes, der eine ausgleichende und manchmal auch eine führende Rolle unter den christlichen Staaten spielte. Andere besondere Dynamiken betrafen klimatische Ereignisse von begrenzter zeitlicher Reichweite (z. B. der Vulkanwinter von 536) oder von größerem Ausmaß (z. B. die mittelalterliche Warmzeit). Schließlich sind auch Pandemien wie die „Justinianische Pest“ (541-544) oder der „Schwarze Tod“ (1346-1353) gut dokumentierte historische Ereignisse, die die europäischen Gesellschaften nachhaltig beeinflussten. Alle oben genannten historischen Entwicklungen kennzeichnen dieses Zeitalter als eine äußerst heterogene Periode in der europäischen Geschichte, und aus diesem Grund wird erwartet, dass synchrone und diachrone Verschiebungen in den früheren menschlichen Ernährungsgewohnheiten, in der Kinderernährung, in den Strategien der Tier- und Pflanzenhaltung und in der räumlichen Mobilität diese Ereignisse widerspiegeln. Heutzutage kann eine breite Palette archäologischer Methoden eingesetzt werden, um diese Veränderungen nachzuweisen. In dieser Dissertation wird die Analyse stabiler Isotope als wichtigstes Forschungsmittel eingesetzt und mit anderen Beweismitteln kombiniert, um die größtmögliche Auflösung zu erzielen. Stabile Isotopenverhältnisse, die an osteologischen menschlichen oder tierischen Überresten und an verkohlten organischen Pflanzenproben gemessen wurden, sind in der Archäologie zur Beantwortung zahlreicher archäologischer Fragen verwendet worden. Dazu gehören u. a. die Rekonstruktion menschlicher Ernährungsgewohnheiten, die Untersuchung von Praktiken der Tierhaltung und des Pflanzenanbaus, das Erkennen wahrscheinlicher Wohnorte bestimmter Individuen und/oder die Untersuchung von Still- und Entwöhnungszeiten in früheren Bevölkerungen. Die menschlichen Lebenswege wurden hier durch „Big Data“-Sammlungen, Meta-Analysen, Bayes‘sche Modellierung und umfangreiche eigene Isotopenanalysen untersucht. Es wurden auch nicht-isotopische Proxies verwendet, da mehrere Formen archäologischer Beweise in ein Modell einbezogen werden können, um die Genauigkeit und Präzision der Rekonstruktion zu erhöhen. Mithilfe dieses transdisziplinären, Multi-Proxy- und Multiskalen-Ansatzes konnten Veränderungen in den menschlichen Subsistenzpraktiken, den Ernährungsstrategien für Kleinkinder und der räumlichen Mobilität sowohl auf regionaler Ebene (z. B. spezifische archäologische Fundorte) als auch in größeren räumlich-zeitlichen Koordinaten nachgewiesen werden. Ein wichtiger Punkt in dieser Arbeit ist daher der Multiskalenansatz. Je nach Forschungsfrage kann eine Analyse auf verschiedenen Skalen durchgeführt werden. Big-Data-Meta-Analysen können in der Tat Verschiebungen und/oder die Verbreitung bestimmter archäologischer Daten belegen, die ansonsten auf Standortebene unsichtbar sind oder unterschätzt werden. Unterschiedliche Maßstäbe können zu unterschiedlichen Auflösungen und Interpretationseinschränkungen führen. Je größer der Maßstab, desto größer ist die Möglichkeit zu beobachten, wie sich menschliche Lebensweisen über eine begrenzte Anzahl historischer Variablen hinweg verändert haben (oder auch nicht). Eine „Big Data“-Meta-Analyse verringert die Auswirkungen abweichender Verhaltensweisen auf die endgültige Interpretation und ermöglicht somit die Erkennung der wichtigsten Trends. Kürzlich wurden neuartige statistische Modelle vorgeschlagen, um diese zu untersuchen. Die Entwicklung von Programmen für maschinelles Lernen und die Implementierung künstlicher Intelligenz wird es wahrscheinlich auch ermöglichen, historische Korrelationen zu verfeinern. Dies gilt jedoch immer dann, wenn die gewählte Skala der Menge und Art der verfügbaren Daten angemessen ist. In dieser Dissertation wurden einige der räumlich-zeitlichen Bayes'schen „Big Data“-Optionen von https://isomemoapp.com/ (IsoMemo) zum ersten Mal vorgestellt. Darüber hinaus wurde die Verwendung der neuesten Version von FRUITS (jetzt ReSources), einem Bayes‘schen Ernährungsmischungsmodell, als mögliche hochauflösende Anwendung von Bay

Nitrogen and metals as multiple stressors affecting the auto-remediation role of salt marshes : consequences to the ecosystem services

Tese de doutoramento, Biologia (Ecologia), Universidade de Lisboa, Faculdade de Ciências, 2010The fast increase of human population and activities during the 20th century led to an increment in the loading of both land-derived nitrogen from anthropogenic diffuse sources and metal industrial discharges to coastal and transitional waters. Thus, estuaries were subdued to large discharges of nitrogen and metals, which may lead to eutrophication and historical contamination. Salt marshes provide crucial ecosystem functions, such as nitrogen cycling and sequestration, as well as phytoremediation. Therefore, this thesis focuses on a better understanding of nitrogen cycling in warm-temperate salt marshes, metal compartmentalization in salt marsh plants and effects of multiple stressors (nitrogen enrichment and metal historical contamination) on the ability to auto-remediate estuarine systems. Nitrogen sequestration and cycling in salt marshes, namely through nitrogen incorporation in biomass and organic nitrogen burial, is species-specific (Sarcocornia fruticosa, Sarcocornia perennis, Halimione portulacoides, Scirpus maritimus and Spartina maritima) and greatly depends on the maturity of the salt marsh (S. maritima), rather than on the estuary. Denitrification occurring in S. maritima salt marshes is also an important remediation process for nitrogen, namely during winter. H. portulacoides ability to accumulate high metals concentrations is higher in the roots than in the aboveground material and metal compartmentalization mostly occurs in the cell wall, thus, outside key metabolic sites. Regarding the studied multiple stressors, nitrogen loading and metals contamination did not affect the phytoremediation capacity of H. portulacoides for Zn, Cu and Ni, and enhanced the Cd accumulation in this plant species. Denitrification in metals-contaminated salt marsh was higher during the studied season (winter), when compared to a non-contaminated salt marsh. As a whole, multiple stressors affected the auto-remediation capacity of salt marshes. Since ecosystem functions seem to be species-specific, one cannot exclude that multiple stressors threaten the provided ecosystem services and, consequently, ecosystem health and equilibrium may be endangered.Ao longo do século XX, o aumento da população humana nas zonas costeiras e o aumento da pressão exercida no ambiente, inerentes à sua presença e actividades, aumentaram de forma muito rápida, o que conduziu a um grande aumento de descargas azoto de fontes difusas e origem antropogénica, tal como ao aumento de descargas de resíduos industriais (e.g. metais) para as massas de águas marinhas e de transição. Deste modo, os estuários foram sujeitos a grandes descargas de azoto e de metais, cujas consequências são de ordem diversa, nomeadamente eutrofização e contaminação por metais, denominadas, respectivamente, por eutrofização cultural e contaminação histórica por metais. Os sapais desempenham funções ecológicas extremamente importantes, nomeadamente como bio-estabilizadores; também constituem um dos ecossistemas mais produtivos e prestam serviços muito importantes, tais como recliclagem e sequestro de azoto e fitoremediação. Tendo em conta a importância destes ecossistemas, o presente trabalho tem por objectivo estudar e compreender o ciclo do azoto nos sapais; a compartimentação dos metais nos diferentes órgãos das plantas de sapal, e ainda os efeitos dos stresses múltiplos (enriquecimento em azoto e contaminação histórica por metais) na capacidade de auto-remediação dos sapais, bem como os efeitos nos serviços prestados por estes ecossistemas. O ciclo do azoto nos sapais foi estudado por meio de 3 casos de estudo incluídos no Capítulo I. Este trabalho consistiu na monitorização bimensal da biomassa e concentração de azoto nos diferentes órgãos das halófitas de sapal e no rizosedimento. De acordo com os resultados obtidos, a acumulação/sequestro e transferência de azoto pelas plantas de sapal é específica para cada espécie (nomeadamente, Sarcocornia fruticosa, Sarcocornia perennis, Halimione portulacoides, Scirpus maritimus e Spartina martitima) e não foi possível estabelecer uma relação entre a capacidade de retenção de azoto e a respectivo mecanismo fotossintético. Este trabalho demonstra que os processos de reciclagem de azoto, promovidos pelas plantas de sapal, contribuem para a redução da eutrofização (via sequestro de azoto), evidenciando os serviços prestados por estes ecossistemas e o papel crucial das halófitas na manutenção das funções e da saúde do ecossistema. Através da monitorização da biomassa de S. maritima, conteúdo em azoto na planta, nos detritos e no sedimento, este trabalho permitiu concluir que o sapal mais maturo e que está sujeito uma pressão antropogénica superior, apresenta maior produção de biomassa e produção de azoto na parte subterrânea da planta. Apresenta também uma taxa de decomposição mais lenta, contribuindo deste modo para um maior sequestro de azoto no sedimento. Sapais sujeitos a uma pressão antropogénica menos intensa produzem maior biomassa (e incorporam maior quantidade de azoto) na parte aérea da planta. Os resultados deste caso de estudo permitem concluir que a capacidade de retenção de azoto depende, de forma determinante, da maturidade do sapal em que se insere, bem como das características fisico-químicas inerentes. Além disso, este trabalho realça o facto de as funções prestadas pelos sapais, nomeadamente o sequestro de N, contribuírem para a redução da eutrofização em águas de transição. Foi realizado um estudo sazonal num sapal colonizado por S. maritima e na área adjacente sem vegetação. Através da quantificação de fluxos de oxigénio, NH4-N, NOx-N, nitrificação potencial e desnitrificação (“15N-isotope pairing technique”), observou-se que as taxas de nitrificação potencial foram significativamente superiores no outono e no inverno e que não houve diferenças significativas entre os dois tipos de sedimento analisados: sedimento não colonizado e sedimento colonizado por S. maritima. As taxas de desnitrificação em sedimentos sem vegetação (máx. 151±24 mol N2m-2h-1 (média ± DP) (verão, período nocturno)) estão compreendidas nos intervalos de valores obtidos noutros sistemas comparáveis. As taxas de desnitrificação no sedimento colonizado por S. maritima foram de modo geral superiores aos valores obtidos para a lagoa de Veneza. Relativamente à sazonalidade, as taxas de desnitrificação apresentaram valores superiores no inverno também no período nocturno (676 ± 497 mol N2m-2h-1) (média ± DP). No estuário deste caso de estudo, o estuário do Tejo, a desnitrificação nos sapais de S. maritima, quando comparadas com as obtidas na zona sem vegetação, apresentaram valores superiores no inverno. Este processo pode contribuir potencialmente para uma grande redução da concentração de azoto no estuário do Tejo nesta estação do ano (devido ao aumento da pluviosidade, das descargas fluviais e da escorrência superficial), contribuindo para a redução da disponibilidade de nitrato na coluna de água na primavera seguinte. O Capítulo II diz respeito à acumulação e compartimentação de metais em halófitas de sapal, tendo como caso de estudo a halófita Halimione portulacoides. Tendo em conta a elevada capacidade dos sedimentos colonizados por plantas de sapal para acumular elevadas concentrações de metais, e consequentemente a capacidade das plantas para tolerarem estas mesmas concentrações, este estudo teve por objectivo esclarecer quais as estratégias de H. portulacoides para evitar a toxicidade por metais nos diferentes órgãos e ao nível da célula. Neste sentido, foi realizada uma extracção sequencial ao nível da folha, caule e raiz de H. portulacoides e determinadas as concentrações de metais (Zn, Pb, Co, Cd, Ni e Cu) em diferentes fracções do material vegetal. De acordo com este estudo, todos os órgãos da planta acumulam os metais maioritariamente na parede celular (53 % nas folhas a 65 % nas raízes) sendo o conteúdo a nível intracelular consideravelmente inferior (21% nas raízes a 32% nas folhas). Deste modo, as concentrações metais elevadas existentes no ambiente sedimentar não causam toxicidade às plantas de sapal. Isto deve-se ao facto destas imobilizarem os metais em diferentes compartimentos celulares (parede celular, fracção proteica e intracellular) e fora de locais vitais em termos metabólicos, o que deverá ser crucial para a sobrevivência de H. portulacoides em sapais com elevada contaminação por metais. No Capítulo III é abordado de duas formas distintas, os efeitos dos stresses múltiplos. i.e., excesso de azoto e contaminação por metais, na capacidade de auto-remediação dos sapais e consequentes ameaças para os serviços prestados por estes ecossistemas. No intuito de compreender melhor como é afectada a capacidade de fitoremediação das plantas de sapal (fitoacumulação de metais) pela “eutrofização cultural”, foi realizada uma experiência sob condições controladas. A contaminação histórica foi simulada expondo as plantas (H. portulacoides) a elevadas concentrações de metais (Zn, Cu, Ni, Cd) e foram testados diferentes níveis de enriquecimento em azoto na forma de nitrato, de modo a simular diferentes níveis de eutrofização. De acordo com o presente trabalho, e tendo em conta as condições testadas, a “eutrofização cultural” parece não afectar a capacidade de fitoremediação de Zn, Cu e Ni por H. Portulacoides. Mais, o serviço de fitoremediação de Cd parece ser promovido. Todavia, a elevada toxicidade do Cd e a sua bioacumulação devem ser tidas em conta, tal como a vulnerabilidade dos sapais, cuja redução terá consequências drásticas para a saúde do ecossistema. Tendo em conta a possibilidade de auto-remediação de N nos sapais através do processo de desnitrificação, o segundo caso de estudo deste capítulo, teve como objectivo testar se a desnitrificação em sapais é afectada pela contaminação por metais. Deste modo, foi comparada a taxa de desnitrificação (“15N-isotope pairing technique”), durante o inverno, em sapais com diferentes níveis de contaminação por metais. As taxas de desnitrificação foram inferiores no sapal não contaminado e também inferiores em condições de luz, i.e. durante o período diurno. Nas condições testadas, a taxa diária de desnitrificação obtida foi cerca de 2285 ± 420 μmol N m-2 dia-1 no sapal de S. maritima não contaminado e 11046 ± 7398 μmol N m-2 dia-1 no sapal contaminado. No entanto, a variabilidade é bastante superior no sapal contaminado. Em suma, este estudo contribuiu para avaliar a capacidade de auto-remediação dos sapais através da desnitrificação, tendo em conta stresses múltiplos, i.e. “eutrofização cultural” e “contaminação histórica” por metais. Todavia, serão úteis mais resultados comparáveis com este. De um modo geral, a presente tese evidencia os serviços dos sapais na redução/mitigação potencial da eutrofização, ainda que, no mesmo sistema, apresente alguma variação espacial. A espécie de sapal Spartina maritima, nativa da Europa, contribui para a remediação de azoto através da intercepção do azoto proveniente de montante e reduzindo a descarga de azoto reactivo para o oceano. Este processo poderá ser efectuado através da incorporação de azoto na biomassa (e.g. aminoácidos e proteínas), acumulação de azoto orgânico nos sedimentos colonizados (e.g. acumulação de detritos vegetais e aumento das taxas de sedimentação) e desnitrificação. Além disso, demonstra-se a capacidade das plantas de sapal para acumular elevadas concentrações de metais e consequentemente proceder à fitoremediação do ambiente estuarino envolvente. Por último, os stresses múltiplos estudados (enriquecimento em azoto e contaminação por metais) não afectaram a capacidade de fitoremediação de Zn, Cu e Ni por H. portulacoides. Por outro lado, estes factores aumentaram a capacidade de acumulação de Cd por esta espécie. Todavia, a toxicidade de Cd e a bioacumulação ao longo da cadeia trófica, tal como a vulnerabilidade dos sapais não deve ser desprezada. A desnitrificação no sapal contaminado por metais (Al, Fe, Zn, Mn, Pb, Cr, Cu, Ni, Co, Cd e o metalóide As) foi superior na estação do ano estudada (inverno), o que sugere uma adaptação de S. maritima e da comunidade microbiana às elevadas concentrações de metais no sedimento. Contudo, tal como acima mencionado, será relevante obter outros resultados comparáveis. Em suma, a capacidade dos sapais de auto-remediação de azoto e metais é afectada pelos stresses múltiplos estudados. Dado que muitas funções das halófitas de sapal são específicas para cada espécie não poderemos excluir que os stresses múltiplos possam constituir uma ameaça aos serviços prestados pelos sapais e consequentemente ameaçar a saúde e o equilíbrio do ecossistema.Fundação para a Ciência e a Tecnologia(SFRH/BD/23634/2005

Source-tracking cadmium in New Zealand agricultural soils: a stable isotope approach

Cadmium (Cd) is a toxic heavy metal, which is accumulated by plants and animals and therefore enters the human food chain. In New Zealand (NZ), where Cd mainly originates from the application of phosphate fertilisers, stable isotopes can be used to trace the fate of Cd in soils and potentially the wider environment due to the limited number of sources in this setting. Prior to 1997, extraneous Cd added to soils in P fertilisers was essentially limited to a single source, the small pacific island of Nauru. Analysis of Cd isotope ratios (ɛ114/110Cd) in Nauru rock phosphate, pre-1997 superphosphate fertilisers, and Canterbury (Lismore Stony Silt Loam) topsoils (Winchmore Research Farm) has demonstrated their close similarity with respect to ɛ114/110Cd. We report a consistent ɛ114/110Cd signature in fertiliser-derived Cd throughout the latter twentieth century. This finding is useful because it allows the application of mixing models to determine the proportions of fertiliser-derived Cd in the wider environment. We believe this approach has good potential because we also found the ɛ114/110Cd in fertilisers to be distinct from unfertilised Canterbury subsoils. In our analysis of the Winchmore topsoil series (1949-2015), the ɛ114/110Cd remained quite constant following the change from Nauru to other rock phosphate sources in 1997, despite a corresponding shift in fertiliser ɛ114/110Cd at this time. We can conclude that to the present day, the Cd in topsoil at Winchmore still mainly originates from historical phosphate fertilisers. One implication of this finding is that the current applications of P fertiliser are not resulting in further Cd accumulation. We aim to continue our research into Cd fate, mobility and transformations in the NZ environment by applying Cd isotopes in soils and aquatic environments across the country

Modelação da exposição a poluentes tóxicos relacionados com o tráfego

Doutoramento em Ciências e Engenharia do AmbienteAtualmente, a poluição atmosférica constitui uma das principais causas ambientais de mortalidade. Cerca de 30% da população europeia residente em áreas urbanas encontra-se exposta a níveis de poluição atmosférica superiores aos valores- limite de qualidade do ar legislados para proteção da saúde humana, representando o tráfego rodoviário uma das principais fontes de poluição urbana. Além dos poluentes tradicionais avaliados em áreas urbanas, os poluentes classificados como perigosos para a saúde (Hazard Air Pollutants - HAPs) têm particular relevância devido aos seus conhecidos efeitos tóxicos e cancerígenos. Neste sentido, a avaliação da exposição tornase primordial para a determinação da relação entre a poluição atmosférica urbana e efeitos na saúde. O presente estudo tem como principal objetivo o desenvolvimento e implementação de uma metodologia para avaliação da exposição individual à poluição atmosférica urbana relacionada com o tráfego rodoviário. De modo a atingir este objetivo, foram identificados os parâmetros relevantes para a quantificação de exposição e analisados os atuais e futuros potenciais impactos na saúde associados com a exposição à poluição urbana. Neste âmbito, o modelo ExPOSITION (EXPOSure model to traffIc-relaTed aIr pOllutioN) foi desenvolvido baseado numa abordagem inovadora que envolve a análise da trajetória dos indivíduos recolhidas por telemóveis com tecnologia GPS e processadas através da abordagem de data mining e análise geoespacial. O modelo ExPOSITION considera também uma abordagem probabilística para caracterizar a variabilidade dos parâmetros microambientais e a sua contribuição para exposição individual. Adicionalmente, de forma a atingir os objetivos do estudo foi desenvolvido um novo módulo de cálculo de emissões de HAPs provenientes do transporte rodoviário. Neste estudo, um sistema de modelação, incluindo os modelos de transporteemissões- dispersão-exposição, foi aplicado na área urbana de Leiria para quantificação de exposição individual a PM2.5 e benzeno. Os resultados de modelação foram validados com base em medições obtidas por monitorização pessoal e monitorização biológica verificando-se uma boa concordância entre os resultados do modelo e dados de medições. A metodologia desenvolvida e implementada no âmbito deste trabalho permite analisar e estimar a magnitude, frequência e inter e intra-variabilidade dos níveis de exposição individual, bem como a contribuição de diferentes microambientes, considerando claramente a sequência de eventos de exposição e relação fonte-recetor, que é fundamental para avaliação dos efeitos na saúde e estudos epidemiológicos. O presente trabalho contribui para uma melhor compreensão da exposição individual em áreas urbanas, proporcionando novas perspetivas sobre a exposição individual, essenciais na seleção de estratégias de redução da exposição à poluição atmosférica urbana, e consequentes efeitos na saúde.Currently, air pollution represents one of the main environmental causes of mortality. About 30% of European citizens in urban areas are exposed to air pollution levels that exceed the air quality limits set by the legislation for the protection of human health, with road transport being the most significant pollution source. In addition to the traditional air pollutants evaluated in urban areas, the hazardous air pollutants (HAPs) has been the subject of particular concern because of their known toxic and carcinogenic effects. In this sense, the evaluation of exposure becomes essential in determining the relationship between urban air pollution and health effects. The main objective of the current study is the development and implementation of a consistent approach for the quantification of individual exposure to trafficrelated air pollutants. For this purpose, relevant parameters of exposure quantification were identified and the current and future potential impacts on human health associated with exposure to urban air pollution were analysed. In this context, the ExPOSITION model (EXPOSure model to traffIc-relaTed aIr) was developed by using a novel approach based on the trajectory analysis of the individuals collected by mobile phones with GPS and processed using the data mining approach and geo-spatial analysis within GIS. Also, the ExPOSITION model considers a probabilistic approach to characterize the variability of microenvironmental parameters and its contribution to personal exposure. Additionally, in order to achieve the objectives of the current study, a new module to quantify emissions of traffic-related HAPs was developed. In this study, a modelling system, including transport-emissions-dispersionexposure models was applied to the Leiria urban area for quantification of individual exposure to PM2.5 and benzene. The modelling results were validated based on measurements obtained by personal monitoring and biological monitoring evidencing a good agreement between the model results and measurement data. The methodology developed and implemented in this work allows to estimate and analyse the magnitude, frequency and the inter and intravariability of personal exposure levels, as well as the contribution of different microenvironments, clearly addressing the sequence of exposure events and source-receptor relationship, which is essential for health impact assessment and epidemiological studies. This research work contributes to a better understanding of individual exposure in urban areas, providing new perspectives on individual exposure, essential in the selection of strategies to reduce exposure to urban air pollution and related health effects

Proceedings of Abstracts 10th International Conference on Air Quality Science and Application

This 10th International Conference in Air Quality - Science and Application is being held in the elegant and vibrant city of Milan, Italy. Our local hosts are ARIANET and ARPA Lombardia both of whom play a leading role in assessing and managing air pollution in the area. The meeting builds upon the series that began at the University of Hertfordshire, UK in July 1996. Subsequent meetings have been held at the Technical University of Madrid, Spain (1999), Loutraki, Greece (2001), Charles University, Prague, Czech Republic (2003), Valencia, Spain (2005), Cyprus (2007), Istanbul, Turkey (2009) Athens, Greece (2012) and Garmisch-Partenkirchen, Germany (2014). Over the last two decades controls to limit air pollution have increased but the problem of poor air quality persists in all cities of the world. Consequently, the issue of the quality of air that we breathe remains at the forefront of societal concerns and continues to demand the attention of scientists and policy makers to reduce health impacts and to achieve sustainable development. Although urbanisation is growing in terms of population, transport, energy consumption and utilities, science has shown that impact from air pollution in cities is not restricted to local scales but depends on contributions from regional and global scales including interactions with climate change. Despite improvements in technology, users still demand robust management and assessment tools to formulate effective control policies and strategies for reducing the health impact of air pollution. The topics of papers presented at the conference reflect the diversity of scales, processes and interactions affecting air pollution and its impact on health and the environment. As usual, the conference is stimulating cross-fertilisation of ideas and cooperation between the different air pollution science and user communities. In particular, there is greater involvement of city, regional and global air pollution, climate change, users and health communities at the meeting. This international conference brings together scientists, users and policy makers from across the globe to discuss the latest scientific advances in our understanding of air pollution and its impacts on our health and environment. In addition to the scientific advances, the conference will also seek to highlight applications and developments in management strategies and assessment tools for policy and decision makers. This volume presents a collection of abstracts of papers presented at the Conference. The main themes covered in the Conference include: Air quality and impact on regional to global scales Development/application/evaluation of air quality and related models Environmental and health impact resulting from air pollution Measurement of air pollutants and process studies Source apportionment and emission models/inventories Urban meteorology Special session: Air quality impacts of the increasing use of biomass fuels Special session: Air quality management for policy support and decisions Special session: Air pollution meteorology from local to global scales Special session: Climate change and human health Special Session: Modelling and measuring non-exhaust emissions from traffic Special session: Transport related air pollution - PM and its impact on cities and across EuropeFinal Published versio

Human experience in the natural and built environment : implications for research policy and practice

22nd IAPS conference. Edited book of abstracts. 427 pp. University of Strathclyde, Sheffield and West of Scotland Publication. ISBN: 978-0-94-764988-3