Environmental geochemistry of Potentially Toxic Elements (PTEs) and Persistent Organic Pollutants (POPs) as a tool of exposure evaluation and chemical risk assessment

Environmental pollution is one of the most challenging environmental issues to tackle due to its impact to human health and the ecosystem. One of the main objectives of environmental geochemistry is to investigate, characterise, and reveal the patterns of organic compounds and inorganic elements and further unveil their possible sources. Geogenic features and anthropogenic activities are the main sources of environmental contamination which are likely to release these contaminants into atmospheric, soil and water media. Moreover, anthropogenic activities let out chemicals produced from industrial activities, domestic, livestock and municipal wastes (including wastewater), agrochemicals, and petroleum-derived products. Organic pollutants cover a large group of synthetized pollutants and Persistent Organic Pollutants (POPs) have received a specific attention due to their physico-chemical properties, high toxicity, and subject to long-range atmospheric transfer. Polychlorinated biphenyls (PCBs), Polycyclic Aromatic Hydrocarbons (PAHs) and Organochlorines Pesticides (OCPs) are the main POPs that are subject to different regulation schemes to their irreversible adverse effects to both human and wildlife health. Stockholm Convention, Rotterdam and Basel, World Health organisation (WHO) and United Nations Economic Commission for Europe POPs Protocol have so far addressed, threated and introduced legislation which ban or fix threshold’s values of these POPs into environment. Potentially Toxic Elements (PTEs) are widespread metals/metalloids related to geogenic and/or anthropogenic activities. PTEs are one of the major concerns in the environment because their concentrations are increasing due to accelerated population growth rate, higher level of urbanisation and industrialisation providing a great variety of anthropogenic contamination/pollution sources. They have often been given special emphasis because their accumulation in different matrices can cause soil and land degradation and they can be transferred into the human body as a consequence of dermal contact, inhalation and ingestion through food chain and drinking water. PTEs are generally non-biodegradable having long biological half-lives and tend to accumulate in soils being absorbed to clay minerals and organic matter. However, their bioavailability is influenced by different physicochemical processes (e.g. pH, Eh) and physiological adaptation. PTEs and POPs can be observed in different environmental media but soil is considered an important reservoir due to its physico-chemical properties which confer high retention capacity of these pollutants. Soil contamination has been increasing worldwide and has become the focus of attention in recent years. Several soil parent materials are natural sources of certain organic contaminants, elements, and these can pose a risk to the environment and human health at elevated concentrations. For that, various geostatistical computations have been used to identify source patterns of different pollutants related to underlying geological features and/or anthropogenic activities, and to further distinguish mineralisation from contamination. Several single and complex contamination/mineralisation indices such as Enrichment Factor, Geo-accumulation Index or Single Pollution Index have been elaborated to quantify the contamination or mineralisation status of different PTEs. They are generally based on intervention limits (thresholds) or background/baseline values of a single element based on National Legislation, as a reference. Indices based on intervention limits (thresholds) are easily interpretable and comparable, but they disregard the compositional nature of geochemical data; hence they can be biased and/or spurious. This PhD research project reveals novel geostatistical computations that will lay out sources patterns of Potentially Toxic Elements (PTEs) and Persistent Organic Pollutants (POPs), and assess the soils contamination levels in the central-southern Italy. Series of follow up studies have provided an invaluable baseline for these contaminants distribution in Italy to push towards an institutional response for more adequate regulation of these pollutants worldwide. A further ongoing research project is currently investigating the content and bioavailability of mercury and Potentially Toxic Elements (PTEs) in artisanal and small-scale gold mining (ASGM) districts of Kedougou (Senegal). This study in particular will represent a fundamental stepping stone to build a baseline review of PTEs in ASGM of Kedougou (Senegal) and evaluate human health risks from exposure of PTEs. It is envisaged that the results of this study should trigger more detailed surveys in contaminated areas as well as ad-hoc risk-based studies, which in the long-term will constitute a strong argument to cause an adequate institutional response by the Senegalese regulating authorities for a full application the Minamata convention

Sedimentation on the continental margin off the Orange River and the Namib Desert

This study is the first detailed reconnaissance survey of the bathymetry, bedrock geology and the superficial sediments of the continental margin off the Orange River and the Namib Desert. The study area is bounded by latitudes 25° and 3o0 s. The Orange shelf is up to 100 km wide and 200 m deep, and the Walvis shelf off Lllderitz is up to 80 km wide and 400 m deep, the inner shelf is underlain by. Precambrian bedrock and is usually less than lOi km wide and shallower than 100 m. Tripp Seamount penetrate the upper slope in a depth of 1000 m and rises to within 150 m of sea level, the level of the Orange Banks on the outer orange shelf. South of the Orange River unfossiliferous ferruginous sandstones and mudstones crop out as seaward-dipping scarps on the middle shelf. North of the Orange River, similar scarps are composed of quartzose lime wackestones, identical to a Palaeogene suite on the Agulhas Bank. The shallow outer orange shelf is underlain in places by Upper Middle Miocene nummulitic _limestones, which are overlain by glauconitic conglomeratic phosphorites. Quartz-free algal limestones are found both on the Orange Banks and on the tip of Tripp Seamount. Authigenic pyrite and gypsum were found in two samples of semi-consolidated Neogene clay on the slope off Lüderitz. Pyrite is formed by combining teErigen-. ous adsorbed iron with sulphur released by anaerobic reduction of sea-water sulphate. The dissolution of planktonic foraminiferal tests provides calcium ions which combine with sulphate to form gypsum, once the calcium/sulphate solubility product is exceeded. On the Walvis shelf off LUderitz residual glauconite was reworked from older Neogene sediments, particularly on Lllderitz Bank. North of latitude 26°S residual phosphorite pellets were probably formed in Neogene diatomaceous oozes and then concentrated during a Late-Tertiary regression. Erosion of semi-consolidated .Neogene clays and ?Palaeogene quartzose' limestones. on ·the middle and outer Walvis shelf led to deposition of very fine residual quartz sand south of LUderitz. Coarse quartz ~and was reworked from littoral sandstones on the middle shelf south of the Orange River. The effect on sedimentation in the hinterland of poleward shifts of climatic belts during Quaternary interglacials and the reverse movement during glacials is assessed. Recent terrigenous sediments are derived by erosion of poorly consolidated Karoo sediments in the catchment of the Upper Orange. Erratic but powerful floods transport the sediments to the coast in suspension each summer. At the mouth in tense wave action dominates the submarine delta of the Orange River and fractionates the sediment load. Sand is transported equatorwards by littoral drift and is blown off beaches towards the Namib Sand Sea during violent Trade-Wind gales each sunnner. In contrast, silt and clay are transported polewards by a countercurrent, particularly during westerly winter storms. Recent biogenic sedimentation is controlled by upwelling in the B~nguela Current System, which is most intense off the wind dominated Sperrgebiet, south of LUderitz. Weaker upwelling off the Orange River allows oceanic planktonic foraminifera to penetrate to the middle shelf, whereas on the Walvis shelf in the study area they only reach the outer shelf. Towards latitude 25°s the Benguela Current System decays and interacts with poleward-flowing warm oxygen-poor water. Periodic mass mortalities of oxygen-starved phytoplankton lead to some of the most organic-rich sediments in the world

The ecology and palaeoecology of Chironomidae in fresh, saline, and estuarine habitats in eastern Australia - towards an understanding of the past and future

The late Quaternary period (40 ka BP), encompassing the Last Glacial Maximum (21 to 18 ka BP), Little Ice Age (~3 ka BP), and period of heaviest anthropogenic impact following European settlement is explored in terms of the palaeoecological and ecological assembly of eastern Australian aquatic Chironomidae (Insecta: Diptera: non-biting midges) species relative abundance distribution patterns in fresh and estuarine habitats. Transitional spatiotemporal gradients were employed to examine larval assemblage patterns, dynamics and processes by locating all study sites at climatic or estuarine ecotones. The southeastern Australian coastal sites included the Clyde River, Curalo Lagoon, W om boyne, Termeil, Meroo, and Werriga Lakes while the fresh lakes included tropical Lake Euramoo and temperate Lake Selina. At the Clyde River, chironomid larval assemblages had non-random distribution patterns that were strongly structured by the estuarine gradient and with minimal seasonal response and a robust diversity of around 44 species. The lagoons and coastal lakes had depauperate species assemblage dynamics that were strongly affected by extremes in salinity and sediment disturbance associated with flood events or breaches by the sea with some influence from ENSO phenomena and anthropogenic impact. Recurrent subfossil assemblages were associated with taphonomic influences whilst recurrent live larval assemblage compositions were attributed to environmental conditions extreme for most aquatic insects. These assemblage patterns and dynamics from the estuarine ecotones were in contrast to those observed at the climatic ecotones of the freshwater lakes. Highly coordinated assemblage patterns were observed at lake Euramoo and these were attributed to a broadly tolerant larval chironomid fauna mostly persisting in swampy lake margins from 6,000 yr B.P. to the present where habitats were minimally affected by shifting lake level and temperature. At Lake Selina, assemblage patterns were much more dynamic and responsive to climatic changes associated with shifts in water level and temperature between 40,000 to 3,000 yr B.P.; however these lentic assemblages were also more strongly influenced by lotic environments. The underlying assembly processes responsible for the observed patterns and dynamics of the larval chironomid assemblages are complex. This means that allogenic, autogenic, and uniformitarian theories are difficult to adequately and independently test. Nevertheless it is clear that the assembly processes acting over the past 40,000 years are highly unlikely to be different to those operating today and there is minimal support for the activity of autogenic processes operating amongst the chironomid assemblages studied in eastern Australia. This may have resulted from the scales of observation chosen and effects from time-averaging on subfossil assemblages because these were observed to have important effects. Other important factors included the definition of boundaries between microhabitats in the ecological surveys and between zones for subfossil assemblages. This strongly influences the perception of equilibrium and stasis that are closely tied with the assessment of the strength and coordination of ecological interaction

Metric concepts and implications in describing compositional changes for world river's water chemistry

The paper is designed to give the reader an outline that is useful for understanding the importance of distance, as a metric concept, and its implications when compositional (geochemical) data are managed from a statistical point of view in a given sample space. Application examples are shown by considering the construction of confidence regions and mixing models. The analyzed data are related to the chemistry of the most important rivers of the world as referring to the GEMS/WATER Global Register of River Inputs when each sample (river) is represented as a composition. A compositional vector of d parts, x = [x(1),x(2),...,x(d)], is defined as a vector in which the only relevant information is contained in the ratios between its components. All the components of the vector are assumed positive and are called parts (variables), while the whole compositional vector, with the sum of the parts equal to a constant, represents the composition. In this case data are not represented by variables free to vary from 00 to +infinity within a Euclidean space but occupy a restricted part of it called the simplex. The d-part simplex. S(d), is a subset of a d-dimensional real space. In this context the metric of the R space, with the definition of basic algebraic operations and of inner product, norm and distance, thus giving an Euclidean vector space structure, cannot be applied since the scale is relative and not absolute. (C) 2011 Elsevier Ltd. All rights reserved

Geomorphology from space: A global overview of regional landforms

This book, Geomorphology from Space: A Global Overview of Regional Landforms, was published by NASA STIF as a successor to the two earlier works on the same subject: Mission to Earth: LANDSAT views the Earth, and ERTS-1: A New Window on Our Planet. The purpose of the book is threefold: first, to serve as a stimulant in rekindling interest in descriptive geomorphology and landforms analysis at the regional scale; second, to introduce the community of geologists, geographers, and others who analyze the Earth's surficial forms to the practical value of space-acquired remotely sensed data in carrying out their research and applications; and third, to foster more scientific collaboration between geomorphologists who are studying the Earth's landforms and astrogeologists who analyze landforms on other planets and moons in the solar system, thereby strengthening the growing field of comparative planetology

Cartography

The terrestrial space is the place of interaction of natural and social systems. The cartography is an essential tool to understand the complexity of these systems, their interaction and evolution. This brings the cartography to an important place in the modern world. The book presents several contributions at different areas and activities showing the importance of the cartography to the perception and organization of the territory. Learning with the past or understanding the present the use of cartography is presented as a way of looking to almost all themes of the knowledge

2004-2005, University of Memphis bulletin

University of Memphis bulletin containing the undergraduate catalog for 2004-2005.https://digitalcommons.memphis.edu/speccoll-ua-pub-bulletins/1445/thumbnail.jp

Conference on Early Mars: Geologic and Hydrologic Evolution, Physical and Chemical Environments, and the Implications for Life

Topics considered include: Geology alteration and life in an extreme environment; developing a chemical code to identify magnetic biominerals; effect of impacts on early Martin geologic evolution; spectroscopic identification of minerals in Hematite-bearing soils and sediments; exopaleontology and the search for a Fossil record on Mars; geochemical evolution of the crust of Mars; geological evolution of the early earth;solar-wind-induced erosion of the Mars atmosphere. Also included geological evolution of the crust of Mars

2006-2007, University of Memphis bulletin

University of Memphis bulletin containing the undergraduate catalog for 2006-2007.https://digitalcommons.memphis.edu/speccoll-ua-pub-bulletins/1447/thumbnail.jp