Environmental impacts of mining at Calico, California, are poorly understood in comparison to the details of its history of silver production. Human health risks associated with arsenic from the lode rock, as well as mercury from the silver milling process, include central nervous system damage, organ failure, and death. To quantify the potential human health risk and manage remediation of this site, tailings from the Garfield Mill site were digitally mapped and chemically analyzed by portable x-ray fluorescence, which permitted volumetric estimates of total mill tailings and the arsenic and mercury budget, as well as identification of anomalies in the distribution of these elements within the tailings deposit. Final products include a high-resolution digital orthomosaic map showing the extent of the tailings deposit, giving contours of arsenic and mercury distribution and identifying areas of high concern for future remediation. The information gathered during this study will be of immense use to the city of Barstow, providing a basis for future public health studies and assessments of human health risks in the area.

The crisis of freshwater has been a big concern worldwide. Water contamination that occurs through the discharge of toxic pollutants from different natural and anthropogenic sources have worsened the situation. Adsorption has emerged as a simple and economical water treatment procedure although the challenge is to find the right adsorbent that can efficiently remove the target contaminant followed by their easy recovery from the reaction vessel. In this dissertation, I have focused on the synthesis, characterizations and applications of environmentally compatible and magnetic humic acid coated magnetite nanoparticles (HA-MNP) as a potential adsorbent for water purification. Phosphate is an essential nutrient for many plants and organisms in the environment. However, it can also cause water pollution when present in excess amounts. The adsorption experiments showed that the laboratory synthesized nanoparticles (HA-MNP) can remove more than 90% of phosphate from water mainly through the mechanism of chemisorption. The overall removal process is spontaneous, endothermic and favorable. Water contamination by arsenic is considered one of the biggest natural disasters in human history. In the study, HA-MNP has been applied for the successful trapping and separation of two highly toxic inorganic As species, As(III) and As(V) from water. The removal of As(V) was faster than As(III) for the same initial arsenic concentration and HA-MNP loading. The binding of As species is mainly attributed to three different phases, rapid surface association, intraparticle diffusion and equilibrium adsorption. Selenium is a micronutrient for humans that can be toxic at modest concentrations. The remediation of toxic selenium species, Se(IV) and Se(VI) by using HA-MNP has been found effective under a variety of environmental conditions except at highly alkaline pH and the presence of sulfate and phosphate in aqueous solution. Selenite or Se(IV) forms strong inner sphere complexes while Se(VI) forms relatively weaker outer sphere complexes with the adsorbent sites. The oxidation and adsorption of As(III) is explored by using the photocatalytic and adsorptive behavior of HA-MNP. The higher removal efficiency is attained through the reactive oxygen species mediated photo-conversion As(III) to As(V). Combination of oxygen and 350 nm light provides the best results.

Perfluoroalkyl substances (PFASs) are contaminants of emerging concern, and have been detected in drinking water, wildlife, humans, and the environment. Cyclodextrins (CDs), cyclic sugars composed of glucose monomers, are proposed as a potential remediation strategy. CDs can form host-guest complexes with hydrophobic molecules; this complexation could be capitalized on for PFAS removal and sequestration. These dissertation projects aim to study the fundamental host-guest interactions between a variety of PFASs and CDs for eventual applications in environmental and biological remediation. 1D and 2D Nuclear magnetic resonance (NMR) spectroscopic methods were employed to determine the strength, dynamics, and structure of the CD:PFAS host-guest complexes. Legacy and emerging PFASs were studied with the three native CDs (α-, β-, and γ-CDs) as well as β-CD derivatives. β-CD and its derivatives exhibit the strongest complexation with all studied PFASs, with association constants of 102-105 M-1, depending on PFAS chain length, functional groups, and branching. The host-guest complex was not significantly disturbed under different environmental conditions, such as changing pH, ionic strength, and in the presence of humic acid. A competition study between perfluorooctanoic acid (PFOA), β-CD, and human serum albumin (HSA), the most abundant protein in blood serum, was then conducted using NMR, circular dichroism, and fluorescence spectroscopies. Excess β-CD was able to totally reverse all PFOA binding to HSA. Finally, the host-guest complex was studied within a biological organism to test its viability as a remediation strategy. The attenuation of the toxicity of PFOA in zebrafish embryos, a model organism for toxicology studies, was tested with β-CD. Excess β-CD increased the LC50 (lethal concentration for 50 % of the population) of PFOA compared to PFOA in the absence of β-CD (p < 0.0001). These dissertation projects suggest that the encapsulation of PFASs by CDs has potential in PFAS remediation strategies.

<p>Over time, the Baltic Sea has been contaminated by increasing discharges of pollutants from human activities. Persistent organic pollutants (POPs) have caused toxic effects in wildlife and excess of nutrients have led to eutrophication. Furthermore, there are indications that certain polyhalogenated compounds similar in structure to man-made POPs are produced by the biota present in this sea. In the late 1990’s both methoxylated polybrominated diphenyl ethers (MeO-PBDEs) and hydroxylated-PBDEs (OH-PBDEs) were identified in fish and seals living in this environment. OH-PBDEs can originate from metabolism of PBDEs, but both OH- and MeO-PBDEs are also known to be natural products in marine environments. Another group of POPs, the polybrominated dibenzo-<i>p</i>-dioxins (PBDDs), are not produced commercially, but are known to be by-products of chemical industry and of the combustion of, e.g., brominated flame retardants (BFRs). In contrast to the OH- and MeO-PBDEs, PBDDs have not previously been shown to be natural products, although certain related compounds have been indicated to have a natural origin.</p><p>This thesis describes the identification of PBDDs, OH-PBDEs and MeO-PBDEs in algae, blue mussels and fish living in the Baltic Sea. Several of these compounds were also detected in cyanobacteria. Moreover, PBDDs were present in fish, mussels, shrimp and crabs from different regions of the Baltic Sea and from the west coast of Sweden, but not in organisms from freshwater environments. The levels of these compounds in Baltic fish generally exceeded those of their chlorinated analogues. The origin of the PBDDs identified is somewhat unclear, but the high levels present in blue mussels and the pattern of congeners observed indicate natural production. The presence of PBDDs, OH-PBDEs and MeO-PBDEs in fish and shellfish constitutes a potential risk to both humans and wildlife and requires further investigation.</p>

The Big South Fork National River and Recreation Area encompasses more than 50,585 hectares (125,000 acres) of the Cumberland Plateau along the border of Tennessee and Kentucky. Highly dissected and steep terrain have made accessibility to much of the park limited, thus little work has been done to investigate the formation of these soils. Seven native soil profiles were selected for chemical and physical analysis representing Pennsylvanian-aged acidic sandstone and shale geology and landforms. The objectives of this study included the characterization of selected native profiles by physical and chemical analysis, as well as classification using US Soil Taxonomy, to determine baseline soil fertility through chemical analysis, to provide fertilizer recommendations for Bicolor Lespedeza (Lespedeza bicolor) to be grown as wildlife food plots. The parent materials and site- specific geology, including the Pennington Formation, were compared to the profiles in order to establish any relationships that might exist. The methods of chemical analysis included: total carbon analysis, cation exchange capacity, percent base saturation, pH, particle size analysis, KCl total acidity, total elemental analysis and Mehlich I extraction. From the data, soils examined from an upland summit have the lowest Mehlich I extractable phosphorus (M1P) ranging from 0.8-3.14 mg kg-1, and this soil was classified as a Typic Hapludult. Soils examined on backslopes and sideslopes had M1P values ranging from 0.3-11.53 mg kg-1 and these soils were classified as either Lithic Dystrudepts or Typic Dystrudepts. The footslope soils examined have M1P values ranging from 1.95-19.79 mg kg-1 and were classified as Typic Hapludults. Floodplain soils had M1P values from 7.69-56.85 mg kg-1 and were classified as Fluventic Dystrudepts. Landscape position and parent material play major roles in the formation of soils, and their degree of weathering controls the amount of plant available nutrients. Using geologic and topographic maps for comparison, it was concluded that the development of these soils was directly related to the underlying geology and the surrounding topography throughout various landscapes. This information can be used as a guide to aid in predicting the chemical and physical properties of native soils on the Cumberland Plateau.

Over time, the Baltic Sea has been contaminated by increasing discharges of pollutants from human activities. Persistent organic pollutants (POPs) have caused toxic effects in wildlife and excess of nutrients have led to eutrophication. Furthermore, there are indications that certain polyhalogenated compounds similar in structure to man-made POPs are produced by the biota present in this sea. In the late 1990’s both methoxylated polybrominated diphenyl ethers (MeO-PBDEs) and hydroxylated-PBDEs (OH-PBDEs) were identified in fish and seals living in this environment. OH-PBDEs can originate from metabolism of PBDEs, but both OH- and MeO-PBDEs are also known to be natural products in marine environments. Another group of POPs, the polybrominated dibenzo-p-dioxins (PBDDs), are not produced commercially, but are known to be by-products of chemical industry and of the combustion of, e.g., brominated flame retardants (BFRs). In contrast to the OH- and MeO-PBDEs, PBDDs have not previously been shown to be natural products, although certain related compounds have been indicated to have a natural origin. This thesis describes the identification of PBDDs, OH-PBDEs and MeO-PBDEs in algae, blue mussels and fish living in the Baltic Sea. Several of these compounds were also detected in cyanobacteria. Moreover, PBDDs were present in fish, mussels, shrimp and crabs from different regions of the Baltic Sea and from the west coast of Sweden, but not in organisms from freshwater environments. The levels of these compounds in Baltic fish generally exceeded those of their chlorinated analogues. The origin of the PBDDs identified is somewhat unclear, but the high levels present in blue mussels and the pattern of congeners observed indicate natural production. The presence of PBDDs, OH-PBDEs and MeO-PBDEs in fish and shellfish constitutes a potential risk to both humans and wildlife and requires further investigation.

Persistent organic pollutants (POPs) is a group of chemicals that are toxic, undergo long-range transport and accumulate in biota. Due to their persistency the distribution and recirculation in the environment often continues for a long period of time. Thereby they appear virtually everywhere within the biosphere, and poses a toxic stress to living organisms. In this thesis, attempts are made to contribute to the understanding of factors that influence the distribution of POPs with focus on processes in the marine environment. The bioavailability and the spatial distribution are central topics for the environmental risk management of POPs. In order to study these topics, various field studies were undertaken. To determine the bioavailable fraction of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated naphthalenes (PCNs), and polychlorinated biphenyls (PCBs) the aqueous dissolved phase were sampled and analysed. In the same samples, we also measured how much of these POPs were associated with suspended particles. Different models, which predicted the phase distribution of these POPs, were then evaluated. It was found that important water characteristics, which influenced the solid-water phase distribution of POPs, were particulate organic matter (POM), particulate soot (PSC), and dissolved organic matter (DOM). The bioavailable dissolved POP-phase in the water was lower when these sorbing phases were present. Furthermore, sediments were sampled and the spatial distribution of the POPs was examined. The results showed that the concentration of PCDD/Fs, and PCNs were better described using PSC- than using POM-content of the sediment. In parallel with these field studies, we synthesized knowledge of the processes affecting the distribution of POPs in a multimedia mass balance model. This model predicted concentrations of PCDD/Fs throughout our study area, the Grenlandsfjords in Norway, within factors of ten. This makes the model capable to validate the effect of suitable remedial actions in order to decrease the exposure of these POPs to biota in the Grenlandsfjords which was the aim of the project. Also, to evaluate the influence of eutrophication on the marine occurrence PCB data from the US Musselwatch and Benthic Surveillance Programs are examined in this thesis. The dry weight based concentrations of PCB in bivalves were found to correlate positively to the organic matter content of nearby sediments, and organic matter based concentrations of PCB in sediments were negatively correlated to the organic matter content of the sediment.

Production and use of hydraulic ester oil is on the increase worldwide. This becomes a substitute to mineral based hydraulic oil and has drawn more concern because of its more friendly environmental effects. Based on the growing use of hydraulic ester oils in automobiles, transformation of fresh and old hydraulic ester oil was studied in a podsol soil (soil 1) and a clayey soil (soil 2). Functional groups present in the oil and effect of soil types on transformation of the oil were also determined. Replicates of the two soils types were contaminated with fresh or old ester based hydraulic fluid. The oils were recovered from the soil by extraction with acetone. The organic phase was evaporated to dryness, and a small drop of the resulting extract was used for Fourier Transformation Infra Red Spectrometer analysis. The remaining extract was dissolved in hexane and analyzed by gas chromatography. Different intermediate compound patterns were observed in the two studied soils during the transformation studies, which went on for 30 days. Aliphatic-, carbonyl-, aromatic- and ether- groups were the main functional groups present in the tested hydraulic ester oils. Presence or absence of these functional groups distinguishes ester oil from mineral oil.

Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are two structurally related groups of chemicals, generally referred to as `dioxins´. These are of great concern due to their high toxicity and global spread. Other groups of compounds with similar chemical structure and toxicity mechanisms are the brominated analogues polybrominated dibenzo-p-dioxins (PBDDs) and polybrominated dibenzofurans (PBDFs), and the dioxin-like polychlorinated biphenyls (PCBs). Numerous studies have been undertaken to investigate sources and transport routes of dioxins. However, much remains to be done, including analytical, inventories of dioxin-like compounds, such as PBDD/Fs, and the development of more convenient analytical methods. The currently standard procedure for analyzing dioxins (and dioxin-like compounds) is to use Soxhlet extraction followed by multi-step clean-up and gas chromatography - high resolution mass spectrometry (GC- HRMS) for detection. Unfortunately, this method is very solvent, labor and time-consuming, making it very expensive. The main aim of the studies this thesis was to develop pressurized liquid extraction (PLE) with integrated clean up techniques for fast, convenient preparation of dioxin samples. PLE with integrated clean-up has previously been used for extracting dioxins from biological samples, but in these studies the possibility of extending its use to abiotic samples was explored. The results show that PLE with an integrated carbon trap is suitable for analyzing dioxins in various types of soil samples, sediment and flue gas samples. The results also showed that it has potential for analyzing dioxins in fly ash. The thesis focuses on developments of the methodology for dioxin analysis, but also includes results obtained from PBDDs and dioxin-like PCB analyses. In addition, the possibility of using various other kinds of detection techniques rather than GC-HRMS, such as enzyme-linked immunosorbent assays (ELISAs) or two-dimensional gas chromatography with micro electron capture detection (GCxGC-µECD) was explored. The results indicate that ELISA and GCxGC-µECD could serve as complementary detection systems in some cases. However, it is not yet possible to fully replace GC-HRMS. A further refinement of the PLE with in-cell clean-up technique is the modular approach developed in these studies. With this technique it is possible to include various steps for both clean-up and fractionation. For example, sulphuric acid impregnated silica could be combined with active carbon for the simultaneous removal of lipids (along with other interferences) and fractionation of PCBs and PCDD/Fs. It was shown that the method could provide data that agreed reasonably well with both reference values and values obtained using traditional methods. In general PLE proved to have high extraction efficiency and to yield very similar congener profiles to the reference method. In addition, it was shown that it allowed one-step extraction and clean-up of a salmon sample. Such single-step procedures are the ultimate goals for any extraction technique, and it would be highly desirable to develop one-step methods that could be extended to other types of samples. For the rest of the matrices tested (soil, sediment, mussel and crab tissue and flue gas) the method was successful, however a final polishing step is currently required, involving either dilution or clean-up using miniaturized multilayer silica columns, to obtain extracts that are pure enough for GC-HRMS analysis. Using the developed modular-PLE system substantial costs could be saved. It was estimated that the method could reduce the cost of preparing samples by up to 90%, which would greatly facilitate large-scale inventories.

The environmental bioavailability of contaminants, rather than their total concentrations in the soil compartment play a decisive role for the risks associated with contaminated sites. Various soil constituents and abiotic conditions have strong influence on bioavailability, which may vary substantially between different locations. It is therefore necessary to site-specifically use tools that reflect the fractions of contaminants that are available to biota and pose the highest potential environmental risks. Bioassays provide integrated toxic responses which include effects from unknown contaminants or combinatory toxic effects from mixtures of contaminants. Thus, biological effect data greatly contribute to establish more realistic exposure and risk-scenarios at contaminated sites. The work underlying this thesis presents possible techniques for high capacity screening for site-specific hazards at contaminated areas. By combining rapid water extractions and cell-based in vitro designs measures of the toxic potential in soils was obtained. Toxicologically bioavailable fractions of mixed metal pollution, including arsenic, were primarily investigated in this thesis. In two of the studies, environmental availability and toxicological bioavailability of arsenic was explored in CCA-contaminated soils. Application of cell-based in vitro screening techniques was also conducted at a metal contaminated industrial site to obtain spatial distribution of toxicity. Multivariate association techniques were employed in the interpretation of environmental exposure and cytotoxicity data. It was shown that cell-based in vitro systems for both basal cytotoxicity and specific end-points targeting arsenic could assess the toxic potential from extracts obtained by several water-based extraction techniques including Pressurised Liquid Extraction (PLE). The cell-based in vitro systems were found to add important information on the site-specific differences in arsenics genotoxic potential from CCA-contaminated soils. The results highlight the importance of taking speciation and toxicological bioavailability into account in the risk analysis, rather than to base risk estimates on total load of contaminants. The presented screening approach was successfully applied at a metal polluted industrial site where spatial distribution of toxicity was obtained. PLE extraction also provided means for combined toxicological and chemical screening of explosives in soils from live-fire training ranges. Multivariate association techniques highly facilitated the interpretation of complex environmental data. The PLE was found to be a rapid extraction technique that has sufficient environmental relevance to be used in environmental impact analyses. It was also concluded that other cell-based in vitro systems that target specific toxic effects have large potential for being used in screening for a variety of environmental chemicals. Keywords: Environmental availability, Environmental bioavailability, Toxicological bioavailability, mixture toxicity, hazard screening, contaminated soils, heavy metals, arsenic, CCA, explosives, soil extraction, water extracts, cell-based in vitro tests, cytotoxicity, genotoxicity, PLE, MVDA, PCA, PLS. / Föroreningars biotillgänglighet snarare än deras totala koncentration i markmiljön styr den risk som kan förknippas med förorenade områden. Biotillgängligheten är ofta långt från 100% p.g.a. en rad olika bindningsytor och processer i jorden som reducerar biotillgängligheten. Således kan biotillgängligheten variera kraftigt mellan olika förorenade platser och även inom samma plats till följd av de specifika förhållanden som råder på respektive plats. Tillämpning av biologiska indikatorer som ger ett mått på den samlade giftigheten från biotillgängliga föroreningar är därför viktiga verktyg i platsspecifika exponerings- och farobedömningar. Många biologiska tester är ofta laborativt intensiva och dyra och lämpar sig mindre väl i testning av ett stort antal prover vilket är önskvärt om en tillräcklig geografisk täckning ska uppnås över ett förenat område. Testsystem som har kapacitet att hantera många prover till en rimlig kostnad är därför mycket användbart för screening i ett inledande skede av en miljöriskanalys av ett förorenat område. Föreliggande avhandlingsarbete presenterar möjliga lösningar i att kombinera snabb vattenextraktionsmetodik med cellbaserade in vitro system för platsspecifik toxikologisk faroscreening av metallförorenade områden. Metodiken erbjuder hög kapacitet för många jordprover. Tillämpning av metodiken har gjorts mot huvudsakligen metallföroreningar, inklusive arsenik. I två delarbeten studerades två modelljordar från CCA-förorenade fastigheter avseende tillgänglighet och giftighet av framför allt arsenik. Vidare studerades om det med applicerad metodik gick att illustrera geografisk utbredning av toxicitet, mätt i cellbaserade in vitro system, som biotillgängliga föroreningar uppvisar på ett metallförorenat industriområde. Slutligen studerades lämpligheten i att använda PLE för kombinerad kemisk och toxikologisk screening av jordar från militära skjutfält som var förorenade med explosivämnen. Cellbaserade in vitro system för mätning av både generell toxicitet och mer specifika effektmarkörer för arsenik visade sig användbara vid mätning från flera vattenbaserade extraktionsmetoder, inklusive PLE (trycksatt vätskeextraktion). Resultaten visade på PLEs tillämplighet som en snabb extraktionsmetod med bibehållen relevans för miljöanalyser. Applikation av cellbaserade in vitro system på vattenextrakt från förorenad jord gav värdefull information bl.a. om platsspecifik genotoxisk potential där specieringen av arsenik hade avgörande betydelse i en fallstudie med CCA-förorenade jordar. Vattenextraktion av jordprover kombinerat med cellbaserade in vitro system kunde också ge en geografisk bild av den omedelbara faran från biotillgängliga metallföroreningar inom ett industriområde. Vattenextraktion med PLE visade sig även användbart för screening av explosivämnen där extrakten direkt kunde användas för såväl kemisk karakterisering som för toxikologisk analys. Även andra typer av in vitro system än de som användes i detta arbete har stor framtida potential för tillämpning i faroscreening av ett stort antal olika typer av miljöföroreningar.