This master‘s thesis deals with ecotoxicity assessment of plasma-activated solutions. Various plasma-activated solutions were prepared in the experiments. In the vast majority of tests, it was plasma-activated tap water – PAW. Depending on the test organism, dilution water was further processed, namely dilution water for Thamnocephalus platyurus and Daphnia magna. In this master‘s thesis the ecotoxicological effects were assessed through aquatic ecotoxicity tests with an aquatic plant Lemna minor, on a crustaceans T. platyurus and D. magna and on agricultural crops Lactuca sativa and Allium cepa L. . Crustaceans are fresh-water organisms on which the water contamination can be quickly and quite easily assessed. These plasma-activated solutions were also tested for acute ecotoxicity of soil organisms by ecotoxicological contact tests with Eisenia fetida, springtails Folsomia candida and seeds of L. sativa. Tests on T. platyurus and D. magna were performed in time intervals and a change in mortality was observed depending on PAW concentration. If the test results allowed, the LC50, IC50, A and NR escapism values were calculated. When the measured and calculated values did not allow such a calculation, the overall effect of PAW on organisms was assessed and a significant difference was calculated for the L.sativa root growth inhibition test. The final results showed that PAW has an ecotoxic effect on aquatic organisms, while it has rather beneficial effects on terrestrial organisms.

<p>Per-and  polyfluoroalkyl  substances  (PFAS)  are  a  large  group  of  emerging  contaminants  that include astrong carbon-flourine bond that makes the compounds resistant to physical, chemical and  biological  degradation.  They  are  found  in  drinking  water  supplies,  daily  human  products, manufacturing  facilities,  and  in  areas  where  aqueous  film-forming  foam  (AFFF)was  used  to extinguish fires. Toxicity levels of these chemicals can vary depending on the characteristics of the specific chemical; longer carbon chain has shown to be more bioaccumulative and toxic than shorter chain length PFAS. Many studies have recognized perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) to be a substantial concern due to their known toxicity to wildlife. For example, studies show strong evidence that PFOA and PFOS suppress the antibody response from animals. Due to adverse health effects and public concern, the U.S stopped perfluorooctanoic acid (PFOA) manufacturing and switched to the production of an alternative fluorinated compound known  as  hexafluoropropylene  oxide  (HFPO)  dimer  acid  or  GenX,  which  is  thought  to  beless bioaccumulative and therefore, potentially less toxic. These anthropogenic pollutants are one of many stressors acting on aquatic organisms like anurans. Natural stressors such as the devastating fungal  pathogen Batrachocytrium  dendrobatidis(Bd)  is  another  stressor  impacting  amphibian populations.  Despite the co-occurrence of these stressors, no studies have examined interactive effects of the fungal pathogen Bd and PFAS, or whether PFAS effects carry over into the terrestrial environment aftera larvae  exposure. This study  tested the growth and developmental effects of PFOS, PFOA, and GenX, on gray treefrog (Hyla versicolor) tadpoles, followed by a Bd challenge in metamorphs. Our results demonstrate that a PFAS larval exposure interacted witha terrestrial Bdchallenge to influence growth and development. Bdexposed animals were significantly shorter (smaller snout vent length)  and had a significant increase in body condition and mass. This is the first study to report effects on amphibian terrestrial life stages after larval exposure to PFAS and to report an increased sensitivity to Bd. The environmentally relevant concentrations tested in this study  (<10  parts  per  billion)  lend  ecological  significance  to  these  results  however,  additional studies are needed to understand the mechanisms behind these effects.</p>

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Polychlorinated biphenyls (PCBs) are persistent organic pollutants that can bioaccumulate in organisms. PCBs are documented endocrine disrupting chemicals and are known to cause developmental, reproductive, and neurobiological disorders. This study examines the bioaccumulation of PCBs in the northern diamondback terrapin (Malaclemys terrapin terrapin), a species that is endemic to the brackish waters of the East Coast salt marshes of the United States. The two populations studied are located in Cape May County, NJ, a site with low levels of contamination and Jamaica Bay, NY, which is a highly contaminated site. While PCBs bioaccumulation has been extensively researched, many studies involve lethal sampling techniques. Such techniques can be detrimental to populations and may not be viable for long-term studies. This study examined the utility of the chorioallantoic membrane (CAM) as a non-lethal sampling technique for PCB analysis. In order to determine the viability of the CAM, maternal transfer of contaminants was also analyzed. Ten terrapin samples from each field location were analyzed. Egg and CAM samples were obtained from both field sites and liver samples were also collected from Cape May County terrapins. PCB levels and congener profiles were similar in both field locations. While PCB congeners were detected in liver, egg, and CAM samples, less chlorinated congeners preferentially partitioned in the CAM. Liver and egg sample PCB concentrations were strongly correlated, but the CAM concentrations were weakly correlated to liver and egg samples. Examination of homolog groups indicated a strong correlation between hexachlorinated biphenyls in all three sample types. Preliminary study results indicated that maternal transfer of PCB contaminants does occur with selective partitioning of congeners into the CAM. / Biology

The majority of research studying the ecological impacts of the coal mining industry on freshwater systems has focused on abandoned-mined land, and the associated acid drainage and metals toxicity. Treated discharges from active mining and preparation facilities, however, can also impair lotic ecosystems through total dissolved solids (TDS) toxicity, caused primarily by the reagents used for pH modifications and the oxidation of reduced sulfur. Such impairment was best detected through application of (1) benthic macroinvertebrate surveys using metrics of biotic impairment such as relative Ephemeroptera abundance and Ephemeroptera-Plecoptera-Trichoptera (EPT) minus the tolerant caddisfly family Hydropsychidae (2) in situ growth of Corbicula fluminea during 96-d exposure and (3) laboratory testing using Ceriodaphnia dubia. Traditional metrics such as total taxa richness, EPT, diversity and biotic indices were not sensitive to elevated TDS levels. Further study using strength of evidence, regression analysis and manipulation of laboratory formulated media, indicated that the mine effluent was the primary causal agent of the observed biotic impairment, and its toxicity could be attributed to sodium/sulfate-dominated TDS, which is significantly ameliorated by water hardness. Finally, although testing with lentic cladocerans, such as Ceriodaphnia, is consistent, cost-effective and sensitive to TDS related toxicity, the ecological relevance and protective capability of such testing is questionable when assessing contaminant effects on sensitive macroinvertebrates indigenous to lotic systems. A more ecologically relevant laboratory bioassay using the mayfly, Isonychia bicolor, in simulated lotic microcosms provided more sensitive endpoints than Ceriodaphnia and Pimephales promelas. Although the heartiness of Isonychia in laboratory conditions is poorly understood relative to standardized test organisms, these results, along with potential toxic impacts from numerous sodium/sulfate-dominated wastewaters discharging into freshwater systems, may have important implications to future national pollution discharge and elimination system (NPDES) permit testing. Currently, however, strong recommendations can only be made using Ceriodaphnia endpoints. Potential acute toxicity to aquatic organisms in high hardness solution (~790 mg/L as CaCO₃) is possible where sodium/sulfate-dominated TDS levels exceed ~7000 uS/cm (5167 mg/L), with potential chronic toxicity occurring at ~3200 uS/cm (2342 mg/L). These endpoints were significantly reduced in solutions of lower hardness (88 mg/L as CaCO₃), with acute and chronic toxicity occurring at 5100 uS/cm (3754 mg/L) and ~2100 uS/cm (1523 mg/L), respectively. Point source discharges causing instream TDS concentrations to exceed these levels risk impairment to aquatic life. / Master of Science

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<p> Per- and polyfluoroalkyl substances (PFAS) are a class of persistent environmental contaminants that have become ubiquitous, resulting in widespread exposure among humans and wildlife. Amphibians are regularly exposed in the field, making them susceptible to sublethal effects of PFAS exposure. In amphibians exposed to PFAS, deleterious effects have been observed, including reduction in body condition measured using the scaled mass index (SMI) and degraded hepatic condition, among others. PFAS may dysregulate lipid metabolism by altering signaling cascades regulated by peroxisome proliferator activated receptors (PPAR), but whether changes in energy stores can explain changes in amphibian SMI and/or hepatic condition remain underexplored. Since lipids are a critical energy reserve for anurans, understanding whether lipid metabolism is being perturbed is critical. The central objective of this thesis was to investigate the effect of PFAS on lipid homeostasis in <em>Xenopus laevis </em>tadpoles within the context of a PPAR mechanism of action (MOA), considering apical, molecular, and lipidomic endpoints. I conducted three studies: (a) a study to characterize SMI and the relative expression of the hepatic xPPARα/β/γ during metamorphosis, (b) a pharmaceutical exposure to assess the <em>in vivo</em> effects of xPPARα/β/γ agonism on hepatic gene expression for select downstream targets (<em>apoa5, fabp1, acox1,​ pck1</em>), and (c) a chronic PFAS exposure to investigate the effects of environmentally relevant concentrations (PFOS, PFHxS, PFOA, PFHxA at 0.5 ppb; binary mixture of PFOS:PFHxS at 1 ppb) on lipid homeostasis through apical endpoints (mass, snout vent length, SMI, hepatic condition), relative hepatic gene expression, and Multiple Reaction Monitoring (MRM) profiling of the hepatic lipidome for changes in relative class abundance. In study (a), I identified SMI and hepatic expression of <em>xPPARα/β/γ</em> is dynamic during late metamorphosis, indicating the potential for heightened susceptibility. However, in study (b), pharmaceutical agonists had no effect on <em>X. laevis</em> at high doses. For study (c), I did not observe effects on a majority of apical endpoints, including SMI, but detected a significant sex-specific reduction in hepatic condition for male<em> X. laevis</em> tadpoles exposed to single-chemical perfluorosulfonic acid (PFSA) treatments. For gene expression, I observed a transient downregulation for apolipoprotein-V (<em>apoa5</em>) at Nieuwkoop and Faber (NF) stage 62 for <em>X. laevis</em> tadpoles exposed to single-chemical perfluorocarboxylic acid (PFCA) treatments. Lipid profiling detected transient dysregulation of predominantly membrane lipids in-response to short-chain PFAS treatments at NF 58. Overall, our findings indicate PFAS may exert toxicity during anuran metamorphosis through multiple mechanisms of action (MOA) with sex-specific and developmental-stage specific outcomes.</p>