Periodic monitoring of contaminant levels in fish from the Yukon Territory indicated that organochlorine (OC) contaminants had rapidly declined since the early 1990s. This study examined OC concentrations, including chlordane (sigma-CHL), sigma-DDT, hexachlorocyclohexane (sigma-HCH), toxaphene (sigma-CHB), sigma-PCB and chlorinated benzenes (sigma-CBz) in sentinel fish (species of consistent annual observation and collection) from two Yukon lakes (Kusawa, Quiet), and from the aquatic food web of a focus lake (Lake Laberge) across several temporal points between 1993 and 2003. OC analysis and phytoplankton counts from dated sediment cores as well as climate data were also collected. Population, morphological (length, weight, age), biochemical (lipid content, delta-13C, delta-15N) and OC contaminant data for fish and invertebrates (zooplankton, snails, clams) were reviewed to elucidate the primary causes for these OC declines. Although some spatial differences in contaminant levels exist between the Yukon lakes, OC concentrations were declining for lake trout in all three lakes, with declines also noted for burbot from Lake Laberge. Several other fish species as well as zooplankton from Lake Laberge exhibited decreases in contaminant levels except northern pike, which registered consistently higher levels from 1993 to 2001. There was no evidence to support the hypotheses of changes in fish trophic levels or food sources with the exception of burbot, which marginally decreased, and northern pike, which climbed a half trophic level. Through OC flux analysis in dated sediments, the hypothesis that declines in abiotic deposition affected the contaminant levels in the food web was also negated. The closure of the Lake Laberge commercial fishery resulted in faster fish growth and larger fish populations, which are contributing to biomass dilution of OC concentrations, higher OC biomagnification factors for some species and likely changes in predator-prey interactions as resource competition increases. The large ratio of OC decreases in the lower vs. higher trophic levels of Lake Laberge have increased food web magnification factors (FWMF) for all six OC groups. It is also suspected that above-average temperatures and below-average precipitation in the lower Yukon region over the 1990s may have contributed towards an increase in lake primary production resulting in biomass dilution of contaminants in zooplankton for all three study lakes. Concurrently, shifts in the Lake Laberge zooplankton community, from climate fluctuations or increased fish predation, have gone from an abundance of Cyclops scutifer in 1993 to dominance by Diaptomus pribilofensis in 2001, although sample sites were limited. Characteristics specific to each species (e.g. body size, composition and metabolism) likely play a role in the significant OC declines measured in zooplankton. Fluctuations in population dynamics, species characteristics and OC contaminant concentrations in the Lake Laberge ecosystem may continue for several years to come. Sentinel species such as lake trout, burbot, whitefish, cisco and plankton should continue to be monitored in all three Yukon lakes for future temporal correlations with contaminants or climate change. / May 2006

Contaminated areas resulting from anthropogenic activities have, for the most part, concentrations of contaminants that exceed Tier 1 standards below which the risk is considered acceptable. However, contaminants that have been in soil for a prolonged period can become recalcitrant over time, due to various physico-chemical and biological processes. Sequestered and recalcitrant contaminants are not readily biologically available to living organisms. However, they are easily measured analytically because of the strong acid extractions that are used in the analytical methodologies. Because toxicity is a function of exposure concentration(s), exposure duration, and bioavailability, contaminants in soil can be present at concentrations that exceed established standards but they represent minimal risk to ecological receptors because the contaminants are not fully available. To predict toxicity and estimate risk, it is imperative that an accurate and reliable measure of bioavailability be available. Several surrogate measures of bioavailability were compared to the results of a battery of toxicity tests using Cu, Pb, and Zn-contaminated soils collected from a former industrial area and Cu and Zn-contaminated soils collected from a former mining site. CaCl₂extractions, hydroxypropyl-β-cyclodextrin (cyclodextrin) extractions, Simulated Earthworm Gut (SEG) tests, and bioaccumulation tests were performed using the soils. Overall, SEG-extractable Cu was most predictive of adverse effects in industrial soils, likely due to enzymatic activity and/or increased ionic strength of the solution. For the mining soils, all chemical measures of bioavailability correlated with several biological responses; however, CaCl₂-extractable Cu and SEG-extractable Cu and Zn best predicted earthworm responses. Total Cu concentrations in soil correlated best with adverse effects to plants. No method was a good predictor of all biological effects for a single organism when data from the two sites were combined. The SEG test may provide a good indication of metal toxicity at contaminated sites with varying soil physico-chemical characteristics but further validation is required.

Contaminated areas resulting from anthropogenic activities have, for the most part, concentrations of contaminants that exceed Tier 1 standards below which the risk is considered acceptable. However, contaminants that have been in soil for a prolonged period can become recalcitrant over time, due to various physico-chemical and biological processes. Sequestered and recalcitrant contaminants are not readily biologically available to living organisms. However, they are easily measured analytically because of the strong acid extractions that are used in the analytical methodologies. Because toxicity is a function of exposure concentration(s), exposure duration, and bioavailability, contaminants in soil can be present at concentrations that exceed established standards but they represent minimal risk to ecological receptors because the contaminants are not fully available. To predict toxicity and estimate risk, it is imperative that an accurate and reliable measure of bioavailability be available. Several surrogate measures of bioavailability were compared to the results of a battery of toxicity tests using Cu, Pb, and Zn-contaminated soils collected from a former industrial area and Cu and Zn-contaminated soils collected from a former mining site. CaCl₂extractions, hydroxypropyl-β-cyclodextrin (cyclodextrin) extractions, Simulated Earthworm Gut (SEG) tests, and bioaccumulation tests were performed using the soils. Overall, SEG-extractable Cu was most predictive of adverse effects in industrial soils, likely due to enzymatic activity and/or increased ionic strength of the solution. For the mining soils, all chemical measures of bioavailability correlated with several biological responses; however, CaCl₂-extractable Cu and SEG-extractable Cu and Zn best predicted earthworm responses. Total Cu concentrations in soil correlated best with adverse effects to plants. No method was a good predictor of all biological effects for a single organism when data from the two sites were combined. The SEG test may provide a good indication of metal toxicity at contaminated sites with varying soil physico-chemical characteristics but further validation is required.

There is considerable need for higher-tier aquatic risk assessment and information on toxicant-induced molecular alterations in lower aquatic invertebrates. Thus the current study&rsquo / s priorities were two-fold: a novel approach utilizing higher-tier ecotoxicity bioassay-guided ATR-FTIR (Attenuated Total Reflectance Fourier Transform Infrared) spectroscopy to better understand the impact of the presence of fish predation pressure &ndash / mimicked by predator-exuded info-chemicals &ndash / on cypermethrin or salinity toxicity to Daphnia pulex &ndash / key-stone species in lake ecosystems &ndash / and ultimately better assess toxicant-induced alterations at both organismal and molecular levels. This approach indicates that even low concentrations of cypermethrin/salinity had significant molecular and organismal effects on daphnids. Fish kairomone acted as a major factor affecting toxicant severity, interacting antagonistically below a threshold and synergistically above. Moreover, molecular ATR-FTIR spectroscopic results, clearly consistent with organismal responses, showed that both cypermethrin and salinity lead to decreased contributions of lipid and proteins to the investigated daphnid systems. It is further suggested that the action mechanism of the fish-exuded kairomone occurs via the lipid metabolism of Daphnia. Hence, infrared spectroscopic results enabled detection of early molecular alterations, whose effects might not always be observable at the organismal level. The results of this study clearly indicate that the simplistic nature of standard ecotoxicology tests hinders a precise judgment of threats imposed by chemicals of interest. Furthermore, it has been shown that ATR-FTIR spectroscopy has considerable potential for studies on daphnid responses to varying environmental conditions. Thus, this study presents a starting point for increasing the environmental realism of aquatic risk assessment.

There is a growing need to develop rapid and cost-effective ecotoxicological tools for risk assessment because traditional methods examine endpoints such as mortality, which do not provide any insight into the mode of action (MOA) of the chemical. Research presented within this thesis illustrates the potential of 1H NMR-based metabolomics as a rapid and routine ecotoxicological tool that can elucidate a chemical’s MOA and also aid in the identification of metabolites of exposure. Metabolomics involves measuring the fluctuations in the endogenous metabolites of an organism within a cell, tissue, bio-fluid or whole organism in response to an external stressor. We focused on the model polycyclic aromatic hydrocarbon (PAH) phenanthrene, and the perfluoroalkyl acids (PFAAs) perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), due to their recalcitrant nature and widespread prevalence in soil environments. 1H NMR-based metabolomics analysis of the exposure of Eisenia fetida earthworms to sub-lethal phenanthrene exposure via filter paper contact tests revealed a concentration-dependent two-phased MOA: a linear correlation between the metabolic response and exposure concentration at low concentrations followed by a plateau in the responses at high concentrations. Alanine, glutamate, maltose, cholesterol and phosphatidylcholine emerged as potential indicators of phenanthrene exposure. An increased energy demand and an interruption in the conversion of succinate to fumarate in the Krebs cycle were observed due to phenanthrene exposure. Sub-lethal PFOA and PFOS exposure to E. fetida via contact tests for two days revealed heightened responses with higher PFOA and PFOS concentrations. Leucine, arginine, glutamate, maltose, and ATP were identified as potential indicators of PFOA or PFOS exposure. E. fetida responses were then investigated after exposure for two, seven and fourteen days to an artificial soil that was spiked with sub-lethal PFOS concentrations. An exposure time-dependent operation of two separate MOAs were identified. Both the contact tests and artificial soil exposure studies identified an elevation in fatty acid oxidation, a disruption in energy metabolism and biological membrane structure, and also an interruption of ATP synthesis following PFOA and PFOS exposure. This thesis illustrates the promise of NMR-based metabolomics as a routine tool for ecotoxicological assessment of contaminated sites.

There is a growing need to develop rapid and cost-effective ecotoxicological tools for risk assessment because traditional methods examine endpoints such as mortality, which do not provide any insight into the mode of action (MOA) of the chemical. Research presented within this thesis illustrates the potential of 1H NMR-based metabolomics as a rapid and routine ecotoxicological tool that can elucidate a chemical’s MOA and also aid in the identification of metabolites of exposure. Metabolomics involves measuring the fluctuations in the endogenous metabolites of an organism within a cell, tissue, bio-fluid or whole organism in response to an external stressor. We focused on the model polycyclic aromatic hydrocarbon (PAH) phenanthrene, and the perfluoroalkyl acids (PFAAs) perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), due to their recalcitrant nature and widespread prevalence in soil environments. 1H NMR-based metabolomics analysis of the exposure of Eisenia fetida earthworms to sub-lethal phenanthrene exposure via filter paper contact tests revealed a concentration-dependent two-phased MOA: a linear correlation between the metabolic response and exposure concentration at low concentrations followed by a plateau in the responses at high concentrations. Alanine, glutamate, maltose, cholesterol and phosphatidylcholine emerged as potential indicators of phenanthrene exposure. An increased energy demand and an interruption in the conversion of succinate to fumarate in the Krebs cycle were observed due to phenanthrene exposure. Sub-lethal PFOA and PFOS exposure to E. fetida via contact tests for two days revealed heightened responses with higher PFOA and PFOS concentrations. Leucine, arginine, glutamate, maltose, and ATP were identified as potential indicators of PFOA or PFOS exposure. E. fetida responses were then investigated after exposure for two, seven and fourteen days to an artificial soil that was spiked with sub-lethal PFOS concentrations. An exposure time-dependent operation of two separate MOAs were identified. Both the contact tests and artificial soil exposure studies identified an elevation in fatty acid oxidation, a disruption in energy metabolism and biological membrane structure, and also an interruption of ATP synthesis following PFOA and PFOS exposure. This thesis illustrates the promise of NMR-based metabolomics as a routine tool for ecotoxicological assessment of contaminated sites.

Dagligen utsätts vi för en stor mängd kemikalier, som har visat sig vara mer eller mindre farliga. Många av dessa kemikalier har en negativ påverkan genom att förgifta miljön men också oss människor. Barn och foster är speciellt utsatta för skadliga kemikalier och främst hormonstörande kemikalier. Detta eftersom de befinner sig i ett kritiskt utvecklingsstadium från fostertiden fram till vuxen ålder. Idag fokuserar mycket av arbetet kring kemikalier på redan födda barn, men mycket lite eller inget arbete görs i förebyggande syfte för att skydda foster under graviditeten. Den yrkesgrupp som träffar gravida och ger råd kring graviditeten är barnmorskor. Därför syftar denna studie till att undersöka hur gravida och barnmorskor upplever kommunikationen mellan dem om skadliga kemikalier. Utöver upplevelsen undersöker också studien vilka hinder och möjligheter som finns för en god riskkommunikation mellan barnmorskor och gravida kring skadliga kemikalier. Det teoretiska perspektivet för uppsatsen är Ulrich Beck och hans teori om risksamhället samt teorier om riskkommunikation. Studien har en kvalitativ ansats och metoderna som har använts är intervju och enkät. Intervjuer för att undersöka barnmorskornas upplevelser och enkäten var en internetbaserad enkät som har figurerat på ett socialt media (Facebook) för att få svar på gravidas upplevelser. Resultatet visar på flera hinder som barnmorskan upplever till exempel tidsbrist, brist på arbetsrutiner, riktlinjer och arbetsmaterial, okunskap och ett bristande intresse hos kollegor och organisation. Upplevda möjligheter är att frågan har börjat väckas. Det finns möjligheter till att utveckla arbetsrutiner och riktlinjer och att alla intervjuade barnmorskor är positiva till att frågan får mer utrymme. Upplevelsen av kommunikationen är bland annat att både barnmorskorna och gravida upplever att debatten och vetenskapen är svår att tolka, det finns en känsla av att det mesta utgör en risk samt att debatten och kommunikationen behöver nyanseras och få en vetenskaplig grund. Studiens slutsatser är att att dagens obefintliga riskkommunikation mellan gravida och barnmorskor bör utvecklas då både barnmorskor och gravida efterfrågar en kommunikation kring riskerna. / We are on a daily basis exposed to a large amount of chemicals that have been shown to be more or less dangerous. Many of these chemicals have a negative effect by poisoning the environment, but also humans. Children and fetuses are especially vulnerable to harmful chemicals and particularly endocrine disrupting chemicals. This is because they are in a critical stage of development from the fetal period to adulthood. Today, much of the work on chemicals are concentrate to already born children, but very little or no work is done as a preventive measure to protect the fetus during pregnancy. Midwives are the profession that meet the pregnant women continuously during the pregnancy and already informs the pregnant woman about different risks associated with the pregnancy. Therefore is the aim of this study to explore how pregnant women and midwives are experiencing their communication on harmful chemicals during pregnancy. In addition to the experience, is the aim to explore obstacles and opportunities that are needed for a good risk communication between midwives and pregnant women about harmful chemicals. The theoretical perspective of this paper is Beck and his "risk society" and theories of risk communication. The study has a qualitative approach and methods that have been used are interview and questionnaire. Interviews to explore midwives’ experiences and the survey were an online survey that has appeared on a social media (Facebook). The result indicates several obstacles that the midwife experience, for example: lack of time, lack of guidelines, work routines and working material. Ignorance and a lack of interest among colleagues and organization. Perceived opportunities are that the question has begun to be brought into action, there are opportunities to develop operating procedures and guidelines and that the interviewed midwives have a positive attitude to give the issue more space. The experience of the communication is that both the midwives and pregnant women perceive that the debate and the science is difficult to interpret, there is a sense that almost everything represents a risk and that the debate and the communication needs to be qualified and have a scientific basis. The study's conclusions are that today's non-existent risk communication between pregnant women and midwives should be developed as both midwives and pregnant women ask for a communication about the risks.

Mercury (Hg) is a global pollutant, yet Hg biomagnification, the increase in Hg with trophic level, remains poorly characterized in many regions, especially at subtropical latitudes. The present study assessed subtropical reservoirs of eastern China, which provided an opportunity to quantify Hg biomagnification under highly altered conditions that included high atmospheric Hg deposition, use of reservoirs for fisheries, manipulation of food webs through stocking and high fishing pressure, and increasing eutrophication. Despite China’s Hg emission and deposition rates that are among the highest worldwide, low fish Hg concentrations and Hg biomagnification rates were found; this was explained by food web structure and fish species characteristics. Stocked species occupied lower trophic levels and had significantly lower Hg concentrations relative to wild fishes. Evidence of decreased Hg concentrations with eutrophication (as indicated by chlorophyll-a) was observed, suggesting algal biodilution and/or somatic growth dilution. Relative to temperate lakes, zooplankton density dilution may also be causing reduced Hg concentrations in subtropical biota. Hydrogeomorphic features, such as water retention time and percent crop cover, explained Hg bioaccumulation factors and Hg concentrations at the base of the food web. Eutrophication and hydrogeomorphic features also influenced the bioavailability of selenium, which can protect against the toxicity of Hg at adequate concentrations, and the concentration of eicosapentaenoic acid, a beneficial fatty acid, in the planktivorous Bighead Carp (Hypophthalmichthys nobilis). This may indicate that the risk of exposure to the neurotoxicant methylmercury relative to benefits of fish consumption may increase with eutrophication in some fish species. Overall, the findings of this study suggest food web structure, eutrophication, and hydrogeomorphic features together explain low Hg concentrations in anthropogenically modified subtropical reservoirs in eastern China. / Thesis (Ph.D, Biology) -- Queen's University, 2014-07-01 11:35:12.637

Il lavoro qui presentato è incentrato sulla caratterizzazione dei Fontanili - risorgive semi-natural1 comuni della regione Lombardia (Nord Italia), GDES rilevanti per il progetto GENESIS sulle acque sotterranee (progetto europeo finanziato nell'ambito del 7th Framework Programme). Gli obiettivi di questo lavoro di dottorato sono stati: - Caratterizzare gli ecosistemi Fontanili sulla base delle conoscenze scientifiche disponibili; - Individuare le risposte ecotossicologiche di un indigeno specie bentoniche macroinvertebrati alla contaminazione agricola attraverso la sperimentazione in Fontanili per verificare se il metodo applicato può servire come bioindicatore della contaminazione negli ecosistemi Fontanili. Gli obiettivi indicati sono affrontati nelle sezioni seguenti. Sezione 3 caratterizza gli ecosistemi Fontanili sulla base delle conoscenze scientifiche disponibili. La sezione 4 è una rivista di indicatori biologici per la valutazione della qualità delle acque con particolare attenzione alla macroinvertebrati. La sezione 5 presenta i risultati degli studi su Fontanili selezionati con l'uso di un test biologico in situ di alimentazione con un anfipode indigena Echinogammarus stammeri. I capitoli 6 e 7 sono esperimenti di laboratorio condotti per misurare le risposte delle anfipodi di inquinanti agricoli rilevati nei Fontanili studiati. A parte il lavoro condotto in Italia, l'autore insieme a Sarah Joseffson dal Dipartimento di Scienze acquatica e Valutazione, Università Svedese di Scienze Agrarie a Uppsala, in Svezia eseguito uno studio "Trasferimento di inquinanti organici persistenti da acquatico a ambienti terrestri con insetti acquatici come vettori" nel 2012. La descrizione e preliminari risultati di questo lavoro di studio possono essere trovati nell'appendice I. / The work presented here is focused on characterization of fontanili - semi-natural1 springs common in the Lombardy region (North Italy), relevant groundwater dependent ecosystems for the GENESIS project on groudwater systems (European project funded under the 7th Framework Programme). The objectives of this PhD work were: - to characterize the fontanili ecosystems based on the available scientific knowledge; - to identify ecotoxicological responses of an indigenous macroinvertebrate benthic species to agricultural contamination through experimentation in fontanili ecosystems This will test if the applied method can serve as a bioindicator of contamination in the fontanili ecosystems. The mentioned objectives are addressed in the following sections. Section 3 characterizes the fontanili ecosystems based on the available scientific knowledge. Section 4 is an overview of biological indicators as water quality assessment with focus on macroinvertebrates. Section 5 presents the results of field studies on selected fontanili sites with the use of an in situ feeding bioassay with an indigenous amphipod Echinogammarus stammeri. Chapters 6 and 7 are laboratory experiments conducted to measure the responses of the amphipods to commonly detected agricultural pollutants in the studied fontanili. Apart from the work conducted in Italy, the author together with Sarah Joseffson from the Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences in Uppsala, Sweden performed a study “Transfer of persistent organic pollutants from aquatic to terrestrial environments with aquatic insects as vectors” in 2012. The description and preliminary results of this study work can be found in Appendix I.

Periodic monitoring of contaminant levels in fish from the Yukon Territory indicated that organochlorine (OC) contaminants had rapidly declined since the early 1990s. This study examined OC concentrations, including chlordane (sigma-CHL), sigma-DDT, hexachlorocyclohexane (sigma-HCH), toxaphene (sigma-CHB), sigma-PCB and chlorinated benzenes (sigma-CBz) in sentinel fish (species of consistent annual observation and collection) from two Yukon lakes (Kusawa, Quiet), and from the aquatic food web of a focus lake (Lake Laberge) across several temporal points between 1993 and 2003. OC analysis and phytoplankton counts from dated sediment cores as well as climate data were also collected. Population, morphological (length, weight, age), biochemical (lipid content, delta-13C, delta-15N) and OC contaminant data for fish and invertebrates (zooplankton, snails, clams) were reviewed to elucidate the primary causes for these OC declines. Although some spatial differences in contaminant levels exist between the Yukon lakes, OC concentrations were declining for lake trout in all three lakes, with declines also noted for burbot from Lake Laberge. Several other fish species as well as zooplankton from Lake Laberge exhibited decreases in contaminant levels except northern pike, which registered consistently higher levels from 1993 to 2001. There was no evidence to support the hypotheses of changes in fish trophic levels or food sources with the exception of burbot, which marginally decreased, and northern pike, which climbed a half trophic level. Through OC flux analysis in dated sediments, the hypothesis that declines in abiotic deposition affected the contaminant levels in the food web was also negated. The closure of the Lake Laberge commercial fishery resulted in faster fish growth and larger fish populations, which are contributing to biomass dilution of OC concentrations, higher OC biomagnification factors for some species and likely changes in predator-prey interactions as resource competition increases. The large ratio of OC decreases in the lower vs. higher trophic levels of Lake Laberge have increased food web magnification factors (FWMF) for all six OC groups. It is also suspected that above-average temperatures and below-average precipitation in the lower Yukon region over the 1990s may have contributed towards an increase in lake primary production resulting in biomass dilution of contaminants in zooplankton for all three study lakes. Concurrently, shifts in the Lake Laberge zooplankton community, from climate fluctuations or increased fish predation, have gone from an abundance of Cyclops scutifer in 1993 to dominance by Diaptomus pribilofensis in 2001, although sample sites were limited. Characteristics specific to each species (e.g. body size, composition and metabolism) likely play a role in the significant OC declines measured in zooplankton. Fluctuations in population dynamics, species characteristics and OC contaminant concentrations in the Lake Laberge ecosystem may continue for several years to come. Sentinel species such as lake trout, burbot, whitefish, cisco and plankton should continue to be monitored in all three Yukon lakes for future temporal correlations with contaminants or climate change.