Indoor air quality investigations often focus on air and settled dust samples to assess chemical and biological contamination. Although the information provided by these techniques is useful, HVAC filters represent a new option for investigating contaminants in the indoor environment. This dissertation explores the potential use of HVAC filters as long-term, passive samplers by investigating the contaminants found in HVAC dust and other indoor locations and by evaluating the likelihood that HVAC filters will capture indoor particles. A field investigation of heavy metal and culturable microbial contaminants found in air, settled dust and HVAC filter dust corroborated the hypothesis that HVAC filters hold promise as a sampling mechanism in residences. However, several factors including filter efficiency, HVAC cycling and particle size seemed to influence the results. Also, it was unclear how the composition of the microbial communities varied with sampling location. Subsequently, the bacterial and fungal communities present in several sampling locations within residences and in an unoccupied test house were investigated. In residences, the microbial communities encountered in HVAC filter dust were not different from those in high surface dust. High efficiency HVAC filters also seem to be a viable alternative to long-term air sampling. Occupants influence the composition of the microbial communities in residences and are viii associated with Actinobacteria and Firmicutes, while Proteobacteria dominate the air samples and might have an outdoor air origin. A fate analysis to assess the magnitude of the different particle removal mechanisms revealed that small and large particles are likely to deposit on surfaces, while intermediate sized particles stay suspended in air longer. HVAC filters can collect particulate matter over a broad size range and may be effective overall samplers of particle-bound contaminants. Nevertheless, filter efficiency and air recirculation rate are important parameters that influence the likelihood that filters will capture particles, while air exchange rate has little effect. The results from this study indicate that HVAC filters can be used as an alternative to traditional indoor sampling mechanisms for contaminants associated with particles.

The Swedish otter (Lutra lutra) population decreased markedly after the 1950’s and was considered to be seriously threatened for decades. Pollution from industries and other anthropogenic activities were suspected to be the major cause of the decline. The otter is a top-predator in aquatic systems and therefore particularly susceptible to bioaccumulative and toxic substances. For this reason, the species can be regarded as a valuable indicator of environmental health. Today, the Swedish otter population is increasing and has been reestablished in many areas. However, the otter is still missing in some regions of Sweden, especially in the southeast. The aim of this study was to investigate past and present levels, and temporal trends, of environmental contaminants in otters from Småland.The study is based on data of environmental contaminants in liver and muscle tissue from dead otters found in Småland during 1966-2014. I found that the perfluorinated compounds PFOS and PFOA have increased in otters since the 1970’s which is alarming and should be given special concern in future monitoring. Also, while mercury (Hg) is rather stable, selenium (Se) concentrations are decreasing, resulting in Hg exceeding Se on molar mass basis in several otters. This indicates that all of the available Se is bound to mercury, which may imply that the otters are vulnerable to additional Hg contamination. My conclusions are that the present concentrations of the studied environmental contaminants have probably not affected the otter population in general. However, otters may be exposed to toxic levels of some contaminants in certain areas that are more polluted from anthropogenic activities. This could be harmful to individual otters or their reproduction, and therefore, continued monitoring is highly relevant.

10 pp. / Introduction: Adult human beings may drink up to two liters/day (approx. two quarts/day) of fresh water to stay alive. However, we can consume up to two quarts/hour of water, depending on the level of activity, ambient temperature, and humidity conditions (Born 2013). We also need fresh water to cook with and to clean ourselves. About 40% of our food production depends on irrigation (UN Water 2013) using water with low salinity and other contaminants. Climate scientists project increasing temperatures and possibly less rainfall in the Southwest now and into the near future, see Extension Publication #AZ1458 (Artiola et al. 2008). Thus, climate change is likely to stress the limited water resources of Arizona and affect water quality by concentrating contaminants and stressing water-dependent environments. This publication presents brief summaries of the types of water sources, their water quality, and possible uses in Arizona. Since the types and amounts of constituents found in water, whether nutrients, pathogens, contaminants or pollutants, help determine its possible uses, it is necessary to measure water quality to determine treatment options for a given use. To assist in this task, we present a triangle-shaped diagram (Figure 8) which divides water quality into three major groups: Pathogens, Salinity, and Specific Contaminants, placing major water sources in relation to the three groups. Home and well owners can use this diagram as a general aid to evaluate various sources of water, determine their likely water quality, and identify appropriate uses for them.

Ecotoxicology studies attempt to evaluate the consequences of exposure to environmental contaminants by defining exposure and effects parameters across multiple levels of biological organization. Genetic markers are well-suited for these studies as they can track both somatic and evolutionary effects. In the studies reported here, connections among contaminant levels in environmental media and biota, in vitro bioassay results, and changes in individual- and population-level biomarkers were explored. Sediment and/or wildlife samples were collected from each of three sites of documented environmental contamination, Sumgayit and Baku in the Republic of Azerbaijan and East Fork Poplar Creek in Tennessee. Sumgayit and Baku are heavily contaminated with petroleum and petrochemical wastes. Sediments from several areas and tissues from turtles inhabiting a contaminated wetland contained high levels of several compounds, including mercury, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine pesticides. Sediment extracts produced variable responses in the Salmonella/microsome mutagenicity assay and did not necessarily reflect contaminant burden. Micronucleus counts in European pond turtles were not statistically different from counts in the same species from an uncontaminated reference site. The counts were statistically correlated with tissue levels of mercury, heptachlor, DDD, hexachlorobenzene, and trans-nonachlor. These results confirmed that Sumgayit and Baku are heavily contaminated with a complex mixture of pollutants and demonstrated that genotoxic effects from exposure to contaminated sediments appear to be slight. East Fork Poplar Creek is a stream that receives contaminant influx from a former Department of Energy nuclear weapons production facility and several point and non-point sources around the city of Oak Ridge, Tennessee. In this study, coefficient of variation in cellular DNA content and randomly amplified polymorphic DNA markers were examined in central stonerollers and compared to previous studies in which the same markers were evaluated in red-breasted sunfish from the same sites. While assay responses were attenuated in stonerollers compared to the sunfish, there is some evidence of genetic damage in both species at the most contaminated sampling site. A common problem in the wildlife studies was high within sample variability combined with small sample size, which most likely masked potential contaminant-induced differences in markers used in these studies.

Aquaculture feeds, traditionally composed mainly of fishmeal and fish oil, currently represent the largest cost to fish farmers. With aquaculture growing at an average of 8.8% per year and limited supply of fishmeal and fish oil, suitable alternatives must be found. In addition to increasing sustainability and lowering production costs, the use of plant and/or animal ingredients has the potential to lower flesh levels of persistent organic pollutants (POPs) such as polychlorinated biphenyls. Fish oil and to a lesser extent fishmeal, are considered to be the largest source POPs in farmed fish. Using alternative feed ingredients however, can compromise fish growth and the flesh quality of the final product. Lipid sources including flaxseed oil, canola oil, poultry fat and the protein sources canola protein concentrate, soy protein concentrate and poultry by-product meal were examined as alternatives to fish oil and fishmeal in one on-farm field study and one laboratory feeding trial with Atlantic salmon (Salmon salar) and two laboratory feeding trials conducted on sablefish (Anoplopoma fimbria), a relatively new marine aquaculture species. The nutritive value of the alternative ingredients was assessed on the basis of fish growth performance, proximate composition, fatty acid composition and apparent digestibility coefficients. Sensory attributes were evaluated in the sablefish studies while flesh POP levels were determined in both species. The use of alternative dietary lipids showed no negative effects on fish performance. However replacement of fishmeal with plant proteins in some cases, negatively affected fish growth. Flesh levels of persistent organic pollutants were significantly decreased (p<0.05) with the use of alternative dietary lipids, and flesh levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were also depressed. Activated carbon treated anchovy oil and finishing diets were examined in the Atlantic salmon laboratory feeding trial and were effective at lowering flesh POP levels while providing high levels of EPA and DHA. The use of alternative feed ingredients will soon be inevitable in aquaculture feeds. The current research shows alternative lipids and proteins can be incorporated successfully in sablefish and Atlantic salmon feeds with minimal effects on fish growth and quality.

The American eel (Anguilla rostrata) has suffered a serious population decline in Lake Ontario since the early 1980s due to a decline in recruitment of juveniles migrating from the Sargasso Sea. This has resulted in the closure of the Lake Ontario fishery in 2004 and its listing as endangered under the Ontario Species at Risk act in June of 2008 in Ontario. Due to their complex life cycle, little is known about eels once they leave their freshwater habitats and migrate to the Sargasso Sea to reproduce. Ocean conditions, habitat destruction, disease, reduced lipid content, over-fishing, physical barriers (hydroelectric dams), and chemical contamination are all possible reasons for recruitment decline and may be acting cumulatively. Maternally derived dioxin-like contaminants (DLCs) accumulated during the growth phase of eels in Lake Ontario are toxic to fish embryos, and embryotoxicity is expressed as a series of malformations known as blue sac disease (BSD). I assessed whether these toxicants are in high enough concentrations in sexually maturing, eels to be embryotoxic to their offspring, as assessed by using Japanese medaka (Oryzias latipes), a surrogate species. Medaka embryos were first injected with 2,3,7,8-tetracholordibenzo-p-dioxin (TCDD) to establish their sensitivity to this test chemical expressed as an 11-day EC50 of 3.79 pg/mg, for the induction of BSD. Medaka embryos were injected with eel extracts and their response compared to the TCDD toxicity curve to assess whether extracts caused developmental problems and to estimate the relative concentration of DLCs. Eel extracts from all collection sites caused no dioxin-like toxicity to Japanese medaka embryos. However, significantly higher toxicity at 10 eeq relative to triolein was found for all extracts with no differences among sites, suggesting the presence of non-dioxin-like toxicants. The low level of maternal tissue contamination by DLCs implied by this bioassay is mirrored in chemical monitoring of persistent organic pollutants in Lake Ontario fish. If correct, the low levels of toxicity of extracts to embryos could contribute to the observed increase of eels entering L. Ontario from 2003 to 2008. / Thesis (Master, Biology) -- Queen's University, 2010-09-01 09:31:19.466

Chemical exposure in humans rarely consists of a single chemical. The everyday exposure is characterized by thousands of chemicals mainly present at low levels. Despite that fact, risk assessment of chemicals is carried out on a chemical-by-chemical basis although there is a consensus that this view is too simplistic. This thesis aims to validate a statistical method to study the impact of mixtures of contaminants and to use that method to investigate the associations between circulating levels of a large number of environmental contaminants and atherosclerosis and the metabolic syndrome in an elderly population. Contaminants measured in the circulation represented various classes, such as persistent organic pollutants, plastic-associated chemicals and metals. There was little co-variation among the contaminants and only two clusters of PCBs could be discerned. Gradient boosted CARTs were used to assess additive and multiplicative associations between atherosclerosis, as measured by the intima-media thickness (IMT) and the echogenicity of the intima-media complex (IM-GSM), and prevalent metabolic syndrome. Systolic blood pressure was the most important predictor of IMT while the influence of the contaminants was marginal. Three phthalate metabolites; MMP, MEHP and MIBP were strongly related to IM-GSM. A synergistic interaction was found for MMP and MIBP, and a small antagonistic interaction was found for MIBP and MEHP. Associations between the contaminants and prevalent metabolic syndrome were modest, but three pesticides; p,p’-DDE, hexachlorbenzene and trans-nonachlor along with PCBs 118 and 209 and mercury were the strongest predictors of prevalent metabolic syndrome. This thesis concludes that many contaminants need to be measured to get a clear picture of the exposure. Boosted CARTs are useful for uncovering interactions. Multiplicative and/or additive effects of certain contaminant mixtures were found for atherosclerosis or the metabolic syndrome.

An understanding of the dispersion of contaminants in turbulent flows is important in many fields ranging from air pollution to chemical engineering, and random walk models provide one approach to understanding and calculating aspects of dispersion. Two types of random walk model are investigated in this thesis. The first type, so-called "one-particle models", are capable of predicting only mean concentrations while the second type, "two-particle models", are able to give some information on the fluctuations in concentration as well. Many different one-particle random walk models have been proposed previously and several criteria have emerged to distinguish good models from bad. In this thesis, the relationships between the various criteria are examined and it is shown that most of the criteria are equivalent. It is also shown how a model can be designed to (i) satisfy the criteria exactly and (ii) be consistent with inertial subrange theory. Some examples of models which obey the criteria are described. The theory developed for one-particle models is then extended to the two-particle case and used to design a two-particle model suitable for modelling dispersion in high Reynolds number isotropic turbulence. The properties of this model are investigated in detail and compared with previous models. In contrast to most previous models, the new model is three-dimensional and leads to a prediction for the particle separation probability density function which is in agreement with inertial subrange theory. The values of concentration variance from the new model are compared with experimental data and show encouraging agreement.

We have developed a regional mass balance model for the St. Lawrence River near Cornwall, Ontario that describes the fate and transport of mercury in three forms, elemental mercury (Hg0), divalent mercury (Hg2+), and methyl mercury (MeHg), in a five compartment environment (air, water, sediments, periphyton, and benthos). Our first objective was to construct a steady-state mass balance model to determine the dominant sources and sinks of mercury in this environment. Our second objective was to construct a dynamic mass balance model to predict and hindcast mercury concentrations in this environment. We compiled mercury concentrations, fluxes, and transformation rates from previous studies completed in this section of the river to develop the model in STELLA®. The inflow of mercury was the major source to this system, accounting for 0.42 mol month-1, or 95.5% of all mercury inputs, whereas outflow was 0.28 mol month-1, or 63.6% of all losses, and sediment deposition was 0.12 mol month-1, or 27.3% of all losses. The dynamic mass balance model provides estimated results that are consistent with measured data and predicts historical local industrial emissions to be approximately 400 kg year-1. Uncertainty estimates were greatest for advective fluxes in surface water, porewater, periphyton, and benthic invertebrates. This model is useful for predicting and hindcasting mercury concentrations in other aquatic environments because it contains the three main environmental compartments, all forms of mercury, and compartments (e.g. periphyton) not included in previous mercury multi-media models.

Aquaculture feeds, traditionally composed mainly of fishmeal and fish oil, currently represent the largest cost to fish farmers. With aquaculture growing at an average of 8.8% per year and limited supply of fishmeal and fish oil, suitable alternatives must be found. In addition to increasing sustainability and lowering production costs, the use of plant and/or animal ingredients has the potential to lower flesh levels of persistent organic pollutants (POPs) such as polychlorinated biphenyls. Fish oil and to a lesser extent fishmeal, are considered to be the largest source POPs in farmed fish. Using alternative feed ingredients however, can compromise fish growth and the flesh quality of the final product. Lipid sources including flaxseed oil, canola oil, poultry fat and the protein sources canola protein concentrate, soy protein concentrate and poultry by-product meal were examined as alternatives to fish oil and fishmeal in one on-farm field study and one laboratory feeding trial with Atlantic salmon (Salmon salar) and two laboratory feeding trials conducted on sablefish (Anoplopoma fimbria), a relatively new marine aquaculture species. The nutritive value of the alternative ingredients was assessed on the basis of fish growth performance, proximate composition, fatty acid composition and apparent digestibility coefficients. Sensory attributes were evaluated in the sablefish studies while flesh POP levels were determined in both species. The use of alternative dietary lipids showed no negative effects on fish performance. However replacement of fishmeal with plant proteins in some cases, negatively affected fish growth. Flesh levels of persistent organic pollutants were significantly decreased (p<0.05) with the use of alternative dietary lipids, and flesh levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were also depressed. Activated carbon treated anchovy oil and finishing diets were examined in the Atlantic salmon laboratory feeding trial and were effective at lowering flesh POP levels while providing high levels of EPA and DHA. The use of alternative feed ingredients will soon be inevitable in aquaculture feeds. The current research shows alternative lipids and proteins can be incorporated successfully in sablefish and Atlantic salmon feeds with minimal effects on fish growth and quality.