Thesis (Ph. D.)--University of Alabama at Birmingham, 2006. / Title from first page of PDF file (viewed Feb. 22, 2007). Includes bibliographical references (p. 84-95).

The transition from a hunter-gatherer lifestyle to a farming lifestyle, i.e. the Neolithisation, is arguably the most important event in human prehistory. While the geography and dating of the Neolithisation is well known, the process is still under debate, especially if it occurred through diffusion of ideas or with migrating farmers. The process accelerated when alternative use of domesticated animals increased. Especially the use of dairy products, and the consumption of unprocessed milk, appears to be of importance. As milk consumption (lactose digestion) is dependent upon genetic components, it is debated whether the genetic disposition allowed for dairy production to evolve, or if the usages of dairy products added selection pressure that eventually lead to present day allele frequencies. Molecular genetics have the potential to solve this and similar questions, but only if the contamination problem, where authentic DNA can be distinguished from modern contaminating DNA, can be resolved. Here I investigate the nature and extent of contamination with modern human DNA in museum specimens and explore several approaches to minimise this contamination and to authenticate DNA results from ancient humans. I use real-time quantification, pyrosequencing and FLX-generated clonal sequencing assays to generate data on ancient humans and ancient dogs. I further use the techniques to study the development of lactase persistence and the nature of animal domestication. The results presented show that sample-based contamination is extensive, but can be minimised if treated with bleach. I retrieved authentic HVSI sequences from 30 Neolithic hunter-gatherers and farmers from Sweden, of which eighteen also yielded nuclear data indicating that the farmers had a higher frequency of the allele linked to lactase persistence compared to the hunter-gatherers. I conclude that genetic data from ancient humans as well as from ancient animals can be retrieved and used, but only under high stringency.

Food product contamination leading to a food borne illness is real and has potentially devastating impact on supply chain operations and cost. However, it is not well understood from the quantitative perspective. This research seeks to fill this gap by providing a generic model of a multi-stage food supply chain consisting of a supplier/grower, processing center and retailer(s) and analyzing the impact of food product contamination in this model. The supplier corresponds to the farm/grower of the raw material such as fruits and vegetables, the processing center processes the raw material into a final food product and the retailer corresponds to the supermarkets and grocery stores selling the food product to a customer. A situation where a contamination occurs at the supplier or processing center potentially resulting in a food borne illness to the customer is considered. The contamination is discovered through periodic sampling tests conducted by the grower, processing center or through the outbreak of a food borne illness. The supply chain is modeled utilizing a G/G/1 queuing system at the processing center and an order- up to policy at the retailer(s). This research develops and compares multi-stage supply chain models with varying number of retailers. The negative dependence of contamination on the origin and mode of detection of the contamination is quantified. The differences in individual food product attributes which can impact the cost of contamination are analyzed. The impact of supply chain structure and properties and detection policies on the severity of potential contamination cases is studied. The most cost effective sampling strategies which companies can adopt in the event of product contamination are derived. The payoff from the implementation of a quality control process which can eradicate contamination is evaluated. A numerical study of the impact of a real-world contamination event on a tomato and lettuce supply chain is also conducted. Finally, a traceability system capable of tracking and tracing back products in the event of a food product recall is incorporated in the supply chain model. The value of traceability for different supply chain scenarios is assessed through the implementation of an ARENA based simulation model.

The Great Lakes has been impaired by elevated concentrations of contaminants, and different regulatory actions are taken to decrease theses concentrations. Recent research of Dr. Azim suggests a decline in mercury levels in the Lake Erie, and an increase in the Hg concentration in the fish communities. This research is a follow up study to examine whether the contaminant levels are indeed increasing. In the first chapter we evaluate the temporal trends of polychlorinated biphenyls (PCBs) in Lake Erie fish over the last 30 years by conducting the Exponential and Dynamic Linear Modeling analysis. DLM analysis in the chapter two detects the PCB and Hg contaminant trends in a broader range. There is a high variability in two contaminants trends. These patterns may be because of factors such as fish physiological parameters, and the impact of invasive species. The results of my research will contribute to the Toxics Reduction Strategy.

The Great Lakes has been impaired by elevated concentrations of contaminants, and different regulatory actions are taken to decrease theses concentrations. Recent research of Dr. Azim suggests a decline in mercury levels in the Lake Erie, and an increase in the Hg concentration in the fish communities. This research is a follow up study to examine whether the contaminant levels are indeed increasing. In the first chapter we evaluate the temporal trends of polychlorinated biphenyls (PCBs) in Lake Erie fish over the last 30 years by conducting the Exponential and Dynamic Linear Modeling analysis. DLM analysis in the chapter two detects the PCB and Hg contaminant trends in a broader range. There is a high variability in two contaminants trends. These patterns may be because of factors such as fish physiological parameters, and the impact of invasive species. The results of my research will contribute to the Toxics Reduction Strategy.

Ingestion exposure estimates typically use a default bioavailability of 100%, thereby assuming that the entirety of an ingested dose is absorbed into systemic circulation. However, the actual bioavailability of ingested contaminants is oftentimes lower than 100%. The research described herein investigates the use of the Simulator of the Human Intestinal Microbial Ecosystem (SHIME) for the calculation of <i>in vitro</i> bioaccessibility (IVBA), a conservative predictor of bioavailability, of mercury (Hg) from traditional northern foods and arsenic (As) from soils. The primary objective of the research described herein is to address data-gaps which have hindered attempts to incorporate IVBA into risk assessment on more than a case-by-case basis. The hypotheses of this thesis are that (1) the bioaccessibility of contaminants is dependent upon concentration due to kinetic limitations on dissolution, (2) gastrointestinal (GI) microbes in the ileum and colon alter contaminant bioaccessibility and/or speciation, (3) the GI microbial effect on bioaccessibility is toxicologically relevant, and (4) metal bioaccessibility is predictable according to dissolution kinetics.<p> Mercury bioaccessibility from country food samples was independent of total Hg concentration (F=0.5726, P=0.578) whereas As bioaccessibility was inversely related to total As concentration for Nova Scotia mine tailings, synthesized ferrihydrite with adsorbed AsV, and synthesized amorphous scorodite (P=2 x 10-10). Isotherm analysis indicated that, at high soil As concentrations, saturation of simulated GI fluids limited As bioaccessibility under gastric conditions whereas kinetic limitations constrained As bioaccessibility under intestinal conditions. Additionally, we demonstrated that GI microbes may affect Hg bioaccessibility, either increasing or decreasing bioaccessibility depending upon the type of food. For example, the bioaccessibility of HgT decreased in the presence of GI microbial activity for caribou kidney, caribou tongue, seal blood, seal brain, seal liver, and walrus flesh. In contrast, HgT bioaccessibility from Arctic char and seal intestine increased in the presence of GI microbial activity. Similarly, colon microbial activity increased (Fishers Protected LSD, P<0.05) As bioaccessibility from synthesized amorphous scorodite (56 110%), Nova Scotia mine tailings (140 300%), an agricultural soil (53%) and an ironstone soil (350%) containing elevated arsenic concentrations. However, under small intestinal conditions, this microbial effect was transient and demonstrated a small effect size. The toxicological relevance of microbial effects upon As bioaccessibility was assessed using a juvenile swine model with co-administration of oral antibiotics (neomycin and metronidazole). This study research indicated that microbial effects on As bioaccessibility are not reflected in the juvenile swine model. For example, the microbial communities present in the pigs proximal colon clustered according to antibiotic treatment (e.g. microbial communities of antibiotic treated pigs differed from non-treated pigs). Despite this, the urinary arsenic excretion (and hence arsenic bioavailability) of antibiotic-treated juvenile swine orally exposed to soil-borne arsenic was equivalent (Holm-Sidak, P=0.930) to the urinary arsenic excretion of juvenile swine not treated with antibiotics. Therefore, in vitro GI models may not need to include a microbially active intestinal stage when measuring As IVBA.<p> Metal bioaccessibility from soils appears predictable according to fundamental chemical properties of the metal-of-concern. Specifically, metal bioaccessibility of 7 of the 13 metals (V, Ni, Zn, Cu, U, Cd, & Ba but not Tl, Pb, As, Se, Cr, and Hg) regulated according to Canadian Council of Ministers of the Environment Soil Quality Guidelines (CCME SQG) were strongly dependent (R2 = 0.7) on water exchange rate constants of metal cations (kH20) indicating that desorption kinetics may serve as the foundation of a predictive model of metal bioaccessibility.

Contamination of drinking water with metals is a major problem facing many areas of United States and the World. There is a need for an inexpensive remediation technology for the removal of metals in drinking water that can be applied to small rural water systems. This research will focus on the development of a process for removal of select metals from drinking water by limestone-based material. Metals in drinking water considered for this research include lead and selenium. Limestone-based material has demonstrated the potential to reduce select metals (lead, cadmium and arsenic) in drinking water, with the additional benefit of low-cost disposal of a stable waste product in ordinary landfills. Earlier research by the principal investigators using limestone-based material for drinking water treatment has clearly shown that this material can achieve metals removal of greater than 90 percent. This project will investigate techniques to improve removal efficiency of limestone-based material through adsorption and precipitation. This research will assist in the development of a granular adsorbent product that will remove metals and that can be manufactured and sold for use at the drinking water source, at point-of-use, or at point-of entry.

Pollen contamination is a severe problem in production breeding programs since it reduces the expected gain. In an attempt to solve this problem Skogforsk created an isolation experiment in the advanced Scots pine (Pinus sylvestris) seed orchard Västerhus in Västerbotten, Sweden. This experiment involves covering blocks of trees with a tent during the pollination period so that they only can mate with each other inside. To evaluate the effects of this tent treatment one tree from inside a tent with supplementary mass pollination (SMP) and one tree from the open control were chosen for this study. 48 seeds from each tree were sampled and genotypes at 9 microsatellite (SSR) loci. The likelihood and exclusion methods for paternity assignment were used to establish the fathers to these seeds. The results showed 0% contamination inside the tent and 4-8% outside in the control. The number of fathers contributed to the fertilization of the 48 seeds was 9 inside and 15 outside. The selfing rate was unexpectedly high, 10% inside the tent and 19% outside. The mating system inside the tent need to be further evaluated to fully understand what other effect the treatment has on the future progeny.

Current Canadian policies do not adequately prevent water contamination or mitigate the effects of existing polychlorinated biphenyl pollution. There is conflict between the Canadian government and the Inuit people over how to approach the pollution problem, arising from a clash of cultural values and traditions. Legislation related to healthcare is an inherently sensitive issue and some measures that seem acceptable to westernized societies are not appropriate for the Inuit. The purpose of this thesis is to answer (a) why polychlorinated biphenyls (PCBs) are in the Arctic, (b) what the effects of PCBs are on the Arctic people, and (c) how healthcare policy can address the issue.

Les Atikamekw sont un peuple autochtone du Québec réparti dans les communautés de Manawan, Wemotaci et Opitciwan. Ils consomment de la nourriture traditionnelle (gibier, poisson et sauvagine) qui contient potentiellement des contaminants environnementaux, dont des métaux lourds et des polluants organiques persistants. Or, la consommation de nourriture traditionnelle comporte maints avantages nutritionnels, socio-culturels, spirituels et économiques. Des inquiétudes ont été soulevées par les Atikamekw quant à la présence de contaminants dans leur nourriture et leur organisme. Une étude épidémiologique transversale participative a été menée auprès de 189 Atikamekw, dont 63 enfants. Les objectifs principaux sont de dresser le profil d'exposition aux contaminants et lorsque les expositions sont confirmées, de trouver des pistes de solutions visant la conciliation des bénéfices et des risques de la consommation de nourriture traditionnelle. Concrètement, cette étude vise à valider l'utilisation des questionnaires de fréquences alimentaires et 24h-rappel dans le but de dégager un profil d'exposition au méthylmercure (MeHg) selon la fréquence de consommation de nourriture traditionnelle. Pour ce faire, des questionnaires de fréquences alimentaires, 24h-rappel et socio-démographiques ont été administrés et les niveaux de MeHg ont été déterminés par des analyses sanguines et capillaires, par spectrométrie d'absorption atomique à vapeur froide. Les grands consommateurs de nourriture traditionnelle avaient des apports supérieurs en protéines, fer, zinc, cuivre, niacine et vitamine B12 et moindres en lipides, sucres totaux, acides gras monoinsaturés et saturés que les petits consommateurs de nourriture traditionnelle, mais avaient des niveaux de MeHg plus élevés (p<0,05). L'utilisation des questionnaires alimentaires permet de dégager d'une part le profil nutritionnel et d'autre part l'exposition au mercure, ce qui permet à la nutritionniste de transmettre l'information nutritionnelle adaptée aux différents groupes de consommateurs de nourriture traditionnelle tout en évitant la surexposition au mercure. Selon le profil de ces grands consommateurs (âge et genre), des interventions pourront être effectuées par exemple autour de la diversification des espèces et de la grosseur des poissons consommés et des lieux de pêche, ou tout autre mesure jugées pertinentes par la communauté. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Atikamekw, Bénéfices, Risques, Nourriture traditionnelle, 24h-rappel, FFQ, Méthylmercure, Profil d'exposition.