9 research outputs found

    Perfluoroalkyl carboxylates and sulfonates and precursors in relation to dietary source tracers in the eggs of four species of gulls (Larids) from breeding sites spanning Atlantic to Pacific Canada

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    In the present study, we identified and examined the spatial trends, sources and dietary relationships of bioaccumulative perfluorinated sulfonate (PFSA; C6, C8, and C10 chain lengths) and carboxylate (PFCA; C6 to C15 chain lengths) contaminants, as well as precursor compounds including several perfluorinated sulfonamides, and fluorotelomer acids and alcohols, in individual eggs (collected in 2008) from four gull species [glaucous-winged (Larus glaucescens), California (Larus californicus), ring-billed (Larus delawarensis) and herring (Larus argentatus) gulls] from 15 marine and freshwater colony sites in provinces across Canada. The pattern of PFSAs was dominated by perfluorooctane sulfonate (PFOS; >89% of ΣPFSA concentration) regardless of egg collection location. The highest ΣPFSA concentrations were found in the eggs collected in the urbanized areas in the Great Lakes and the St. Lawrence River area [Big Chicken Island 308ng/g ww, Toronto Harbour 486ng/g ww, and Ile Deslauriers (HG) 299ng/g ww]. Also, eggs from all freshwater colony sites had higher ΣPFSA concentrations, which were significant (p<0.05) in many cases, compared to the marine sites with the exception of the Sable Island colony in Atlantic Canada off the coast of Nova Scotia. C6 to C15 chain length PFCAs were detected in the eggs, although the pattern was variable among the 15 sites, where PFUnA and PFTrA dominated the pattern for most colonies. Like the ΣPFSA, the highest concentrat

    Flame retardants in eggs of four gull species (Laridae) from breeding sites spanning Atlantic to Pacific Canada

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    To compare legacy and emerging flame retardant (FR) contamination in Canadian marine and freshwater ecosystems, eggs of four gull species (Laridae) were collected from 26 colonies spanning Pacific to Atlantic Canada, including in the Great Lakes basin. Fourteen polybrominated diphenyl ether (PBDE) congeners and 20 non-PBDE FRs were analyzed, but BDE-47, -99, -100, -153, -154 and -209, hexabromocyclododecane (HBCD) and Dechlorane Plus (DP) syn- and anti-isomers were common, and where concentrations of ∑PBDEs (37-610 ng/g wet weight, ww) ≫ HBCD (0.5-12 ng/g ww) > ∑DP (not quantifiable-5.5 ng/g ww). All other FRs were generally not detectable. Stable nitrogen and carbon isotopes used as dietary tracers provided insights into the diet choice influences on the exposure sources and contamination patterns (e.g., PBDE congener compositions) for individual gulls from the same colony. Eggs from gulls breeding near metropolitan regions of higher human densities showed greater PBDE burdens than from other ecosystems. Crown Copyrigh

    Industrial Symbiosis: Old Wine in Recycled Bottles? Some Perspective from the History of Economic and Geographical Thought

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    ‘‘Industrial symbiosis’’ (IS) is a central concept in the industrial ecology literature, which describes geographically proximate interfirm relationships involving the exchange of residual materials, water, and energy. Despite its obvious relevance to regional science, economic geography, and urban economics, the issue is only beginning to be addressed in these subdisciplines. This situation is paradoxical as both recovery linkages and the very concept of IS were discussed in some depth by numerous economists and geographers several decades ago. The goals of this article are to document this intellectual history, in the process gaining a better understanding of the phenomenon while shedding additional light on current controversies. In doing so, the authors further hope to restimulate economists, geographers, and regional scientists’ interest in the topic and to illustrate the long-standing importance of geographical co-location in facilitating the ‘‘internalization of externalities’’ of industrial operations

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    A guide to dynamical analysis

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