Rising demand for minerals and metals, including for use in the technology sector, has led to a resurgence of interest in exploration of mineral resources located on the seabed. Such resources, whether seafloor massive (polymetallic) sulfides around hydrothermal vents, cobalt-rich crusts (CRCs) on the flanks of seamounts or fields of manganese (polymetallic) nodules on the abyssal plains, cannot be considered in isolation of the distinctive, in some cases unique, assemblages of marine species associated with the same habitats and structures. In addition to mineral deposits, there is interest in extracting methane from gas hydrates on continental slopes and rises. Many of the regions identified for future seabed mining are already recognized as vulnerable marine ecosystems (VMEs). Since its inception in 1982, the International Seabed Authority (ISA), charged with regulating human activities on the deep-sea floor beyond the continental shelf, has issued 27 contracts for mineral exploration, encompassing a combined area of more than 1.4 million km 2 , and continues to develop rules for commercial mining. At the same time, some seabed mining operations are already taking place within continental shelf areas of nation states, generally at relatively shallow depths, and with others at advanced stages of planning. The first commercial enterprise, expected to target mineral-rich sulfides in deeper waters, at depths between 1,500 and 2,000 m on the continental shelf of Papua New Guinea, is scheduled to begin early in 2019. In this review, we explore three broad aspects relating to the exploration and exploitation of seabed mineral resources: (1) the current state of development of such activities in areas both within and beyond national jurisdictions, (2) possible environmental impacts both close to and more distant from mining activities and (3) the uncertainties and gaps in scientific knowledge and understanding which render baseline and impact assessments particularly difficult for the deep sea. We also consider whether there are alternative approaches to the management of existing mineral reserves and resources, which may reduce incentives for seabed mining.
With the continuing shift of industrial activities in developing and transition economies, which often have poor regulation (and weak self-regulation of industries), additional global challenges regarding POPs and other contaminated sites may be expected. In this respect, a comprehensive application of the "polluter pays principle" in these countries will also be a key to facilitate the clean-up of contaminated areas and the prevention of future contaminated sites. The threats and challenges of contaminated sites and the high costs of securing/remediating the problems highlight the need for a comprehensive approach based upon integrated pollution prevention and control. If applied to all polluting (and potentially polluting) industrial sectors around the globe, such an approach will prove to be both the cheapest and most sustainable way to underpin the development of industries in developing and transition economies.
Because the Bayan Mandahu redbeds of Inner Mongolia share similar sedimentary facies and fossil assemblages with the Djadokhta Formation of pre-Altai Gobi, the two units are interpreted as stratigraphic correlatives, both of Campanian age. Sedimentary facies indicate that the Bayan Mandahu redbeds were deposited in semiarid, alluvial to eolian environments. An assemblage of fossil vertebrates found in the Bayan Manduhu consists of ceratopsian, ankylosaurian, and theropod dinosaurs; turtles; crocodiles; and small lizards and mammals. Six different kinds of fossil vertebrate eggs are present. The most common fossil vertebrates occur in association with eolian deposits and are interpreted as the remains of autochthonous "faunal" components, many of which died in situ during sandstorm events. In contrast, rare and fragmentary specimens of large dinosaurs occur in coarse-grained alluvial deposits and are interpreted as the remains of allochthonous faunal components. The low diversity of this fossil assemblage and overall small to medium size of its constituents indicate a relatively stressed paleoenvironment, an interpretation which is compatible with our sedimentological conclusions. A diverse trace fossil assemblage is present and includes rhizoliths and endogenic traces. Endogenic traces are well preserved and typically associated with eolian deposits, suggesting that the deposits were at least seasonally damp and cohesive. The opinion that the Late Cretaceous Gobi Basin was a large inland lake, still advocated by some authors, cannot be maintained within the context of our sedimentologic and paleontologic data. In contrast with the perennial lacustrine sedimentation that was characteristic of the underlying Lower to lower Upper Cretaceous units in the Gobi Basin, the Bayan Mandahu redbeds and correlative Djadokhta Formation mark a pronounced shift toward eolian and intermittent lacustrine sedimentation in an increasingly arid climate.
In this study we explored the use of butter as a sampling matrix to reflect the regional and global scale distribution of PCBs and selected organochlorine pesticides/metabolites in air. This was because persistent organic pollutants (POPs) concentrate in dairy fats, where concentrations are controlled by feed intake (primarily from pasture/silage), which is in turn primarily controlled by atmospheric deposition. Butter sigmaPCB concentrations varied by a factor of approximately 60 in 63 samples from 23 countries. They were highest in European and North American butter and lowest in southern hemisphere (Australian, New Zealand) samples, consistent with known patterns of historical global usage and estimated emissions. Concentrations in butter reflected differences in the propensity of PCB congeners to undergo long range atmospheric transport from global source regions to remote areas and the relatively even distribution of HCB in the global atmosphere. Concentrations of p,p'-DDT, p,p'-DDE, and HCH isomers all varied over many orders of magnitude in the butter samples, with highest levels in areas of current use (e.g. India and south/central America for DDT; India, China, and Spain for HCH). We conclude that butter is sensitive to local, regional, and global scale spatial and temporal atmospheric trends of many POPs and may therefore provide a useful sampling medium for monitoring purposes. However, to improve the quantitative information derived on air concentrations requires an awareness of climatic and livestock management factors which influence air-milk fat transfer processes.
The ingestion of microplastic fragments, spheres, and fibers by marine mollusks, crustaceans, and fish, including a number of commercially important species, appears to be a widespread and pervasive phenomenon. Evidence is also growing for direct impacts of microplastic ingestion on physiology, reproductive success and survival of exposed marine organisms, and transfer through food webs, although the ecological implications are not yet known. Concerns also remain over the capacity for microplastics to act as vectors for harmful chemical pollutants, including plastic additives and persistent organic pollutants, although their contribution must be evaluated alongside other known sources. The potential for humans, as top predators, to consume microplastics as contaminants in seafood is very real, and its implications for health need to be considered. An urgent need also exists to extend the geographical scope of studies of microplastic contamination in seafood species to currently underrepresented areas, and to finalize and adopt standardized methods and quality-assurance protocols for the isolation, identification, and quantification of microplastic contaminants from biological tissues. Such developments would enable more robust investigation of spatial and temporal trends, thereby contributing further evidence as a sound basis for regulatory controls. Despite the existence of considerable uncertainties and unknowns, there is already a compelling case for urgent actions to identify, control, and, where possible, eliminate key sources of both primary and secondary microplastics before they reach the marine environment. Integr Environ Assess Manag 2017;13:516-521. © 2017 SETAC.
This study reports concentrations and human dietary intake of hexabromocyclododecanes (HBCDs), polychlorinated biphenyls (PCBs) as well as selected "novel" brominated flame retardants (NBFRs) and organochlorine pesticides, in ten staple food categories. Samples were sourced from areas in Taizhou City, eastern China, where rudimentary recycling and disposal of e-waste is commonplace, as well as from nearby non-e-waste impacted control areas. In most instances, concentrations in foods from e-waste recycling areas exceeded those from control locations. Concentrations of 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) and bis-(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (BEH-TBP) in samples from e-waste sites were 3.09-62.2ng/g and 0.81-16.3ng/g lipid weight (lw), respectively; exceeding consistently those in foods acquired from control sites by an order of magnitude in many cases. In contrast, while concentrations of HBCD in some foods from e-waste impacted areas exceed those from control locations; concentrations in pork, shrimp, and duck liver are higher in control samples. This highlights the potential significance of non-e-waste sources of HBCD (e.g. building insulation foam) in our study areas. While concentrations of DDT in all foods examined except pork were higher in e-waste impacted samples than controls; our exposure estimates were well below the provisional tolerable daily intake of 0.01mg/kgbw/day derived by the Joint FAO/WHO Meeting on Pesticide Residues. Concentrations of ΣPCBs resulted in exposures (650 and 2340ng/kgbw/day for adults and children respectively) that exceed substantially the Minimal Risk Levels (MRLs) for ΣPCBs of 20ng/kgbw/day derived by the Agency for Toxic Substances & Disease Registry. Moreover, when expressed in terms of dioxin-like toxicity equivalency based on the four dioxin-like PCBs monitored in this study (DL-PCBs) (PCB-105, 118, 156, and 167); concentrations in e-waste impacted foods exceed limits set by the European Union in 6 of the 8 food groups studied and result in dietary exposures for children (10.2pgTEQ/kgbw/day) that exceed the WHO tolerable daily intake of 1-4pgTEQ/kgbw/day.
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