The need to include alkylated polycyclic aromatic hydrocarbons in human health risks assessments for oil contaminated seafood after crude oil spills is set forth. This is placed within the context of ...a brief review of the literature for PAHs and human health risk assessments after oil spills. The example of human health risk assessments for oil contaminated seafood after the Deepwater Horizon oil spill is reviewed with the conclusion that PAHs such as alkylated chrysenes/triphenylenes/benzanthracenes should have been included in the human health risk assessment and not dismissed as present in very low concentrations relative to their parent PAHs.
•Higher molecular weight alkylated PAHs should have been included in seafood safety assessments following the DWH oil spill.•Recent innovations in analytical methodology should be used in analyses of higher molecular weight alkylated PAHs in seafood.•Improvements are needed in the knowledge of the human health risks of the numerous alkylated PAHs released to the environment.
Four decades of research have provided a reasonable understanding of the outline of the biogeochemical cycles of persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) in ...coastal ocean and surface ocean ecosystems, including atmospheric transport to the sea, air-sea exchange processes, and the role of particulate matter in removing these chemicals from surface waters. It is clear that deep ocean fish are contaminated with POPs. However, despite available sampling and analytical capabilities, deep ocean ecosystems are much less sampled and understood. A multidecade assessment of POPs and PAHs in US coastal waters using bivalve sentinel organisms documents high concentrations near urban areas and also some stations where concentrations have begun to decline. The results are consistent with coastal sediments near urban areas being a leaky sink for POPs and PAHs, and sources from land continuing to contribute these contaminants to the sea. Other studies document coastal and continental margin surface sediments as a sink, albeit a potentially leaky sink, for POPs and PAHs. Floating plastic debris, including small pellets, has reemerged as an oceanic environmental concern. A "Pellet Watch" assessing plastic pellets and associated POPs and PAHs is underway. Enhanced studies of deep-ocean ecosystems are recommended. The findings are also relevant to biogeochemical cycles for emerging organic pollutants.
The Internet can bestow significant benefits upon those who use it. The prima facie case for an urban-rural digital divide is widely acknowledged, but detailed accounts of the spatial patterns of ...digital communications infrastructure are rarely reported. In this paper we present original analysis of data published by the UK telecommunications regulator, Ofcom, and identify and reflect on the entrenched nature of the urban-rural digital divide in Great Britain. Drawing upon illustrative case vignettes we demonstrate the implications of digital exclusion for personal and business lives in rural, and in particular remote rural, areas. The ability of the current UK policy context to effectively address the urban-rural digital divide is reviewed and scenarios for improving digital connectivity amongst the ‘final few’, including community-led broadband, satellite broadband and mobile broadband, are considered. A call is made for digital future proofing in telecommunications policy, without which the already faster urban areas will get ‘faster, fastest’ leaving rural areas behind and an increasingly entrenched urban-rural divide.
•There is a clear urban-rural digital divide in Great Britain.•Digital connectivity and Internet services are poorest in deep rural areas.•Where broadband is made available, urban and rural broadband uptake is similar.•Poor digital connectivity threatens the social and economic health of rural areas.•Alternative technologies/delivery models will help future-proof rural digital infrastructure.
Reflections about three influential environmental contaminants papers published in
Ambio
are presented. The PCB Story by Jensen in (1972) had a very important influence on environmental chemistry. ...This is captured by way of comments and personal anecdotes. Wania’s and MacKay’s (1993) paper highlights the physical chemistry underlying transport of PCBs and organochlorine pesticides from temperate zone ecosystems to Polar Regions. Their paper exemplifies how principles of chemistry and environmental processes informed understanding the biogeochemical cycles of chemicals of environmental concern (CEC). Mergler et al.’s (2007) paper reviews knowledge of methyl mercury exposure and impacts in humans and served as an example of how to approach exposure and human health concerns for all CECs. All great progress. Then, the question: “How we missed for two decades the importance of plastics in the environment identified in a paper published the same year as The PCB Story? Are we missing yet another important environmental contaminant now?
WHAT WAS RELEASED? Rullkötter, Jürgen; Farrington, John W.
Oceanography (Washington, D.C.),
03/2021, Letnik:
34, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The severity of oil spills depends on the quantity of material released and its physical and chemical properties. The total amount of petroleum spilled during the Deepwater Horizon incident and the ...relative fractions of the chemical compound classes of the Macondo oil were obtained by measurements, observations, and model calculations, with a significant amount of uncertainty. Because petroleum is an extremely complex mixture of many thousands or more of gaseous, liquid, and solid constituents, full elucidation of their compositions at the molecular level is impossible with presently available analytical techniques. This paper reviews published work on widely used analytical techniques and points out that scientists’ varying approaches to research questions and preferences for methods of analysis constitute a source of uncertainty. In addition, the focus is on two technical advancements developed over the last two decades, namely two-dimensional gas chromatography and Fourier transform ion cyclotron resonance mass spectrometry. Both were particularly valuable in the analysis of the spilled Macondo oil and its weathering products. Among the different processes of alteration of the original oil, only in situ oil burning is dealt with in this paper. This review reveals the paucity of data on this mitigation process and shows the need for more systematic coordination of methods in burned oil research studies.
► Plastic fragments from the open ocean and remote and urban beaches were analyzed. ► PCBs, PAHs, DDTs, PBDEs, NP, BPA concentrations ranges from 1 to 10,000ng/g. ► Concentrations showed large ...piece-to-piece variability. ► Hydrophobic organic compounds were sorbed from seawater. ► NP, BPA, and PBDEs came mainly from additives and were detected even in open ocean.
To understand the spatial variation in concentrations and compositions of organic micropollutants in marine plastic debris and their sources, we analyzed plastic fragments (∼10mm) from the open ocean and from remote and urban beaches. Polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), dichloro-diphenyl-trichloroethane and its metabolites (DDTs), polybrominated diphenyl ethers (PBDEs), alkylphenols and bisphenol A were detected in the fragments at concentrations from 1 to 10,000ng/g. Concentrations showed large piece-to-piece variability. Hydrophobic organic compounds such as PCBs and PAHs were sorbed from seawater to the plastic fragments. PCBs are most probably derived from legacy pollution. PAHs showed a petrogenic signature, suggesting the sorption of PAHs from oil slicks. Nonylphenol, bisphenol A, and PBDEs came mainly from additives and were detected at high concentrations in some fragments both from remote and urban beaches and the open ocean.
Community-led broadband initiatives represent a relatively recent shift in rural broadband provision. They are locally-led organisations that voluntarily spring up to respond to the lack, or ...perceived lack, of adequate broadband in their communities. Particularly present in rural spaces, few studies have investigated this mode of broadband delivery, which is gaining attention in the United Kingdom and internationally. This paper seeks to explore the implications of the participatory nature of such broadband initiatives, identifying a) whether pursuing a participatory community-led model for broadband deployment plays a role in enhancing rural social resilience, and b) specifically how leadership and informal digital champions are positioned and perceived throughout this process, and their relationship with rural social resilience. The conceptual framework of ‘social resilience’ acts as a contemporary analytical tool for understanding the impact of community-led broadband. Using findings from 56 semi-structured interviews across two phases from two community-led broadband organisations, Broadband for the Rural North (B4RN) in England and Broadband for Glencaple and Lowther (B4GAL) in Scotland, this paper contributes to both digital scholarship and the theoretical development of ‘resilience’ as a concept.
Community-led broadband is shown to reflect a ‘localism’ development approach, and this process has strengthened local rural identity for individuals. The role of digital champions, as leaders in the community-led broadband movement, is key to developing the digital resource within rural communities. However, it can also be problematic, entrenching existing inequalities and feelings concerning exclusion, ultimately detracting from individuals' ability to participate. The process and the eventual presence of new technology have contributed to new spatial understandings of community identity, based on regional linkages, and new communities of interest. We conclude that community-led broadband, and in particular the leadership and participation processes, can contribute to social resilience overall, but ultimately is another example of uneven rural development.
•Community-led broadband reflects a ‘localism’ development approach.•These processes are ultimately an example of uneven rural development.•Digital leaders are critical for resource identification and engagement.•Such leaders can entrench existing inequality, weakening resilience.•Resilience theory identifies interdependencies that influence broadband development.
Research funded under the Gulf of Mexico Research Initiative provided new insights into the biogeochemical processes influencing the fate of petroleum chemicals entering the Gulf of Mexico from the ...Deepwater Horizon (DWH) accident. This overview of that work is based on detailed recent reviews of aspects of the biogeochemistry as well as on activities supported by the US Natural Resource Damage Assessment. The main topics presented here are distribution of hydrocarbons in the water column; the role of photo-oxidation of petroleum compounds at the air-sea interface; the role of particulates in the fate of the DWH hydrocarbons, especially marine oil snow (MOS) and marine oil snow sedimentation and flocculent accumulation (MOSSFA); oil deposition and accumulation in sediments; and fate of oil on beaches and in marshes. A brief discussion of bioaccumulation is also included. Microbial degradation is addressed in a separate paper in this special issue of Oceanography. Important future research recommendations include: conduct a more robust assessment of the mass balance of various chemical groupings and even individual chemicals during specific time intervals; seek a better understanding of the roles of photo-oxidation products, MOS, and MOSSFA and their relationships to microbial degradation; and determine the fates of the insoluble highly degraded and viscous oil residues in the environment.
This article focuses on the fate and effects of oil spills and some aspects of responding oil spills. Despite the fact that they are less than 10% of the oil inputs to the marine environment averaged ...over the world and decades of time, accidental oil spills' fates and effects are discussed first in this article because many of the lessons learned from research in fates and effects of spilled oil also apply to chronic oil inputs. Then oil spill cleanup and mitigation measures are discussed.
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