Biogeochemical controls on organic contaminants in the Atlantic and Southern Oceans
[eng] During the last two centuries, the increase of human population and economic development has led to a rising demand for goods and resources. Such development has also led to the synthesis of millions of new organic chemicals, with hundreds of thousands of these currently used in agriculture an...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/222699 |
| Acceso en línea: | https://hdl.handle.net/2445/222699 http://hdl.handle.net/10803/695045 |
| Access Level: | acceso abierto |
| Palabra clave: | Oceanografia química Química ambiental Atlàntic (Oceà) Antàrtic (Oceà) Biogeoquímica Chemical oceanography Environmental chemistry Atlantic Ocean Antarctic Ocean Biogeochemistry |
| Sumario: | [eng] During the last two centuries, the increase of human population and economic development has led to a rising demand for goods and resources. Such development has also led to the synthesis of millions of new organic chemicals, with hundreds of thousands of these currently used in agriculture and industrial applications, as well as in consumer products. A fraction of this myriad of synthetic chemicals, together with hydrocarbons derived from the use of fossil fuels, reach the environment. This mixture of organic compounds with diverse properties and uses, invisible to the human eye, constitutes a form of pollution to the Earth system of unusual complexity. Addressing chemical pollution is a major challenge due to the large number of chemicals involved, which in addition have different and diverse physico-chemical properties and present different mechanisms of toxicity to organisms, ecosystems and humans. For decades, researchers, environmental agencies and regulatory bodies have sought to prioritize those organic contaminants that need to be regulated because of their potential for long-range transport, ubiquitous occurrence, persistence, bioaccumulation potential, toxicity, and ecological impact. However, the massive production and release of these substances into the environment surpass research and regulatory capacities, endangering the sustainability of the Earth’s system. This mismatch has led to the definition of “novel entities” as one of the planetary boundaries in the current context of global change, essential for the planet’s resilience. A recent study confirms that this threshold, along with five others, has already been exceeded, increasing the risk of irreversible changes to the Earth system. Mostly during the last century, some synthetic chemicals were regulated and banned, even though they are still found in the environment. However, just in the recent decades, an increasing number of chemicals, potentially thousands of contaminants of emerging concern (CECs), have dispersed globally, accumulating in various environmental compartments, with transport, biogeochemical cycles and sinks strongly dependent on their physicochemical properties and chemical structure. They are found in soils, fresh and sea water, ice, air, and biota, from microorganisms to large predators. Many CECs originate from common consumer products such as clothing, cosmetics, furniture, and paints. Among CECs, organophosphate esters (OPEs) and perfluoroalkyl acids (PFAAs) have raised increasing concern due to their ubiquity, persistence, toxicity and bioaccumulation in food webs. Nevertheless, knowledge not only on their occurrence, but their transport, cycling and sinks in the oceans is limited. The study of persistent organic pollutants (POPs) and CECs in the ocean is important, especially in remote regions, as these are sentinels of global pollution, which can only occur for chemicals persistent enough to undergo long-range transport. For instance, candidates for regulation as POPs under the Stockholm Convention should meet the criteria on persistence, toxicity, long-range transport, and biomagnification. This thesis contributes to the study of oceanic and Antarctic pollution with the overall objective of assessing the occurrence, biogeochemistry and sinks of three families of organic pollutants in the ocean: PFAAs, OPEs and semivolatile aromatic compounds (SALCs) within the dissolved black carbon (DBC). Despite their differences in sources and physicochemical properties, these three families share the ability for long-range transport, persistence , and toxic effects on ecosystems and human health. |
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