16 ott. 2018 - Nicoletta Ademollo

Dinamiche di microinquinanti organici persistenti ed emergenti negli ecosistemi marini polari

Presenta: Nicoletta Ademollo

CNR IRSA, Istituto di Ricerca Sulle Acque, Roma

The polar regions are reported to be the final sink for semi-volatile organic contaminants, because of the long range global transport through air mass movements and ocean currents. The global change affect the formation and extension of sea ice and snow covering. The mechanism of ice formation/melting may impact the contaminant dynamics as well as the carbon cycle, the mobility of contaminants and biodiversity. Moreover, the list of chemicals found in Arctic ecosystems continue to increase and temporal trends have been reported for some current-use chemicals. Persistent organic pollutants (POPs) reach the Arctic by air mass movements, sea streams, and river flows. Because of its proximity to industrial areas in the Northern hemisphere, the Arctic has a high input of contaminants via long-range transport. In addition, the Arctic has been affected by human activity since long time because of its resource utilisation, including harvesting of living resources, mineral extraction, and the construction of military infrastructure. Moreover, there is concern about the possibility of coming oil prospection in the Greenland Sea and specifically in the area of interest for TUNU. Antarctica is a remote continent where volatile contaminants are transported mainly by air mass movements. Fractionation by condensation in cold environments has been proposed as a mechanism whereby POPs can reach polar regions. There, due to the low temperatures and winter darkness, POP degradation is very slow, thus ice can entrap POPs and release them in the environment through ice melting, where they enter the trophic webs, bioaccumulate in the tissues of organisms and biomagnify. The study of the composition of Dissolved Organic Carbon (DOC), the occurrence of organic contaminants, and the biodegradation capability of natural microbial communities is of strategic importance to describe the impact of allochthonous sources on the marine ecosystem. Anthropogenic impacts can change the quality of the natural DOC, with repercussions on the spread, persistence and bioavailability of allochthonous organic matter, including the fate and the toxic effects exerted by some POPs.

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