First evidence of legacy chlorinated POPs bioaccumulation in Antarctic sponges from the Ross sea and the South Shetland Islands.

Antarctica is no longer pristine due to the confirmed presence of anthropogenic contaminants like Persistent Organic Pollutants (POPs). Benthic organisms are poorly represented in contamination studies in Antarctica although they are known to bioaccumulate contaminants. Sponges (Phylum Porifera) are dominant members in Antarctic benthos, both in terms of abundance and biomass, and are an important feeding source for other organisms, playing key functional roles in benthic communities. To the best of our knowledge, legacy chlorinated POPs such as polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and dichlorodiphenyltrichloroethane (DDT) and their metabolites have never been investigated in this Phylum in Antarctica. The aim of this work was to evaluate the bioaccumulation of PCBs, HCB, o,p'- and p,p'-DDT and their DDE and DDD isomers in 35 sponge samples, belonging to 17 different species, collected along the coast of Terra Nova Bay (Adèlie Cove and Tethys Bay, Ross Sea), and at Whalers Bay (Deception Island, South Shetland Islands) in Antarctica. Lipid content showed a significant correlation with the three pollutant classes. The overall observed pattern in the three study sites was ΣPCBs>ΣDDTs>HCB and it was found in almost every species. The ΣPCBs, ΣDDTs, and HCB ranged from 54.2 to 133.7 ng/g lipid weight (lw), from 17.5 to 38.6 ng/g lw and from 4.8 to 8.5 ng/g lw, respectively. Sponges showed contamination levels comparable to other Antarctic benthic organisms from previous studies. The comparison among sponges of the same species from different sites showed diverse patterns for PCBs only in one out of four cases. The concentration of POPs did not vary significantly among the three sites. The predominance of lower chlorinated organochlorines in the samples suggested that long-range atmospheric transportation (LRAT) could be the major driver of contamination as molecules with a high long range transport potential (e.g. low chlorinated PCBs, HCB) prevails on heavier ones.

PBDEs and PCBs in terrestrial ecosystems of the Victoria Land, Antarctica.

The Victoria Land (East Antarctica) is characterized by the presence of lakes and ponds where rare water is found during the Summer months. These freshwater ecosystems are an important resource for migrating seabirds that use them and leave there their droppings and feathers, contributing to enrich the water with organic matter. Persistent organic pollutants (POPs) are long-range transported to polar regions and their detection in the Antarctic ecosystems date back to the 1960s. Most studies have been related to POP concentrations in marine environment, and terrestrial ecosystems have been poorly investigated. This study reports the concentration of PBDEs (23 congeners) and PCBs (21 among non-, mono-, di-, and ortho congeners) in lake sediment, soil and vegetation mat (community of algae, cyanobacteria, bryophites) collected close to six lakes in the Victoria Land (74°31'S-74°97'S, 165°07'E-162°51'E): Edmonson Point 14 and 15A, Carezza, Enigma, Tarn Flat 20, Inexpressible Island 10B. The ∑PBDEs averaged 0.09-0.28 ng/g and BDEs 28, 47 and 154 were higher in mat and soils, while BDEs 183 and 47 in sediment samples. PCBs ranged <0.003-0.807 ng/g and congeners nos. 114, 138, and 187 were the most abundant. In addition, TEQs were derived for the non-and mono-ortho PCBs detected and values were very low in each matrix (0.010 pg/g in the soil, 0.012 pg/g in sediment and mat). The long-range atmospheric transport can be confirmed as the most important POP source in Antarctica, although the scientific stations and seabird colonies may be potential local sources and contribute to contaminant release.