DUGi

Unexpected occurrence of volatile dimethylsiloxanes in antarctic soils, vegetation, phytoplankton, and krill

http://dugi.udg.edu/item/http:@@@@hdl.handle.net@@2072@@297941

Volatile methyl siloxanes (VMS) are high-production synthetic compounds, ubiquitously found in the environment of source regions. Here, we show for the first time the occurrence of VMS in soils, vegetation, phytoplankton, and krill samples from the Antarctic Peninsula region, which questions previous claims that these compounds are "flyers" and do not significantly reach remote ecosystems. Cyclic VMS are the predominant compounds, with concentrations ranging from the limits of detection to 110 ng/g in soils. Concentrations of cyclic VMS in phytoplankton are negatively correlated with sea surface salinity, indicating a source from ice and snow melting and consistent with snow depositional inputs. After the summer snow melting, VMS accumulate in the Southern Ocean and Antarctic biota. Therefore, once introduced into the marine environment, VMS are eventually trapped by the biological pump and, thus, behave as "single hoppers". Conversely, VMS in soils and vegetation behave as "multiple hoppers" due to their high volatility

This work was financially supported by the Generalitat de Catalunya (Consolidated Research Groups “2014 SGR 418- Water and Soil Quality Unit”, 2014 SGR 291-ICRA, and 2014SGR495-Global Change and Genomic Biogeochemistry). The authors acknowledge financial support of the Spanish Ministry of Science and Innovation through the projects SCARCE (Consolider Ingenio 2010 CSD2009-00065), Nano- Trojan (CTM2011-24051), and ATOS (POL2006-00550/ CTM)

American Chemical Society (ACS)