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Climatic and Biogeochemical Controls on the Remobilization and Reservoirs of Persistent Organic Pollutants in Antarctica
journal contribution
posted on 2013-05-07, 00:00 authored by Ana Cabrerizo, Jordi Dachs, Damià Barceló, Kevin C. JonesAfter
decades of primary emissions, reservoirs of persistent organic
pollutants (POPs) have accumulated in soils and snow/ice in polar
regions. These reservoirs can be remobilized due to decreasing primary
emissions or due to climate change-driven warmer conditions. Results
from a sampling campaign carried out at Livingston Island (Antarctica)
focusing on field measurements of air–soil exchange of POPs
show that there is a close coupling of the polychlorinated biphenyls
(PCBs) in the atmosphere and snow/ice and soils with a status close
to air–surface equilibrium to a net volatilization from Antarctic
reservoirs. This remobilization of PCBs is driven by changes in temperature
and soil organic matter (SOM) content, and it provides strong evidence
that the current and future remobilization and sinks of POPs are a
strong function of the close coupling of climate change and carbon
cycling in the Antarctic region and this is not only due to warming.
Whereas an increase of 1 °C in ambient temperature due to climate
change would increase current Antarctic atmospheric inventories of
PCBs by 21–45%, a concurrent increase of 0.5% SOM would counteract
the influence of warming by reducing the POP fugacity in soil. A 1
°C increase in Antarctic temperatures will induce an increase
of the soil–vegetation organic carbon and associated POPs pools
by 25%, becoming a net sink of POPs, and trapping up to 70 times more
POPs than the amount remobilized to the atmosphere. Therefore, changes
in soil biogeochemistry driven by perturbations of climate may increase
to a larger degree the soil fugacity capacity than the decrease in
air and soil fugacity capacity due to higher temperatures. Future
research should focus on quantifying these remobilization fluxes and
sinks for the Antarctic region.