GEOSCIENCES MEETING
B R A Z I L - T E X A S A &M U N I V E R S I T Y
SCIENCE AND EDUCATION INTERNATIONALIZATION
LONG-RANGE TRANSPORT OF PERSISTENT ORGANIC POLLUTANTS TO
ANTARCTICA
Gilvan T. Yogui1, Jose L. Sericano2, Rosalinda C. Montone3
1
[email protected] (Universidade Federal de Pernambuco)
[email protected] (Texas A&M University)
3
[email protected] (Universidade de São Paulo)
2
Persistent organic pollutants (POPs) are man-made semivolatile organic chemicals that are
prone to undergo long-range atmospheric transport, are persistent in nature, accumulate in
living organisms, biomagnify in food chains, and are likely to cause adverse effects in the
environment and/or humans. Historically, POPs have been mainly produced in developed
countries of the northern hemisphere. However, they are detected in remote areas far away
from pollution sources such as the deep ocean and Antarctica. POPs are transported from low
to high latitudes through two phenomena known as cold trapping and hopping effect. The
former is the transfer of POPs from the gas to condensed phase upon a decrease in
temperature while the latter consists on a series of volatilization/deposition events that will
eventually trap these chemicals in the polar regions. Several authors have shown that
terrestrial vegetation facilitates re-volatilization of POPs back to the atmosphere, boosting the
hopping effect. Nonetheless, around 80% of the southern hemisphere’s surface is covered by
oceans. This study proposes a novel mechanism coupling ocean and atmosphere for
explaining the long-range transport of POPs to the Antarctic environment. Outputs of the
Global Distribution Model (Globo-POP) showed this ocean-atmosphere coupling in the
southern hemisphere, evidencing the role of each compartment in the distribution and fate of
contaminants. According to model simulations, the zonal transport of POPs across the
southern hemisphere’s atmosphere is around two orders of magnitude as large as in the ocean.
Conversely, the surface ocean stores 2-4 times more POPs than the atmosphere. The surface
ocean is a natural sink of POPs but wind-driven processes such as storms are supposed to
transfer significant amounts of POPs back to the atmosphere, boosting the hopping effect
similarly to vegetation on continents. Field evidences showed a significant, positive
correlation between concentration of PBDEs (a class of POPs) in Antarctic lichens and local
precipitation at King George Island (maritime Antarctica). This suggests that wet deposition
processes may scavenge less volatile POPs from the Antarctic atmosphere, facilitating their
entry in the Antarctic ecosystem. Besides the ocean-atmosphere coupling, migrating animals
such as seabirds and marine mammals can also serve as a source of POPs to the Antarctic
environment. Our investigations at King George Island have shown that migratory seabirds
(e.g., skua) may contain 20 times more contaminants than endemic penguins, evidencing
biological transport of POPs to Antarctica. However, the input of POPs from migrating
animals is estimated to be several orders of magnitude lower than the ocean-atmosphere
coupling mechanism.
March 26-29, 2012
Porto de Galinhas, Pernambuco, Brazil
Abstract O-29