An integrated study of the chemical composition of Antarctic aerosol to investigate natural and anthropogenic sources

Environmental contextOwing to its remoteness, Antarctica is an excellent natural laboratory for conducting studies on the behavior of marine aerosols and for monitoring the impact of global human activities. The aim of this study is to provide an extensive chemical characterization of Antarctic aerosol and to investigate its sources. A distinction among anthropogenic, crustal, and biogenic sources was defined using several chemical markers. AbstractDuring the 2010-11 austral summer, an aerosol sampling campaign was carried out at a coastal Antarctic site (Terra Nova Bay, Victoria Land). In this work, previously published data about water-soluble organic compounds and major and trace elements were merged with novel measurements of major ions, carboxylic acids and persistent organic pollutants (polychlorobiphenyls, polycyclic aromatic hydrocarbons, polychlorinated naphthalenes, polybrominated diphenylethers and organochlorine pesticides) in order to provide a chemical characterisation of Antarctic aerosol and to investigate its sources. The persistent organic pollutants were determined using a high-volume sampler, able to collect both particulate and gaseous fractions, whereas remaining compounds were determined by performing an aerosol size fractionation with a PM10 cascade impactor. Ionic species represented 58% (350ng m-3) of the sum of concentrations of all detected compounds (596ng m-3) in our Antarctic PM10 aerosol samples due to natural emission. Trace concentrations of persistent organic pollutants highlighted that the occurrence of these species can be due to long-range atmospheric transport or due to the research base. Factor analysis was applied to the dataset obtained from the samples collected with the PM10 sampler in order to make a distinction between anthropogenic, crustal and biogenic sources using specific chemical markers.