Contamination of Antarctic snow by polycyclic aromatic hydrocarbons dominated by combustion sources in the polar region

Abstract

Environmental context. Is long-range transport from populated and industrialised areas to blame for pollution of remote regions? We report that, for the world's most remote region, Antarctica, and one prominent class of global pollutants, polycyclic aromatic hydrocarbons, long-range transport from other continents has not contributed significantly to recent snow contamination. Rather, the major sources are regional scientific stations and ocean transport, mostly tourism.Abstract. Firn samples attributed to the period between 2002 and 2005 were collected from a snow pit on the Ekström Shelf Ice in the Weddell Sea (70843.8 0 S, 8825.1 0 W). Low-volume meltwater samples (5 mL) were extracted by solid-phase microextraction (SPME) and analysed for polycyclic aromatic hydrocarbons (PAHs) by gas chromatography-mass spectrometry. The recovery of the analytical method for the 4-6 ring PAHs was low. PAH concentrations in snow were found within the range of 26-197 ng L À1 . The most prevailing substances were determined to be naphthalene, 1-and 2methylnaphthalene, acenaphthylene, acenaphthene and phenanthrene, with naphthalene accounting for an overall mean of 82% of total PAH. Potential emission sources of PAHs in snow were studied using back-trajectory statistics and available emission data of combustion sources in and around Antarctica. The distance to the sources (ships and research stations) in this region was found to control the snow PAH concentrations. There was no indication for intercontinental transport or marine sources.

Sources and fate of polycyclic aromatic hydrocarbons in the Antarctic and Southern Ocean atmosphere

“…In Antarctica and the Southern Ocean, the occurrence of PAHs has been described in soils and sediments [Cabrerizo et al, 2012;Martins et al, 2010], ice/snow [Cincinelli et al, 2005;Kukučka et al, 2010], and marine and terrestrial biota [Curtosi et al, 2009;Cabrerizo et al, 2012]. The presence of these chemicals in terrestrial and marine compartments in such a remote region suggests that long-range atmospheric transport, with the subsequent atmospheric deposition facilitated by cold trapping [Bengtson-Nash, 2011] could account for the observed levels of PAHs in Antarctica.…”

Prospects for reconstructing paleoenvironmental conditions from organic compounds in polar snow and ice

“…For the same compounds, Gabrieli et al (2010b) used online SPE on a CFA system and obtained a recovery of 71-93% and LODs ranging between 0.007 and 0.466 ng/L using HPLC with fluorescence detection using an initial sample of 250-500 g of melted ice. Kukučka et al (2010) achieved both lower sample volume and lower LODs using solid phase micro-extraction (SPME) followed by thermal desorption and GC-MS analysis. This method gave good recoveries for small PAHs but it did not give satisfactory recoveries for PAHs with 4-6 rings (Table 1).…”

Long-range atmospheric transport of polycyclic aromatic hydrocarbons is worldwide problem - results from measurements at remote sites and modelling

“…19 Potential emission sources of PAHs are stations and ships, both stronger in summer. The distance to the sources (ships and research stations) in this region was found to control the snow PAH concentrations.…”

“…The sampling and analytical methodology, including QA was described elsewhere. [19][20][21] Detection and quantification limits were controlled by both laboratory and field blanks.…”

“…Snow samples were collected by ejection into borosilicate glass bottles using a movable rod. PAHs were extracted by automated solid-phase microextraction (SPME, polydimethylsiloxane-divinylbenzene fibre at 60 °C, direct immersion 19 ). The SPME extraction efficiency is low (underestimates) for 4-6 ring PAHs.…”