Determination of Cd, Pb, and Cu in the Atmospheric Aerosol of Central East Antarctica at Dome C (Concordia Station)

Abstract

Trace heavy metals Cd, Pb, and Cu were determined (by square wave anodic stripping voltammetry) in aerosol samples collected at Dome C (the Italo-French Station Concordia), a remote site of the Central East Antarctic plateau, for which no data are available until now. During the Austral Summer 2005–2006, three PM10 high-volume impactors were installed in two locations nearby of Concordia station: the first one very close and downwind of the station (about 50 m north), the other two (very close to each other) in a ‘distant’ site, upwind of the station and close to the astrophysics tent (not used in that expedition) at ~800 m south of Station Concordia. For each sample, the availability of the mass of the aerosol collected (obtained by differential weighing carried out on site), in addition to the volume of the filtered air, allowed us to express results both in terms of metal mass fractions in the aerosol and in the usual way of metal atmospheric concentrations. Metal contents increased in the order Cd < Pb < Cu with the following ranges of values: Cd 1.0–8.4 µg g−1 (0.09–3.1 pg m−3), Pb 96–470 µg g−1 (12–62 pg m−3), and Cu 0.17–20 mg g−1 (0.027–2.4 ng m−3). From the metal temporal profiles obtained we estimated the following background values for the area of Dome C, expressed both in mass fractions and in atmospheric concentrations: Cd 1.2 ± 0.2 µg g−1 (0.24 ± 0.13 pg m−3), Pb (here fixed as upper limit) 113 ± 13 µg g−1 (21 ± 8 pg m−3), and Cu 0.91 ± 0.48 mg g−1 (0.12 ± 0.07 ng m−3). The highest values were observed in the first part of the season, and particularly for the site close to the station, possibly related to sample contamination linked to intense activity at the Concordia station connected with the beginning of the expedition, including aircraft arrivals/departures. Increments of up to 10 times (and even 20 times for Cu) were recorded with respect to the background values. The metal excesses of the contaminated over background samples were found approximately, except for Cu, in the same proportion of the metal contents of the special Antarctic blend (SAB) diesel fuel, which is used almost exclusively at Concordia Station. The effect of the wind direction was also observed. Thus in the intermediate period of the campaign, when the wind direction reversed for several days with respect to the prevailing one, Cd and Pb metal contents decreased at the sampling point installed close to the station, now upwind of Concordia station, and increased at the ‘clean’ site astrophysics tent, turned downwind at the main station. No simple and easily interpretable effect of the wind direction was observed for Cu, which suggests that some other extemporaneous and not clearly identified factor may have intervened in this case. These results suggest that the human impact at Dome C influences mainly the zone very close to the station, but also the area in the neighborhood, including the supposed clean site of the astrophysics tent (about 800 m far from the station), when the wind direction reverses with respect to the prevailing one, leaving the site downwind of the station Concordia. Since no other data are reported for the Dome C area, our results are compared with literature data referred to the South Pole Station (the only other plateau site for which data are available) and several other coastal Antarctic sites, observing that our results (excluding Cu) are the lowest ever observed for Antarctic aerosol.

Seasonal Evolution of the Chemical Composition of Atmospheric Aerosol in Terra Nova Bay (Antarctica)

“…The total atmospheric concentrations of trace metals (Cd, Cu, and Pb) are in good agreement with those previously reported for the same study site, with the only exception of Cu [10,11,13,33], for which values 1 order of magnitude higher were recorded by Toscano et al [10] and Annibaldi et al [11]. A general agreement with our Cd, Cu, and Pb values was observed in studies carried out in other Antarctic areas [4,52,54].…”

A Review of Atmospheric Aerosols in Antarctica: From Characterization to Data Processing

“…Under specific conditions, they can precisely locate the distant origin of a certain pollutant detected in Antarctica [161]. The back trajectory models can only provide plausible hypotheses regarding the location of the pollutant and its possible route of transport [23,41,42]. However, a detailed study of air mass history can confirm a local origin for some anthropogenic aerosols [160].…”

“…The special focus of this work is Antarctica because, as it is considered one of the least polluted places on Earth, it is ideal for measuring the spread of global pollutants. In addition, its special climate and prevailing winds make this region one of the final sinks for many pollutants, especially POPs [38][39][40] and heavy metals [41][42][43].…”

Erratum: Illuminati et al. Determination of Cd, Pb, and Cu in the Atmospheric Aerosol of Central East Antarctica at Dome C (Concordia Station). Molecules 2021, 26, 1997

“…The authors wish to make the following corrections to the paper [ 1 ]: Two p -values referred to correlations in Section 2.4 are not correct due to oversight.…”