Abstract
Anthropogenic emissions have severely perturbed the marine
biogeochemical cycle of lead (Pb). Here, we present new Pb concentration
and isotope data for surface seawater from GEOTRACES section GA02,
sampled in the western South Atlantic in 2011. The South Atlantic is
divided into three hydrographic zones: equatorial (0–20°S), subtropical (20–40°S), and subantarctic
(40–60°S). The equatorial zone is dominated by previously deposited Pb
transported by surface currents. The subtropical zone largely reflects
anthropogenic Pb emissions from South America, whilst the subantarctic
zone presents a mixture of South American anthropogenic Pb and natural
Pb from Patagonian dust. The mean Pb concentration of 16.7 ± 3.8 pmol/kg
is 34 % lower than in the 1990s, mostly driven by changes in the
subtropical zone, with the fraction of natural Pb increasing from 24 %
to 36 % between 1996 and 2011. Although anthropogenic Pb remains
predominant, these findings demonstrate the effectiveness of policies
that banned leaded gasoline.
Original language | English |
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Article number | 114798 |
Number of pages | 14 |
Journal | Marine Pollution Bulletin |
Volume | 189 |
Early online date | 10 Mar 2023 |
DOIs | |
Publication status | Published - 1 Apr 2023 |
Keywords
- Lead
- Isotopic composition
- Seawater
- Pollution
- GEOTRACES