Air Concentrations of Gaseous Elemental Mercury and Vegetation–Air Fluxes within Saltmarshes of the Tagus Estuary, Portugal
In situ air concentrations of gaseous elemental mercury (Hg(0)) and vegetation–atmosphere fluxes were quantified in both high (Cala Norte, CN) and low-to-moderate (Alcochete, ALC) Hg-contaminated saltmarsh areas of the Tagus estuary colonized by plant species <i>Halimione portulacoides</i&g...
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MDPI AG
2021-02-01
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| Series: | Atmosphere |
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| Online Access: | https://www.mdpi.com/2073-4433/12/2/228 |
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| author | Rute Cesário Nelson J. O’Driscoll Sara Justino Claire E. Wilson Carlos E. Monteiro Henrique Zilhão João Canário |
| author_facet | Rute Cesário Nelson J. O’Driscoll Sara Justino Claire E. Wilson Carlos E. Monteiro Henrique Zilhão João Canário |
| author_sort | Rute Cesário |
| collection | DOAJ |
| description | In situ air concentrations of gaseous elemental mercury (Hg(0)) and vegetation–atmosphere fluxes were quantified in both high (Cala Norte, CN) and low-to-moderate (Alcochete, ALC) Hg-contaminated saltmarsh areas of the Tagus estuary colonized by plant species <i>Halimione portulacoides</i> (Hp) and <i>Sarcocornia fruticosa</i> (Sf). Atmospheric Hg(0) ranged between 1.08–18.15 ng m<sup>−3</sup> in CN and 1.18–3.53 ng m<sup>−3</sup> in ALC. In CN, most of the high Hg(0) levels occurred during nighttime, while the opposite was observed at ALC, suggesting that photoreduction was not driving the air Hg(0) concentrations at the contaminated site. Vegetation–air Hg(0) fluxes were low in ALC and ranged from −0.76 to 1.52 ng m<sup>−2</sup> (leaf area) h<sup>−1</sup> for Hp and from −0.40 to 1.28 ng m<sup>−2</sup> (leaf area) h<sup>−1</sup> for Sf. In CN, higher Hg fluxes were observed for both plants, ranging from −9.90 to 15.45 ng m<sup>−2</sup> (leaf area) h<sup>−1</sup> for Hp and from −8.93 to 12.58 ng m<sup>−2</sup> (leaf area) h<sup>−1</sup> for Sf. Mercury flux results at CN were considered less reliable due to large and fast variations in the ambient air concentrations of Hg(0), which may have been influenced by emissions from the nearby chlor-alkali plant, or historical contamination. Improved experimental setup, the influence of high local Hg concentrations and the seasonal activity of the plants must be considered when assessing vegetation–air Hg(0) fluxes in Hg-contaminated areas. |
| first_indexed | 2024-03-09T05:17:49Z |
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| id | doaj.art-1c5f7a4efcff4b9bb23ae6c0959d0442 |
| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-03-09T05:17:49Z |
| publishDate | 2021-02-01 |
| publisher | MDPI AG |
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| series | Atmosphere |
| spelling | doaj.art-1c5f7a4efcff4b9bb23ae6c0959d04422023-12-03T12:43:52ZengMDPI AGAtmosphere2073-44332021-02-0112222810.3390/atmos12020228Air Concentrations of Gaseous Elemental Mercury and Vegetation–Air Fluxes within Saltmarshes of the Tagus Estuary, PortugalRute Cesário0Nelson J. O’Driscoll1Sara Justino2Claire E. Wilson3Carlos E. Monteiro4Henrique Zilhão5João Canário6Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, PortugalDepartment of Earth and Environmental Science, Acadia University, Irving Environmental Science Center, Wolfville, NS B4p 2r6, CanadaCentro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, PortugalDepartment of Earth and Environmental Science, Acadia University, Irving Environmental Science Center, Wolfville, NS B4p 2r6, CanadaCentro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, PortugalCentro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, PortugalCentro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, PortugalIn situ air concentrations of gaseous elemental mercury (Hg(0)) and vegetation–atmosphere fluxes were quantified in both high (Cala Norte, CN) and low-to-moderate (Alcochete, ALC) Hg-contaminated saltmarsh areas of the Tagus estuary colonized by plant species <i>Halimione portulacoides</i> (Hp) and <i>Sarcocornia fruticosa</i> (Sf). Atmospheric Hg(0) ranged between 1.08–18.15 ng m<sup>−3</sup> in CN and 1.18–3.53 ng m<sup>−3</sup> in ALC. In CN, most of the high Hg(0) levels occurred during nighttime, while the opposite was observed at ALC, suggesting that photoreduction was not driving the air Hg(0) concentrations at the contaminated site. Vegetation–air Hg(0) fluxes were low in ALC and ranged from −0.76 to 1.52 ng m<sup>−2</sup> (leaf area) h<sup>−1</sup> for Hp and from −0.40 to 1.28 ng m<sup>−2</sup> (leaf area) h<sup>−1</sup> for Sf. In CN, higher Hg fluxes were observed for both plants, ranging from −9.90 to 15.45 ng m<sup>−2</sup> (leaf area) h<sup>−1</sup> for Hp and from −8.93 to 12.58 ng m<sup>−2</sup> (leaf area) h<sup>−1</sup> for Sf. Mercury flux results at CN were considered less reliable due to large and fast variations in the ambient air concentrations of Hg(0), which may have been influenced by emissions from the nearby chlor-alkali plant, or historical contamination. Improved experimental setup, the influence of high local Hg concentrations and the seasonal activity of the plants must be considered when assessing vegetation–air Hg(0) fluxes in Hg-contaminated areas.https://www.mdpi.com/2073-4433/12/2/228gaseous elemental mercury (Hg(0))mercury fluxHg(0) volatilizationdynamic flux chamber (DFC)saltmarsh vegetationcoastal wetlands |
| spellingShingle | Rute Cesário Nelson J. O’Driscoll Sara Justino Claire E. Wilson Carlos E. Monteiro Henrique Zilhão João Canário Air Concentrations of Gaseous Elemental Mercury and Vegetation–Air Fluxes within Saltmarshes of the Tagus Estuary, Portugal Atmosphere gaseous elemental mercury (Hg(0)) mercury flux Hg(0) volatilization dynamic flux chamber (DFC) saltmarsh vegetation coastal wetlands |
| title | Air Concentrations of Gaseous Elemental Mercury and Vegetation–Air Fluxes within Saltmarshes of the Tagus Estuary, Portugal |
| title_full | Air Concentrations of Gaseous Elemental Mercury and Vegetation–Air Fluxes within Saltmarshes of the Tagus Estuary, Portugal |
| title_fullStr | Air Concentrations of Gaseous Elemental Mercury and Vegetation–Air Fluxes within Saltmarshes of the Tagus Estuary, Portugal |
| title_full_unstemmed | Air Concentrations of Gaseous Elemental Mercury and Vegetation–Air Fluxes within Saltmarshes of the Tagus Estuary, Portugal |
| title_short | Air Concentrations of Gaseous Elemental Mercury and Vegetation–Air Fluxes within Saltmarshes of the Tagus Estuary, Portugal |
| title_sort | air concentrations of gaseous elemental mercury and vegetation air fluxes within saltmarshes of the tagus estuary portugal |
| topic | gaseous elemental mercury (Hg(0)) mercury flux Hg(0) volatilization dynamic flux chamber (DFC) saltmarsh vegetation coastal wetlands |
| url | https://www.mdpi.com/2073-4433/12/2/228 |
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