“…1 ), which is in agreement with published atmospheric Hg data 40 . Our Hg 0 isotope observations broadly agree with the limited observations from Utqiagvik (formerly Barrow; n = 2 41 ), and ALT ( n = 2 56 ), except for the case of Δ 199 Hg at Utqiagvik, discussed below. Fig.…”
Section: Resultssupporting
confidence: 86%
“…2 and 4b ). Rather, the observed June-August Hg 0 δ 202 Hg of 0.58 ± 0.17‰ is more similar to δ 202 Hg observations of Hg II in Arctic coastal snow associated with AMDEs of 0.43‰ (median, IQR 0.08 to 0.75, n = 58) 41 , 43 , 56 (this study). Similar to Δ 199 Hg, the atmospheric Hg 0 δ 202 Hg observations are therefore compatible with a dominant contribution of AMDE deposited Hg, but not terrestrial Hg.…”
Section: Resultssupporting
confidence: 85%
“…Sherman et al 41 also observed that as snow re-emits Hg 0 with positive Δ 199 Hg, the residual snow Hg II fraction progressively attains Δ 199 Hg as low as −5.1‰. We observe low snow Δ 199 Hg down to −2.4‰ in Ny-Ålesund in 2011 and 2019, and so did others in Toolik, AK (USA) and in ALT 43 , 56 . Snow Δ 199 Hg/Δ 199 Hg regression slopes are near 1.0 in our Ny-Ålesund snow data (Fig.…”
During Arctic springtime, halogen radicals oxidize atmospheric elemental mercury (Hg0), which deposits to the cryosphere. This is followed by a summertime atmospheric Hg0 peak that is thought to result mostly from terrestrial Hg inputs to the Arctic Ocean, followed by photoreduction and emission to air. The large terrestrial Hg contribution to the Arctic Ocean and global atmosphere has raised concern over the potential release of permafrost Hg, via rivers and coastal erosion, with Arctic warming. Here we investigate Hg isotope variability of Arctic atmospheric, marine, and terrestrial Hg. We observe highly characteristic Hg isotope signatures during the summertime peak that reflect re-emission of Hg deposited to the cryosphere during spring. Air mass back trajectories support a cryospheric Hg emission source but no major terrestrial source. This implies that terrestrial Hg inputs to the Arctic Ocean remain in the marine ecosystem, without substantial loss to the global atmosphere, but with possible effects on food webs.
“…1 ), which is in agreement with published atmospheric Hg data 40 . Our Hg 0 isotope observations broadly agree with the limited observations from Utqiagvik (formerly Barrow; n = 2 41 ), and ALT ( n = 2 56 ), except for the case of Δ 199 Hg at Utqiagvik, discussed below. Fig.…”
Section: Resultssupporting
confidence: 86%
“…2 and 4b ). Rather, the observed June-August Hg 0 δ 202 Hg of 0.58 ± 0.17‰ is more similar to δ 202 Hg observations of Hg II in Arctic coastal snow associated with AMDEs of 0.43‰ (median, IQR 0.08 to 0.75, n = 58) 41 , 43 , 56 (this study). Similar to Δ 199 Hg, the atmospheric Hg 0 δ 202 Hg observations are therefore compatible with a dominant contribution of AMDE deposited Hg, but not terrestrial Hg.…”
Section: Resultssupporting
confidence: 85%
“…Sherman et al 41 also observed that as snow re-emits Hg 0 with positive Δ 199 Hg, the residual snow Hg II fraction progressively attains Δ 199 Hg as low as −5.1‰. We observe low snow Δ 199 Hg down to −2.4‰ in Ny-Ålesund in 2011 and 2019, and so did others in Toolik, AK (USA) and in ALT 43 , 56 . Snow Δ 199 Hg/Δ 199 Hg regression slopes are near 1.0 in our Ny-Ålesund snow data (Fig.…”
During Arctic springtime, halogen radicals oxidize atmospheric elemental mercury (Hg0), which deposits to the cryosphere. This is followed by a summertime atmospheric Hg0 peak that is thought to result mostly from terrestrial Hg inputs to the Arctic Ocean, followed by photoreduction and emission to air. The large terrestrial Hg contribution to the Arctic Ocean and global atmosphere has raised concern over the potential release of permafrost Hg, via rivers and coastal erosion, with Arctic warming. Here we investigate Hg isotope variability of Arctic atmospheric, marine, and terrestrial Hg. We observe highly characteristic Hg isotope signatures during the summertime peak that reflect re-emission of Hg deposited to the cryosphere during spring. Air mass back trajectories support a cryospheric Hg emission source but no major terrestrial source. This implies that terrestrial Hg inputs to the Arctic Ocean remain in the marine ecosystem, without substantial loss to the global atmosphere, but with possible effects on food webs.
“…32,45 After exposure to sunlight, Hg(II) in snow is possibly photoreduced by halogens and the residual Hg(II) generally displayed a more negative Δ 199 Hg value, 5,46 as low as −3.45‰ in high Arctic fresh snow. 25 Similarly, the more negative Δ 199 Hg values were also detected in aerosol samples from the high Arctic. 25 Subsequently, atmospheric Hg(II) with a negative Δ 199 Hg value was likely transported southward by the cold air mass in winter, especially during the polar vortex in the low troposphere (Figures S7 and S8), resulting in the relatively low Δ 199 Hg D values in S12 and S24.…”
Section: Significant Variations Of Odd-mifmentioning
The determination of the mass-independent fractionation
of even
Hg isotopes (even-MIF, Δ200Hg) in atmospheric samples
adds another intriguing feature to the Hg isotope system. Despite
our lack of sufficient experimental verification and the momentary
absence of a valid mechanism to explain its occurrence, even-MIF could
be instrumental in understanding the cycle and deposition of atmospheric
Hg. In contrast to slightly positive Δ200Hg values
(<0.30‰) frequently observed in most atmospheric samples,
large Δ200Hg values (up to 1.24‰) determined
in precipitation from Peterborough (Ontario, Canada) stand out and
could provide valuable information for the origin of the even-MIF
mystery. We now report a systematic analysis of high-resolution rainfall
and snowfall samples collected in winter during cold weather at Peterborough,
Canada. Dissolved and particulate Hg both displayed large variations
of odd-MIF (from −0.93‰ to 2.02‰ for Δ199Hg), which may result from long-range transportation, as
the negative odd-MIF in particulate Hg is likely a result of long-distance
transport of arctic atmospheric Hg(II). Dissolved Hg revealed significant
even-MIF values (from 0.25‰ to 1.19‰ for Δ200Hg) and a negative relationship between Δ200Hg and Δ204Hg, which provide further evidence for
the previously proposed conceptual model of Δ200Hg.
Disconnected odd-MIF and even-MIF trends were detected in sequentially
collected precipitation samples, which further suggests different
sources or mechanisms for Δ199Hg and Δ200Hg. Particularly, the high Δ200Hg values
highlight the transport of stratospheric Hg through a polar vortex
to the sampling region, stimulating further systematic investigation.
The new Δ200Hg data for particulate Hg add to existing
information on atmospheric Hg(II) worldwide, suggesting a global distribution
of Hg characterized by even-MIF in the atmosphere, and further constrain
the model of atmospheric Hg deposition.
“…It also causes decreased bone density and kidney damage [18]. Finally, mercury is a toxic metallic element that affects human health, wildlife, aquatic ecosystems (severe and persistent toxicity has been documented from the contaminated fish consumption from fresh and marine waters [4]) and, in general, soils, water and air [19][20][21][22][23][24].…”
The complexing properties of two water-soluble resorcin[4]arenes (tetrasodium 5,11,17,23-tetrakissulfonatemethylen 2,8,14,20-tetra(butyl)resorcin[4]arene, Na4BRA, and tetrasodium 5,11,17,23-tetrakissulfonatemethylen-2,8,14,20-tetra(2-(methylthio)ethyl)resorcin[4]arene, Na4SRA) with polluting heavy metals such as Cu2+, Pb2+, Cd2+ and Hg2+ were studied by conductivity, and the findings were confirmed by using other techniques to try to apply this knowledge to removing them. The results indicate that Na4BRA is able to complex Cu2+ in a 1:1 ratio and Pb2+ in a 1:2 ratio, while Na4SRA complexes Hg2+ in a 1:1 ratio. On the contrary, no indications have been observed that either of the resorcin[4]arenes studied complexes the Cd2+ ions. The results suggest that the bonds established between the sulfur atoms located at the lower edge of the SRA4− and the solvent hydrogens could prevent the entry of the guest into the host cavity. However, in the case of Hg2+ ions, the entry is favoured by the interactions between the sulfur donor atoms present on the lower edge of Na4SRA and the Hg2+ ions. Therefore, it can be said that Na4BRA is selective for Cu2+ and Pb2+ ions and Na4SRA is selective for Hg2+ ions.
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