@article{fdi:010091884,
  title = {{A}rsenic, selenium, and mercury speciation in hypersaline lakes of the {A}ndean {A}ltiplano : link between extreme levels and biodiversity repartition},
  author = {{G}u{\'e}dron, {S}t{\'e}phane and {T}olu, {J}. and {A}mouroux, {D}. and {T}essier, {E}. and {M}olina, {C}. and {B}ueno, {M}. and {M}estrot, {A}. and {T}isserand, {D}. and {A}cha, {D}.},
  editor = {},
  language = {{ENG}},
  abstract = {{A}rsenic ({A}s) and mercury ({H}g) are highly toxic contaminants whereas selenium ({S}e) is both an essential trace element and potentially harmful at higher concentrations. {T}he hyper-saline lakes of southern {B}olivian {A}ltiplano, which are ecological niches for endemic species, are also expected to be enriched in these toxic trace elements. {T}he biogeochemistry of {A}s, {H}g, and {S}e in such high-altitude extreme environments (e.g., high {UV} radiation and salt content) remains poorly understood. {I}n this study, we investigated the concentrations and chemical forms (speciation) of {A}s, {H}g, and {S}e in sediment, water, and air samples of {L}agunas {C}olorada ({LC}), {V}erde ({LV}), and {B}lanca ({LB}) in the {S}outh {L}ipez region (>4200 m a.s.l.). {W}e compared them with the repartition of biodiversity (invertebrates, algae, and bacteria). {E}xtreme {A}s concentrations were found in water (up to 82 mg {L}-1), and the main {A}s species was inorganic {A}s({V}), with neither biogenic methylated {A}s nor volatile {A}s forms being detected in water and air, respectively. {S}e concentrations in water were of 0.1 to 1.4 mu g {L}-1, and {S}e existed under different redox states, i.e., {S}e({IV}), {S}e({VI}), and reduced {S}e (0, -{II}), including biogenic methylated {S}e(-{II}) (trimethyl selenonium). {V}olatile {S}e compounds (e.g., dimethyl selenide) were detected in water and air samples. {H}g was enriched in the surface water (6 to 30 ng {L}-1) compared to other regional water bodies, and a significant amount of methyl-{H}g and gaseous {H}g(0) was detected. {T}he drastic disparity between {A}s, {S}e and {H}g concentrations and speciation between lakes has important implications for their cycling in these extreme aquatic systems. {W}hile {A}s mostly accumulated in its oxidized and non-volatile form, {H}g and {S}e concentrations can be controlled by significant conversion to reduced and methylated forms, allowing efficient evasion to the atmosphere. {F}inally, the salinity, including major ions, and high levels of {A}s were among the main drivers of biodiversity repartition between lakes.},
  keywords = {{S}outh {L}ipez ; {H}igh altitude lakes ; {E}xtreme environment ; {S}ediment ; {A}tmosphere ; {BOLIVIE} ; {ANDES}},
  booktitle = {},
  journal = {{J}ournal of {G}eochemical {E}xploration},
  volume = {267},
  numero = {},
  pages = {107577 [11 ]},
  ISSN = {0375-6742},
  year = {2024},
  DOI = {10.1016/j.gexplo.2024.107577},
  URL = {https://www.documentation.ird.fr/hor/fdi:010091884},
}