@article{fdi:010068831,
  title = {{S}ynergistic effects of mining and urban effluents on the level and distribution of methylmercury in a shallow aquatic ecosystem of the {B}olivian {A}ltiplano},
  author = {{A}lanoca, {L}. and {G}u{\'e}dron, {S}t{\'e}phane and {A}mouroux, {D}. and {A}udry, {S}. and {M}onperrus, {M}. and {T}essier, {E}. and {G}oix, {S}ylvaine and {A}cha, {D}. and {S}eyler, {P}atrick and {P}oint, {D}avid},
  editor = {},
  language = {{ENG}},
  abstract = {{L}ake {U}ru {U}ru (3686 m a.s.l.) located in the {B}olivian {A}ltiplano region receives both mining effluents and urban wastewater discharges originating from the surrounding local cities which are under rapid development. {W}e followed the spatiotemporal distribution of different mercury ({H}g) compounds and other metal(oid) s (e.g., {F}e, {M}n, {S}b, {T}i and {W}) in both water and sediments during the wet and dry seasons along a north-south transect of this shallow lake system. {A}long the transect, the highest {H}g and metal(oid) concentrations in both water and sediments were found downstream of the confluences with mining effluents. {A}lthough a dilution effect was found for major elements during the wet season, mean {H}g and metal(oid) concentrations did not significantly differ from the dry season due to the increase in acid mine drainage ({AMD}) inputs into the lake from upstream mining areas. {I}n particular, high filtered (<0.45 mu m) monomethylmercury ({MMH}g) concentrations (0.69 +/- 0.47 ng {L}-1) were measured in surface water representing 49 +/- 11% of the total filtered {H}g concentrations ({TH}g{F}) for both seasons. {E}nhanced {MMH}g lability in relation with the water alkalinity, coupled with abundant organic ligands and colloids (especially for downstream mining effluents), are likely factors favoring {H}g methylation and {MMH}g preservation while inhibiting {MMH}g photodegradation. {L}ake sediments were identified as the major source of {MMH}g for the shallow water column. {D}uring the dry season, diffusive fluxes were estimated to be 227 ng m(-2) d(-1) for {MMH}g. {T}his contribution was found to be negligible during the wet season due to a probable shift of the redox front downwards in the sediments. {D}uring the wet season, the results obtained suggest that various sources such as mining effluents and benthic or macrophytic biofilms significantly contribute to {MMH}g inputs in the water column. {T}his work demonstrates the seasonally dependent synergistic effect of {AMD} and urban effluents on the shallow, productive and evaporative high altitude lake ecosystems which promotes the formation of natural organometallic toxins such as {MMH}g in the water column.},
  keywords = {{BOLIVIE} ; {ANDES} ; {ORURO} ; {URU} {URU} {LAC}},
  booktitle = {},
  journal = {{E}nvironmental {S}cience : {P}rocesses and {I}mpacts},
  volume = {18},
  numero = {12},
  pages = {1550--1560},
  ISSN = {2050-7887},
  year = {2016},
  DOI = {10.1039/c6em00547k},
  URL = {https://www.documentation.ird.fr/hor/fdi:010068831},
}