@article{fdi:010062571,
  title = {{O}ccurrence of 1,1 '-dimethyl-4,4 '-bipyridinium ({P}araquat) in irrigated soil of the {L}ake {C}had {B}asin, {N}iger},
  author = {{C}rampon, {M}. and {C}opard, {Y}. and {F}avreau, {G}uillaume and {R}aux, {J}. and {M}erlet-{M}achour, {N}. and {L}e {C}oz, {M}. and {I}brahim, {M}. and {P}eulon-{A}gasse, {V}. and {P}ortet-{K}oltalo, {F}.},
  editor = {},
  language = {{ENG}},
  abstract = {{I}ncreased use of agrochemical products to improve yields for irrigated crops in sub-{S}aharan {A}frica has been accompanied by a significant increase in the risk of environmental contamination. {D}etailed examples of the fate of pesticides after initial spreading on crop fields are scarce in tropical regions, where safe practices and related health risks are poorly understood by smallholder farmers. {I}n the semi-arid environment of the {L}ake {C}had {B}asin, {SE} {N}iger, both intrinsic properties of pesticides and extrinsic factors such as soil and climate helped to characterize processes leading to an accumulation of pesticides in soils. {A}nalysis by {HPLC}-{UV} of a 6 m deep soil profile showed the presence of {P}araquat at concentrations from 953 +/- 102 mu g kg(-1) to 3083 +/- 175 mu g kg(-1) at depths between 0.80 and 2.75 m below the land surface. {S}oil analysis revealed that up to approximately 15 % of the total soil matrix consists of smectites, a clay mineral capable of retaining cationic pesticides such as {P}araquat, and a very low content of organic matter (<0.15 wt.% {TOC}). {P}araquat could be stored and not bioavailable in a clayey barrier at approximately 2-m depth and therefore does not represent an immediate risk for populations or environment in this form. {H}owever, if the {P}araquat application rate remains constant, the clayey barrier could reach a saturation limit within 150-200 years and 180-220 years if we consider a {DT}50 in soil of similar to 1,000 days ({FAO}). {C}onsequently, it could lead to a deeper infiltration and so a pollution of groundwater. {S}uch a scenario can represent a health risk for drinking water and for the {L}ake {C}had, which is a major resource for this densely populated region of semi-arid {A}frica. {F}urther analyses should focus on deeper layers and groundwater {P}araquat contents to validate or invalidate the hypothesis of storage in this clay-rich layer.},
  keywords = {{S}oil pollution ; {P}araquat ; {V}ertisol ; {S}ahel ; {L}ake {C}had ; {S}emi-arid region ; {NIGER} ; {TCHAD} {LAC}},
  booktitle = {},
  journal = {{E}nvironmental {S}cience and {P}ollution {R}esearch},
  volume = {21},
  numero = {18},
  pages = {10601--10613},
  ISSN = {0944-1344},
  year = {2014},
  DOI = {10.1007/s11356-014-3064-8},
  URL = {https://www.documentation.ird.fr/hor/fdi:010062571},
}