title: The dynamics of arsenic in four paddy fields in the Bengal delta.
abstract: Irrigation with arsenic contaminated groundwater in the Bengal Delta may lead to As accumulation in the soil and rice grain. The dynamics of As concentration and speciation in paddy fields during dry season (boro) rice cultivation were investigated at 4 sites in Bangladesh and West Bengal, India. Three sites which were irrigated with high As groundwater had elevated As concentrations in the soils, showing a significant gradient from the irrigation inlet across the field. Arsenic concentration and speciation in soil pore water varied temporally and spatially; higher As concentrations were associated with an increasing percentage of arsenite, indicating a reductive mobilization. Concentrations of As in rice grain varied by 2-7 fold within individual fields and were poorly related with the soil As concentration. A field site employing alternating flooded-dry irrigation produced the lowest range of grain As concentration, suggesting a lower soil As availability caused by periodic aerobic conditions.
authors.affiliation: Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK.
authors.forename: Jacqueline L
authors.initials: JL
authors.lastname: Stroud
authors.forename: Gareth J
authors.initials: GJ
authors.lastname: Norton
authors.forename: M Rafiqul
authors.initials: MR
authors.lastname: Islam
authors.forename: Tapash
authors.initials: T
authors.lastname: Dasgupta
authors.forename: Rodger P
authors.initials: RP
authors.lastname: White
authors.forename: Adam H
authors.initials: AH
authors.lastname: Price
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Meharg
authors.forename: Steve P
authors.initials: SP
authors.lastname: McGrath
authors.forename: Fang-Jie
authors.initials: FJ
authors.lastname: Zhao
mesh_terms: D057914:Agricultural Irrigation; D001151:Arsenic / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D001459:Bangladesh; D005618:Fresh Water / Q000032:analysis / Q000737:chemistry; D007194:India; D012275:Oryza / Q000378:metabolism*; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism
chemical_list: D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D001151:Arsenic