title: Temporal and seasonal variability of arsenic in drinking water wells in Matlab, southeastern Bangladesh: a preliminary evaluation on the basis of a 4 year study.
abstract: Temporal and seasonal variability of As concentrations in groundwater were evaluated in As-affected areas of Matlab, southeastern Bangladesh. Groundwater samples from 61 randomly selected tubewells were analyzed for As concentrations over a period of three years and four months (from July 2002 to November 2005) and monitored seasonally (three times a year). The mean As concentrations in the sampled tubewells decreased from 153 to 123 μg/L during July 2002 to November 2005. Such changes were pronounced in tubewells with As concentration >50 μg/L than those with As concentrations <50 μg/L. Similarly, individual wells revealed temporal variability, for example some wells indicated a decreasing trend, while some other wells indicated stable As concentration during the monitoring period. The mean As concentrations were significantly higher in Matlab North compared with Matlab South. The spatial variations in the mean As concentrations may be due to the differences in local geological conditions and groundwater flow patterns. The variations in mean As concentrations were also observed in shallow (<40 m) and deep (>40 m) wells. However, to adequately evaluate temporal and seasonal variability of As concentration, it is imperative to monitor As concentrations in tubewells over a longer period of time. Such long-term monitoring will provide important information for the assessment of human health risk and the sustainability of safe drinking water supplies.
authors: KTH-International Groundwater Arsenic Research Group, Department of Land and Water Resources Engineering, Royal Institute of Technology, Stockholm, Sweden. prosun@kth.se
authors: Prosun
authors: P
authors: Bhattacharya
authors: Mohammed
authors: M
authors: Hossain
authors: Shamsun Naima
authors: SN
authors: Rahman
authors: Clare
authors: C
authors: Robinson
authors: Bibhash
authors: B
authors: Nath
authors: Marina
authors: M
authors: Rahman
authors: M Mainul
authors: MM
authors: Islam
authors: Mattias
authors: M
authors: Von Brömssen
authors: Kazi Matin
authors: KM
authors: Ahmed
authors: Gunnar
authors: G
authors: Jacks
authors: Dulaly
authors: D
authors: Chowdhury
authors: Mahfuzar
authors: M
authors: Rahman
authors: Mohammed
authors: M
authors: Jakariya
authors: Lars Åke
authors: LÅ
authors: Persson
authors: Marie
authors: M
authors: Vahter
mesh_terms: D001151:Arsenic / Q000032:analysis*; D001459:Bangladesh; D060766:Drinking Water / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D060587:Groundwater / Q000032:analysis*; D012621:Seasons; D014874:Water Pollutants, Chemical / Q000032:analysis*; D060986:Water Wells / Q000032:analysis
chemical_list: D060766:Drinking Water; D014874:Water Pollutants, Chemical; D001151:Arsenic