title: Evaluation of spatial variability of soil arsenic adjacent to a disused cattle-dip site, using model-based geostatistics.
abstract: This study investigated the spatial variability of total and phosphate-extractable arsenic (As) concentrations in soil adjacent to a cattle-dip site, employing a linear mixed model-based geostatistical approach. The soil samples in the study area (n = 102 in 8.1 m(2)) were taken at the nodes of a 0.30 × 0.35 m grid. The results showed that total As concentration (0-0.2 m depth) and phosphate-extractable As concentration (at depths of 0-0.2, 0.2-0.4, and 0.4-0.6 m) in soil adjacent to the dip varied greatly. Both total and phosphate-extractable soil As concentrations significantly (p = 0.004-0.048) increased toward the cattle-dip. Using the linear mixed model, we suggest that 5 samples are sufficient to assess a dip site for soil (As) contamination (95% confidence interval of ±475.9 mg kg(-1)), but 15 samples (95% confidence interval of ±212.3 mg kg(-1)) is desirable baseline when the ultimate goal is to evaluate the effects of phytoremediation. Such guidelines on sampling requirements are crucial for the assessment of As contamination levels at other cattle-dip sites, and to determine the effect of phytoremediation on soil As.
authors: Faculty of Agriculture Food and Natural Resources, The University of Sydney, Sydney, NSW 2006, Australia.
authors: Nabeel K
authors: NK
authors: Niazi
authors: Thomas F A
authors: TF
authors: Bishop
authors: Balwant
authors: B
authors: Singh
mesh_terms: D000822:Animal Husbandry / Q000379:methods; D000818:Animals; D001151:Arsenic / Q000032:analysis*; D002417:Cattle; D004784:Environmental Monitoring / Q000379:methods*; D004787:Environmental Pollution / Q000706:statistics & numerical data*; D008956:Models, Chemical; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D013223:Statistics as Topic
chemical_list: D012987:Soil; D012989:Soil Pollutants; D001151:Arsenic