less water soluble, and adsorbs more
strongly on the soil components compared to the inorganic arsenic
species. Consequently, the increase in the contents of inorganic
arsenic species could qualitatively support the reduction in ASA
contents resulted largely from transformation of ASA in the surface
soils between the two sampling campaigns. Overall, the mean total
arsenic concentration did not change significantly, while that of
ASA decreased (from 0.52 to 0.12 mg kg1)