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The study was carried out in an intensively cultivated agricultural area of central Spain where high arsenic (As) concentrations in groundwater were previously reported. The concentrations and distribution of As in soils and crops (wheat, potato, sugar beet and carrot) were determined to know the effect of irrigation with As-rich groundwater in the agricultural fields, and to estimate its impact on the food chain contamination. Irrigation water shows high As concentrations ranging between 38 and 136 microg/l. Total As contents in the studied agricultural soils are higher than 10 mg/kg exceeding the As content in two control areas and the results of this study reflect that irrigation with As-rich groundwater led to the elevated As levels in the agricultural soils. Total As concentration in soils of a sugar beet plot (36 mg/kg) is higher than that found in soils of the less intensively watered field (11 mg/kg), and more than 3.5 times higher than that in the soils of the control area irrigated with uncontaminated water (<10 mg/kg). Water soluble As in soils ranges between 0.03 and 0.9 mg/kg exceeding the limit of 0.04 mg/kg for agricultural use and shows a significant correlation with total As and organic matter (OM) content in soils. Arsenic contents in potato tuber samples are 35 times higher than that measured in potato tuber of uncontaminated control sites (0.03 mg/kg). Elevated As contents (3.9-5.4 mg/kg DW) were also found in root samples of sugar beet. The As contents in vegetable samples are higher than As content (0.1 mg/kg DW) in plants of uncontaminated control areas, and the limits for foodstuffs (0.5-1 mg/kg DW) set by legislation of many countries reflecting the risk of food chain contamination by As in this study area.

Irrigation with arsenic (As)‐rich water in agricultural soil may increase high levels of As in crops and cause food chain contamination. In this study, a greenhouse experiment was established using Spanish agricultural soil (Valladolid and Segovia provinces), that are extensively cultivated for carrot plant, to investigate the process of As uptake, bioaccumulation, and translocation of As from root to shoot and leaves in carrot plant. Arsenic concentrations in different organs of carrot plant, rhizosphere soil, and soil solutions were determined by hydride generation atomic absorption spectrometry (AAS). High concentrations of As in irrigation water, and the alkaline and sandy character of this soil enhanced As uptake in carrot plants indicating the potential health risk from consumption of carrots cultivated in these areas. Bioaccumulation of As into the leaves and roots increased with increase of As concentration in irrigation water. Both roots and leaves demonstrated a higher accumulation rate of As at an As concentration of 41 than 131 µg L−1 in the soil solution. The ratios of Asroot/Asleaves showed no statistically significant differences for the different irrigation treatments, and had an average value of 0.36 indicating the high magnitude of As translocation from roots to leaves in carrot plants. The leaves of carrots had a higher affinity for As than roots did. The correlation between As uptake by leaves or roots of carrots and the soluble As in rhizosphere soil did not demonstrate a linear or a plateau curve, indicating a slow but continuous constant As absorption which could be prolonged over time with high potential environmental risks.

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