Arsenic and trace elements in soil, water, grapevine and onion in Jáchal, Argentina

Highlights: • In soils and water of Jáchal, high levels of trace elements were detected. • In grapevine and onion, As, Cr, Cu, Fe and Zn exceeded limits established by law. • Correlation analyses suggested a common source of potentially toxic metals. • Soils characteristics enhance trace elements mobility. Contamination by trace elements (TE) is an increasing concern worldwide. In some areas, crop production could be limited by the presence of metals and metalloids, so it is important to determine their concentrations and mobility. The region of Jáchal, province of San Juan, Argentina, has good growing conditions for onion and grapevine production, but their quality and yield are affected by high TE concentration in soils and water. Soils, water, grapevine and onion were sampled and TE content determined. In soils elevated As, B, Cr, Hg, and Tl concentrations were detected (506 ± 46, 149 ± 3, 2714 ± 217, 16 ± 7, and 12 ± 3 μg g^{− 1}, respectively, for maximum values measured), and physicochemical properties of the soil promotes these elements mobility. Water samples had high As, B, Cr, and Fe concentrations (1438 ± 400, 10,871 ± 471, 11,516 ± 2363, and 3071 ± 257 μg L^{− 1}, respectively, for maximum values measured) while in onion bulbs and grapevine berries, As, Cr, Cu, and Fe (92 ± 7 and 171 ± 20, 1412 ± 18 and 2965 ± 32, 17 ± 3 and 126 ± 88, and 418 ± 204 and 377 ± 213 μg g^{− 1}, respectively, for maximum values measured) exceeded the limits for food consumption established by Argentinian law. Correlation analyses indicated that: i) there is a common source of TE in this area, ii) each elements concentration in plants is associated with different soil variables and different soils depths, and iii) the lack of correlation between soil and water indicates that concentration in water is not constant over the time and/or there exists a differential accumulation of elements in soils depending on their own properties. Data obtained demonstrate very high concentration of TE in soil, grapevines, and onion plants in Jáchal region, and different remediation techniques are necessary to stabilize and minimize the bioavailability of these elements.