Translocation of potential toxic elements from soil to black cabbage (Brassica oleracea L.) growing in an abandoned mining district area of the Apuan Alps (Tuscany, Italy).

In the Apuan Alps (Tuscany, Italy), long-lasting mining activities have favored the mobilization of numerous metals present in sulfosalts originated from low-grade metamorphism mineralization. Such materials, rich in potentially toxic elements such as antimony, arsenic, barium, copper, lead, thallium, tin and zinc, represent the substrate on which soils of different thicknesses have been formed and is currently used for agricultural activities. High concern is particularly arising about the food safety due to traditional horticultural practices, since it is very common in this area to cultivate vegetables in private gardens for both self-consuming and/or local market. In this context, a monitoring survey on both soils and vegetables was performed over the area, with particular attention to Brassica oleracea L. as traditional food crop, to assess the degree of contamination of the area, the possible translocation to vegetables and the potential human risk linked to vegetable ingestion. This analysis reveals a different degree of soil contamination in the area and a general high human risk linked to cabbage cultivation and ingestion in the whole area.

Soil Organic Carbon and Carbonates are Binding Phases for Simultaneously Extractable Metals in Calcareous Saltmarsh Soils.

The ability of the simultaneously extracted metals/acid volatile sulfides (∑SEM/AVS) index to ascertain environmental risk from potentially toxic elements in calcareous saltmarsh soils was tested using structural equation modeling. This technique allows the detection of both direct and indirect relationships among AVS, SEM, and other soil variables, representing results in a graphical view. The dataset included 90 soil samples from 21 different sites belonging to 6 different saltmarshes and featured a wide range of soil chemicophysical properties. Variables included in the a priori model were hydroperiod, pH, soil redox potential, labile organic carbon, carbonates, total iron, and total amount of potentially toxic elements (PTEs). The best optimized model pointed out the main soil properties that affect AVS accumulation and SEM speciation in these soils. Effect plots of AVS and SEM calculated with the partial linear mixed-effects models included in the piecewise structural equation modeling showed a significant and positive influence of pH and carbonates on AVS and a highly significant effect of carbonates and labile organic carbon on SEM. Single SEM components were also considered separately, to define the potential contributions of labile organic carbon or carbonates as alternative binding phases. Simultaneously extracted Cu, Ni, and Zn were preferentially bound to carbonates, followed by labile organic carbon, whereas Pb and Cd were easily bound to labile organic carbon. Environ Toxicol Chem 2019;38:2688-2697. © 2019 SETAC.

A new paper sensor method for field analysis of acid volatile sulfides in soils.

Monitoring of biogenic sulfide is important because acid volatile sulfides (AVS) represent a reactive pool responsible for immobilization of toxic metals. We propose a new sulfide paper sensor method for semiquantitative determination of AVS in which developed color is compared to a reference chart. The method was validated against the ion-selective microelectrode and the purge-and-trap methods. For fieldwork, readings should fall within 1 to 10 µmoles S2- . Considering that the volume of soil used ranged between 1 and 16 cm3 , the corresponding soil sulfides concentration range spans from 0.06 to 10 mmoles S2- cm-3 . The sulfide paper sensor method is highly suitable for field screening and has sensitivity levels comparable to laboratory methods. Environ Toxicol Chem 2018;37:3025-3031. © 2018 SETAC.