Enhancing the prediction of arsenic bioavailability in soils with the diffusive gradient in thin film technique

The diffusive gradient in thin films technique (DGT), with a resin gel based on Lewatit® FO 36 was used for the first time to predict arsenic (As) bioavailability in soils collected in different environmental contexts. The predicted bioavailability, determined by fluxes to DGT, was compared with the bioavailability and bioaccumulation in the plants (Calendula officinalis), where a strong correlation was observed (r = 0.8857 (C_E/C_roots) and r = 0.9208 (C_E/C_shoots); p < 0.05; n > 40). Arsenic, predominantly accumulated in the roots of plants from all soil samples, reached concentrations up to 507.8 mg kg^-1. To better understand the As distribution within the various soil-bearing phases, sequential extraction procedures were performed and revealed low mobility and availability of As, particularly in A and R soil samples, where As pollution is primarily caused by anthropogenic activities such as mining and industrial activities. The obtained results show that Calendula officinalis plants can be grown on soils contaminated by arsenic, while the low translocation factors indicate that accumulate arsenic predominantly in the root system.