In recent years interest has grown in the occurrence and the effects of pharmaceuticals in the environment. The aim of this work is to evaluate the risk of fertilizing crops with manure from livestock treated with anthelmintics. The present study was designed to follow the fate of the commonly used anthelmintic drug, ivermectin (IVM) and its metabolites in soybeans (Glycine max (L.) Merr.), a plant that is grown and consumed world-wide for its high content of nutritional and health-beneficial substances. In vitro plantlets and soybean plants, cultivated in a greenhouse, were used for this purpose. Our results showed the uptake of IVM and its translocation to the leaves, but not in the pods and the beans. Four IVM metabolites were detected in the roots, and one in the leaves. IVM exposure decreased slightly the number and weight of the beans and induced changes in the activities of antioxidant enzymes. In addition, the presence of IVM affected the proportion of individual isoflavones and reduced the content of isoflavones aglycones, which might decrease the therapeutic value of soybeans. Fertilization of soybean fields with manure from IVM-treated animals appears to be safe for humans, due to the absence of IVM in beans, the food part of plants. On the other hand, it could negatively affect soybean plants and herbivorous invertebrates.

Environmental context: Bioaccumulation of nanoparticles in plants used for food and feed could be a major exposure pathway to nanoparticles, resulting in ecological and health risks. Isotopic labelling of nanoparticles enables their sensitive tracing in the presence of background elements in complex plant matrices. We investigate nine individual cases of plant–NP interactions and show the role of plants in the uptake and translocation of nanoparticles or their dissolution into metals. Unintended releases of nanoparticles (NPs) into agricultural soil have recently raised concerns regarding NP accumulation in plants. In this study, specially synthesised isotopically labelled 107Ag-NPs, 65Cu-NPs and 70ZnO-NPs were exposed to three representative plants (Arabidopsis thaliana, Solanum lycopersicum (tomato) and Phragmites australis (common reed)) in hydroponic cultivation and, separately, to tomato plants cultivated in soil at concentrations of 2 mg L-1. Metal concentrations in all samples were analysed by inductively coupled plasma mass spectrometry following acid digestion. The use of isotopically labelled NPs confirmed that elevated levels of metals were from the NP source used for the experiments. Although the highest concentrations of NPs or metals were detected in roots in both hydroponic and soil cultivations, varied levels of translocation to shoots were observed in different plants under hydroponic cultivation. In soil cultivation, where tomato plants were grown to full maturity, low levels of 107Ag (0.38 mg kg-1) with respect to controls were recorded in tomato fruits; 70Zn showed the highest level of translocation to tomato stems (2.72 mg kg-1) and leaves (13.93 mg kg-1). Furthermore, the amounts of NPs retained in the soil (at different depths) after harvesting tomato plants were also determined; the highest concentrations of respective isotopes (1.25 mg kg-1 of 107Ag, 0.79 mg kg-1 of 65Cu, 4.06 mg kg-1 of 70Zn) were found in the top soil layer (~3 cm). Analysis of NPs exposed to plants in hydroponic medium indicated that the presence of plants increases the dissolution of NPs. Scanning electron microscopy analysis enabled determination of the location of 107Ag-NPs in the roots of tomato plants grown in soil; these NPs were found to accumulate mainly in the cortical cells.