Pharmaceutical contamination in edible plants grown on soils amended with wastewater, manure, and biosolids: a review

Recycling reclaimed wastewater, manure, and biosolids in agricultural soils is a sustainable technique of irrigation and fertilization in the context of the circular economy, yet the presence of contaminants such as pharmaceuticals induces the contamination of crop plants, food, and, in turn, humans. Here, we review the transfer of pharmaceuticals in crop plants with focus on pharmaceutical sources and properties, soil characteristics, root uptake, translocation, and accumulation. We discuss pharmaceutical accumulation in crop plants grown on soils amended with reclaimed wastewater, biosolids, and manure. The presence of pharmaceutical metabolites in plants is also summarized. We observed a decrease of the concentration and of the number of pharmaceuticals from wastewater to soils, then to plants, with typically less than 1% of the initial total pharmaceutical amount being detected in edible crop plants. Pharmaceutical accumulation decreases in the order of leaves, fruits, roots, and grain. Leafy vegetables showed the highest accumulation of pharmaceuticals, reaching few thousands of nanograms per gram dry weight. Pharmaceuticals can be degraded into metabolites that also accumulate in edible plants, yet their behaviour and risk for health are poorly known.