Plant Uptake of Persistent and Mobile Chemicals in Rocket (Eruca sativa)─A Greenhouse Study on Agricultural Wastewater Reuse

With increasing water stress, agricultural wastewater reuse is becoming more prevalent worldwide. In this context, persistent and mobile (PM) chemicals may be especially relevant, yet data on their uptake by plants are still scarce. This study investigates the uptake of 61 PM chemicals by and distribution in rocket ( Eruca sativa ) in pot experiments from spiked water and treated municipal wastewater. The relative uptake (RU; share of theoretical maximum uptake) into rocket exceeded 10% for 18 PM chemicals, among others, perfluoropropionic acid (72% RU), trifluoroacetic acid (67%), and tetrafluoroborate (40%). The median plant uptake ( p ≤ 0.05) and translocation factor ( p < 0.0001) were significantly higher for PM chemicals than reported for less polar chemicals into leafy greens from literature. Irrigation of rocket with reclaimed municipal wastewater resulted in the accumulation of 23 analytes. However, a toxicological threshold of concern approach showed that no critical exposure is reached for these compounds at normal consumption levels. Comparing wastewater treatment plant effluent concentrations with plant uptake data led to a prioritization of PM chemicals, which might be especially relevant for agricultural wastewater reuse and should be considered in risk assessment.