Determination of Aristolochic Acids in Soil, Water, and Herbal Plants in Medicinal Plant Cultivation Areas: An Emerging Environmental Contaminant Worth Concerning

Nephrotoxic and carcinogenic aristolochic acids (AAs) were recently identified as an emerging class of environmental contaminants in farmland soil and groundwater of the Balkan Peninsula, released from the decay of Aristolochia clematitis, an AA-containing weed that grows extensively in affected areas. In this study, we tested the hypothesis that medicinal herb cultivation areas that include AA-producing plants are also contaminated with AAs. The results of the study revealed for the first time extensive soil contamination by AAs in AA-containing herb cultivation areas. Alarmingly, liquid chromatography–tandem mass spectrometry (LC–MS/MS) analysis of soil and herbal plant samples collected in three nearby plantation zones for non-AA-producing herbs detected AA-I in roughly half of the tested samples. Despite being detected at concentrations lower than that from the AA-containing herb cultivation areas, AA-I was detected at a similar frequency (∼60%) in the areas with and without AA-containing herbs, indicating the free AAs had diffused to surrounding areas, leading to a broad contamination of non-AA-producing herbs.