Analysis of Honey and Environmental Samples from BEN Endemic Villages in Serbia: Identification of a Novel Human Exposure Pathway for Aristolochic Acids and Aristolactams

Dietary exposure to aristolochic acids (AAs) through AA-tainted flour is closely linked to the development of Balkan endemic nephropathy (BEN), a chronic kidney disease that is prevalent in rural farming villages in the Balkan region; however, additional exposure pathways would better explain the incidence rate of BEN. This study reveals for the first time that inhalation of AA-contaminated air, which often contains aristolactams (ALs)─genotoxic metabolites of AAs─represents an unrecognized exposure route. The presence of AAs was confirmed in local honey, and subsequent analysis of face masks worn by volunteers near flowering Aristolochia clematitis (A. clematitis) weeds indicated that AAs may be airborne. Further investigation into the transport of AA-containing particles was conducted by analyzing outdoor residential surfaces (e.g., windowsills) in Serbia, detecting AA-I or AL-I in more than 20% of the samples, with concentrations ranging from 13 to 2470 pg and 1 to 8985 pg per 225 cm², respectively. Additionally, it was found that burning A. clematitis generates particle-bound ALs. Given that A. clematitis weeds are often burned alongside wheat remnants for cooking, heating, and fertilizer production, these findings highlight airborne AAs and ALs as potentially key agents in the induction of BEN. In conjunction with the WHO’s notice that biomass burning significantly contributes to the high prevalence of respiratory diseases in the Balkans, this study identifies AAs and their analogs as air pollutants. Therefore, it is imperative to eliminate A. clematitis weeds from affected areas and to cease their use as heating and cooking fuel.