Natalie ANECK-HAHN ^1* Magdalena C. Van Zijl ^1* Laura Quinn ^2* Caitlin Swiegelaar ^2* Nontete Nhlapo ^2* Willeke de Bruin ^1* Lise Korsten ¹

• ¹ University of Pretoria, Pretoria, South Africa
• ² National Metrology Institute of South Africa (NMISA), Pretoria, South Africa

Fruit and vegetable processing facilities may contaminate wastewater via contaminants found in the produce and disinfecting chemicals used. These contaminants may include agrochemicals, pesticides, and disinfectants such as chlorine and quaternary ammonium compounds. Some compounds may exhibit harmful endocrine-disrupting activity. This study investigated the impact of a minimally processed vegetable facility on wastewater quality via in vitro bioassays and chemical screening. Estrogen activity was assessed via a yeast estrogen screen, and (anti-)androgenic and glucocorticoid activities were evaluated via an MDA-kb2 reporter gene assay. The samples were screened via gas and liquid chromatography-tandem mass spectrometry (GC-MS/MS and LC-MS/MS) to identify target compounds, and GC coupled with time-of-flight mass spectrometry (GC-TOFMS) was used for nontargeted screening. Sample complexity and chemical profiles were assessed using GC-TOFMS. Estrogenic activity was detected in 16 samples (n=24) with an upper limit of 595±37 ng/L estradiol equivalents (EEqs). The final wastewater before discharge had an EEq of 0.23 ng/L, which is the ecological effect-based trigger value for the estrogenic activity of wastewater (0.2-0.4 ng/L EEq). Androgenic activity was detected in one sample with a dihydrotestosterone equivalent (DHTEq) value of 10±2.7 ng/L. No antiandrogenic activity was detected. The GC-MS/MS and LC-MS/MS results indicated the presence of multiple pesticides, nonylphenols, triclocarban, and triclosan. Many of these compounds exhibit estrogenic activity, which may explain positive YES assay findings. These findings showed that wastewater from the facility contained detergents, disinfectants, and pesticides and displayed hormonal activity. Food processing facilities release large volumes of wastewater, which may affect the quality of the water eventually being discharged into the environment. We recommend expanding conventional water quality monitoring efforts to include additional factors like endocrine activity and disinfectant byproducts.