Abstract:
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 (QACs). 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 (YES), 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 non-targeted 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 within the ecological effect-based trigger value range 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 LCMS/MS results indicated the presence of multiple pesticides, nonylphenols,
triclocarban, and triclosan. Many of these compounds exhibit estrogenic
activity, which may explain the 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.
