Plant
uptake and metabolism of emerging organic contaminants, such
as personal-care products, pose potential risks to human health. In
this study, jalapeno pepper (Capsicum annuum) plants
cultured in hydroponic media were exposed to both 14C-labeled
and unlabeled triclocarban (TCC) to investigate the accumulation,
distribution, and metabolism of TCC following plant uptake. The results
revealed that TCC was detected in all plant tissues; after 12 weeks,
the TCC concentrations in root, stem, leaf, and fruit tissues were
19.74 ± 2.26, 0.26 ± 0.04, 0.11 ± 0.01, and 0.03 ±
0.01 mg/kg dry weight, respectively. More importantly, a substantial
portion of the TCC taken up by plants was metabolized, especially
in the stems, leaves, and fruits. Hydroxylated TCC (e.g., 2′-OH
TCC and 6-OH TCC) and glycosylated OH-TCC were the main phase I and
phase II metabolites in plant tissues, respectively. Bound (or nonextractable)
residues of TCC accounted for approximately 44.6, 85.6, 69.0, and
47.5% of all TCC species that accumulated in roots, stems, leaves,
and fruits, respectively. The concentrations of TCC metabolites were
more than 20 times greater than the concentrations of TCC in the above-ground
tissues of the jalapeno pepper plants after 12 weeks; crucially, approximately
95.6% of the TCC was present as metabolites in the fruits. Consequently,
human exposure to TCC through the consumption of pepper fruits is
expected to be substantially higher when phytometabolism is considered.