Contaminants of emerging concern (CECs) in agriculture represent a growing global challenge for food safety and public health. In this review, we synthesized evidence on how substances such as pharmaceuticals, microplastics, and per- and polyfluoroalkyl substances (PFAS) enter soils, accumulate in crops, and affect ecological and human health. We found that CECs pose complex risks, including antimicrobial resistance and sublethal impacts on plant and soil systems, while key knowledge gaps persist. These findings underscore the urgent need for coordinated regulation and sustainable practices to reduce contamination at its source. Closing these gaps will enable resilient food systems and equitable environmental health outcomes worldwide. Contaminants of emerging concern (CECs) in agricultural systems pose complex and evolving risks to environmental and human health. These substances, including pharmaceuticals, microplastics, engineered nanomaterials, and per- and polyfluoroalkyl substances (PFAS), enter agricultural soils through diverse pathways such as wastewater irrigation, biosolid, and manure application, and the use of agro-plastics. This review synthesizes current knowledge on the environmental fate, plant uptake mechanisms, and ecological and health impacts of CECs within the soil–plant continuum. Overlooked issues such as co-contaminant interactions, environmentally relevant exposure scenarios, and sublethal effects on plant physiology and soil health are summarized. The paper also explores the implications of CEC accumulation for food safety and antimicrobial resistance. In response to these challenges, we outline future priorities, including improved regulatory frameworks, advanced analytical and modelling tools, and the integration of green chemistry and sustainable production practices to reduce CEC release at source. Research to date has demonstrated that CECs may pose risks to both human and ecosystem health within agricultural systems. As we seek to harness the benefits of resources like biosolids and treated wastewater, we must now establish a strong foundation for resilient and sustainable agriculture, which is driven by coordinated regulation, informed policy, and targeted research to close critical knowledge gaps.

Legacy and novel per- and polyfluoroalkyl substances (PFAS) are emerging contaminants of global concern, and understanding the cross-media transport of PFAS in soil profiles, groundwater and surface water is critical for their environmental modelling and risk assessment across terrestrial-aquatic interface. This study investigated such transport by quantifying vertical-transport potential throughout 0-6 m soil profiles and the retentive effects of critical soil components, while characterizing spatiotemporal variations under hydrological dynamics in an area of similar to 65 km(2) adjacent to the Yangtze River in central China. Source apportionment identified industrial emissions as primary input of PFAS in topsoil, and short-chain or fluorotelomer-based PFAS exhibited a greater downward transport potential. Organic carbon was the key soil component controlling PFAS vertical attenuation (contributing 32.7%-48.2%), with solid organic carbon (SldOC) strongly retaining longer-chain PFAS and dissolved organic carbon (DOC) preferentially immobilizing shorter-chain PFAS. Iron oxide, particularly amorphous iron fraction, was another crucial soil component governing PFAS vertical attenuation (contributing 37.7%-57.3%). Clay exhibited greater retention of PFAS than sand or silt. A quantitative structure-property relationship (QSPR) for anionic PFAS, based on molecular hydrophobicity and electronegativity, was developed for predicting soil-groundwater partitioning. Spatial heterogeneity and PFAS hotspots in groundwater and surface water were found to be more pronounced during flood period relative to normal and dry periods, which may be attributed to intense soil leaching/runoff and active hydraulic exchanges. High concentrations of PFAS in soil, groundwater and surface water are posing potential risks to human health and ecosystems, and these risks became especially pronounced when cross-media transport of PFAS from soil to adjacent water bodies through leaching and runoff was considered. The findings advanced the understanding of contamination mechanisms and driving factors of PFAS across the terrestrial-aquatic interface, informing environmental modelling and risk management.

The detrimental effects of tire particles are closely related to additive leaching, yet how the exposure sequence of sunlight and natural organic matter (NOM) regulates this process remains unclear. We investigated the release dynamics of 11 additives, dissolved organic carbon, and nontarget molecular features in tire tread particle (TTP) leachates over 21 d under two exposure scenarios: (i) dry-photoaging followed by incubation in different NOM, and (ii) wet-photoaging occurring directly in humic acid (HA). For dry-photoaged TTPs, NOM suppressed the release of most organic additives with increasing photoaging duration and NOM concentration through surface passivation and depletion of leachable reservoirs, whereas Zn and diphenylguanidine release were enhanced by up to 44.5% and 47.2%, respectively. By comparison, HA facilitated organic additive release but suppressed Zn during wet-photoaging, with additive levels remaining below those from dry-photoaged TTPs. Compared to dry-photoaging, wet-photoaging in HA also resulted in lower contributions of quantified additives to measured DOC (2-5%), greater reduction in environmentally persistent free radicals (22%), and enhanced formation of 3HA* and 1O2, indicating the photosensitizing role of HA. Nontarget screening further revealed greater diversity of molecular features after prolonged HA incubation than in NOM-free or early stage HA treatments. These findings underscore the exposure-order-dependent divergence in reshaping chemical complexity and the fate of tire-derived mixtures.

Electron beam (E-beam) irradiation is increasingly used in applications including sterilization, material modification, and wastewater treatment. In this study, the removal, dechlorination, mineralization, and detoxification of three model halogenated organic contaminants (HOCs), i.e., triclosan (TCS), chlorpyrifos (CPF) and PCB-28, under E-beam irradiation were systematically evaluated. We used C-14 labeling to quantify mineralization, track intermediate products, and verify carbon mass balances. At an initial concentration of 20 mu g L-1, 90% removal of TCS, CPF, and PCB-28 parent compounds was an achieved at absorbed doses of 2.20, 2.30, and 5.21 kGy, respectively. Complete disappearance occurred at 5 kGy for TCS and CPF and at 10 kGy for PCB-28, corresponding to less than 3 s of irradiation. Notably, E-beam irradiation induced the cleavage of aromatic rings, leading to mineralization to (CO2)-C-14 as unequivocal evidence for complete decomposition. Mineralization reached 94.40% for TCS, 75.43% for CPF, and 65.80% for PCB-28 at 200 kGy. Controlled atmosphere experiments revealed that & centerdot;OH was the primary species responsible for parent compound removal and ring cleavage, while e(aq)(-) and H & centerdot; predominantly contributed to reductive dechlorination. Under O-2-saturated conditions, mineralization of TCS and CPF was further enhanced to 99.2% and 94.1% at 200 kGy, respectively. The presence of dissolved organic matter exhibited a moderate promotional or inhibitory effect on HOC removal at low absorbed doses (< 2 kGy), while its influence became negligible at doses >5 kGy, suggesting broad applicability of E-beam irradiation technology. Toxicity assays indicated 8.5- and 4.1-fold reductions in the acute toxicity of TCS and CPF aqueous samples, respectively, after 2 kGy irradiation. The rapid mineralization and detoxification demonstrated E-beam irradiation as a highly effective and clean technology to remove persistent organic contaminants from water.

Widespread tire wear emissions introduce substantial tire additives (TAs) into terrestrial ecosystems; however, the real-world occurrence and environmental risk of TAs accumulated in plants remain poorly understood. Here, all 20 target TAs were detected in 100% of roadside soil samples from southeastern China, while only 16 of these were identified in paired plants with lower detection frequency (38%-100%) due to their metabolic masking as conjugates. Using an in vitro gastrointestinal model, we demonstrated that these conjugates were efficiently converted back to parent compounds during digestion, greatly increasing the concentrations of 16 persistent TAs by 2.7-22.3-fold and enabling the detection of the 4 previously undetected TAs. Gastric acidity and intestinal enzymes promoted the deconjugation of TA conjugates during gastrointestinal digestion, significantly elevating the bioaccessibility of plant-sourced TAs and the associated dietary risks. Our findings uncover the prevalence of conjugated TAs in field vegetation impacted by vehicular traffic, underscoring the critical need to incorporate plant conjugation and digestive deconjugation into future risk assessment frameworks.

Bisphenol A (BPA) is one of the most used plasticizers and a known endocrine disrupting chemical. In plants, BPA is easily conjugated to form conjugates such as glycosyl BPA, and humans can be exposed to such conjugates when ingesting BPA-contaminated plant foods. This study considered the potential of deconjugation of glycosyl BPA in a simulated human gastrointestinal tract system and evaluated the subsequent changes in biological activity using the Caco-2 colon cell model. Glycosyl BPA was found in both soil and lettuce with concentrations ranging from not detected (ND) to 82.51 ng/g dry weight in edible plant tissues, and the level of glycosyl BPA was correlated significantly with that of BPA. Gastrointestinal digestion triggered progressive deglycosylation of glycosyl BPA with the deconjugation rate significantly higher in the intestinal phase (41.7-47.8%) than the gastric phase (13.4-23.3%). Deglycosylation of glycosyl BPA was associated with decreased Caco-2 cell activity and increased markers of oxidative stress and inflammatory responses in the cell. The re-released BPA may be key to the increased toxic effects. These findings highlight the underestimated health risks posed by plant-derived conjugated xenobiotics through transformation reactivation in the human digestive system.

The detrimental effects of tire particles are closely related to additive leaching, yet how the exposure sequence of sunlight and natural organic matter (NOM) regulates this process remains unclear. We investigated the release dynamics of 11 additives, dissolved organic carbon, and nontarget molecular features in tire tread particle (TTP) leachates over 21 d under two exposure scenarios: (i) dry-photoaging followed by incubation in different NOM, and (ii) wet-photoaging occurring directly in humic acid (HA). For dry-photoaged TTPs, NOM suppressed the release of most organic additives with increasing photoaging duration and NOM concentration through surface passivation and depletion of leachable reservoirs, whereas Zn and diphenylguanidine release were enhanced by up to 44.5% and 47.2%, respectively. By comparison, HA facilitated organic additive release but suppressed Zn during wet-photoaging, with additive levels remaining below those from dry-photoaged TTPs. Compared to dry-photoaging, wet-photoaging in HA also resulted in lower contributions of quantified additives to measured DOC (2-5%), greater reduction in environmentally persistent free radicals (22%), and enhanced formation of 3HA* and 1O2, indicating the photosensitizing role of HA. Nontarget screening further revealed greater diversity of molecular features after prolonged HA incubation than in NOM-free or early stage HA treatments. These findings underscore the exposure-order-dependent divergence in reshaping chemical complexity and the fate of tire-derived mixtures.

Sulfonylureas are among the most used herbicides globally, including regions dominated by volcanic ash-derived soils (VADS), which possess unique physicochemical properties. Despite their high solubility and persistence, the behavior and fate of sulfonylureas in VADS remain poorly understood, limiting accurate risk assessments. We aim to explore the environmental dynamics of sulfonylureas in VADS and identify key VADS descriptors via principal component analysis (PCA) to understand the dominant factors influencing sulfonylurea adsorption in VADS. Using bensulfuron-methyl (BSM) and rimsulfuron (RS) as model sulfonylureas, batch adsorption kinetics and adsorption-desorption studies were conducted in ten different VADS from Chile. The sulfonylurea sorption in VADS and solute transport mechanisms were predicted by combining adsorption kinetics and adsorption-desorption modelling. The pseudo-second-order model elucidated the involvement of variable charge materials in sulfonylurea adsorption, wherein OM content and the halloysite/kaolinite ratio played significant roles in the two and three-step sorption processes. Freundlich isotherms describe the sulfonylurea adsorption in all soils (Kf values between 0.04 and 171.6 µg1 − 1/n mL1/n g− 1), indicating non-linear, irreversible adsorption consistent with chemisorption. The PCA effectively identified bulk density, C_EH_aM, C-EHT/OC ratio, cation exchange capacity ( CEC ), and specific nutrient content as key soil descriptors for explaining sulfonylurea adsorption variability in VADS. This study highlights the need for context-specific management of sulfonylurea application in VADS, emphasizing soil pH adjustment, OM enhancement, and the development of predictive adsorption modelling to mitigate leaching and groundwater contamination risks.

Global restrictions on legacy per- and polyfluoroalkyl substances (PFAS) have resulted in the increased use of replacements including short-chain PFAS and novel alternatives such as ether-PFAS or compounds with F partially substituted by H or Cl. Bioaccumulation of PFAS in soil ecosystems is generally under-investigated but has great ecological safety and human health significance. This review compares the differential behaviors of legacy and novel PFAS in plants and soil-dwelling invertebrates to assess PFAS bioaccumulation and influencing factors in soil ecosystems. The potential effects of PFAS molecular structures and physiological characteristics of biota are discussed. Shortened fluorocarbon chains (e.g., perfluorobutanoic acid, PFBA), ether insertions (e.g., hexafluoropropylene oxide dimer acid, GenX), and H/F substitutions (e.g., 1H,1H,2H,2H-perfluorooctanesulfonic acid, 6:2 FTSA) in novel PFAS increase soil bioavailability and plant translocation from roots to aboveground tissues. Greater CF2 units and Cl/F substitution (e.g., 6:2 chlorinated polyfluorinated ether sulfonate, 6:2 Cl-PFESA) in novel PFAS contribute to retention in plant roots and accumulation in invertebrate tissues. Based on the bioaccumulation of legacy and novel PFAS, the development of predictive bioaccumulation models, frameworks for human exposure and ecological risk assessment, and options for PFAS contamination management and risk mitigation are discussed and highlighted as research priorities.

The hazardous perfluoroalkane sulfonic acids (PFSAs) are being replaced by novel alternatives, and ryegrass demonstrates a promising potential for phytoremediation. This study explored the differential uptake, translocation and distribution patterns of different chain-length PFSAs as well as alternative sodium p-perfluorous nonenoxybenzene sulfonate (OBS) and 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFAES), collectively designated as per- and polyfluoroalkyl substances (PFAS), in ten Italian ryegrass cultivars, and identified the roles of specific PFAS functional groups and plant protein in ryegrass bioaccumulation. Long-chain PFSAs showed high contamination loads in whole ryegrass plants, with majority in roots (e.g., approximately 87.5 % for perfluorooctane sulfonate, PFOS); whereas short-chain homologues exhibited lower pollution burdens and were readily translocated to ryegrass leaves (e.g., about 96.4 % for perfluorobutane sulfonate, PFBS). For PFAS with similar fluorocarbon chain lengths, OBS showed the highest ryegrass contamination loads (146 ng average) and root bioaccumulation factors (2.94 average), followed by 6:2 Cl-PFAES and PFOS. The aromatic ring of OBS, chlorine atom of 6:2 Cl-PFAES, and more CF2 units of PFOS contribute to their retention in ryegrass roots, thus retarding migration to leaves; these PFAS functional groups may augment the effect of plant protein on the bioaccumulation. A molecular indicator (named HE) of PFAS considering interaction mechanisms with protein was proposed to assess protein effects on the bioaccumulation of different PFAS in ryegrass. Protein loads can be used to predict phytoremediation potentials of PFAS by ryegrass. These findings may advance the understanding of novel PFAS accumulation in plants and inform plant screening for PFAS phytoremediation.

In highly urbanized areas, heavy vehicular traffic generates large amounts of tire wear particles (TWPs) and tire additives and transformation products (TATPs), which are released into roadside environments. TATPs can cause acute and sublethal toxicities to nontarget organisms, but their levels and distribution in roadside soils are poorly understood. This study assessed TATP contamination in roadside soils along busy highways in Southern California. Representative TATPs (15) were monitored, and the total concentrations (ΣTATPs) ranged from 33.6 to 1747.5 ng/g. Compounds such as 1,3-diphenylguanidine (DPG) and benzothiazole and its derivatives (BTHs) were consistently detected at higher levels. The TATP contamination profile was influenced by season and surface runoff with higher levels in summer. TATP levels decreased with increasing distance from the road. Traffic volume positively correlated with total TATP levels, while the proportion of trucks contributed to elevated levels of paraphenylenediamine antioxidants (PPDs). These findings highlight the significant presence of TATPs in roadside soils, posing risks as secondary pollution sources for downstream ecosystems. Research is urgently needed to understand the transformations of TATPs in roadside soils, their transport potential to sensitive environments, and the mitigation role of natural and engineered infrastructures along highways.

Many per- and polyfluoroalkyl substances (PFAS) have either carboxylic acid or sulfonic acid as their polar functional group. Studies to date have consistently shown that accumulation of short-chain PFAS containing sulfonic acid in fruits is much more limited than those with carboxylic acid, but the underlying mechanisms are not known. In this study, using the functional group as the sole variable, the concentrations of perfluoropentanoic acid (PFPeA) and perfluorobutanesulfonic acid (PFBS) in various organs of tomato plants were monitored following different treatments to evaluate their transport patterns and identify biological barriers. Concentrations in fruits of tomato grown in nutrient solution with 0.80 μM PFAS were up to 34.83 μg/g for PFPeA, but only 0.07 μg/g for PFBS after exposure for an entire growing season. Redistribution experiments showed that 65.01% of PFPeA accumulated during the seedling stage was translocated to fruits upon maturity, whereas for PFBS, 99.99% still remained in leaves, and the level in fruits was below detection. After feeding young leaves with PFPeA or PFBS, 89.55% of PFPeA entered fruits, while PFBS was again not detected in the fruits, indicating the absence of a source-sink relationship between leaves and fruits for PFBS. Translocation out of roots appeared to be the primary bottleneck for PFBS, and preferential deposition into leaves over fruits further diminished its accumulation in fruits. Therefore, the functional group sulfonic acid impedes translocation of PFAS to fruits and plays a mitigating role in the food chain transfer of short-chain PFAS in terrestrial ecosystems and, further, human exposure.

Tertiary treated wastewater (e.g., recycled water) and treated sewage sludge (e.g., biosolids) are increasingly recognized as valuable yet underutilized resources in agriculture. While recycled water and Class A biosolids provide agronomic benefits, they also contain numerous unregulated organic chemicals (UOCs) at trace levels. Field-derived data on UOC fate and uptake into food crops remains scarce. This large-scale field study investigated the accumulation of 44 priority UOCs, including pharmaceuticals, personal care products, plasticizers, flame retardants, and illicit drugs, in radish, broccoli, and spinach grown with recycled water and Class A biosolids at 0, 0.430, 1.08, and 2.15 metric tons/ha. Using validated UPLC-ESI-MS2 methods, 15 UOCs were detected in edible tissues at concentrations ranging from 2.10 to 994 ng/g dry weight. Cannabinoids, methamphetamine, phthalates, and fragrances were most frequently detected. Three PFAS compounds were present in the inputs but not detected in vegetable samples. Estimated adult dietary intake of UOCs totaled 277 µg/yr, or 0.011 µg/kg bw/d for a 70 kg person, based on U.S. EPA standardized consumption data. Although most UOCs lack chronic toxicity thresholds, available therapeutic and acute effects levels suggest the estimated exposure is several orders of magnitude lower. These values were presented for context only and do not imply safety or replace formal risk assessment. Crop responses varied by species, with radish biomass increasing at lower biosolids rates and spinach decreasing at higher rates. These results provide field-based insights into UOC accumulation in food production systems to support safe, sustainable use of recycled resources in a circular economy, while emphasizing the need for formal risk assessment.

Erythromycin, a widely used macrolide antibiotic, frequently enters agricultural soils through organic amendments (e.g., manure, sludge) and wastewater irrigation. However, the influence of agricultural management practices on the fate of such antibiotics in soil is poorly understood. In this study, we employed 14C-erythromycin to explore its transformation and fate under different agricultural management practices, including chicken manure amendment, activated sludge amendment (surface or mixing applications), and flooding. Erythromycin was rapidly mineralized in the unamended soil (t1/2 = 7.5 days, 91.8% at 120 days). However, the addition of chicken manure or flooding significantly inhibited the mineralization (47.3 and 69.0% at 120 days, respectively), promoted bound residue formation, and extended its half-life to 23.7-36.8 days. In contrast, activated sludge amendment enhanced erythromycin transformation with mixing applications (t1/2 = 7.2 days), while the surface application had limited effect (t1/2 = 8.0 days). High-throughput sequencing analysis revealed that these practices significantly altered soil microbial communities, and in particular, fluctuations in the abundances of Proteobacteria, Firmicutes, and Actinobacteria may have influenced erythromycin transformation. These findings underscore the urgent need to understand the environmental fate and risks of antibiotics under different agricultural practices and identify management practices that can effectively reduce antibiotic persistence and protect environmental health.

The number of emerging contaminants in our soil–water environments is increasing at an explosive rate. Risk avoidance as a strategy is often overlooked yet may be one of the most effective ways to safeguard human health in the future.

Per- and polyfluoroalkyl substances (PFAS) persistence within environmental media has led to ubiquitous exposure within humans and wildlife. We previously found that exposure of zebrafish embryos to perfluorooctanesulfonamide (PFOSA) from 0.75 to 6 h post-fertilization (hpf) resulted in a concentration-dependent delay in epiboly - a critical developmental landmark in fish and amphibian species. Therefore, for this study, we explored whether 1) similar mechanisms underlie epiboly delays induced by PFOSA or Cytochalasin B (CCB), a potent inhibitor of actin polymerization that disrupts normal epiboly progression, and 2) PFOSA-induced epiboly delay is associated with a decrease in embryonic ATP, as PFOSA is a potent uncoupler of oxidative phosphorylation in vitro. Although PFOSA and CCB induced a similar magnitude of epiboly delay beginning at 4 hpf following initiation of exposure at 0.75 hpf, PFOSA did not, contrary to CCB, significantly decrease yolk-associated actin within embryos. Using mRNA-sequencing, we also found that, consistent with chemical-specific differences in effects on actin polymerization, PFOSA-exposed embryos were also transcriptionally different from CCB-exposed embryos. Moreover, phenotypically matched, PFOSA-exposed embryos at 6 hpf were transcriptionally similar to vehicle-exposed embryos at 5 hpf, and PFOSA delayed the maternal-to-zygotic transition (MZT) beginning at 5 hpf. Finally, PFOSA-induced delayed epiboly was associated with decreased ATP concentrations, an effect that was partially mitigated by co-exposure to exogenous ATP. Overall, our findings suggest that PFOSA exposure during early embryonic development decreases ATP production in the absence of effects on actin polymerization in vivo, an effect that is associated with PFOSA-induced delays in epiboly and the MZT.

The use of neonicotinoids in agricultural seed treatments faces increased scrutiny due to their adverse effects such as induced pollinator decline. Cycloxaprid is a promising alternative to traditional neonicotinoids with higher efficiency and improved safety profiles. This study systematically investigated the uptake, translocation, and metabolism of cycloxaprid in rice, maize, and water spinach after seed treatment, using 14C isotope tracing and high-resolution mass spectrometry. Results indicated that less than 11% of cycloxaprid was absorbed by the seedlings, with over 85% released into soils. Cycloxaprid predominantly accumulated in the roots and lower leaves, with minimal translocation to upper leaves or edible parts. Subcellular analysis revealed that cycloxaprid and its metabolites predominantly bonded with internal plant matrix molecules, limiting their transport within the plants. Additionally, seven metabolites of cycloxaprid were identified, and a preliminary metabolic pathway in plants was proposed. Compared to conventional neonicotinoids, cycloxaprid displayed lower potential for plant uptake and vertical translocation, thereby reducing risks to nontarget species like pollinators. These findings provide important theoretical support for the promotion of cycloxaprid as a safe seed treatment agent and offer new perspectives for the sustainable use and risk management of neonicotinoid pesticides.

The persistence of pharmaceutical contaminants like ketoprofen (KET) in aquatic environments poses escalating ecological and health risks, yet conventional Fenton processes remain constrained by acidic pH dependency and unsustainable chemical inputs. Here, we present a nature-inspired, self-sustaining micro-Fenton (MFenton) system that harnesses indigenous facultative anaerobic iron-reducing microbial consortia to achieve > 80 % KET degradation under circumneutral pH without exogenous reagents. Unlike single-strain bio-Fenton models, this community-driven strategy leverages synergistic iron-redox cycling where DIRB (Dissimilatory Iron-Reducing Bacteria) biogenically generate Fe(II) and H2O2 through alternating anaerobic-aerobic phases, enabling in-situ hydroxyl radical (HO˙) production at pH 7.0. Decoding microbial black-box interactions, we identify Sporanaerobacter, Sedimentibacter, Clostridium, Petrimonas, and Actinomyces as keystone genera orchestrating Fe2+/H2O2 dynamics, while UPLC-ESI-HRMS analyses reveal KET degradation pathways dominated by side-chain decarboxylation (yielding 3-ethylbenzophenone) and ketone CC cleavage (forming benzoic acid). Crucially, this system eliminates pH adjustment needs and reduces energy demand compared to conventional Fenton methods, offering a scalable prototype for low-carbon pharmaceutical wastewater remediation. Our findings redefine the boundaries of microbially-driven advanced oxidation, providing mechanistic insights into how natural iron-redox networks can be engineered for contaminant elimination in dynamic environments.