Occurrence, source apportionment and ecological risk assessment of thirty antibiotics in farmland system

Remediation strategy of biochar with different addition approaches on antibiotic resistance genes in riparian zones under dry wet alternation

The global prevalence of antibiotic resistance genes (ARGs) has aroused increasing concern due to its threat to ecological security and human health. Although biochar has been widely used for pollution remediation including ARGs, little is known its regulation on antibiotics and ARGs propagation under riparian zones, where undergo frequent occurrence of dry and wet alternations (DWA) caused by water-level fluctuation. Therefore, this study investigated the regulative effects of biochar through different addition approaches on ARGs spread in riparian zone sediments. Under DWA, the presence of biochar (2 % w/w) inhibited microbial diversity and function expression, especially for tiled biochar. In addition, compared with DWA, the tiled biochar decreased ARGs abundance by 45.36 %, while the well-mixed increased that by 269.02 %. The ARGs abundance in sediments was positively correlated with mobile genetic element abundance (R2=0.996, p < 0.05), indicative of high horizontal gene transfer potential of ARGs. Metabolomics revealed that both DWA and biochar significantly altered microbial metabolism pathways in sediments, involving sulfur metabolism and histidine metabolism. Furthermore, ARGs propagation in riparian zones may be dominantly driven by MGEs, especially by transposases and integrase. These findings highlight the tiled biochar remediation effects on ARGs in riparian zones under DWA caused by global warming.

Remediation of antibiotic pollution in the global environment by iron-based materials activating advanced oxidation processes: A systematic review

Antibiotic pollution and its associated resistance genes have emerged as a global environmental and health concern, with widespread detection in various environmental media such as water, soil, atmosphere, and sediment, as well as in organisms. Hence, it is imperative to develop effective remediation technologies for the targeted treatment of antibiotic pollution to mitigate its environmental and health risks. This paper reviews the status of antibiotic pollution in major countries, territories, and regions worldwide. Addressing the risks cause by antibiotics and their resistance genes and achieving efficient remediation of antibiotic pollutants. Additionally, the study explores the issue of antibiotic use and resistance in detail from a global perspective. It provides a critical scientific foundation for controlling global antibiotic resistance through multi-dimensional integrated analysis. In 2021, 4.71 million deaths globally were attributed to antibiotic resistance, with countries such as India and China being the most affected. It also examined the predominant types and sources of antibiotic pollutants, as well as key remediation technologies for addressing antibiotic contamination. Antibiotics such as amoxicillin and ciprofloxacin are commonly found in surface waters at concentrations ranging from 1 to 120 μg L-1. Furthermore, this paper highlighted the distinctive advantages of advanced oxidation processes (AOPs) in addressing antibiotic pollution, demonstrating removal efficiencies exceeding 90 % under optimal conditions. Our review underscored the pivotal role of iron-based materials and porous biochar in AOPs, showing promising results in various environmental settings. Future research should prioritize the development of multifunctional iron-based composites with improved catalytic stability, environmental compatibility, and recyclability. Moreover, expanding the field-scale application of these materials, particularly in low-resource or high-risk regions, will be essential to translate laboratory successes into global impact. This analysis is designed to inform and guide future initiatives to control and eliminate antibiotic contamination.

Influence of the source and molecular weights on sulfathiazole/sulfadiazine binding in sedimentary dissolved organic matter

Sedimental dissolved organic matter (DOM) plays a crucial role in the migration of antibiotics in a lake environment, which is strongly associated with its physicochemical properties influenced by temporal and spatial variations. This study systematically investigated the binding behavior of sulfathiazole (ST) and sulfadiazine (SD) to DOM across different molecular weights (MWs) in sediments from Poyang Lake using multiple spectroscopic techniques. Results showed that the MW fractions of DOM from the onset of the dry season were higher than those before flooding. Additionally, key carbon parameters, including dissolved organic carbon and fluorescent components, were present in greater proportion in the truly dissolved phase and the low MW fraction of DOM. These properties of the low MW fraction of DOM enhanced its binding capacity for the two sulfonamides, with the partitioning coefficient (logKcoc) values of 5.20 and 5.06 for ST and SD, respectively. Dialysis experiments investigating the interaction between different concentrations of DOM and sulfonamides indicated that humic-like and protein-like components significantly influenced the migration of ST and SD, respectively. Moreover, protein-like components exerted a more substantial impact on the migration of sulfonamides in heavily polluted sampling sites, while the humic-like substances played a more significant role for the samples from the wetland protection area. The results enhanced the understanding of the significance of DOM sources and MW in influencing the environmental fate of antibiotics in lake ecosystems.

Hierarchical Cu-doped MoS2 microspheres with efficient visible-light-driven peroxymonosulfate activation for micropollutant degradation: Nanostructure engineering and reaction mechanism

Transition metal doping and nanostructure engineering are effective strategies to overcome the limitations of photocatalysts in peroxomonosulfate (PMS) activation. In this study, Cu-doped MoS2 with a hierarchical microspheric architecture was synthesized via a one-step hydrothermal method and employed for tetracycline (TC) degradation through PMS activation. Under visible light irradiation, the Cu0.06-MoS2 catalyst achieved an 86.2% TC removal efficiency within 40 min, which was 2.3 times higher than that of pristine MoS2. The effects of various operation parameters, including initial PMS concentration, reaction temperature, solution pH, and coexisting inorganic anions on the TC degradation efficiency were thoroughly investigated. Characterization results and theoretical calculations demonstrated that the redox cycles of Cu2+/Cu+ and Mo6+/Mo4+, as well as the 3D microspheric structure of Cu0.06-MoS2, support its ultra-high charge transfer capability and abundant exposure of active sites, thereby promoting efficient photocatalytic activation of PMS for TC degradation. Reactive species quenching experiments and EPR analysis revealed that ·O2-, •OH, and SO4•- are the primary reactive oxygen species involved in TC degradation. This study provides a promising direction for the development of highly efficient micropollutant degradation utilizing transition metals-modified sulfide photocatalysts with a 3D architecture.

Traceability analysis and risk assessment of river antibiotics based on dissolved organic matter spectral features and the positive matrix factorization receptor model

Identifying pollution sources is crucial for controlling antibiotic contamination and preventing risks to aquatic environments. This study quantified four categories of antibiotics (quinolones,macrolides, sulfonamides, and tetracyclines) in Dafeng River during the dry season using SPE-UHPLC-MS，analyzing their sources and risks. The source apportionment results for antibiotics using the Positive Matrix Factorization (PMF) model were validated against those identified based on Dissolved Organic Matter (DOM) fluorescence characteristics. Redundancy Analysis (RDA) was employed to clarify the relationship between specific source risks in the PMF model and DOM fluorescence characteristics. The findings include: (1) A total of 43 antibiotics were detected, with concentrations ranging from 19.04 to 1037.11 ng/L. The overall significant risk rate (RQ ≥ 0.01) was 55.1 %. (2) Excitation-Emission Matrix coupled with Parallel Factor Analysis (EEM-PARAFAC) identified three fluorescence components in the watershed's water body DOM: fulvic-like (C1), humic-like (C2), and tyrosine-like (C3). (3) The PMF model identified five pollution sources for antibiotics. Livestock discharge was the predominant source of concentration, while sewage treatment plants posed the primary source risk, consistent with the DOM spectroscopy results. (4) The RDA demonstrated a close relationship between DOM fluorescence characteristics and specific source risks of antibiotics.

Historical distribution and multi-dimensional environmental risk assessments of antibiotics in coastal sediments affected by land-based human activities

Coastal sediment cores provide important records of land-based antibiotics' deposition. This study examined sediment cores from the Hangzhou Bay, East China Sea, dating back to 1980-2020 using 210Pbex. The 40-year analysis revealed a mismatch between sediment depth and age. Wastewater treatment facilities have significantly reduced antibiotics discharge into the sea. We identified 27 antibiotics, with enrofloxacin (ERFX) and nadifloxacin (NDFX) exhibiting the highest average concentrations of 84.9 and 83.4 ng/g, respectively. Quinolones (QNs) were prominent, displaying strong co-occurrence and similar distribution patterns shaped by comparable soil-water distribution coefficient (Kd). QNs correlated positively with total antibiotic concentration, serving as indicators. We proposed a multi-dimensional risk assessment of antibiotics, encompassing ecological and antimicrobial resistance (AMR) risks, complementing each other. The assessment revealed antibiotics with distinct risks: sulfacetamide (SCM) and clindamycin (CLIN) exhibited high ecological risks, while ERFX, ciprofloxacin (CFX), norfloxacin (NFX), gatifloxacin (GTFX), moxifloxacin (MXFX), and marbofloxacin (MBFX) presented high AMR risks.

Distribution and risk characteristics of antibiotics in China surface water from 2013 to 2024

The continuous release of large quantities of antibiotics into the aquatic environment has led to widespread water pollution in China. Therefore, this study investigated the antibiotic pollution levels and ecological risks of surface water in seven major Chinese watersheds based on research papers from 2013 to 2024. Measured concentrations and ecotoxicity data of sulfonamides (SAs), tetracyclines (TCs), fluoroquinolones (FQs), and macrolides (MLs) in the aquatic environments of China were collected and compiled. The environmental concentration and distribution characteristics of antibiotics in seven major watersheds were statistically analyzed to carry out the evaluation of multiple ecological risks of antibiotics in watersheds across the country, and at the same time, the traceability analysis of antibiotic pollution in different regions was carried out, which will provide a certain theoretical basis for the precise management of antibiotic pollution in the future. The results showed that the distribution and environmental risks of the four antibiotics in different watersheds varied greatly, with the Yangtze River Basin, the Huanghuai Basin, and the Pearl River Basin being affected by anthropogenic activities, economic development, and other factors, with a wider range of antibiotic sampling sites and higher detection concentrations, and with the Northwestern Basin, the Southwestern Basin, and the Songhua and Liaohe River Basins having an overall lower risk of antibiotics. FQs were detected at high concentrations in all the basins, mostly posing high risk to aquatic environments. SAs were the most frequently detected but had the lowest ecological risk. The results of the more refined risk assessment (joint probability curves, JPCs) were ranked in order of risk, with FQs ≥ TCs > MLs > SAs. These results can be used as a reference for integrated management and sustainability studies on basins across the country.

Plot-scale observation on antibiotics migration in surface runoff and leachate from chicken-raising orchard of Entisol during rainstorms

Field investigation on manure-sourced veterinary antibiotics migrating via runoff processes under natural rainfalls is quite limited due to hydrological complexity. The impact of manure application on antibiotics migration in soil is also scarcely discussed at the plotscale. This study examined the dynamic changes of concentration and mass flux of eight antibiotics migrating from chicken-raising orchards during rainstorms. Results showed instantaneous presence of antibiotics in the flow samples collected upon generation of surface runoff and leachate. Their concentrations responded strongly towards the flow rate, with concentration peaks mostly overlapping with flow peaks. Chicken-raising treatment resulted in significantly higher runoff generation than orchard without chickens. The total mass flux of antibiotics reached up to 5.46 and 9.41 μg/(m2·h) for surface runoff and leachate respectively, with sulfonamides (SAs) showing the highest migration (0.02-4.52 μg/(m2·h)) and tetracyclines (TCs) and quinolones (QLs) the lowest (10-4-10-1 μg/(m2·h)). Leaching performed as an important pathway for contaminant migration in the studied soil, with mass fluxes 1.5-11 times higher than those of surface runoff, and manure-derived colloids accelerated antibiotics leaching. pH, colloid concentration and instantaneous rainfall intensity were the primary influencing factors, all displaying positive correlations with antibiotics migration (p < 0.05). This study implied that raising chickens in orchard poses a risk of antibiotic contamination to surrounding ecosystem. It also highlighted the importance of exploring soil hydrological process in assessing their migration, particularly the previously underestimated contribution of subsurface flow via leaching.

Antibiotic Resistance Genes in Agricultural Soils: A Comprehensive Review of the Hidden Crisis and Exploring Control Strategies

This paper aims to review the sources, occurrence patterns, and potential risks of antibiotic resistance genes (ARGs) in agricultural soils and discuss strategies for their reduction. The pervasive utilization of antibiotics has led to the accumulation of ARGs in the soil. ARGs can be transferred among microorganisms via horizontal gene transfer, thereby increasing the likelihood of resistance dissemination and heightening the threat to public health. In this study, we propose that physical, chemical, and bioremediation approaches, namely electrokinetic remediation, advanced oxidation, and biochar application, can effectively decrease the abundance of ARGs in the soil. This study also highlights the significance of various control measures, such as establishing a strict regulatory mechanism for veterinary drugs, setting standards for the control of ARGs in organic fertilizers, and conducting technical guidance and on-farm soil monitoring to reduce the environmental spread of ARGs and protect public health.

Vertical Distribution and Drivers of Antibiotic Resistance Genes in Agricultural Soil Irrigated with Livestock Wastewater

Livestock wastewater reuse could be a potential source for the distribution of antibiotics, antibiotic resistance bacteria (ARB), and antibiotic resistance genes (ARGs) in agricultural soil. In this study, soil samples were collected from different depths (0-60 cm) of farmland that has been subjected to long-term application of livestock wastewater. The vertical distribution of antibiotics, bacterial communities, and ARGs were assessed to identify the driving factors that could potentially influence the distribution of ARB and ARGs. The results demonstrated distinguished distributions of antibiotics along the soil depths, with tetracyclines (TCs) mainly found in the top 10 cm of the soil (0.11-0.31 μg/kg), while quinolones (QNs), sulfonamides (SAs), and macrolides (MLs) were detected in all 60 cm of soil depth (0.01-0.22 μg/kg). The selection pressure of antibiotics to microorganisms led to the proliferation of ARB, especially tetracycline-resistant bacteria and erythromycin-resistant bacteria. In terms of the distribution/abundance of ARGs, novA and tetA (58) were relatively higher in 0-10 cm surface soil, while vanRM and vanRF were mainly detected in the deeper soil. Different ARGs may have the same host bacteria, which lead to the emergence of multidrug resistant bacteria, such as Ilumatobacter sp., Aggregatilinea sp., Rhabdothermincola sp., and Ornithinimicrobium sp. Soil pH, electrical conductivity (EC), and moisture content (MC) could affect the distribution and proliferation of ARB and were found negatively correlated with most of the ARGs except macB. Therefore, it is potentially possible to eliminate/inhibit the spread of ARGs by adjusting these soil parameters. These findings provide insights into the distribution and dissemination of antibiotics, ARB, and ARGs in agricultural practices of livestock wastewater irrigation and provide effective mitigation strategies to ensure the safe use of livestock wastewater in agriculture.

Overall Evaluation of Antibiotics Occurrence from Large-Scale Livestock Farms in Sichuan Basin, China: Spatial Distribution, Source Apportionment, and Risk Assessment

The widespread application of antibiotics in intensive livestock production is increasingly contributing to antibiotic contamination, and their potential ecological risk to environmental media by resourceful utilization of livestock manure as fertilizers in China has been recognized. This study conducted a comprehensive investigation on 79 large-scale livestock farms and collected 86 livestock excrements and 20 soil and 20 surface water samples distributed in Sichuan Basin, where no similar studies were carried out before. In total, four tetracyclines (TCs), eight sulfonamides (SAs), and eight fluoroquinolones (QNs) were monitored by liquid chromatography-triple quadrupole mass spectrometry. The findings revealed that antibiotics occurrence varied remarkably in excrement (feces or manure) among different livestock farms and different livestock species, following the descending order as QNs > TCs > SAs of detection rates and as TCs > QNs > SAs of detected concentrations, respectively. By source apportionment, livestock manure was demonstrated as a possible source for TCs and QNs detected in soil, while the detection of antibiotics in surface water was probably related to other sources. The central, south, and southwest of Sichuan Basin displayed a higher contamination of antibiotics from livestock manure. The ecological risk of antibiotics was obtained from a medium to heavy level, particularly TCs from swine farms to green algae, water flea, and inflated duckweed in aquatic water and QNs from all livestock farms to sensitive organisms in soil. Overall, the prioritized resource utilization of livestock manure would probably increase the contamination level and ecological risk to environment; hence, rational and effective measurement was highly recommended for antibiotics prevention in some regions of Sichuan Basin.

A nationwide probabilistic risk assessment and a new insight into source-specific risk apportionment of antibiotics in eight typical river basins in China: Human health risk and ecological risk

China is the largest producer and consumer of antibiotics, a nationwide study on the contamination of antibiotics in China is urgently needed, and source apportionment towards risks associated with antibiotics is now attracting increasing attention. In this study, based on eight antibiotics at 666 sampling sites, spatial variations and probabilistic risks (human health and ecological risk) of antibiotics in eight river basins in China were analyzed. Source-specific health and ecological risk associated with antibiotics in a typical basin was apportioned quantitatively. Results showed that mean antibiotic concentration in Haihe River Basin (HaiRB) and Yellow River Basin (178.25 and 257.36 ng·L-1, respectively) was higher than other basins. In HaiRB, the contribution of livestock and poultry breeding (31.89 %) was the largest of all sources for health risk, whereas pharmaceutical wastewater (35.97 %) was the most dominant source for ecological risk. To determine the most important source for risks associated with antibiotics, the concept of risks-targeted key source was proposed, and a risks-targeted key source apportionment model was developed. Results showed that pharmaceutical wastewater should be prior controlled among all sources. The concept and apportionment model of risks-targeted key source proposed in this study are applicable and referential for related studies.

Dynamic interaction of antibiotic resistance between plant microbiome and organic fertilizers: sources, dissemination, and health risks

Antibiotic resistance is a global health problem driven by the irrational use of antibiotics in different areas (such as agriculture, animal farming, and human healthcare). Sub-lethal concentrations of antibiotic residues impose selective pressure on environmental, plant-associated, and human microbiome leading to the emergence of antibiotic-resistant bacteria (ARB). This review summarizes all sources of antibiotic resistance in agricultural soils (including manure, sewage sludge, wastewater, hospitals/pharmaceutical industry, and bioinoculants). The factors (such as the physicochemical properties of soil, root exudates, concentration of antibiotic exposure, and heavy metals) that facilitate the transmission of resistance in plant microbiomes are discussed. Potential solutions for effective measures and control of antibiotic resistance in the environment are also hypothesized. Manure exhibits the highest antibiotics load, followed by hospital and municipal WW. Chlortetracycline, tetracycline, and sulfadiazine have the highest concentrations in the manure. Antibiotic resistance from organic fertilizers is transmitted to the plant microbiome via horizontal gene transfer (HGT). Plant microbiomes serve as transmission routes of ARB and ARGS to humans. The ingestion of ARB leads to human health risks (such as ineffectiveness of medication, increased morbidity, and mortality).

Assessing Lettuce Exposure to a Multipharmaceutical Mixture under Hydroponic Conditions: Findings through LC-ESI-TQ Analysis and Ecotoxicological Assessments

The escalating global water scarcity demands innovative solutions, one of which is hydroponic vegetable cultivation systems that increasingly use reclaimed wastewater. Nevertheless, even treated wastewater may still harbor various emerging organic contaminants, including pharmaceuticals. This study aimed to comprehensively assess the impact of pharmaceuticals, focusing on bioconcentration factors (BCFs), translocation factors (TFs), pharmaceutical persistence in aqueous environment, ecotoxicological end points, and associated environmental and health risks. Lettuce (Lactuca sativa) was cultivated hydroponically throughout its entire growth cycle, exposed to seven distinct concentration levels of contaminants ranging from 0 to 500 μg·L-1 over a 35-day period. The findings revealed a diverse range of BCFs (2.3 to 880 L·kg-1) and TFs (0.019-1.48), suggesting a high potential of pharmaceutical uptake and translocation by L. sativa. The degradation of 20 pharmaceuticals within the water-lettuce system followed first-order degradation kinetics. Substantial ecotoxicological effects on L. sativa were observed, including increased mortality, alterations in root morphology and length, and changes in biomass weight (p < 0.05). Furthermore, the estimated daily intake of pharmaceuticals through L. sativa consumption suggested considerable health risks, even if lettuce would be one of the many vegetables consumed. It is hypothetical, as the values were calculated. Moreover, this study assessed the environmental risk associated with the emergence of antimicrobial resistance (AMR) in aquatic environments, revealing a significantly high risk of AMR emergence. In conclusion, these findings emphasize the multifaceted challenges posed by pharmaceutical contamination in aquatic environments and the necessity of proactive measures to mitigate associated risks to both environmental and human health.

Exposure of Enchytraeus crypticus to ciprofloxacin - A multi- and transgenerational study

The increased consumption of antibiotics and their partial metabolism by the human and animal body have led to the frequent identification of such compounds in various environmental matrices. Ciprofloxacin (CIP) is one of the most widely used antibiotics worldwide and it has low mobility and high sorption to soil, leading to the potential to accumulate and persist on organic fertilizers (manure and sewage sludge) and agricultural soils. Therefore, the presence of CIP in the agricultural environment has become an emerging concern as it may negatively affect soil organisms and soil quality, and contribute to the spread of antibiotic-resistant bacteria, thus threatening food security and public health. In this study, we aimed to evaluate the multigenerational and transgenerational effects of CIP on the reproduction of Enchytraeus crypticus to properly assess the long-term impacts of such exposure. Our results for the multigenerational test showed that the reproduction of the organisms was affected from the third to the last (sixth) generation, highlighting the importance of long-term evaluation. There was also evidence of tolerance to reproduction of E. crypticus, as there was no statistical difference between concentrations for all generations, including for among the last three generations themselves. For the transgenerational tests, almost all results showed no statistical difference from the controls, indicating that the effects of CIP may be reversible when the organisms are transferred to clean media. However, since the last generations in the transgenerational tests showed significant differences from the first of the multigenerational tests, the adverse effects may still persist to some extent in the subsequent generations. Thus, when evaluating the effects of CIP on soil media, its persistence and behavior in this matrix must be considered. We strongly recommend that further long-term exposure studies be conducted and considered in regulatory decision-making, especially for persistent compounds.

Ecological criteria for antibiotics in aquatic environments based on species sensitivity distribution

Due to the substantial production and use of antibiotics, they inevitably remain in aquatic environments, posing a serious threat to aquatic ecosystems. However, there are currently no criteria of antibiotics for ecological risk in the water environment. In the present study, three types of antibiotics (tetracyclines, sulfonamides and quinolones) that are often detected in water environments were investigated. Toxicity data regarding bacteria, algae, plants, invertebrates and vertebrates were selected, and the species sensitivity distribution was used to obtain the ecological risk criteria of antibiotics to aquatic organisms. Animals are the least sensitive to antibiotics. The overall toxicity of antibiotics is most sensitive to bacteria and cyanobacteria, followed by green algae and plants. The recommended ecological criteria for tetracyclines, quinolones, and sulfonamides are 22, 17, and 94 μg/L, respectively. Ofloxacin needs to be used with caution because it has a small acute predicted no-effect concentration (PNEC) of 0.6 μg/L. The ecological risk criterion for chronic toxicity of total antibiotics was determined to be 1.4 μg/L. The PNECs measured for the quinolone, tetracycline, and sulfonamide antibiotics were 0.5, 2.2, and 2.4 μg/L, respectively. Norfloxacin had the highest chronic toxicity zone of 353, indicating that chronic poisoning is most likely to occur. Moreover, there was an exponential correlation between acute PNEC and chronic PNEC. In addition, a quantitative structure-activity relationship model was constructed for acute ecological risk criteria of antibiotics to aquatic organisms. These findings can expand the ecological risk threshold data on the effects of antibiotics on aquatic organisms, and provide a theoretical basis for the environmental risk assessment of antibiotics.

Are earthworms the victim, facilitator or antidote of antibiotics and antibiotic resistance at the soil-animal-human interface? A One-Health perspective

The transfer of antibiotics and antibiotic resistance (AR) to the soil systems poses ecological hazards to various organisms, including earthworms. Understanding the complex interactions between earthworms, antibiotics, and AR in the soil system requires a comprehensive assessment. Hence, the present review investigates the behaviour, fate, impacts, and mechanisms involved in the interaction of earthworms with antibiotics and AR. The antibiotics and AR detected in earthworms and their associated media, such as vermicompost, are presented, but several other antibiotics and AR widely detected in soils remain understudied. As receptors and bioassay organisms, earthworms are adversely affected by antibiotics and AR causing (1) acute and chronic toxicity, and (2) emergence of AR in previously susceptible earthworm gut microbiota, respectively. The paper also highlights that, apart from this toxicity, earthworms can also mitigate against antibiotics, antibiotic-resistant bacteria and antibiotic-resistance genes by reducing bacterial diversity and abundance. The behaviour and fate processes, including biodegradation pathways, biomarkers of antibiotics and AR in earthworms, are discussed. In addition, the factors controlling the behaviour and fate of antibiotics and AR and their interactions with earthworms are discussed. Overall, earthworms mitigate antibiotics and AR via various proximal and distal mechanisms, while dual but contradictory functions (i.e., mitigatory and facilitatory) were reported for AR. We recommend that future research based on the One-World-One-Health approach should address the following gaps: (1) under-studied antibiotics and AR, (2) degradation mechanisms and pathways of antibiotics, (3) effects of environmentally relevant mixtures of antibiotics, (4) bio-augmentation in earthworm-based bioremediation of antibiotics, (5) long-term fate of antibiotics and their metabolites, (6) bio-transfers of antibiotics and AR by earthworms, (7) development of earthworm biomarkers for antibiotics and AR, (8) application of earthworm-based bioremediation of antibiotics and AR, (9) cascading ecological impacts of antibiotics and AR on earthworms, and (10) pilot-scale field applications of earthworm-based bioremediation systems.

Determination and Ecological Risk Assessment of Quinolone Antibiotics in Drinking and Environmental Waters Using Fully Automated Disk-Based SPE Coupled with UPLC-MS/MS

Quinolone antibiotics (QNs) contamination in the aquatic environment is a global public health issue considering their resistance and mobility. In this study, a simple, efficient, and sensitive method was developed for the accurate quantification of fifteen QNs in water using automated disk-based solid-phase extraction (SPE) coupled with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). By utilizing a 3M SDB-XC disk to enrich QNs from a 1000 mL water sample, the detection limits were improved to 0.008-0.055 ng/L due to the satisfactory enrichment factors of 897-1136, but only requiring about 60 min per six samples. The linearity of the method ranged from 0.05 to 100 μg/L for the 15 QNs, with correlation coefficients of 0.9992-0.9999, and the recoveries were in the range of 81-114%, with relative standard deviations of 0.2-13.3% (n = 6). The developed method was applicable for the quantification of trace QNs at low ng/L levels in drinking and environmental waters. The results showed that no QNs were detected in tap water, while three and four QNs were detected in the river water of Zhoushan and the seawater of Daiquyang and Yueqing Bay, East China, respectively, with a total concentration of 1.600-8.511 ng/L and 1.651-16.421 ng/L, respectively. Among the detected QNs, ofloxacin (OFL) was the predominant compound in river water, while enrofloxacin (ENR) was predominant in seawater. The risk quotient (RQ) results revealed that QNs posed a low risk to crustaceans and fish, but a low-to-medium risk to algae, and OFL presented the main ecological risk factor in river water, while ENR and CIP in seawater. Overall, the proposed automated disk-based SPE-UPLC-MS/MS method is highly efficient and sensitive, making it suitable for routine analysis of QNs in drinking and environmental waters.

Assessing Lettuce Exposure to a Multi-Pharmaceutical Mixture in Soil: Insights from LC-ESI-TQ Analysis and the Impact of Biochar on Pharmaceutical Bioavailability

Agricultural practices introduce pharmaceutical (PhAC) residues into the terrestrial environment, potentially endangering agricultural crops and human health. This study aimed to evaluate various aspects related to the presence of pharmaceuticals in the lettuce-soil system, including bioconcentration factors (BCFs), translocation factors (TFs), ecotoxicological effects, the influence of biochar on the PhAC bioavailability, persistence in soil, and associated environmental and health risks. Lettuce (Lactuca sativa L.) was exposed to a mixture of 25 PhACs in two scenarios: initially contaminated soil (ranging from 0 to 10,000 ng·g-1) and soil irrigated with contaminated water (ranging from 0 to 1000 μg·L-1) over a 28-day period. The findings revealed a diverse range of BCFs (0.068-3.7) and TFs (0.032-0.58), indicating the uptake and translocation potential of pharmaceuticals by lettuce. Significant ecotoxicological effects on L. sativa, including weight change and increased mortality, were observed (p < 0.05). Interestingly, biochar did not significantly affect PhAC uptake by L. sativa (p > 0.05), while it significantly influenced the soil degradation kinetics of 12 PhACs (p < 0.05). Additionally, the estimated daily intake of PhACs through the consumption of L. sativa suggested negligible health risks, although concerns arose regarding the potential health risks if other vegetable sources were similarly contaminated with trace residues. Furthermore, this study evaluated the environmental risk associated with the emergence of antimicrobial resistance (AMR) in soil, as medium to high. In conclusion, these findings highlight the multifaceted challenges posed by pharmaceutical contamination in agricultural environments and emphasize the importance of proactive measures to mitigate the associated risks to both environmental and human health.

The boom era of emerging contaminants: A review of remediating agricultural soils by biochar

Emerging contaminants (ECs) are widely sourced persistent pollutants that pose a significant threat to the environment and human health. Their footprint spans global ecosystems, making their remediation highly challenging. In recent years, a significant amount of literature has focused on the use of biochar for remediation of heavy metals and organic pollutants in soil and water environments. However, the use of biochar for the remediation of ECs in agricultural soils has not received as much attention, and as a result, there are limited reviews available on this topic. Thus, this review aims to provide an overview of the primary types, sources, and hazards of ECs in farmland, as well as the structure, functions, and preparation types of biochar. Furthermore, this paper emphasizes the importance and prospects of three remediation strategies for ECs in cropland: (i) employing activated, modified, and composite biochar for remediation, which exhibit superior pollutant removal compared to pure biochar; (ii) exploring the potential synergistic efficiency between biochar and compost, enhancing their effectiveness in soil improvement and pollution remediation; (iii) utilizing biochar as a shelter and nutrient source for microorganisms in biochar-mediated microbial remediation, positively impacting soil properties and microbial community structure. Given the increasing global prevalence of ECs, the remediation strategies provided in this paper aim to serve as a valuable reference for future remediation of ECs-contaminated agricultural lands.

Distribution, source apportionment, and ecological risk assessment of soil antibiotic resistance genes in urban green spaces

Urban green spaces play a crucial role in cities by providing near-natural environments that greatly impacts the health of residents. However, these green spaces have recently been scrutinized as potential reservoirs of antibiotic resistance genes (ARGs), posing significant ecological risks. Despite this concern, our understanding of the distribution, sources, and ecological risks associated with ARGs remains limited. In this study, we investigated the spatial distribution of soil ARGs using spatial interpolation and auto-correlation analysis. To apportion the source of soil ARGs in urban green spaces of Tianjin, Geo-detector method (GDM) was employed. Furthermore, we evaluated the ecological risk posed by ARGs employing risk quotients (RQ). The results of our study showed a significantly higher abundance of Quinolone resistance genes in the soil of urban green spaces in Tianjin. These genes were mainly found in the northwest, central, and eastern regions of the city. Our investigation identified three main factors contributing to the presence of soil ARGs: antibiotic production, precipitation, livestock breeding, and hospital. The results of ecological risk in RQ value showed a high risk associated with Quinolone resistance genes, followed by Aminoglycoside, Tetracycline, Multidrug, MLSB, Beta Lactam, Sulfonamide, and Chloramphenicol. Mantel-test and correlation analysis revealed that the ecological risk of ARGs was greatly influenced by soil properties and heavy metals. This study provides a new perspective on source apportionment and the ecological risk assessment of soil ARGs in urban green spaces.

Source apportionment and predictable driving factors contribute to antibiotics profiles in Changshou Lake of the Three Gorges Reservoir area, China

Lakes, crucial antibiotic reservoirs, lack thorough exploration of quantitative relationships between antibiotics and influencing factors. Here, we conducted a comprehensive year-long investigation in Changshou Lake within the Three Gorges Reservoir area, China. The concentrations of 21 antibiotics spanned 35.6-200 ng/L, 50.3-348 ng/L and 0.57-57.9 ng/g in surface water, overlying water and sediment, respectively. Compared with abundant water period, surface water and overlying water displayed significantly high antibiotic concentrations in flat and low water periods, while sediment remained unchanged. Moreover, tetracyclines, fluoroquinolones and erythromycin posed notable risks to algae. Six primary sources were identified using positive matrix factorization model, with aquaculture contributing 21.2%, 22.7% and 25.4% in surface water, overlying water and sediment, respectively. The crucial predictors were screened through machine learning, redundancy analysis and Mantel test. Our findings emphasized the pivotal roles of water quality parameters, including water temperature (WT), pH, dissolved oxygen, electrical conductivity, inorganic anions (NO3⁻, Cl⁻ and F⁻) and metal cations (Ca, Mg, Fe, K and Cr), with WT influencing greatest. Total nitrogen (TN), cation exchange capacity, K, Al and Cd significantly impacted sediment antibiotics, with TN having the most pronounced effect. This study can promise valuable insights for environmental planning and policies addressing antibiotic pollution.

Biodegradation strategies of veterinary medicines in the environment: Enzymatic degradation

One Health closely integrates healthy farming, human medicine, and environmental ecology. Due to the ecotoxicity and risk of transmission of drug resistance, veterinary medicines (VMs) are regarded as emerging environmental pollutants. To reduce or mitigate the environmental risk of VMs, developing friendly, safe, and effective removal technologies is an important means of environmental remediation for VMs. Many previous studies have proved that biodegradation has significant advantages in removing VMs, and biodegradation based on enzyme catalysis presents higher operability and specificity. This review focused on biodegradation strategies of environmental pollutants and reviewed the enzymatic degradation of VMs including antimicrobial drugs, insecticides, and disinfectants. We reviewed the sources and catalytic mechanisms of peroxidase, laccase, and organophosphorus hydrolases, and summarized the latest research status of immobilization methods and bioengineering techniques in improving the performance of degrading enzymes. The mechanism of enzymatic degradation for VMs was elucidated in the current research. Suggestions and prospects for researching and developing enzymatic degradation of VMs were also put forward. This review will offer new ideas for the biodegradation of VMs and have a guide significance for the risk mitigation and detoxification of VMs in the environment.

Migration of nanocolloid-carrying antibiotics in paddy red soil during the organic fertilization process

Soil nanocolloids are highly mobile and can act as carriers for the transport of antibiotics to a wider and deeper range of soils; however, the inherent behavior and mechanism of nanocolloid-carrying antibiotics in soil remain unclear. In this study, we conducted a comprehensive investigation of the migration of antibiotics in paddy red soil during the organic fertilization process using four common soil nanocolloids: kaolin (KL), montmorillonite (MT), hematite (HT), and humic acid (HA). The results showed that nanocolloid carriers promoted the intra-medium (from soil surface to the bottom) and inter-medium transfer (from organic fertilizers to soil) of antibiotics. The migration mechanisms of antibiotics carried by the nanocolloids differed: the phenolic hydroxyl and carboxyl groups of HA esterified with the carboxyl groups of quinolones and phenolic hydroxyl groups of tetracyclines, respectively, while the oxygen atoms of HT formed stabilizing complexes with the soil, which could further adsorb antibiotics using their functional group-rich complexes. Smaller antibiotic compounds were adsorbed in the metal oxide interlayer of MT via cation exchange, whereas KL adsorbed antibiotics on its metal oxide surface layer in the same way but were susceptible to desorption. Additionally, nanocolloids changed the adsorption capacity of soil for antibiotics and influenced the enrichment of dominant/functional bacteria (e.g., Burkholderiaceae) and thus varied the vertical distribution of antibiotics in soil. These findings enhance our understanding of the migration behavior and mechanism of nanocolloid-carrying antibiotics in red paddy soil and provide a theoretical foundation for preventing and controlling antibiotic pollution in arable systems.

Pharmaceuticals, hazard and ecotoxicity in surface and wastewater in a tropical dairy production area in Latin America

Pharmaceuticals comprise a complex group of emerging pollutants. Despite the significant number of pharmaceuticals used in veterinary medicine, the input of these compounds into the environment due to livestock activities has been scarcely described. This work assays for the first time in Central America the occurrence of pharmaceuticals in farm wastewater in an area devoted to dairy production, and in the surrounding surface waters. Among 69 monitored pharmaceuticals, a total of eight compounds were detected in wastewater samples collected from seven dairy farms after three sampling campaigns. Six pharmaceuticals were considered either of high (albendazole, lovastatin and caffeine) or intermediate estimated hazard (ciprofloxacin, acetaminophen and ketoprofen) based on the HQ approach, while 26% of the samples were considered of high estimated hazard according to the cumulative ∑HQ approach. Similarly, when ecotoxicological tests were applied, all the samples showed some level of toxicity towards Daphnia magna, and most samples towards Vibrio fischeri and Lactuca sativa. Fourteen pharmaceuticals were detected in surface water samples collected in the surroundings of the dairy production farms, including rural and urban areas. Seven out of these compounds showed high estimated risk (risperidone, diphenhydramine, trimethoprim, fluoxetine, ofloxacin, caffeine and ibuprofen), while three (gemfibrozil, ciprofloxacin and cephalexin) exhibited intermediate estimated risk. In a similar worrisome way, 27% of these samples were estimated to pose high environmental risk according to the pharmaceutical content. Despite being nontoxic for D. magna or V. fischeri, frequent inhibition (>20%) of GI in L. sativa was determined in 34% of surface water samples; such findings raise concern on the apparent inceptive environmental pollution and risk within the area. According to the pharmaceutical content patterns in both kinds of studied matrices, no clear evidence of significant contamination in surface water due to livestock activities could be retrieved, suggesting a main role of urban influence.

An integrated multimedia fate modeling framework for identifying mitigation strategy of antibiotic ecological risks: A case study in a peri-urban river

Antibiotics have been heavily used over the past decades, resulting in their frequent detections in rivers and increasing ecological risks. Recognizing characteristics of antibiotic ecological risks (AERs) and making effective strategies to mitigate the AERs are essential to ensure the safety of aquatic ecosystem and public health. In this study, an integrated technological framework has been proposed toward identifying management options for reducing AERs by jointly utilizing multimedia fugacity modelling and ecotoxicological risk assessment, and applied to characterize the AERs in a peri-urban river in Beijing. Specifically, a level III fugacity model has been successfully established to simulate the fate of antibiotics in the environment, and the manageable parameters have been screened out via sensitivity analysis of the model. Then the validated fugacity model has been used for scenario modellings to optimize mitigation strategies of AERs. Results show most of the antibiotics considered are frequently detected in the river, and pose medium or high risks to aquatic organisms. Relatively, the macrolides and fluoroquinolones present higher ecotoxicological risks than sulfonamides and tetracyclines. Furthermore, the mixture risk quotient and predictive equation of concentration addition suggest joint and synergistic/antagonistic effects of AERs for multiple or binary antibiotics in the environment. Largely, the concentrations of antibiotics in the river are determined by the source emissions into water and soil. Scenario modellings show the improvement of antibiotic removal rates would be considered preferentially to mitigate the AERs. Also, controlling human consumption is conducive to reducing the risks posed by tetracyclines, macrolides and trimethoprim, while controlling animal consumption would benefit the reduction for sulfonamides. Overall, the joint strategy presents the greatest reduction of AERs by reducing antibiotic consumption and together improving sewage treatment rate and antibiotic removal rate. The study provides us a useful guideline to make ecological risk-based mitigation strategy for reducing AERs in environment.