Pharmaceuticals, Their Metabolites, and Other Polar Pollutants in Field-Grown Vegetables Irrigated with Treated Municipal Wastewater

Risk characterisation of chemicals of emerging concern in real-life water reuse applications

Water reuse is a viable option to address temporal or structural water shortages. However, the ubiquitous presence of chemicals of emerging concern (CECs) in natural systems, especially the aquatic environment, represents a significant obstacle to water reuse and the receiving environment. Therefore, an extensive literature review was performed to identify current water reuse practices at field scale, reported types and levels of CECs and their associated risks for human and environmental health. Treated wastewater was the primary reused water source, with agricultural reuse being the most frequently reported reuse application (28 %), followed by indirect-potable reuse (16 %). Contrary to potable reuse, it was observed that almost no studies applied additional treatment before water reuse for agricultural purposes. Based on calculated risk quotients, ecological risks were identified for perfluorooctanesulfonic acid, chlorpyrifos, triclocarban, and ethinylestradiol, and human health risks for perfluorooctanesulfonic acid and perfluorooctanoic acid. Environmental risks could be assessed for 77 % of detected CECs, while the human health risk assessment is limited to 28 %. For agricultural reuse, it was observed that CEC concentrations in produced crops were at acceptable levels. However, a thorough risk assessment of CECs during water reuse is currently limited due to a focus on a defined class of contaminants in the literature, i.e., pharmaceuticals, and falls short of per- and polyfluoroalkyl substances. Therefore, future water reuse studies should include a broader set of CECs and study additional mitigation options to decrease CEC concentrations before or during water reuse. Moreover, environmental harm caused by CECs during water reuse such as adverse effects on the microbial soil community or leaching to non-target sources has hardly been studied in the field and presents a knowledge gap.

Are we ready for the application of the EU Regulation on wastewater reuse in agriculture? A techno-economic preliminary evaluation based on a case-study

Reuse of reclaimed wastewater (RWW) in agriculture represents one of the key strategies to promote for reducing the pressures on water sources, as also fostered by the EU governance. Indeed, the European Regulation 741/2020 on water reuse, entered into force in 2023, was issued with the aim to extend the reuse of treated water in agriculture under safe conditions. It establishes the minimum quality requirements; it also foresees the possibility to add additional requirements, especially for contaminants of emerging concern (CECs), based on "scientific evidence" and the risk assessment. The present study aims at evaluating from both the technical and economic points of view the potential reuse of RWW for irrigating edible crops in a real case study, considering the requirements set by the EU Regulation 741/2020. The Rieti province in the Lazio region of Italy was selected as the case study, since its territory is devoted to agricultural activities which have an important economic impact (e.g. olive trees, potatoes and maize). Firstly, the wastewater treatment plants (WWTPs) here located were classified based upon the quality of the water produced with respect to the classes listed by the EU Regulation. Then, the nutrients and water demand of the crops grown in the same area were compared with the nutrients and water potentially available through the RWW from the WWTPs. Furthermore, a preliminary assessment was carried out considering only four selected CECs present in the RWW produced by the WWTPs. Combining the quality requirements set by EU Regulation and the results of the preliminary risk assessment, in the investigated territory, there are 17 WWTPs potentially suitable for the irrigation of maize, only 1 plant for potato and 8 plants for olive.

Accumulation, translocation and transformation of artificial sweeteners in plants: A critical review

Artificial sweeteners (ASs) have become an increasingly significant concern as an emerging contaminant. The widespread utilization has given rise to environmental consequences that are progressively harder to disregard. ASs infiltrate both aquatic and terrestrial ecosystems through the discharge of wastewater effluents and the application of manure and biosolids. These compounds can be absorbed and accumulated by plants from soil, water and the atmosphere, posing potential risks to ecological systems and human health. However, limited data available on plant absorption, translocation, and metabolism of ASs hinders a comprehensive understanding of their impact on ecosystem. This study aims to comprehensively summarize the global distribution of ASs, along with elucidating patterns of their uptake and accumulation within plants. Furthermore, it seeks to elucidate the pivotal factors governing ASs absorption and translocation, encompassing hydrophilicity, ionic nature, plant physiology, and environmental conditions. Notably, there remains a significant knowledge gap in understanding the biodegradation of ASs within plants, with their specific degradation pathways and mechanisms largely unexplored, thereby necessitating further investigation. Additionally, this review provides valuable insights into the ecotoxicological effects of ASs on plants. Finally, it identifies research gaps and outlines potential avenues for future research, offering a forward-looking perspective on this critical issue.

Regional Water and Food Security Require Joint Israeli-Palestinian Guidelines for Wastewater Reuse and Food Safety

BACKGROUND

Water and food security in Israel and the Palestinian Authority are deeply interconnected due to the region's arid climate and water scarcity, shared water resources, and interrelated agricultural sectors. Therefore, jointly addressing water reuse is vital to supporting sustainable agricultural production and ensuring food safety.

OBJECTIVES

This paper examines the food safety implications of the cross-border trade of fresh fruits and vegetables between the Palestinian Authority and Israel, with an emphasis on the influence of, water technologies, agricultural practices, and environmental health.

METHODS

This paper provides a comprehensive review of existing data to assess water irrigation quality, food safety, and water reuse regulations in the Palestinian Authority and Israel.

RESULTS

Significant discrepancies in food safety, food quality, and exposure to contaminants from fresh produce result from different water reuse regulations, practices, and socioeconomic conditions. Given the volume of trade, consumer mobility, and environmental sustainability, coupled with geopolitical limitations between the Palestinian Authority and Israel, there is an urgent need for a unified regulatory strategy for wastewater reuse ensuring food safety and security. We propose a single, coordinated approach to overseeing wastewater reuse to enhance public health and address contaminants of emerging concern that are not currently regulated. Navigating the political and legislative complexities in a proactive stance requires both Israeli and Palestinian decision-makers to address the matter conscientiously. Existing data and the precautionary principle are sufficient to propose an interim prohibition on treated wastewater irrigation for leafy vegetables to mitigate pollution risks and act as a catalyst for improving irrigation water quality.

CONCLUSIONS

Our proposed strategy for a unified water reuse regulation emphasizes the necessary steps for its implementation and addresses potential obstacles. This strategy underscores the importance of responsible wastewater management in advancing common goals of environmental sustainability, food safety, and human health.

SHORT SYNOPSIS

We propose a coordinated Israeli-Palestinian approach to wastewater reuse to ensure food safety based on shared environmental and health concerns, economic considerations, and the precautionary principle.

A Call for Joint Israeli-Palestinian Guidelines for Water Recycling to Improve Food Security and Safety.

Pharmaceutical metabolite identification in lettuce (Lactuca sativa) and earthworms (Eisenia fetida) using liquid chromatography coupled to high-resolution mass spectrometry and in silico spectral library

Pharmaceuticals released into the aquatic and soil environments can be absorbed by plants and soil organisms, potentially leading to the formation of unknown metabolites that may negatively affect these organisms or contaminate the food chain. The aim of this study was to identify pharmaceutical metabolites through a triplet approach for metabolite structure prediction (software-based predictions, literature review, and known common metabolic pathways), followed by generating in silico mass spectral libraries and applying various mass spectrometry modes for untargeted LC-qTOF analysis. Therefore, Eisenia fetida and Lactuca sativa were exposed to a pharmaceutical mixture (atenolol, enrofloxacin, erythromycin, ketoprofen, sulfametoxazole, tetracycline) under hydroponic and soil conditions at environmentally relevant concentrations. Samples collected at different time points were extracted using QuEChERS and analyzed with LC-qTOF in data-dependent (DDA) and data-independent (DIA) acquisition modes, applying both positive and negative electrospray ionization. The triplet approach for metabolite structure prediction yielded a total of 3762 pharmaceutical metabolites, and an in silico mass spectral library was created based on these predicted metabolites. This approach resulted in the identification of 26 statistically significant metabolites (p < 0.05), with DDA + and DDA - outperforming DIA modes by successfully detecting 56/67 sample type:metabolite combinations. Lettuce roots had the highest metabolite count (26), followed by leaves (6) and earthworms (2). Despite the lower metabolite count, earthworms showed the highest peak intensities, closely followed by roots, with leaves displaying the lowest intensities. Common metabolic reactions observed included hydroxylation, decarboxylation, acetylation, and glucosidation, with ketoprofen-related metabolites being the most prevalent, totaling 12 distinct metabolites. In conclusion, we developed a high-throughput workflow combining open-source software with LC-HRMS for identifying unknown metabolites across various sample types.

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.

Occurrence of pharmaceuticals in rice (Oryza sativa L.) plant through wastewater irrigation

The present investigation focuses on the identification of popular PhACs in roots, leaves and rice grains, which are cultivated in soil irrigated with waters and wastewater. The present study reveals the presence of PhACs in rice grains from different brands which are available in the current market, which has thus motivated these experiments. The rice plants were cultivated in garden containers and irrigated with three different water sources. All PhAC compounds were recovered within an 89-111 % range using the extraction technique, reproducibility, and sensitivity (LOQ <25 µg/g). Further, PhAC compounds were identified using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QqTOF-MS). Interestingly, several PhAC compounds were detected in rice grains, aligning with hypotheses and findings from published literature. A total of ten (10) PhACs were found in the root, leaf, and rice grain of the 20 popular PhACs that were targeted. The annual exposure and medical dose equivalent for individual PhACs was negligible. According to our knowledge, this study is the first to show the accumulation of several categories (cocktail) of PhACs in rice grains and show the approximate human health risk assessment by its consumption. The study's results provide valuable insights for researchers, policymakers, and agricultural practitioners working on sustainable agriculture and public health.

A novel approach to identify critical knowledge gaps for food safety in circular food systems

The transition from linear production towards a circular agro-food system is an important step towards increasing Europe's sustainability. This requires re-designing the food production systems, which inevitably comes with challenges as regards controlling the safety of our food, animals and the ecosystem. Where in current food production systems many food safety hazards are understood and well-managed, it is anticipated that with the transition towards circular food production systems, known hazards may re-emerge and new hazards will appear or accumulate, leading to new -and less understood- food safety risks. In this perspective paper, we present a simple, yet effective approach, to identify knowledge gaps with regard to food safety in the transition to a circular food system. An approach with five questions is proposed, derived from current food safety management approaches like HACCP. Applying this to two cases shows that risk assessment and management should emphasize more on the exposure to unexpected (with regards to its nature and its origin) hazards, as hazards might circulate and accumulate in the food production system. Five knowledge gaps became apparent: there's a need for (1) risk assessment and management to focus more on unknown hazards and mixtures of hazards, (2) more data on the occurrence of hazards in by-products, (3) better understanding the fate of hazards in the circular food production system, (4) the development of models to adequately perform risk assessments for a broad range of hazards and (5) new ways of valorization of co-products in which a safe-by-design approach should be adopted.

Optimization and validation of multiresidual extraction methods for pharmaceuticals in Soil, Lettuce, and Earthworms

The presence of human and veterinary pharmaceuticals (PhACs) in the environment poses potential risks. To comprehensively assess these risks, robust multiresidual analytical methods are essential for determining a broad spectrum of PhAC classes in various environmental compartments (soil, plants, and soil organisms). This study optimized extraction methods for analyzing over 40 PhACs from various matrices, including soil, lettuce, and earthworms. A four-step ultrasonic extraction method with varying extraction conditions and subsequent solid phase extraction was developed for soil samples. QuEChERS methods were optimized for extracting PhACs from lettuce and earthworm samples, addressing a literature gap in these less-studied matrices. The quantification of PhACs in soil, lettuce, and earthworm extracts was performed using a single LC-MS/MS method. Following thorough method validation, earthworms and lettuce were exposed to a mixture of 27 pharmaceuticals in a soil environment. The method validation results demonstrated the robustness of these methods for a broad spectrum of PhACs. Specifically, 29 out of 42 PhACs were extracted with an average efficiency > 50% and RSD < 30% from the soil; 40 out of 42 PhACs exhibited average efficiency > 50% and %RSD < 30% from the earthworms, while 39 out of 42 PhACs showed average efficiency > 50% and RSD < 30% from the lettuce. Exposure experiments confirmed the viability of these methods for quantifying a diverse range of PhACs in different environmental compartments. This study presents three thoroughly validated methods for determining more than 40 PhACs in diverse matrices, enabling a comprehensive assessment of PhAC dissemination in the environment.

Evaluation of chemical contamination of crops produced in greenhouse by irrigation with reclaimed water

Using reclaimed water for agricultural irrigation is increasing worldwide to compensate for water scarcity. The aim of this work was to evaluate the uptake of some of the most commonly detected organic contaminants of emerging concern (CECs) and pesticides in regenerated water in a field study. Furthermore, it was studied their distribution and accumulation in the different parts of a crop (soil, plant and fruit). Three crops (cucumber, pepper and melon) were grown under controlled agronomic conditions in a greenhouse. In order to make an accurate evaluation of the process, "regenerated blank water" was spiked with 70 chemicals (including antibiotics, anti-inflammatories, analgesics, anaesthetics, anxiolytics, anticonvulsants, pesticides) at environmental concentrations (∼1 μg/L) and used for continuous crop irrigation. After crop season, the average total concentration of contaminants detected in the soil samples ranged from 132 to 232 μg/kg d.w depending of the crops type. Between 7 and 10 different contaminants were found in the harvested fruits, up to levels of 27.8 μg/kg f.w. cucumber, 12.4 μg/kg f.w. melon and 7.8 μg/kg f.w pepper. In general, cucumber fruit showed higher accumulation levels of contaminants than pepper and melon for most target analytes. The accumulation rates followed the order: root (0.2 %) < stem/leaf (1-4 %) < fruit (1-6 %) < soil (17-30 %). The experimental data obtained in this study were also used to assess the risk associated with the reuse of reclaimed water for crop irrigation as well to identify those contaminants that, due to their physicochemical properties, show higher accumulation rates and environmental impact.

Nutrient recovery from wastewater for hydroponic systems: A comparative analysis of fertilizer demand, recovery products, and supply potential of WWTPs

Nutrient recovery from wastewater treatment plants (WWTPs) for hydroponic cultivation holds promise for closing the nutrient loop and meeting rising food demands. However, most studies focus on solid products for soil-based agriculture, thus raising questions about their suitability for hydroponics. In this study, we address these questions by performing the first in-depth assessment of the extent to which state-of-the-art nutrient recovery processes can generate useful products for hydroponic application. Our results indicate that less than 11.5% of the required nutrients for crops grown hydroponically can currently be recovered. Potassium nitrate (KNO3), calcium nitrate (Ca(NO3)2), and magnesium sulfate (MgSO4), constituting over 75% of the total nutrient demand for hydroponics, cannot be recovered in appropriate form due to their high solubility, hindering their separated recovery from wastewater. To overcome this challenge, we outline a novel nutrient recovery approach that emphasizes the generation of multi-nutrient concentrates specifically designed to meet the requirements of hydroponic cultivation. Based on a theoretical assessment of nutrient and contaminant flows in a typical municipal WWTP, utilizing a steady-state model, we estimated that this novel approach could potentially supply up to 56% of the nutrient requirements of hydroponic systems. Finally, we outline fundamental design requirements for nutrient recovery systems based on this new approach. Achieving these nutrient recovery potentials could be technically feasible through a combination of activated sludge processes for nitrification, membrane-based desalination processes, and selective removal of interfering NaCl. However, given the limited investigation into such treatment trains, further research is essential to explore viable system designs for effective nutrient recovery for hydroponics.

Impact of chemical mixtures from wastewater treatment plant effluents on human immune cell activation: An effect-based analysis

BACKGROUND

Humans are exposed to many different chemicals on a daily basis, mostly as chemical mixtures, usually from food, consumer products and the environment. Wastewater treatment plant effluent contains mixtures of chemicals that have been discarded or excreted by humans and not removed by water treatment. These effluents contribute directly to water pollution, they are used in agriculture and may affect human health. The possible effect of such chemical mixtures on the immune system has not been characterized.

OBJECTIVE

The aim of this study was to investigate the effect of extracts obtained from four European wastewater treatment plant effluents on human primary immune cell activation.

METHODS

Immune cells were exposed to the effluent extracts and modulation of cell activation was performed by multi-parameter flow cytometry. Messenger-RNA (mRNA) expression of genes related to immune system and hormone receptors was measured by RT-PCR.

RESULTS

The exposure of immune cells to these extracts, containing 339 detected chemicals, significantly reduced the activation of human lymphocytes, mainly affecting T helper and mucosal-associated invariant T cells. In addition, basophil activation was also altered upon mixture exposure. Concerning mRNA expression, we observed that 12 transcripts were down-regulated by at least one extract while 11 were up-regulated. Correlation analyses between the analyzed immune parameters and the concentration of chemicals in the WWTP extracts, highlighted the most immunomodulatory chemicals.

DISCUSSION

Our results suggest that the mixture of chemicals present in the effluents of wastewater treatment plants could be considered as immunosuppressive, due to their ability to interfere with the activation of immune cells, a process of utmost importance for the functionality of the immune system. The combined approach of immune effect-based analysis and chemical content analysis used in our study provides a useful tool for investigating the effect of environmental mixtures on the human immune response.

Pharmacokinetics of the Recalcitrant Drug Lamotrigine: Identification and Distribution of Metabolites in Cucumber Plants

Treated wastewater is an important source of water for irrigation. As a result, irrigated crops are chronically exposed to wastewater-derived pharmaceuticals, such as the anticonvulsant drug lamotrigine. Lamotrigine is known to be taken up by plants, but its plant-derived metabolites and their distribution in different plant organs are unknown. This study aimed to detect and identify metabolites of lamotrigine in cucumber plants grown for 35 days in a hydroponic solution by using LC-MS/MS (Orbitrap) analysis. Our data showed that 96% of the lamotrigine taken up was metabolized. Sixteen metabolites possessing a lamotrigine core structure were detected. Reference standards confirmed two; five were tentatively identified, and nine molecular formulas were assigned. The data suggest that lamotrigine is metabolized via N-carbamylation, N-glucosidation, N-alkylation, N-formylation, N-oxidation, and amidine hydrolysis. The metabolites LTG-N2-oxide, M284, M312, and M370 were most likely produced in the roots and were translocated to the leaves. Metabolites M272, M312, M314, M354, M368, M370, and M418 were dominant in leaves. Only a few metabolites were detected in the fruits. With an increasing exposure time, lamotrigine leaf concentrations decreased because of continuous metabolism. Our data showed that the metabolism of lamotrigine in a plant is fast and that a majority of metabolites are concentrated in the roots and leaves.

LC-HRMS method for study of pharmaceutical uptake in plants: effect of pH under aeroponic condition

Global climate changes cause water scarcity in many regions, and the sustainable use of recycled water appears crucial, especially in agriculture. However, potentially hazardous compounds such as pharmaceuticals can enter the food chain and pose severe risks. This paper aims to study the presence of selected pharmaceutical active compounds (PhACs) and their metabolites in crops grown in aeroponic conditions and evaluate the potential of PhAC plant uptake. A solvent extraction with an acidified mixture of acetonitrile and water followed by LC-HRMS was developed and validated for quantifying nine pharmaceuticals and their nine metabolites in three plants. We aimed for a robust method with a wide linear range because an extensive concentration range in different matrices was expected. The developed method proved rapid and reliable determination of selected pharmaceuticals in plants in the wide concentration range of 10 to 20,000 ng g-1 and limit of detection range 0.4 to 9.0 ng g-1. The developed method was used to study the uptake and translocation of pharmaceuticals and their metabolites in plant tissues from an aeroponic experiment at three different pH levels. Carbamazepine accumulated more in the leaves of spinach than in arugula. On the other hand, sulfamethoxazole and clindamycin evinced higher accumulation in roots than in leaves, comparable in both plants. The expected effect of pH on plants' uptake was not significant.

Contaminant uptake in wastewater irrigated tomatoes

As population growth and climate change add to the problem of water scarcity in many regions, the argument for using treated wastewater for irrigation is becoming increasingly compelling, which makes understanding the risks associated with the uptake of harmful chemicals by crops crucial. In this study, the uptake of 14 chemicals of emerging concern (CECs) and 27 potentially toxic elements (PTEs) was studied in tomatoes grown in soil-less (hydroponically) and soil (lysimeters) media irrigated with potable and treated wastewater using LC-MS/MS and ICP-MS. Bisphenol S, 2,4 bisphenol F, and naproxen were detected in fruits irrigated with spiked potable water and wastewater under both conditions, with BPS having the highest concentration (0.034-0.134 µg kg^-1 f. w.). The levels of all three compounds were statistically more significant in tomatoes grown hydroponically (<LOQ - 0.137 µg kg^-1 f. w.) than in soil (<LOQ - 0.083 µg kg^-1 f. w.). Their elemental composition shows differences between tomatoes grown hydroponically or in soil and tomatoes irrigated with wastewater and potable water. Contaminants at determined levels showed low dietary chronic exposure. When the health-based guidance values for the studied CECs are determined, results from this study will be helpful for risk assessors.

Selective accumulation of pharmaceutical residues from 6 different soils by plants: a comparative study on onion, radish, and spinach

The accumulation of six pharmaceuticals of different therapeutic uses has been thoroughly investigated and compared between onion, spinach, and radish plants grown in six soil types. While neutral molecules (e.g., carbamazepine (CAR) and some of its metabolites) were efficiently accumulated and easily translocated to the plant leaves (onion > radish > spinach), the same for ionic (both anionic and cationic) molecules seems to be minor to moderate. The maximum accumulation of CAR crosses 38,000 (onion), 42,000 (radish), and 7000 (spinach) ng g-1 (dry weight) respectively, in which the most majority of them happened within the plant leaves. Among the metabolites, the accumulation of carbamazepine 10,11-epoxide (EPC - a primary CAR metabolite) was approximately 19,000 (onion), 7000 (radish), and 6000 (spinach) ng g-1 (dry weight) respectively. This trend was considerably similar even when all these pharmaceuticals applied together. The accumulation of most other molecules (e.g., citalopram, clindamycin, clindamycin sulfoxide, fexofenadine, irbesartan, and sulfamethoxazole) was restricted to plant roots, except for certain cases (e.g., clindamycin and clindamycin sulfoxide in onion leaves). Our results clearly demonstrated the potential role of this accumulation process on the entrance of pharmaceuticals/metabolites into the food chain, which eventually becomes a threat to associated living biota.

Uptake of different pharmaceuticals in soil and mycorrhizal artichokes from wastewater

The irrigation with treated wastewater is among the main anthropogenic sources for the release of pharmaceuticals (PhACs) into the soils and their translocation into crops, with possible toxic and adverse effects on humans. The arbuscular mycorrhizal fungi (AMF) can be employed for the reduction of organic soil pollutants, even if their efficiency depends on the mycorrhizal fungi, the plant colonized, and the type and concentration of the contaminant. This study aimed to evaluate the uptake of PhACs from wastewaters of different qualities used for the irrigation of mycorrhizal artichoke plants, the presence in their edible parts and the role of the arbuscular mycorrhizal fungi. The research was carried out on artichoke plants not inoculated and inoculated with two different AMF and irrigated with treated wastewater (TW), groundwater (GW) or GW spiked with different and selected PhACs (SGW). The inocula were a crude inoculum of Septoglomus viscosum (MSE) and a commercial inoculum of Glomus intraradices and Glomus mosseae (MSY). The results of the present study showed that carbamazepine and fluconazole were found in the artichoke only with SGW irrigation. The mycorrhizal plants showed a reduction of the pharmaceutical's uptake, and within the AMF, MSE was more effective in preventing their absorption and translocation.

Occurrence and risk of iodinated X-ray contrast media in source and tap water from Jiangsu province, China

Microcontaminants in the water environment have received increasing attention due to their adverse effects on human health and wildlife. However, iodinated X-ray contrast media (ICM), a type of microcontaminants, have not yet been systematically documented in source and tap water. This study investigated ICM in water samples via a sampling activity from 25 drinking water sources and their corresponding 30 household taps in south-central Jiangsu Province, China. The total concentrations of ICM ranged from 14.2 to 138.5 ng/L in source water and 3.7 to 101.3 ng/L in tap water, respectively. The calculated average water treatment efficiency to remove ICM is 38.3% with large variation under different processes (ranging from 7.3% to 75.7%), which implied that ICM could not be effectively removed using current treatment technologies. By integrating other ICM into the predominant compound iohexol with relative potency factors, the health risks of total ICM through water consumption were assessed using the Monte Carlo simulation. The results concluded that the risk of ingesting ICM through tap water was not a major health concern for adults, teens, or children in the study area. Nevertheless, due to the lack of long-term toxicity data relevant for humans for ICM, this risk may be underestimated, which requires further research.

Accumulation and risk assessment of antibiotics in edible plants grown in contaminated farmlands: A review

The extensive occurrence of antibiotics in farmland soil might threaten food safety. The bioaccumulation potential of antibiotics in edible vegetables and crops grown under realistic farming scenarios was reviewed and the human health risk was assessed. A total of 51 antibiotics were documented in 37 species of daily consumed crops. Among different classes of antibiotics, tetracyclines (TCs) exhibited higher residue levels in plants than quinolones (QNs), sulfonamides (SAs), and macrolides (MLs), with median values ranging from 5.10 to 15.4 μg/kg dry weight. The favored accumulation of TCs in plants was probably linked to their relatively higher residual concentrations in soils and greater bioconcentration factors. Compared with the plants grown in open field, accumulation of antibiotics was higher in plant grown under greenhouse condition, probably due to the higher residue levels of antibiotics in the greenhouse soil with intensive application of manure. Cocktails of antibiotics were investigated in potato, corn, carrot, tomato, lettuce, and wheat. Among them, corn exhibited relatively high median concentrations of antibiotics (0.400-203 μg/kg dry weight). Antibiotics tended to accumulate in plant root and their concentrations in fruit were generally low. Risk assessment revealed that human health risk was under the alert line through the daily consumption of antibiotic contaminated vegetables and food crops.

Uptake and Transport of Different Concentrations of PPCPs by Vegetables

In many parts of the world, water resources are scarce or even extremely scarce, and the reuse of water resources has become mainstream in today's world. Many regions use treated wastewater for agricultural irrigation, aquaculture, and other activities. However, in recent years, wastewater has been found to contain large amounts of pharmaceuticals and personal care products (PPCPs). Therefore, there is a potential risk of PPCPs being transported in the environment and affecting human health. In this study, we compared the uptake, transport, and accumulation of 27 PPCPs in three types of sprouts (radish, buckwheat, and okra).The bioaccumulation of amantadine, diphenhydramine, chlorpheniramine maleate, sibutramine, hemosibutramine, chlorosibutramine, N-monomethyl sibutramine, N, N-desmethyl sibutramine, and carbamazepine was found to be significantly higher in plants grown for 12 days in media containing 0.5, 5.0, and 50.0 ng/mL PPCPs. With increasing concentration of PPCPs in the culture solution, the amount of PPCPs absorbed by plants and the degree of accumulation also showed an increasing trend. At the same time, it was demonstrated that there was an obvious uptake transfer phenomenon of PPCPs by plants, and the trend of uptake transfer became more and more obvious as the concentration of external environmental pollutants increased. In addition, amantadine, chlorpheniramine maleate, carbamazepine, N, N-desmethyl sibutramine, hemosibutramine, and chlorosibutramine showed more active translocation in some plants (TF > 1.0).

Evaluation and removal efficiencies of a rural WWTP for metals and anions in Lufkin, East Texas (USA)

The present study quantified element concentrations and evaluated the removal efficiencies of the Lufkin Wastewater Treatment Plant (LWWTP): a public municipal wastewater treatment plant in East Texas. Macroelements (Na, K, Mg, Ca, Al, Fe, Se, Zn, P, and S) and microelements (Ni, Pb, Mn, Cr, Mo, Cu, Co, V, As, B, Ba) were detected using ICP-OES and ICP-MS. In addition, the anion concentrations (Br^-, NO₃^-, NO₂^-, PO₄^3-, F^-, Cl^-, and SO₄^2-) and their percent removal from the LWWTP were assessed by using ion chromatography. Whereas macroelements in the influent were above the maximum ceiling limits, the total metal concentrations in the effluent were found below the USEPA (below μg/L) guidelines. In general, the removal efficiencies for metals in LWWTP were ≥ 94%. The removal efficiencies of the anions were > 100% (Br^-), 16.42% (Cl^-), 78.89% (F^-), 182.59% (NO₃^-), > 100% (NO₂^-), 51.81% (PO₄^3-), and 67.01% (SO₄^2-). In addition, Pierson correlation coefficients between the anions and cations, and implications for usage and suggested improvements of the treatment plants are proposed.

Wastewater-derived organic contaminants in fresh produce: Dietary exposure and human health concerns

Irrigation with reclaimed wastewater is a growing practice aimed at conserving freshwater sources, especially in arid and semiarid regions. Despite the apparent advantages to water management, the practice of irrigation with reclaimed wastewater exposes the agroenvironment to contaminants of emerging concern (CECs). In this report, we estimated the unintentional dietary exposure of the Israeli population (2808 participants) to CECs from consumption of produce irrigated with reclaimed wastewater using detailed dietary data obtained from a National Health and Nutrition Survey (Rav Mabat adults; 2014-2016). Human health risk analyses were conducted based on acceptable daily intake (ADI) and threshold of toxicological concern (TTC) approaches. The highest unintentional exposure to wastewater-borne CECs was found to occur through the consumption of leafy vegetables. All analyzed CECs exhibited hazard quotients <1 for the mean- and high-exposure scenarios, indicating no human health concerns. However, for the extreme exposure scenario, the anticonvulsant agents lamotrigine and carbamazepine, and the carbamazepine metabolite epoxide-carbamazepine exhibited the highest exposure levels of 29,100, 27,200, and 19,500 ng/person (70 kg) per day, respectively. These exposure levels exceeded the TTC of lamotrigine and the metabolite epoxide-carbamazepine, and the ADI of carbamazepine, resulting in hazard quotients of 2.8, 1.1, and 1.9, respectively. According to the extreme estimated scenario, consumption of produce irrigated with reclaimed wastewater (leafy vegetables in particular) may pose a threat to human health. Minimizing irrigation of leafy vegetables using reclaimed wastewater and/or improving the quality of the reclaimed wastewater using an advanced treatment would significantly reduce human dietary exposure to CECs.

Fate and impact of wastewater-borne micropollutants in lettuce and the root-associated bacteria

The reuse of water for agricultural practices becomes progressively more important due to increasing demands for a transition to a circular economy. Treated wastewater can be an alternative option of blue water used for the irrigation of crops but its risks need to be evaluated. This study assesses the uptake and metabolization of pharmaceuticals and personal care products (PPCPs) derived from treated wastewater into lettuce as well as the impact on root-associated bacteria under a realistic and worst-case scenario. Lettuce was grown in a controlled greenhouse and irrigated with water or treated wastewater spiked with and without a mixture of fourteen different PPCPs at 10 μg/L or 100 μg/L. After harvesting the plants, the same soil was reused for a consecutive cultivation campaign to test for the accumulation of PPCPs. Twelve out of fourteen spiked PPCPs were detected in lettuce roots, and thirteen in leaves. In roots, highest concentrations were measured for sucralose, sulfamethoxazole and citalopram, while sucralose, acesulfame and carbamazepine were the highest in leaves. Higher PPCP concentrations were found in lettuce roots irrigated with spiked treated wastewater than in those irrigated with spiked water. The absolute bacterial abundance remained stable over both cultivation campaigns and was not affected by any of the treatments (type of irrigation water (water vs. wastewater) nor concentration of PPCPs). However, the irrigation of lettuce with treated wastewater had a significant effect on the microbial α-diversity indices at the end of the second cultivation campaign, and modified the structure and community composition of root-associated bacteria at the end of both campaigns. Five and fourteen bacterial families were shown to be responsible for the observed changes at the end of the first and second cultivation campaign, respectively. Relative abundance of Haliangium and the clade Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium was significantly affected in response to PCPPs exposure. Caulobacter, Cellvibrio, Hydrogenophaga and Rhizobacter were significantly affected in microcosms irrigated with wastewater.

Fate of contaminants of emerging concern in the reclaimed wastewater-soil-plant continuum

Reclaimed wastewater irrigation, a common agricultural practice in water-scarce regions, chronically exposes the agricultural environment to a wide range of contaminants of emerging concern (CECs) including pharmaceuticals and personal care products. Here we provide new data and insights into the processes governing the translocation of CECs in the irrigation water-soil-plant continuum based on a comprehensive dataset from 445 commercial fields irrigated with reclaimed wastewater. We report on CEC exposures in irrigation water, soils, and edible produce (leafy greens, carrots, potatoes, bananas, tomatoes, avocados, and citrus fruits). Our data show that CEC concentrations in irrigation water and their physiochemical properties (mainly charge and lipophilicity) are the main factors governing their translocation and accumulation in the soil-plant continuum. CECs exhibiting the highest detection frequency in plants (lamotrigine, venlafaxine, and carbamazepine) showed a reduction in their leaf accumulation factor with increasing soil organic matter content. The higher soil organic matter likely reduced the available CEC concentration in the soil solution due to soil-CEC interactions, leading to reduced uptake. Interestingly, the concentration of carbamazepine in the leaves showed a saturation-like trend when plotted against its concentration in the soils. This probably resulted from steady-state conditions when uptake equals in-planta decomposition. Our data indicate that due to continuous reclaimed wastewater irrigation, the soil acts as a sink for CECs. CECs in the soil reservoir can be desorbed into the soil solution during the rainy season and be taken up by rain-fed crops.

Contaminants of emerging concerns in recycled water: Fate and risks in agroecosystems

Recycled water (RW) has been increasingly recognized as a valuable source of water for alleviating the global water crisis. When RW is used for agricultural irrigation, many contaminants of emerging concern (CECs) are introduced into the agroecosystem. The ubiquity of CECs in field soil, combined with the toxic, carcinogenic, or endocrine-disrupting nature of some CECs, raises significant concerns over their potential risks to the environment and human health. Understanding such risks and delineating the fate processes of CECs in the water-soil-plant continuum contributes to the safe reuse of RW in agriculture. This review summarizes recent findings and provides an overview of CECs in the water-soil-plant continuum, including their occurrence in RW and irrigated soil, fate processes in agricultural soil, offsite transport including runoff and leaching, and plant uptake, metabolism, and accumulation. The potential ecological and human health risks of CECs are also discussed. Studies to date have shown limited accumulation of CECs in irrigated soils and plants, which may be attributed to multiple attenuation processes in the rhizosphere and plant, suggesting minimal health risks from RW-fed food crops. However, our collective understanding of CECs is rather limited and knowledge of their offsite movement and plant accumulation is particularly scarce for field conditions. Given a large number of CECs and their occurrence at trace levels, it is urgent to develop strategies to prioritize CECs so that future research efforts are focused on CECs with elevated risks for offsite contamination or plant accumulation. Irrigating specific crops such as feed crops and fruit trees may be a viable option to further minimize potential plant accumulation under field conditions. To promote the beneficial reuse of RW in agriculture, it is essential to understand the human health and ecological risks imposed by CEC mixtures and metabolites.

Wastewater fertigation in agriculture: Issues and opportunities for improved water management and circular economy

Water shortages are an issue of growing worldwide concern. Irrigated agriculture accounts for about 70% of total freshwater withdrawals globally, therefore alternatives to use of conventional sources need to be investigated. This paper critically reviews the application of treated wastewater for agricultural fertigation (i.e., water and nutrient recovery) considering different perspectives: legislation, agronomic characteristics, social acceptability, sustainability of treatment technologies. Critical issues that still need further investigation for a wider application of fertigation practices include accumulation of emerging contaminants in soils, microbiological and public health implications, and stakeholders' acceptance. A techno-economic methodological approach for assessing the sustainability of treated wastewater reuse in agriculture is subsequently proposed herein, which considers different possible local conditions (cultivated crops and effluent characteristics). The results showed that tailoring effluent characteristics to the desired nutrient composition could enhance the process economic sustainability; however, water savings have a major economic impact than fertilizers' savings, partly due to limited P reuse efficiency. The developed methodology is based on a practical approach and may be generalized to most agricultural conditions, to evaluate and encourage safe and efficient agricultural wastewater reuse practices.

Uptake, Occurrence, and Effects of Nonsteroidal Anti-Inflammatory Drugs and Analgesics in Plants and Edible Crops

The plant uptake of pharmaceuticals that include nonsteroidal anti-inflammatory drugs (NSAIDs) and analgesics from contaminated environment has benefits and drawbacks. These pharmaceuticals enter plants mostly through irrigation with contaminated water and application of sewage sludge as soil fertilizer. Aquatic plants withdraw these pharmaceuticals from water through their roots. Numerous studies have observed the translocation of these pharmaceuticals from the roots into the aerial tissues. Furthermore, the occurrence of the metabolites of NSAIDs in plants has been observed. This article provides an in-depth critical review of the plant uptake of NSAIDs and analgesics, their translocation, and toxic effects on plant species. In addition, the occurrence of metabolites of NSAIDs in plants and the application of constructed wetlands using plants for remediation are reviewed. Factors that affect the plant uptake and translocation of these pharmaceuticals are examined. Gaps and future research are provided to guide forthcoming investigations on important aspects that worth explorations.

Assessment of reclaimed agro-wastewater polluted with insecticide residues for irrigation of growing lettuce (Lactuca sativa L) using solar photocatalytic technology

Scientific literature is full of works studying the removal of different pollutants from water through different Advanced Oxidation Processes (AOPs). Many of them only suggest it is reused for agricultural purposes or for small crops in pots. This study is based on the reuse of reclaimed agricultural wastewater contaminated with four insecticides (chlorantraniliprole, imidacloprid, pirimicarb and thiamethoxam) for growing lettuce in field conditions. First, solar photocatalysis with TiO2/Na2S2O8 was used on a pilot plant in a sunny area (Murcia, SE of Spain) as an environmentally friendly technology to remove insecticide residues and their main reaction intermediates from contaminated water. The necessary fluence (H, kJ m-2) to accomplish 90% removal (H90) ranged from 0.12 to 1212 kJ m-2 for pirimicarb and chlorantraniliprole, respectively. Only six (derived from imidacloprid, pirimicarb and thiametoxam) of 18 transformation intermediate products studied were detected in reclaimed water during the photoperiod (2000 kJ m-2 of accumulated UVA radiation) although all of them were totally photodegraded after a fluence of 1250 kJ m-2. Secondly, reclaimed agro-wastewater was used to irrigate two lettuce crops grown under greenhouse conditions and under agricultural field conditions. In no cases, insecticide residues nor their TIPs were noticed above their respective LOQs (limits of quantification) in soil and lettuce samples (between 0.03 and 0.04 μg kg-1 for pirimicarb and 2.49 and 2.23 μg kg-1 for thiamethoxam, respectively) when they were irrigated with reclaimed water, while residues of the four insecticides and some of their intermediates were found in soil and lettuce by the end of cultivation when they were irrigated with non-reclaimed contaminated water. According to the results, this technology can be applied in a sustainable way, mainly in areas with water scarcity and high solar radiation, contributing to water utilisation in drought areas and the use of renewable energy.

Pharmaceutical and transformation products during unplanned water reuse: Insights into natural attenuation, plant uptake and human health impact under field conditions

In urban and periurban areas, agricultural soils are often irrigated with surface water containing a complex mixture of contaminants due to wastewater treatment plant (WWTP) effluent discharges. The unplanned water reuse of these resources for crop irrigation can represent a pathway for contaminant propagation and a potential health risk due to their introduction in the food chain. The aim of this study is to provide data about the magnitude of attenuation processes and plant uptake, allowing for a reliable assessment of contaminant transfer among compartments and of the human health risk derived from unplanned water reuse activities. Target compounds are 25 pharmaceuticals, including transformation products (TPs). The field site is an agricultural parcel where maize is irrigated by a gravity-fed surface system supplied by the Jarama river, a water course strongly impacted by WWTP effluents. Throughout the 3-month irrigation period, irrigation water and water infiltrating through the vadose zone were sampled. The agricultural soil was collected before and after the irrigation campaign, and maize was sampled before harvesting. All selected compounds are detected in irrigation water (up to 12,867 ng L^-1). Metformin, two metamizole TPs and valsartan occur with the highest concentrations. For most pharmaceuticals, results demonstrate a high natural attenuation during soil infiltration (>60%). However, leached concentrations of some compounds can be still at concern level (>400 ng L^-1). A persistent behavior is observed for carbamazepine, carbamazepine epoxide and sulfamethoxazole. Pharmaceutical soil contents are in the order of ng g^-1 and positively ionized compounds accumulate more effectively. Results also indicate the presence of a constant pool of drugs in soils. Only neutral and cationic pharmaceuticals are taken up in maize tissues, mainly in the roots. There is an insignificant threat to human health derived from maize consumption however, additional toxicity tests are recommended for 4AAA and acetaminophen.

Ecotoxicological risk assessment of wastewater irrigation on soil microorganisms: Fate and impact of wastewater-borne micropollutants in lettuce-soil system

The implementation of the new Water Reuse regulation in the European Union brings to the forefront the need to evaluate the risks of using wastewater for crop irrigation. Here, a two-tier ecotoxicological risk assessment was performed to evaluate the fate of wastewater-borne micropollutants in soil and their ecotoxicological impact on plants and soil microorganisms. To this end, two successive cultivation campaigns of lettuces were irrigated with wastewater (at agronomical dose (not spiked) and spiked with a mixture of 14 pharmaceuticals at 10 and 100 µg/L each) in a controlled greenhouse experiment. Over the two cultivation campaigns, an accumulation of PPCPs was observed in soil microcosms irrigated with wastewater spiked with 100 μg/L of PPCPs with the highest concentrations detected for clarithromycin, hydrochlorothiazide, citalopram, climbazole and carbamazepine. The abundance of bacterial and fungal communities remained stable over the two cultivation campaigns and was not affected by any of the irrigation regimes applied. Similarly, no changes were observed in the abundance of ammonium oxidizing archaea (AOA) and bacteria (AOB), nor in clade A of commamox no matter the cultivation campaign or the irrigation regime considered. Only a slight increase was detected in clade B of commamox bacteria after the second cultivation campaign. Sulfamethoxazole-resistant and -degrading bacteria were not impacted either. The irrigation regimes had only a limited effect on the bacterial evenness. However, in response to wastewater irrigation the structure of soil bacterial community significantly changed the relative abundance of Acidobacteria, Chloroflexi, Verrucomicrobia, Beta-, Gamma- and Deltaprotebacteria. Twenty-eight operational taxonomic units (OTUs) were identified as responsible for the changes observed within the bacterial communities of soils irrigated with wastewater or with water. Interestingly, the relative abundance of these OTUs was similar in soils irrigated with either spiked or non-spiked irrigation solutions. This indicates that under both agronomical and worst-case scenario the mixture of fourteen PPCPs had no effect on soil bacterial community.

Hazardous impact of diclofenac on mammalian system: Mitigation strategy through green remediation approach

Diclofenac is an anti-inflammatory drug used as an analgesic. It is often detected in various environmental sources around the world and is considered as one of the emerging contaminants (ECs). This paper reviews the distribution of diclofenac at high concentrations in diverse environments and its adverse ecological impact. Recent studies observed strong evidence of the hazardous effect of diclofenac on mammals, including humans. Diclofenac could cause gastrointestinal complications, neurotoxicity, cardiotoxicity, hepatotoxicity, nephrotoxicity, hematotoxicity, genotoxicity, teratogenicity, bone fractures, and skin allergy in mammals even at a low concentration. Collectively, this comprehensive review relates the mode of toxicity, level of exposure, and route of administration as a unique approach for addressing the destructive consequence of diclofenac in mammalian systems. Finally, the mitigation strategy to eradicate the diclofenac toxicity through green remediation is critically discussed. This review will undoubtedly shed light on the toxic effects of pseudo-persistent diclofenac on mammals as well as frame stringent guidelines against its common usage.

Determination of contaminants of emerging concern and their transformation products in treated-wastewater irrigated soil and corn

In many parts of the world, clean water has become increasingly scarce. Irrigation of agricultural land with treated wastewater is commonly used in response to water shortages but there is concern about the environmental fate and transport of contaminants present in the irrigation wastewater. This study aimed to examine the presence of wastewater sourced contaminants in soil and field grown corn (Zea mays) crops spray irrigated with treated wastewater. Soil, corn grain, leaves, and roots were sampled and tested from a long-term wastewater irrigation site as well as a non-irrigated control site in close geographic proximity. Samples were analyzed using comprehensive two-dimensional gas chromatography coupled to time of flight mass spectrometry (GC × GC-TOFMS) and both targeted and non-targeted analyses were conducted to determine chemical differences between the wastewater irrigated and control samples. Target compounds detected and quantified in the samples include herbicides, phthalates, and polycyclic aromatic hydrocarbons. Non-targeted analysis showed chemical differences between each the wastewater irrigated and control samples. Furthermore, new chloro-dimethyl-benzotriazole compounds, which are suspected to be transformation products created by the chlorine disinfection process of the wastewater treatment plant, were tentatively identified in the wastewater effluent. Twenty of these new benzotriazoles were detected and semi-quantified in the wastewater irrigated soil samples at a maximum concentration of 472 ng/g. Eight of the most abundant benzotriazoles were also detected in the corn roots at concentrations up to 56 ng/g.

Antibiotic-Resistant Genes and Bacteria as Evolving Contaminants of Emerging Concerns (e-CEC): Is It Time to Include Evolution in Risk Assessment?

The pressing issue of the abundance of antibiotic resistance genes and resistant bacteria in the environment (ARGs and ARB, respectively) requires procedures for assessing the risk to health. The chemo-centric environmental risk assessment models identify hazard(s) in a dose–response manner, obtaining exposure, toxicity, risk, impact and policy. However, this risk assessment approach based on ARGs/ARB evaluation from a quantitative viewpoint shows high unpredictability because ARGs/ARB cannot be considered as standard hazardous molecules: ARB duplicate and ARGs evolve within a biological host. ARGs/ARB are currently listed as Contaminants of Emerging Concern (CEC). In light of such characteristics, we propose to define ARGs/ARB within a new category of evolving CEC (or e-CEC). ARGs/ARB, like any other evolving determinants (e.g., viruses, bacteria, genes), escape environmental controls. When they do so, just one molecule left remaining at a control point can form the origin of a new dangerous and selection-responsive population. As a consequence, perhaps it is time to acknowledge this trait and to include evolutionary concepts within modern risk assessment of e-CEC. In this perspective we analyze the evolutionary responses most likely to influence risk assessment, and we speculate on the means by which current methods could measure evolution. Further work is required to implement and exploit such experimental procedures in future risk assessment protocols.

Reclaimed water driven lettuce cultivation in a hydroponic system: the need of micropollutant removal by advanced wastewater treatment

For a novel approach of resource-efficient water reuse, a municipal wastewater treatment plant was extended at pilot scale for advanced wastewater treatment, i.e., ozonation and biological activated carbon filtration, and a hydroponic system for reclaimed water driven lettuce cultivation. The treatment specific wastewater lines with the corresponding lettuce plants, differentiated into roots and shoots, were monitored for priority wastewater micropollutants, i.e., acesulfame (sweetener), caffeine (stimulant), carbamazepine, diclofenac, ibuprofen, sulfamethoxazole with acetyl-sulfamethoxazole (human pharmaceuticals), 1H-benzotriazole, and 4/5-methylbenzotriazole (industrial chemicals). As clearly demonstrated, conventional tertiary treatment could not efficiently clean up wastewater. Removal efficiencies ranged from 3% for carbamazepine to 100% for ibuprofen. The resulting pollution of the hydroponic water lines led to the accumulation of acesulfame, carbamazepine, and diclofenac in lettuce root systems at 32.0, 69.5, and 135 μg kg-1 and in the uptake of acesulfame and carbamazepine into lettuce shoots at 23.4 and 120 μg kg-1 dry weight, respectively. In contrast, both advanced treatment technologies when operating under optimized conditions achieved removal efficiencies of > 90% also for persistent micropollutants. Minimizing the pollution of reclaimed water thus met one relevant need for hydroponic lettuce cultivation.

Sunlight powered degradation of pentoxifylline Cs0.5Li0.5FeO2 as a green reusable photocatalyst: Mechanism, kinetics and toxicity studies

The degradation of Pentoxifylline (PXF) was achieved successfully by green energy in a built-in solar photocatalytic system using hybrid LiCs ferrites (Li_0.5Cs_0.5FeO₂) as magnetically recoverable photocatalysts. Kinetics showed a first-order reaction rate with maximum PXF removal of 94.91% at mildly acidic pH; additionally, the ferromagnetic properties of catalyst allowed recovery and reuse multiple times, reducing costs and time in degradation processes. The degradation products were identified by HPLC-MS and allowed us to propose a thermodynamically feasible mechanism that was validated through DFT calculations. Additionally, toxicity studies have been performed in bacteria and yeast where high loadings of Cs showed to be harmful to Staphylococcus aureus (MIC≥ 4.0 mg/mL); Salmonella typhi (MIC≥ 8.0 mg/mL) and Candida albicans (MIC≥ 10.0 mg/mL). The presented setup shows effectiveness and robustness in a degradation process using alternative energy sources for the elimination of non-biodegradable pollutants.

Pharmaceuticals in edible crops irrigated with reclaimed wastewater: Evidence from a large survey in Israel

Pharmaceuticals and other contaminants of emerging concern (CECs) are continuously introduced into the agroecosystem via reclaimed wastewater irrigation, a common agricultural practice in water-scarce regions. Although reclaimed wastewater irrigated crops are sold and consumed, only limited information is available on the occurrence of pharmaceuticals and other CECs in edible produce. Here, we report data on CECs in irrigation water, soils, and crops collected from 445 commercial fields irrigated with reclaimed wastewater in Israel. The following produce were analyzed: leafy greens, carrot, potato, tomato, orange, tangerine, avocado, and banana. Pharmaceuticals and CECs were found in quantifiable levels in all irrigation water, soils, and plants (>99.6%). Leafy greens exhibited the largest number and the highest concentration of pharmaceuticals. Within the same crop, contamination levels varied due to wastewater source and quality of treatment, and soil characteristics. Anticonvulsants (carbamazepine, lamotrigine, and gabapentin) were the most dominant therapeutic group found in the reclaimed wastewater-soil-plant continuum. Antimicrobials were detected in ~85% of the water and soil samples, however they exhibited low detection frequencies and concentrations in produce. Irrigation with reclaimed wastewater should be limited to crops where the risk for pharmaceutical transfer to the food chain is minimal.

Increasing accuracy of field-scale studies to investigate plant uptake and soil dissipation of pharmaceuticals

Pharmaceuticals and personal care products (PPCPs) can enter agricultural fields through wastewater irrigation, biosolid amendments, or urine fertilization. Numerous studies have assessed the risk of PPCP contamination, however there are no standardized methodologies for sample treatment, making the interpretation of results challenging. Various time periods between sampling and analysis have been reported (shipping, storage, etc.), but literature is lacking in the evaluation of PPCP degradation amidst this process. This study assessed the stability of 20 pharmaceuticals (200 μg L^-1) in soil and crops stored at -40 °C for 7, 30, and 310 days. After 310 days, caffeine, meprobamate, trimethoprim, primidone, carbamazepine, anhydro-erythromycin and dilantin were found to be stable (≥75% recovery) in all matrices. On the other hand, acetaminophen, amitriptyline, bupropion, lamotrigine, sulfamethoxazole, naproxen, ibuprofen, and paroxetine were unstable after 30 days in at least one of the matrices investigated. Due to variations in analyte stability, fortification with isotopically-labelled surrogates at the point of sample collection was evaluated in comparison to fortification after shipment and storage, immediately prior to extraction. Chromatographic peak areas of stable analytes were found to be reproducible (±15%) in field-fortified samples, indicating that no additional error occurred during sample handling under field conditions despite having a less controlled environment. Unstable analytes revealed notable differences in peak areas between fortification times, suggesting that fortification immediately after sample collection is crucial to account for analyte losses during shipping and storage, resulting in accurate quantification of PPCPs.

Photocatalytic degradation of four insecticides and their main generated transformation products in soil and pepper crop irrigated with reclaimed agro-wastewater under natural sunlight

This work is the first-ever study of the concurrence of four insecticides (chlorantraniliprole, imidacloprid, pirimicarb and thiamethoxam) and their main transformation products (TPs) in soil and pepper crop irrigated with reclaimed and non-reclaimed water under agricultural field conditions. Field experiments were conducted using different irrigation supplies: control water (CW), wastewater polluted with phytosanitary commercial products containing the studied insecticides (WW) and reclaimed wastewater after a photocatalytic processing with TiO₂/Na₂S₂O₈ at pilot plant under sunlight (RWW). Photocatalytic treatments removed most of the insecticides and their TPs generated during the photoperiod. Neither target insecticides nor their TPs were detected in pepper samples when CW and RWW were used as irrigation source, whereas the four insecticides and two TPs were detected when WW was used. In the experiment carried out with WW, all insecticides and eight TPs were detected in soil samples. The impact of using reclaimed water on the quality of pepper crop was also assessed, showing barely any significant difference.

Plant and soil microbial community responses to different water management strategies in an almond crop

Climate change is one of the main challenges facing the agricultural sector as it strives to meet global food needs. In arid and semiarid areas, the scarcity of water imposes the use of alternative sources - such as reclaimed water (RW) or desalinated water (DW) - and of deficit irrigation strategies, such as regulated deficit irrigation (RDI), in order to maintain productivity. The impact of both alternative water sources and RDI strategies on soil microbial communities in conjunction with the crop response has been little studied, and far less in fruit trees. Here, we evaluated the effects of the irrigation water quantity (RDI or the optimal water amount) and quality (DW or saline RW) on: i) the biomass, composition, and activity of the soil microbial community, and ii) the plant agro-physiological response at the level of the water status, nutrients, vegetative growth, and yield of almond trees. The DW-RDI treatment had a lower vegetative growth than the rest, reducing the nutrient requirements and increasing the contents of organic carbon and nitrogen in soil. This coincided with a significant increase in the bacterial biomass and enzyme activities in soil, as well as with a decrease in plant nutrient use efficiencies and yield. Irrigation with RW increased the fungal biomass. When there were no water restrictions (RW-FI), none of the plant agro-physiological parameters were affected; when RDI was applied (RW-RDI), the highest soil sodicity was reached and vegetative growth and yield were negatively affected, although the plant nutrient use efficiencies did not decrease as much as with DW-RDI. In addition, the plant nutrient use efficiencies were negatively correlated with the soil enzyme activities. These results improve our knowledge of the functioning of plant-soil interactions in Mediterranean crops subjected to different irrigation strategies.

Assessment of the presence of transformation products of pharmaceuticals in agricultural environments irrigated with reclaimed water by wide-scope LC-QTOF-MS suspect screening

The transformation that pharmaceuticals can undergo during the water reclamation cycle, or by biotic/abiotic reactions when reclaimed water (RW) is used for irrigation, can lead to the presence of transformation products (TPs) in agricultural environments. However, data on TPs in real crops are scarce. Herein, a suspect screening approach was applied for the comprehensive investigation of 262 potential TPs, associated with 20 prioritised pharmaceuticals found in real tomato crops exposed to long-term RW irrigation. The occurrence and fate of the TPs was evaluated by the retrospective analysis of RW, soil, leave and tomato samples from 4 intensive production greenhouses. Sample analysis was accomplished by liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS). Up to 18 TPs were tentatively identified, of which 2 were not previously reported. 7 TPs were finally confirmed with analytical standards. 5 TPs were determined in RW, 15 TPs in soil and 2 TPs in leaves. Remarkably, the investigated TPs were not found in tomato fruits. These results shed light on the variety of TPs that can be found in the water reuse cycle and contribute to the assessment of the global risks of wastewater reuse and the safety of the vegetable and fruit production system.

Comparative overview of advanced oxidation processes and biological approaches for the removal pharmaceuticals

Nowadays, pharmaceuticals are the center of significant environmental research due to their complex and highly stable bioactivity, increasing concentration in the water streams and high persistence in aquatic environments. Conventional wastewater treatment techniques are generally inadequate to remove these pollutants. Aiming to tackle this issue effectively, various methods have been developed and investigated on the light of chemical, physical and biological procedures. Increasing attention has recently been paid to the advanced oxidation processes (AOPs) as efficient methods for the complete mineralization of pharmaceuticals. Their high operating costs compared to other processes, however, remain a challenge. Hence, this review summarizes the current and state of art related to AOPs, biological treatment and their effective exploitation for the degradation of various pharmaceuticals and other emerging molecules present in wastewater. The review covers the last decade with a particular focus on the previous five years. It is further envisioned that this review of advanced oxidation methods and biological treatments, discussed herein, will help readers to better understand the mechanisms and limitations of these methods for the removal of pharmaceuticals from the environment. In addition, we compared AOPs and biological treatments for the disposal of pharmaceuticals from the point of view of cost, effectiveness, and popularity of their use. The exploitation of coupling AOPs and biological procedures for the degradation of pharmaceuticals in wastewater was also presented. It is worthy of note that an integrated AOPs/biological system is essential to reach the complete degradation of pharmaceuticals; other advantages of this hybrid technique involve low energy cost, an efficient degradation process and generation of non-toxic by-products.

Comprehensive review on iodinated X-ray contrast media: Complete fate, occurrence, and formation of disinfection byproducts

Iodinated contrast media (ICM) are drugs which are used in medical examinations for organ imaging purposes. Wastewater treatment plants (WWTPs) have shown incapability to remove ICM, and as a consequence, ICM and their transformation products (TPs) have been detected in environmental waters. ICM show limited biotransformation and low sorption potential. ICM can act as iodine source and can react with commonly used disinfectants such as chlorine in presence of organic matter to yield iodinated disinfection byproducts (IDBPs) which are more cytotoxic and genotoxic than conventionally known disinfection byproducts (DBPs). Even highly efficient advanced treatment systems have failed to completely mineralize ICM, and TPs that are more toxic than parent ICM are produced. This raises issues regarding the efficacy of existing treatment technologies and serious concern over disinfection of ICM containing waters. Realizing this, the current review aims to capture the attention of scientific community on areas of less focus. The review features in depth knowledge regarding complete environmental fate of ICM along with their existing treatment options.

Modeling the fate and human health impacts of pharmaceuticals and personal care products in reclaimed wastewater irrigation for agriculture

Wastewater reclamation and reuse for agriculture have attracted a great deal of interest, due to water stress caused by rapid increase in human population and agricultural water demand as well as climate change. However, the application of treated wastewater for irrigation can lead to the accumulation of pharmaceuticals and personal care products (PPCPs) in the agricultural crops, grazing animals, and consequently to human dietary exposure. In this study, a model was developed to simulate the fate of five PPCPs; triclosan (TCS), carbamazepine (CBZ), naproxen (NPX), gemfibrozil (GFB), and fluoxetine (FXT) during wastewater reuse for agriculture, and potential human dietary exposure and health risk. In a reclaimed wastewater-irrigated grazing farm growing alfalfa, it took 100-535 days for PPCPs to achieve the steady-state concentrations of 1.43 × 10^-6, 4.73 × 10^-5, 1.17 × 10^-6, 1.53 × 10^-5, and 7.38 × 10^-6 mg/kg for TCS, CBZ, NPX, GFB, and FXT in soils, respectively. The accumulated concentration of PPCPs in the plant (alfalfa) and grazing animals (beef) ranged 2.86 × 10^-7- 4.02 × 10^-3 and 4.39 × 10^-15- 6.27 × 10^-7 mg/kg, respectively. Human dietary exposure to these compounds through beef consumption was calculated to be 1.67 × 10^-18- 1.74 × 10^-10 mg/kg bodyweight/d, much lower than the acceptable daily intake (ADI). Similar results were obtained for a 'typical' reclaimed wastewater irrigated farm based on the typical setup using our model. Screening analysis showed that PPCPs with relatively high LogD value and lower ratios of degradation rate (in soils) to plant uptake have a greater potential to be transferred to humans and cause potential health risks. We established a modeling method for evaluating the fate and human health effects of PPCPs in reclaimed wastewater reuse for the agricultural system and developed an index for screening PPCPs with high potential to accumulate in agricultural products. The model and findings are valuable for managing water reuse for irrigation and mitigating the harmful effects of PPCPs.

Impact of long-term irrigation with municipal reclaimed wastewater on the uptake and degradation of organic contaminants in lettuce and leek

A two years drip irrigation of lettuce and leek crops with treated municipal wastewater without and with spiking with fourteen wastewater relevant contaminants at 10 μg/L concentration level was conducted under greenhouse cultivation conditions to investigate their potential accumulation in soil and leaves and to assess human health related risks. Lettuce and leek crops were selected as a worse-case scenario since leafy green vegetable has a high potential for organic contaminants uptake. The results revealed limited accumulation of contaminants in soil and plant leaves, their concentration levels being in the range of 1-30 ng/g and 1-660 ng/g range in soil and leaves, respectively. This was likely related to abiotic and biotic transformation or simply binding processes in soil, which limited contaminants plant uptake. This assumption was underpinned by studies of the enantiomeric fractionation of chiral compounds (e.g. climbazole and metoprolol) in soil as pieces of evidence of biodegradation and by the identification of transformation products or metabolites in leaves by means of liquid chromatography - high resolution - mass spectrometry using a suspect screening workflow. The high bioconcentration factors were not limited to compounds with intermediate Dow (100 to 1000) such as carbamazepine but also observed for hydrophilic compounds such as clarithromycin, hydrochlorothiazide and the food additives acesulfame and sucralose. This result assumed that accumulation was not only driven by passive processes (e.g. lipoidal diffusion through lipid bilayer cell membranes or Casparian strip) but might be supported by carrier-mediated transporters. As a whole, this study confirmed earlier reports on the a de minimis human health risk related to the consumption of raw leafy green vegetable irrigated with domestic TWW containing organic contaminants residues.

Influence of Treated Wastewater Irrigation on Soil Nutritional-Chemical Attributes Using Soil Quality Index

Dwindling water resources have drawn global attention to the reuse of treated wastewater (TWW) for irrigation. However, the impact of continuous TWW applications on soil quality and the proper quantification and monitoring frameworks have not been well-understood. This study aims to provides an insight into the impact of flood irrigation of urban TWW on soil nutritional-chemical attributes and the potential application of multiple soil quality indices for a corn cropping system. To achieve that goal, we pursued the Total Data Set (TDS) and Minimum Data Set (MDS) approaches, as well as the Integrated Quality Index (IQI) and Nemoro Quality Index (NQI) models. A total of 17 soil nutritional-chemical indicators (0–50 cm depths) were determined for the soils irrigated with TWW (five sites) and well water (one site as control) in West Azerbaijan province in northwestern Iran. Results revealed a significant difference in the majority of soil nutritional-chemical attributes, IQI-TDS, NQI-TDS, IQI-MDS, NQI-MDS, and corn yield between the TWW-irrigated and well-irrigated soils. Irrigation with TWW resulted in a significant increase in the amount of organic matter and cation exchange capacity by 9–17% and 17–26%, respectively, macronutrients (N, P, K, Ca, and Mg) by 22–164%, and the majority of trace metals (Fe, Mn, Zn, and Cu) by 17–175%, suggesting an improvement in soil nutrients and an increase in productivity. Comparing to the soil in control sites, the TWW irrigation caused a notable increase in the values of IQI-TDS, NQI-TDS, IQI-MDS, and NQI-MDS models ranging 14.6–29.5%, 19.1–25.5%, 21.7–33.3%, and 18.4–23.7%, respectively. This implies that soil quality was ameliorated to a significant extent with TWW irrigation. These improvements resulted in a remarkable increase in corn yield ranging from 12.5% to 28.1%. The regression equations revealed that up to 78%, 47%, 72%, and 36% of the variance in the IQI-TDS, NQI-TDS, IQI-MDS, and NQI-MDS models, respectively, could be captured by corn yield. The results of the regression and correlation analyses showed that the IQI-MDS model was more accurate than the other models in assessing soil quality and predicting crop yield. These findings may be an effective and practical tool for policy making, implementation, and management of soil irrigated with TWW.

Antibiotic resistance development and human health risks during wastewater reuse and biosolids application in agriculture

The reuse of treated wastewater (TWW) and sewage sludge are considered as solutions to the limited water resource and sludge disposal issues, respectively. The associated environmental and human health risks need to be analyzed to assess whether they are safe solutions or not. This paper discusses issues that relate to the accumulation of antibiotics and antibiotic resistance (AR) determinants in agricultural lands and crops, following TWW irrigation and biosolid amendment. Exposure assessment and dose-response assessment are the two important aspects of risk assessment discussed in this paper. Finally, research gaps in current knowledge that are relevant to a comprehensive and quantitative AR risk assessment were identified which includes: 1.) Studies on soil conditions that increase the frequency of horizontal gene transfer (HGT) between native soil resistome and pathogenic microbes in biosolids and TWW 2.) Holistic studies that examine the accumulation or dissipation of antibiotics, antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) from the irrigation/biosolids application stage to crop consumption stage 3.) The influences of soil environmental conditions (e.g. salinity, nutrients) on the fate of ARB and ARGs in soil and translocation in edible plants 4.) The development of dose-response models that explicitly incorporate the potential for ARGs transfer between microbes when quantifying the risks of infection due to ARB.

Occurrence and human health risk assessment of antibiotics and their metabolites in vegetables grown in field-scale agricultural systems

The occurrence of antibiotics (ABs) in four types of commercially grown vegetables (lettuce leaves, tomato fruits, cauliflower inflorescences, and broad bean seeds) was analyzed to assess the human exposure and health risks associated with different agronomical practices. Out of 16 targeted AB residues, seven ABs belonging to three groups (i.e., benzyl pyrimidines, fluoroquinolones, and sulfonamides) were above the method detection limit in vegetable samples ranging from 0.09 ng g^-1 to 3.61 ng g^-1 fresh weight. Data analysis (quantile regression models, principal component and hierarchical cluster analysis) showed manure application, irrigation with river water (indirect wastewater reuse), and vegetable type to be the most significant factors for AB occurrence in the targeted crops. Metabolites were detected in 70 of the 80 vegetable samples analyzed, and their occurrence was both plant- and compound-specific. In 73 % of the total samples, the concentration of AB metabolites was higher than the concentration of their parent compound. Finally, the potential human health risk estimated using the hazard quotient approach, based on the acceptable daily intake and the estimated daily intake, showed a negligible risk for human health from vegetable consumption. However, canonical-correspondence analysis showed that detected ABs explained 54 % of the total variation in AB resistance genes abundance in the vegetable samples. Thus, further studies are needed to assess the risks of antibiotic resistance promotion in vegetables and the significance of the occurrence of their metabolites.

Wide-scope screening for pharmaceutically active substances in a leafy vegetable cultivated under biogas slurry irrigation

The use of livestock waste for the production of biogas and the application of biogas slurry to agricultural soil can resolve livestock waste problems and reduce synthetic fertiliser use. However, the migration of veterinary drugs to land and crops resulting from biogas slurry irrigation is a potential food safety concern. This study employed an ultra-performance liquid chromatography coupled with quadrupole-time of flight high-resolution mass spectrometry system for wide-scope suspect screening of pharmaceutically active substances on crop cultivated under biogas slurry irrigation. Briefly, a total of 22 pak choi samples were obtained from a greenhouse farmed in tropical south Taiwan between March 2019 and March 2020. Molecular spectra and fragmented ions (between m/z 70 and 1100) were acquired. Ion features were searched and matched with a library consisting of 1068 compounds. The matrixes in the crop production environment including soil, livestock wastewater, biogas slurry, and groundwater were included in this study to elucidate potential sources of the pharmaceutically active substances. Results demonstrated 23 suspects were matched with high mass accuracy (mass error within ±5.0 ppm) in pak choi. The detection of both bufexamac and nandrolone were confirmed using standards, where a new system of identification points was applied. Nandrolone was detected throughout the pak choi samples as well as livestock wastewater. Tetracycline, macrolide, and sulfonamide antibiotics were presented in biogas slurry and soil but not pak choi. This is the first study to reveal the presence of multiclass pharmaceutically active substances in a crop supplied as food. Such findings suggest that anabolics and antibiotics should be closely monitored in the corps irrigated by biogas slurry in future.

Uptake of cephalexin by lettuce, celery, and radish from water

The introduction of pharmaceuticals into agricultural lands from the application of biosolids and animal manure, and irrigation with treated wastewater has led to concern for animal and human health after the ingestion of pharmaceutical-tainted agricultural products. In this study, the uptake and accumulation of cephalexin, a commonly prescribed antibiotic, was compared in three common vegetables (lettuce, celery, and radish) grown in nutrient solution for 144 h. During the uptake experiments, cephalexin concentration in the nutrient solution decreased in the order of radish > celery > lettuce, while the accumulation of cephalexin in vegetable roots followed the rank of lettuce > celery > radish. The accumulation of cephalexin was below the limit of detection in radish roots. No accumulation of cephalexin was observed in the shoots of all three vegetables. The behaviors of cephalexin in vivo were further elucidated using in vitro measurements of cephalexin sorption by vegetable roots and transformation in plant enzyme extracts. The affinity of cephalexin to lettuce > celery > radish roots, and the respective sorption coefficients of 687, 303, and 161 mL g-1, coupled to the transformation of cephalexin in root enzyme extracts with estimated reaction rate constants of 0.020, 0.027 and 0.024 hr-1 for lettuce, celery and radish, could help elucidate the accumulation observed in the in vivo experiments. Overall, sorption by plant roots (affinity) and reaction with plant enzymes could collectively influence the uptake and accumulation of cephalexin in vegetables.