Characterization of pharmaceutically active compounds in Beijing, China: Occurrence pattern, spatiotemporal distribution and its environmental implication

Occurrence and risks of pharmaceuticals, personal care products, and endocrine-disrupting compounds in Chinese surface waters

The continuous and rapid increase of chemical pollution in surface waters has become a pressing and widely recognized global concern. As emerging contaminants (ECs) in surface waters, pharmaceutical and personal care products (PPCPs), and endocrine-disrupting compounds (EDCs) have attracted considerable attention due to their wide occurrence and potential threat to human health. Therefore, a comprehensive understanding of the occurrence and risks of ECs in Chinese surface waters is urgently required. This study summarizes and assesses the environmental occurrence concentrations and ecological risks of 42 pharmaceuticals, 15 personal care products (PCPs), and 20 EDCs frequently detected in Chinese surface waters. The ECs were primarily detected in China's densely populated and highly industrialized regions. Most detected PPCPs and EDCs had concentrations between ng/L to µg/L, whereas norfloxacin, caffeine, and erythromycin had relatively high contamination levels, even exceeding 2000 ng/L. Risk evaluation based on the risk quotient method revealed that 34 PPCPs and EDCs in Chinese surface waters did not pose a significant risk, whereas 4-nonylphenol, 4-tert-octylphenol, 17α-ethinyl estradiol, 17β-estradiol, and triclocarban did. This review provides a comprehensive summary of the occurrence and associated hazards of typical PPCPs and EDCs in Chinese surface waters over the past decade, and will aid in the regulation and control of these ECs in Chinese surface waters.

Farmland's silent threat: Comprehensive multimedia assessment of micropollutants through non-targeted screening and targeted analysis in agricultural systems

Intricate agricultural ecosystems markedly influence the dynamics of organic micropollutants, posing substantial threats to aquatic organisms and human health. This study examined the occurrence and distribution of organic micropollutants across soils, ditch sediment, and water within highly intensified farming setups. Using a non-targeted screening method, we identified 405 micropollutants across 10 sampling sites, which mainly included pesticides, pharmaceuticals, industrial chemicals, and personal care products. This inventory comprised emerging contaminants, banned pesticides, and controlled pharmaceuticals that had eluded detection via conventional monitoring. Targeted analysis showed concentrations of 3.99-1021 ng/g in soils, 4.67-2488 ng/g in sediment, and 12.5-9373 ng/L in water, respectively, for Σ40pesticides, Σ8pharmaceuticals, and Σ3industrial chemicals, indicating notable spatial variability. Soil organic carbon content and wastewater discharge were likely responsible for their spatial distribution. Principal component analysis and correlation analysis revealed a potential transfer of micropollutants across the three media. Particularly, a heightened correlation was decerned between soil and sediment micropollutant levels, highlighting the role of sorption processes. Risk quotients surpassed the threshold of 1 for 13-23 micropollutants across the three media, indicating high environmental risks. This study highlights the importance of employing non-targeted and targeted screening in assessing and managing environmental risks associated with micropollutants.

Characterization and source apportionment of pharmaceuticals in surface water of the Yangtze Estuary and adjacent sea

Pharmaceuticals, which are closely linked to human activities, have attracted global attention. This study investigated the occurrence characteristics of 20 pharmaceuticals in surface water of the Yangtze Estuary and adjacent sea. A total of 14 targeted pharmaceuticals were detected in both spring and summer sampling campaigns. The mean concentrations of sulfonamides and non-sulfonamides were 36.60 ± 19.43 ng·L-1 and 50.02 ± 41.07 ng·L-1, respectively. As for non-antibiotics, their concentrations were in the range of 24.34 ± 916.8 ng·L-1 with caffeine accounting for 6.17 ~ 86.70% (average percentage of 42.22%). Meanwhile, spatial distribution patterns showed similarities between antibiotics and non-antibiotics, with high levels occurring near the upper estuary, aquaculture areas, wastewater treatment plants, and the maximum turbidity zone. This phenomenon could be related to the sources of pharmaceuticals and the physicochemical properties of water bodies. Obviously, the first three areas are highly impacted by human activities or serve as important sources of terrestrial contaminants entering the East China Sea. The last area retains high amounts of suspended particles which may exert strong trapping effects on hydrophobic chemicals. Principal component analysis revealed the presence of three potential sources for pharmaceuticals in the Yangtze Estuary, with a relatively high percentage originating from incompletely treated municipal sewage. As for the temporal trend, pharmaceutical contamination was found to be higher in spring compared to summer, potentially due to variations in pharmaceutical consumption patterns, local rainfalls, and water temperatures. These findings provide fundamental data support for implementing appropriate local management strategies for pharmaceutical usages.

Occurrence and seasonal variations of antibiotic micro-pollutants in the Wei River, China

In this study, a systematic monitoring campaign of 30 antibiotics belonging to tetracyclines (TCs), macrolides (MLs), fluoroquinolones (FQs) and sulfonamides (SAs) was performed in the Xi'an section of the Wei River during three sampling events (December 2021, June 2022, and September 2022). The total concentrations of antibiotics in water ranged from 297 to 461 ng/L with high detection frequencies ranging from 45% to 100% for the various antibiotics. A marked seasonal variation in concentrations was found with total antibiotic concentrations in winter being 1.5 and 2 times higher than those in the summer and autumn seasons, respectively. The main contaminants in both winter and summer seasons were FQs, but in the autumn SAs were more abundant, suggesting different seasonal sources or more effective runoff for certain antibiotics during periods of rainfall. Combined analysis using redundancy and clustering analysis indicated that the distribution of antibiotics in the Wei River was affected by the confluence with dilution of tributaries and outlet of domestic sewage. Ecological risk assessment based on risk quotient (RQ) showed that most antibiotics in water samples posed insignificant risk to fish and green algae, as well as insignificant to low risk to Daphnia. The water-sediment distribution coefficients of SAs were higher than those of other antibiotics, indicating that particle-bound runoff could be a significant source for this class of antibiotics.

Occurrence profiling, risk assessment, and correlations of antimicrobials in surface water and groundwater systems in Southwest Nigeria

The presence of antimicrobials in water has grown into a major global health concern. This study thus focused on the presence, ecological implications, and potential health risks associated with nine antimicrobials: five antibiotics (ampicillin, chloramphenicol, ciprofloxacin, metronidazole, and tetracycline) and four parabens (methylparaben, ethylparaben, propylparaben, and butylparaben) in surface water and groundwater samples collected from three Southwestern States in Nigeria (Osun, Oyo, and Lagos States). These antimicrobials were widely detected across the three States with ciprofloxacin being the most dominant having maximum average concentrations of 189 μg L-1 and 319 μg L-1 in surface water and groundwater respectively. The range of average concentrations of antibiotics in surface water are 47.3-235 μg L-1 (Osun), 27.9-166 μg L-1 (Oyo) and 52.1-159 μg L-1 (Lagos). For groundwater, it is 35.3-180 μg L-1 (Osun), 26.5-181 μg L-1 (Oyo) and 32.3-319 μg L-1 (Lagos). The average concentrations of all parabens were 32.4-153 μg L-1, 53.4-80.1 μg L-1, and 83.2-132 μg L-1 for surface water and 46.7-55.7 μg L-1, 53-117 μg L-1, and 62.4-118 μg L-1 for groundwater in Osun, Oyo, and Lagos States respectively. Methylparaben was most frequently detected paraben with average concentrations of 153 μg L-1 and 117 μg L-1 in surface water and groundwater respectively. The measured environmental concentrations of these antimicrobials pose a significant ecological risk while those of ciprofloxacin and ampicillin pose a high health risk to all population groups studied. The average concentrations of antibiotics investigated in this study exceeded their threshold values for Predicted No-Effect Concentrations (PNEC) associated with resistance selection, except for tetracycline.

Fabrication of the flower-like Z-scheme heterojunction photocatalyst Bi-BiOI/UiO 66 for enhanced photodegradation of acetaminophen in simulated wastewater

Acetaminophen is a representative contaminant of emerging persistent organic pollutants that can cause environmental problems when it enters municipal wastewater. An innovative flower-like Z-scheme photocatalyst Bi-BiOI/UiO 66 heterojunction composite was designed and constructed via a one-step solvothermal method. Investigations demonstrated that the Z-scheme structure strongly contributes to increasing the degradation efficiency of micropollutants. The results indicate that the bandgap energy (Eg) of the Bi-BiOI/UiO 66 composite decreases significantly from 3.22 eV to 2.43 eV, in comparison with that of pure copper-based UiO 66. Under suitable conditions (5 mg/L Ace, pH 3, 0.05 g/L), the organic pollutants in the water can be removed completely. A k value of 5.67 × 10-2 min-1 for the Bi-BiOI/UiO 66 heterojunction composite was found to effectively represent the acetaminophen photodegradation process. The reaction mechanism of acetamide in aqueous solution is also discussed. The Bi in Bi-BiOI can use surface plasmon resonance to form an electric field and accelerate the separation of photogenerated electrons and holes. This study highlights the potential of a novel photocatalyst for practical application.

Assessment and Assay Comparison for Detection of Antimicrobial Residues in Freshwater Aquaculture Fish in Erbil Governorate, Iraq

The excessive and uncontrolled application of antibiotics in the fish farming industry, coupled with a lack of health monitoring and medication practices, is a driving force behind the escalating development of antimicrobial resistance. The present study assessed and compared qualitative field diffusion (QFD) and disk diffusion (DD) assays for the detection of antimicrobial residues (ARs) in diverse freshwater aquaculture fish. A total of 380 freshwater aquaculture fish (160 fresh and 180 frozen) samples were systematically collected between January and June 2021 from various retail stores located in Erbil Governorate, Iraq. Based on QFDA results, overall, ARs were detected (52; 15.3%) at a relatively lower frequency with comparatively higher frequency (21; 31.1%) in fresh than (31; 17.2%) frozen fish samples. On the other hand, DDA also revealed a comparable (45; 13.2%) prevalence rate of ARs. However, a low detection was observed more in fresh (17; 10.6%) than frozen (28; 15.6%) fish samples. Moreover, no statistically significant disparity (χ2 = 0.069; p = 0.79) between two assays and types of fish was recorded. In conclusion, the results of the present study showed that detecting a considerable frequency of ARs in these fish samples raises concerns about potential threats to public health. This underscores the necessity for understanding antibiotic application in aquaculture and its potential connection to antibiotic resistance in bacterial pathogens. Such comprehension is pivotal for formulating and implementing effective control and farm management strategies to address this pressing issue.

The environmental risk assessment of constructed wetlands filled with iron and manganese ores in typical antibiotic treatment

Constructed wetlands (CWs) is considered as an efficient and environmentally friendly technology for advanced wastewater treatment to eliminate organic pollutants such as sulfamethoxazole (SMX) and trimethoprim (TMP). Iron (Fe) and manganese (Mn) ores have attracted more and more attention as CWs substrates in treating SMX and TMP, but the potentially negative environmental effects of wetland effluents, ore contaminants leached from the substrates and the risk of transmission of antibiotic resistance genes (ARGs) are still not clear. Three CW groups with different substrates (river sand (C-CW), Fe ore (Fe-CW), and Mn ore (Mn-CW)) were set up to evaluate the average removal rates and environmental risk in treating wastewater containing SMX and TMP. The results showed that the average removal rates of SMX and TMP by Fe-CW and Mn-CW were significantly higher than that of C-CW by 12.46%, 6.59% and 38.93%,15.39% respectively (p < 0.05), suggesting that both Fe and Mn ores facilitated the removal of antibiotics. However, the least abundance of ARGs was found in the layer of Fe ore at the middle layer (ML) in Fe-CW among all CWs, which suggested that Fe ore could reduce the risk of ARGs transmission. Although the environmental risk of Fe-CW and Mn-CW effluent was low, Fe-CW effluent inhibited the growth of Chlorella in both 48h and 72h experiments, while Mn-CW effluent showed an inhibitory effect in 48h and then promoted the growth in 72h. Meanwhile, these findings offer valuable insights for wetland health assessment and substrate selection for CWs.

Surveillance of COVID-19 and influenza A(H1N1) prevalence in China via medicine-based wastewater biomarkers

The simultaneous monitoring of individual or multiple diseases can be achieved by selecting therapeutic medicines used to treat the primary symptoms of the condition as biomarkers in wastewater. This study proposes a novel approach to monitor the prevalence of COVID-19 and influenza A (H1N1) by selecting nine medicines to serve as biomarkers, including three antipyretics, three antivirals, and three cough suppressants. To verify our approach, wastewater samples were collected from seventeen urban and five rural wastewater treatment plants (WWTPs) in a Chinese city over a period of one year. The use of antipyretics increased notably during the COVID-19 pandemic, while the consumption of antivirals for influenza A (H1N1) rose in the post-COVID-19 pandemic period, indicating a minor spike in the occurrence of influenza A (H1N1) after the COVID-19 pandemic. Fever is a significant symptom of COVID-19 and can serve as a reliable indicator of disease prevalence. Our research found that the prevalence of COVID-19 in urban areas was significantly higher (at 78.5 %, 95 % CI: 73.4 % - 83.9 %) than in rural areas (with a prevalence of 48.1 %, 95 % CI: 42.4 % - 53.8 %). The prevalence of COVID-19 in urban areas in this study was consistent with the data reported by the Chinese center for Disease Control and Prevention (82.4 %). Continuous monitoring of WWTPs in urban areas with fluctuating populations and complex demographics can provide early disease warning. Our results demonstrate the feasibility of evaluating community disease prevalence by selecting major therapeutic medicines as biomarkers in wastewater.

Combining large-scale investigation and quantum chemical calculation of pharmaceuticals: Spatiotemporal patterns of occurrence and structural insights into removal

This study investigated the spatiotemporal distribution of 17 pharmaceuticals in wastewater treatment plants (WWTPs) from 17 provinces across China, and explored structural insights into their removal in full-scale wastewater treatment processes by quantum chemistry. Briefly, 10 pharmaceuticals were detected in above 85 % of samples, of which ibuprofen and sulfamethoxazole dominated with concentrations up to the μg/L level. Seasonally, concentrations of psychoactive drugs (PDs) were 1.3-2.6 times higher in summer than in other seasons. Spatially, higher average concentrations were detected in northern WWTPs, and regions with similar economic levels exhibited similar contamination patterns. Pharmaceutical removal in WWTPs ranged from 41.4 % (carbamazepine) to 87.2 % (sulfamethizole), with the secondary treatment segment, especially aerobic treatment units, maintaining an important position. Molecular structural mechanisms behind these removal performances were further revealed. Firstly, we demonstrated a significant association of pharmaceutical overall removal with electrophilicity index (ωcubic) as well as the lowest unoccupied molecular orbital energy (ELUMO). Highly electrophilic pharmaceuticals may persist in WWTPs and their sensitivity to electron exchange reactions accounted for the discrepant removal. In terms of treatment segments, pharmaceuticals with reaction sites masked in molecular structure, such as ibuprofen and venlafaxine, showed a propensity for tertiary treatment suitability. Furthermore, enzymes of aerobic units exhibited excellent docking affinity to pharmaceutical molecules with an average affinity of -7.2 kcal/mol, and hydrogen-bond interactions played an important factor in promoting biodegradation. Our results emphasize the necessity of assessing pharmaceutical contamination on a larger spatiotemporal scale. Moreover, the structural insights into removal phenomena offer scientific molecular-level justification for the design and optimization of pharmaceutical treatment technologies in WWTPs.

Micropollutants but high risks: Human multiple stressors increase risks of freshwater ecosystems at the megacity-scale

Micropollutants in water environments have attracted widespread attention, but how human and natural stressors influence the risks of micropollutants has not been comprehensively revealed. A megacity-scale study of the ecological risks of micropollutants in the surface water of Beijing, China is presented to illustrate the magnitudes of the influences of multiple anthropogenic and natural stressors. A total of 133 micropollutants representing typical land use patterns in Beijing, were quantified with the mean concentration range of ND (not detected) to 272 ng·L-1. The micropollutant concentrations in the south were obviously higher than those detected in the northern areas, and neonicotinoid pesticides showed the highest mean concentration of 311 ng·L-1. The chronic and acute risks of micropollutants to algae, invertebrates, and fishes were determined, and herbicides, organophosphorus esters, and insecticides account for the primary risks to algae, invertebrates, and fishes, respectively. The cropland and impervious cover cause the differences in the pollution and risks of micropollutants. The land use in riparian zones greater than 2 km shows a great influence on the chronic chemical risks (CCRs) for the three groups of species, indicating that too local scale does not explain the local pollution status. Climate conditions and human land use are important drivers explaining the CCRs to which various trophic levels of species are exposed. Results demonstrate that multiple categories of micropollutants pose adverse risks to freshwater in the megacity of Beijing, while climate conditions, pollution discharge, and human land use induce the chemical risk of micropollutants to aquatic organisms, and the land use in different riparian zones show different effects on the risks.

Occurrence and removal rate of typical pharmaceuticals and personal care products (PPCPs) in an urban wastewater treatment plant in Beijing, China

The occurrence and removal rate of 52 typical pharmaceuticals and personal care products (PPCPs) were investigated in a wastewater treatment plant in Beijing, China. Thirty-three PPCPs were found in the influent, with caffeine (CF, 11387.0 ng L-1) being the most abundant, followed by N,N-diethyl-meta-toluamide (DEET, 9568.4 ng L-1), metoprolol (MTP, 930.2 ng L-1), and diclofenac (DF, 710.3 ng L-1). After treatment processes, the cumulative concentration of PPCPs decreased from 2.54 × 104 ng L-1 to 1.44 × 103 ng L-1, with the overall removal efficiency (RE) of 94.3%. Different treatment processes showed varying contributions in removing PPCPs. PPCPs were efficiently removed in sedimentation, anoxic, and ultraviolet units. For individual compounds, a great variation in RE (52.1-100%) was observed. Twenty-two PPCPs were removed by more than 90%. The highly detected PPCPs in the influent were almost completely removed. Aerated grit chamber removed nearly 50% of fluoroquinolone (FQs) and more than 60% of sulfonamides. Most PPCPs showed low or negative removals during anaerobic treatment, except for CF which was eliminated by 64.9%. Anoxic treatment demonstrated positive removals for most PPCPs, with the exceptions of DF, MTP, bisoprolol, carbamazepine (CBZ), and sibutramine. DEET and bezafibrate were efficiently removed during the secondary sedimentation. Denitrification biological filter and membrane filtration also showed positive effect on most PPCPs removals. The remaining compounds were oxidized by 16-100% in ozonation. DF, sulpiride, ofloxacin (OFL), trimethoprim, and phenolphthalein were not amenable to ultraviolet. After the treatment, the residue OFL, CBZ, and CF in receiving water were identified to pose high risk to aquatic organisms. Considering the complex mixtures emitted into the environment, therapeutic groups psychotropics, stimulant, and FQs were classified as high risk. These findings provide valuable insights into adopting appropriate measures for more efficient PPCPs removals, and emphasize the importance of continued monitoring specific PPCPs and mixtures thereof to safeguard the ecosystem.

Ranking the risks of eighty pharmaceuticals in surface water of a megacity: A multilevel optimization strategy

Pharmaceuticals in freshwater posed ecological risks to aquatic ecosystem, however, most risk assessments of pharmaceuticals were conducted at screening level, which were limited by the availability of the toxicity data. In this study, risks of 80 pharmaceuticals including 35 antibiotics, 13 antiviral drugs, 13 illicit drugs, and 19 antidepressants in surface water of Beijing were assessed with a proposed multilevel environmental risk optimization strategy. Target pharmaceuticals were detected in surface water samples with the detection frequency from 1.7 % to 100 % and the total concentrations from 31.1 ng/L to 2708 ng/L. Antiviral drugs were the dominant pharmaceuticals. Preliminary screening-level risk assessment indicated that 20 pharmaceuticals posed low to high risks with risk quotient from 0.14 (chloroquine diphosphate) to 27.8 (clarithromycin). Thirteen pharmaceuticals were recognized with low to high risks by an optimized risk assessment method. Of them, the refined probabilistic risk assessment of joint probability curves coupling with a quantitative structure activity relationship-interspecies correlation estimation (QSAR-ICE) model was applied. Clarithromycin, erythromycin and ofloxacin were identified to pose low risks with maximum risk products (RP) of 1.23 %, 0.41 % and 0.35 %, respectively, while 10 pharmaceuticals posed de minimis risks. Structural equation modeling disclosed that human land use and climate conditions influenced the risks of pharmaceuticals by indirectly influencing the concentrations of pharmaceuticals. The results indicated that the multilevel strategy coupling with QSAR-ICE model was appropriate and effective for screening priority pollutants, and the strategy can be used to prioritize pharmaceuticals and other emerging contaminants in the aquatic environment.

Photo-transformation of acetaminophen sensitized by fluoroquinolones in the presence of bromide

Fluoroquinolones (FQs) are a class of antibiotics with emerging concern. This study investigated the photochemical properties of two representative FQs, i.e., norfloxacin (NORF) and ofloxacin (OFLO). Results showed that both FQs could sensitize the photo-transformation of acetaminophen under UV-A irradiation, during which excited triplet state (³FQ*) was the main active species. In the presence of 3 mM Br^‾, the photolysis rate of acetaminophen increased by 56.3% and 113.5% in the solutions with 10 μM NORF and OFLO, respectively. Such an effect was ascribed to the generation of reactive bromine species (RBS), which was verified by 3,5-dimethyl-1H-pyrazole (DMPZ) probing approach. ³FQ* reacts with acetaminophen through one-electron transfer, producing radical intermediates which then couple to each other. Presence of Br^‾ did not lead to the formation of brominated products but the same coupling products, which suggests that radical bromine species, rather than free bromine, were responsible for the accelerated acetaminophen transformation. According to the identified reaction products and assisted with the theoretical computation, the transformation pathways of acetaminophen under UV-A irradiation were proposed. The results reported herein suggest that sunlight-driven reactions of FQs and Br^‾ may influence the transformation of coexisting pollutants in surface water environments.

Detection and removal technologies for ammonium and antibiotics in agricultural wastewater: Recent advances and prospective

With the extensive development of industrial livestock and poultry production, a considerable part of agricultural wastewater containing tremendous ammonium and antibiotics have been indiscriminately released into the aquatic systems, causing serious harms to ecosystem and human health. In this review, ammonium detection technologies, including spectroscopy and fluorescence methods, and sensors were systematically summarized. Antibiotics analysis methodologies were critically reviewed, including chromatographic methods coupled with mass spectrometry, electrochemical sensors, fluorescence sensors, and biosensors. Current progress in remediation methods for ammonium removal were discussed and analyzed, including chemical precipitation, breakpoint chlorination, air stripping, reverse osmosis, adsorption, advanced oxidation processes (AOPs), and biological methods. Antibiotics removal approaches were comprehensively reviewed, including physical, AOPs, and biological processes. Furthermore, the simultaneous removal strategies for ammonium and antibiotics were reviewed and discussed, including physical adsorption processes, AOPs, biological processes. Finally, research gaps and the future perspectives were discussed. Through conducting comprehensive review, future research priorities include: (1) to improve the stabilities and adaptabilities of detection and analysis techniques for ammonium and antibiotics, (2) to develop innovative, efficient, and low cost approaches for simultaneous removal of ammonium and antibiotics, and (3) to explore the underlying mechanisms that governs the simultaneous removal of ammonium and antibiotics. This review could facilitate the evolution of innovative and efficient technologies for ammonium and antibiotics treatment in agricultural wastewater.

2D defect-engineered Ag-doped γ-Fe2O3/BiVO4: The effect of noble metal doping and oxygen vacancies on exciton-triggering photocatalysis production of singlet oxygen

The selectivity of singlet oxygen (1O2) holds promising applications in complex environmental systems due to its ability to preferentially oxidize target pollutants. Usually, 1O2 in photocatalytic systems is generated via the electron transfer pathway and •O2- plays an important role as an intermediate, while the exciton-based energy transfer pathway for 1O2 generation has been less studied. Here, a 2D Ag-γ-Fe2O3/BiVO4 with oxygen vacancies was designed which was capable of generating 1O2 by an exciton-based energy transfer-dominated approach, as strongly demonstrated by the results of steady-state fluorescence spectroscopy and phosphorescence spectroscopy. In the Z-type heterojunction photocatalyst system, Ag acted as an electron mediator to promote not only the generation of free carriers but also the generation of singlet excitons, while the appropriate concentration of oxygen vacancies further promotes the exciton-triggering photocatalysis production of 1O2. The Ag-γ-Fe2O3/BiVO4 could degrade 99.4% of sulfadiazine within 90 min, and 1O2 played an important role in the degradation of sulfadiazine, as shown by EPR and active species capture experiments. Ecotoxicity predictions indicated that the main byproducts of sulfadiazine degradation by Ag-γ-Fe2O3/BiVO4 were low in toxicity. The prepared photocatalysts provide a new idea for obtaining 1O2 and designing photocatalysts with selectivity.

Spatiotemporal distribution of veterinary and human drugs and its predictability in Japanese catchments

Little is known about the predictability of mass flows of veterinary drugs in Asian catchments, where effluent from livestock farms is a major source. We therefore conducted this study to understand the applicability and limitations of a population-based emission model, which assumed usage of veterinary and human drugs to be evenly distributed over the national livestock or human population throughout the year, and sources to be effluent discharges at livestock farms, households, and sewage treatment plants in Japanese catchments. We monitored five veterinary drugs (lincomycin, sulfamonomethoxine, tiamulin, tylosin, and tilmicosin), two human and livestock drugs (sulfamethoxazole and trimethoprim), two human drugs (carbamazepine and clarithromycin), and a metabolite (sulfapyridine) of a human drug once a month over 2 years in eight Japanese rivers which have active livestock farming in their catchments. Mass flows of carbamazepine and sulfapyridine were stable, while those of veterinary drugs fluctuated widely, especially sulfamonomethoxine and tilmicosin, whose 25 %-100 % ranges averaged 1.5 and 1.2 log units, respectively, attributable mainly to their usage patterns. The model accurately predicted mean mass flows of carbamazepine in the rivers with errors of <±0.3 log unit. Although it slightly to moderately overestimated those of the other four human-related compounds, the incorporation of an empirical correction factor, determined to minimize mean absolute error (MAE) among the rivers, substantially lowered their MAEs to <0.23 log units. However, the MAEs of the five veterinary drugs were as high as 0.42 (sulfamonomethoxine) to 0.60 (tiamulin) log units even with the coefficient, likely due mainly to the spatial distribution of their usage per capita. So as not to overlook spatiotemporal elevation of risks of veterinary drugs, a stochastic method should be applied in their management. This is the first study to assess the use of spatiotemporal homogeneity in usage per capita of veterinary drugs in Asian catchments.

Occurrence, distribution, and ecological risk assessment of pharmaceuticals and personal care products in the surface water of the middle and lower reaches of the Yellow River (Henan section)

Pharmaceuticals and personal care products (PPCPs) are commonly seen emerging organic contaminants in aquatic environments. The transects for the occurrence and distribution of 24 PPCPs along the middle and lower reaches of the Yellow River (Henan section) were investigated in this study. All 24 targeted compounds were detected in surface water, with concentrations in the range from not detected (ND) to 527.4 ng/L. Among these PPCPs, caffeine is found to have the highest concentration and its detection frequency is 100%. The total PPCP concentration ranged from 136 ng/L to 916 ng/L (median, 319.5 ng/L). Spatial analysis showed that the pollution level of PPCPs in the trunk stream was lower than that in most tributaries in the middle and lower reaches of the Yellow River (Henan section). The ecotoxicological risk assessment indicated that norfloxacin, azithromycin, estrone, and triclosan posed high risks to aquatic organisms (RQ > 1), roxithromycin and oxytetracycline imposed moderate risks (0.1 ≤ RQ < 1), and the tributary Jindi River had the highest mixed risk (MRQ = 222).

MOFFeCo/B-CN composites achieve efficient degradation of antibiotics in a non-homogeneous concurrent photocatalytic-persulfate activation system

We synthesized an M_FeCoB_0.4CN_x% (MOF-Fe/Co nanosheets/boron-doped g-C₃N₄) composite catalyst for enhancing the concurrent photocatalytic-persulfate activation (CPPA) system and achieved efficient degradation of antibiotics. The role of MOF-Fe/Co is to activate persulfate, while boron-doped g-C₃N₄ can generate photogenerated electrons for the reduction of Co³⁺/Fe³⁺ to enhance the regeneration of the active center. The rate constant for Tetracycline degradation by the CPPA system was 4.74 and 7.54 times higher than the photocatalytic and persulfate-activated systems, respectively. This composite was shown to be practical and economically viable for antibiotic degradation. The degradation behavior was explored based on experiments, and molecular orbitals and Fukui functions were obtained by density functional theory calculations. Mechanisms were investigated using reactive oxygen species trapping studies and electron spin resonance, and the process was explained in terms of the charge population and electron density difference of MOF-Fe/Co nanosheets. The CPPA system is an ecologically benign technology for removing antibiotic-related risks to the environment and human health.

Seasonal occurrence of multiple classes of antibiotics in East China rivers and their association with suspended particulate matter

Understanding the occurrence and fate of antibiotics from different categories is vital to predict their environmental exposure and risks. This study presents the spatiotemporal occurrence of 45 multi-class antibiotics and their associations with suspended particulate matter (SPM) in Xiaoqing River (XRB) and Yellow River (YRB) via 10-month monitoring in East China. Thirty-five and 31 antibiotics were detected in XRB and YRB, respectively. Among them, fluoroquinolones (FQs) had the highest total mean concentration (up to 24.8 μg/L in XRB and 15.4 μg/L in YRB), followed by sulfonamides (SAs) (14.0 μg/L and 15.4 μg/L) and macrolides (MLs) (1.1 μg/L and 1.6 μg/L). Significant spatial-temporal variations were found in both rivers where higher concentrations of antibiotics were observed in urban and densely populated areas during winter and spring. Hydrological factors such as river flow and water volume, instream attenuation and antibiotic usage may cause the observed variabilities in the seasonal patterns of antibiotic pollution. Using linear regression analysis, for the first time, this study confirmed that the total concentrations of MLs (p < 0.05), FQs (p < 0.001) and SAs (p < 0.001) were strongly correlated with the turbidity/total suspended solids in the studied rivers (except MLs in YRB). It is thus suggested that partitioning processes onto SPM might affect the distribution of detected antibiotics in rivers, which are largely dependent on SPM composition and characteristics. The risk quotient (RQ) determined for up to 87 % of individual compound was below 0.1 in both rivers; however, the high joint toxicity reflected by the mixed RQs of detected antibiotics may rise risk alarm for aquatic species. Further aspects regarding active mechanisms of SPM-antibiotic interactions and ecological risks of coexistence of multiple antibiotics need to be investigated.

Urinary paracetamol (4-acetaminophenol) and its isomer 2-acetaminophenol of Chinese pregnant women: Exposure characteristics and association with oxidative stress biomarkers

N-Acetyl-4-aminophenol (NA4AP, paracetamol/acetaminophen), a widely used pharmaceutical, is ubiquitous in urine samples of general population, raising concern about human health risks; oxidative stress is considered to be a mechanism for its toxicities. N-Acetyl-2-aminophenol (NA2AP) is an isomer of NA4AP; until now, few studies characterized exposure characteristics of NA4AP and NA2AP in pregnant women. In this work, NA4AP and NA2AP concentrations in urine samples (n = 2124) collected at three different trimesters were measured to examine their internal body burden among Chinese pregnant women (n = 708) and their associations with three oxidative stress biomarkers (OSBs, 8-OHG, 8-OHdG, and HNE-MA). NA4AP was detected in 100% of the urine samples (median concentration: 7.96 ng/mL); NA2AP was detected in 94.9% of them (median: 3.05 ng/mL). The intraclass correlation coefficients of their concentrations across three trimesters were poor (<0.4); correlations of NA4AP and NA2AP were weak (r: 0.15-0.23). Pregnant women who had higher household income or urine samples provided in summer (vs. winter) had higher concentrations of NA4AP. Pregnant women who had a college degree or above (vs. less than a high school education) had higher concentrations of NA2AP but urine samples provided in summer (vs. winter) had lower concentrations of NA2AP. The 95th percentile estimated daily intake of NA4AP (2,331 ng/kg-bw/d) based on averaged concentrations of the three trimesters was 40 times lower than the cRfD for NA4AP (2.33 vs. 93 μg/kg-bw/d). Urinary concentrations of NA4AP and NA2AP were associated with higher levels of the selected OSBs. For example, an interquartile range increase in NA4AP was associated with a 26.5% (95% CI: 23.6-29.6%) increase in 8-OHG, a 27.5% (95% CI: 23.8-31.3%) increase in 8-OHdG, and a 33.4% (95% CI: 24.7-42.7%) increase in HNE-MA (p < 0.05). This is the first study to measure their concentrations repeatedly over three trimesters, examine their exposure characteristics, and reveal their associations with the selected OSBs in pregnant women. Further studies are needed to identify non-intentional exposure sources of NA4AP, NA2AP, and another isomer of them (i.e., N-acetyl-3-aminophenol), as well as more health risks related to their exposure.

Spatial distribution and risk assessment of certain antibiotics in 51 urban wastewater treatment plants in the transition zone between North and South China

The release of antibiotics from WWTPs into the environment has raised increasing concern worldwide. The monitoring of antibiotics in WWTPs throughout a region is crucial for emerging pollutant management. A large-scale survey of the occurrence, distribution, and ecological risk of seven antibiotics in 51 WWTPs was conducted in Shaanxi Province, China. Norfloxacin and ofloxacin had the highest detection concentrations of 474.2 and 656.18 ng L^-1, respectively. Antibiotic residues in effluents were decreased by 5.88-94.16 % after different treatment processes. In particular, A²O or mixed processes performed well in removing target antibiotic compounds simultaneously. The ecological risk posed by antibiotic compounds detected in effluents was calculated using the risk quotient (RQ). Norfloxacin, ofloxacin, tetracycline, and roxithromycin posed different levels of potential ecotoxicological risk (RQ = 0.02-7.59). Based on the sum of the RQ values of individual antibiotic compounds, each investigated WWTP showed potential ecological risk. WWTPs with high risk levels were mainly found in the central region, while those in the southern region exhibited low risk levels, and those in the northern region showed risk levels between medium and high. This comprehensive investigation provides promising results to support the safe use and control of antibiotics in the study area.

Derivation of Water Quality Criteria for Carbamazepine and Ecological Risk Assessment in the Nansi Lake Basin

Carbamazepine, as one of several pharmaceutical and personal care products, has gained much attention in recent years because of its continuous discharge in natural waters and toxicity to aquatic ecosystems. However, it is difficult to evaluate and manage carbamazepine pollution because of the lack of a rational and scientific Water Quality Criteria (WQC) of carbamazepine. In this study, the carbamazepine toxicity data of thirty-five aquatic species from eight taxonomic groups were selected, and the species sensitivity distribution (SSD) method was applied to derive the WQC for carbamazepine based on the Log-logistic model, which was 18.4 ng/L. Meanwhile, the occurrence and distribution of carbamazepine in the Nansi Lake basin was studied. Results showed that concentrations of carbamazepine in 29 sampling sites were in the range of 3.3 to 128.2 ng/L, with the mean of 17.3 ng/L. In general, the levels of carbamazepine in tributaries were higher than those in the lakes. In addition, qualitative and quantitative ecological risk assessment methods were applied to assess the adverse effect of carbamazepine on aquatic systems. The hazard quotient (HQ) method showed that there were 24 and 5 sampling sites, in which risk levels were low and moderate, respectively. The joint probability curve (JPC) method indicated that ecological risks might exist in 1.4% and 1.0% of surface water, while a 5% threshold and 1% threshold were set up to protect aquatic species, respectively. Generally, carbamazepine posed a low risk to the aquatic organisms in the Nansi Lake basin.

Degradation of sulfadiazine by UV/Oxone: roles of reactive oxidative species and the formation of disinfection byproducts

Sulfadiazine (SDZ) is a typical persistent sulfonamide antibiotic, which has been widely detected in natural drinking water sources. The degradation of SDZ by UV/Oxone (potassium monopersulfate compound) was explored in this study. The results showed that Cl^- can effectively activate PMS to promote rapid degradation of SDZ in the Oxone process by forming chlorine in the system. Radical quenching tests suggested that radical oxidation, including HO^•, SO₄^•-, and reactive chlorine species (RCS), played an important role by UV/Oxone. It further verified that concentration and distribution of HO^•, SO₄^•-, and RCS were pH-dependent; RCS act as a major contributor at pH 6.0 and pH 7.0 to degrade SDZ in this process. The SDZ degradation rate was firstly increased and then decreased by Cl^- and HCO₃^- (0-10 mM); HA (0-10 mg L^-1) exhibited insignificant influence on SDZ degradation. The degradation pathways of SDZ during UV/Oxone and formation pathways of five disinfection byproducts during subsequent chlorination were proposed. The possible DBP precursors formed by SO₂ extrusion, hydroxylation, and chlorination of SDZ during UV/Oxone pre-oxidation.

Novel sphere-like copper bismuth oxide fabricated via ethylene glycol-introduced solvothermal method with improved adsorptive and photocatalytic performance in sulfamethazine removal

In this research, ethylene glycol-introduced solvothermal method was employed to fabricate a novel sphere-like CuBi₂O₄ material to improve the adsorptive and photocatalytic performance of conventional CuBi₂O₄. A series of characterization has been applied to investigate properties of the obtained CuBi₂O₄ (CBO-EG3). Compared with conventional rod-like CuBi₂O₄ (CBO), the synthesized sphere-like CBO-EG3 exhibited rough surface, larger specific surface area, and more effective separation of photo-generated carriers, which overcome main shortcomings of CuBi₂O₄. The removal efficiency of typical antibiotic sulfamethazine (SMZ) reached almost 100% under the optimal experimental conditions. About 70% of SMZ could be adsorbed in 180-min dark reaction, with residual being photodegraded in 30 min. CBO-EG3 showed much higher photocatalytic efficiency than pure CBO, attributing to its highly effective photo-induced electron and hole separation. Meanwhile, substantial adsorption of pollutant on CBO-EG3 contributed vastly to removal of SMZ, photo-generated electrons and holes inclined to react with adsorbed SMZ directly, and photocatalytic process was mainly led by non-radical reaction. Elimination of SMZ in actual water samples and recycling experiment were also performed to evaluate CBO-EG3's practical application potential. This study delivered a method to promote CuBi₂O₄'s adsorptive and photocatalytic ability, which could expand the application of CuBi₂O₄ in wastewater treatment.

Effects of Fine Particulate Matter on Cardiovascular Disease Morbidity: A Study on Seven Metropolitan Cities in South Korea

Objectives: The primary purpose of this study is to analyze the relationship between the first occurrence of hospitalization for cardiovascular disease (CVD) and particulate matter less than 2.5 μm in diameter (PM2.5) exposure, considering average PM2.5 concentration and the frequency of high PM2.5 concentration simultaneously.

Methods: We used large-scale cohort data from seven metropolitan cities in South Korea. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) using the Cox proportional-hazards model, including annual average PM2.5 and annual hours of PM2.5 concentration exceeding 55.5 μg/m³ (FH55).

Results: We found that the risk was elevated by 11.6% (95% CI, 9.7–13.6) for all CVD per 2.9 μg/m³ increase of average PM2.5. In addition, a 94-h increase in FH55 increased the risk of all CVD by 3.8% (95% CI, 2.8–4.7). Regarding stroke, we found that people who were older and had a history of hypertension were more vulnerable to PM2.5 exposure.

Conclusion: Based on the findings, we conclude that accurate forecasting, information dissemination, and timely warning of high concentrations of PM2.5 at the national level may reduce the risk of CVD occurrence.

Bioavailability and trophic magnification of antibiotics in aquatic food webs of Pearl River, China: Influence of physicochemical characteristics and biotransformation

Information on trophodynamics of antibiotics and subsequent relationships to antibiotic metabolism in river ecosystem is still unavailable, limiting the evaluation of their bioaccumulation and trophodynamics in aquatic food webs. In the present study, concentrations and relative abundance of 11 antibiotics were investigated in surface water, sediment and 22 aquatic taxa (e.g., fish, invertebrates and plankton) from Pearl River, South China. The logarithmic bioaccumulation factors (log BAFs) of antibiotics generally showed positive relationships with their log D (pH-adjusted log Kow), implying that their bioaccumulation of ionizable antibiotics depends on it is in an ionized form. Higher BAFs of antibiotics in benthic biota were observed than those in fish, indicating that sediment ingestion was a possible route of antibiotic exposure. The logarithmic biota-sediment accumulation factors (log BSAFs) of benthic biota increased when log D increased from -4.79 to -0.01, but declined thereafter. Trophodynamics of antibiotics was investigated, and intrinsic clearance were measured in liver microsomes of Tilapia zillii (trophic level [TL]: 2.5), Anabas testudineu (TL: 3.9), and Coilia grayi (TL: 5.0). Only ciprofloxacin (CFX) showed significant trophic magnification (Trophic Magnification Factor [TMF] = 1.95), and a higher metabolism rate in lower trophic levels suggest that metabolic biotransformation play a significant role in driving biomagnification of antibiotics.

Spatial autocorrelation and temporal variation of contaminants of emerging concern in a typical urbanizing river

The distribution and fate of contaminants of emerging concern (CECs) was studied in relation to hydrological conditions, land use characteristics, and spatial contiguity in Houxi River. Thirty-four CECs were detected in the surface water during a three-year sampling campaign. Caffeine was most prevalent (99% frequency), while bisphenol A had the highest median concentration (78.2 ng/L) among the detected CECs. Caffeine and the other prevalent CECs lincomycin and bisphenol A, with median concentrations of 3.89 ng/L, 0.26 ng/L, and 78.2 ng/L, respectively, were positively correlated with land use types related to anthropogenic activities (grass, barren, built up, and cropland areas and landscape indexes for human activities). The analysis of similarities revealed significant annual variations, with increasing trends in both the concentrations and detection frequencies of CECs. Spatial variations were demonstrated by higher concentrations and detection frequencies downstream compared to upstream. The singular value decomposition analysis revealed that the downstream sites were the major contributors (55.6%-100%) to the spatial variability of most CECs. Moran's I analysis based on downstream contiguity indicated strong spatial autocorrelation among the connected sites for most CECs. This was further supported by longer correlation lengths for 18 CECs than the average distance between the sampling sites. The spatial autocorrelation can be attributed to the physicochemical properties of CECs and local hydrological dynamics, including temperature, wind speed, and sunshine hours. For most CECs, local contribution predominated over neighbor influence with an average value of 75.5%. The results of this study provide new insight to evaluate CEC distributions, which will be beneficial to policymakers for the management and prioritization of CEC contaminants in the Houxi watershed.

Occurrence, detection and ecotoxicity studies of selected pharmaceuticals in aqueous ecosystems- a systematic appraisal

Pharmaceutical compounds (PCs) have globally emerged as a significant group of environmental contaminants due to the constant detection of their residues in the environment. The main scope of this review is to fill the void of information on the knowledge on the African occurrence of selected PCs in environmental matrices in comparison with those outside Africa and their respective toxic actions on both aquatic and non-aquatic biota through ecotoxicity bioassays. To achieve this objective, the study focused on commonly used and detected pharmaceutical drugs (residues). Based on the conducted literature survey, Africa has the highest levels of ciprofloxacin, sulfamethoxazole, lamivudine, acetaminophen, and diclofenac while Europe has the lowest of all these PC residues in her physical environments. For ecotoxicity bioassays, the few data available are mostly on individual groups of pharmaceuticals whereas there is sparsely available data on their combined forms.

Animal gut microbiome mediates the effects of antibiotic pollution on an artificial freshwater system

The antibiotic pollution has become an emerging environmental problem worldwide, but the ecological outcomes remain to be elucidated, especially very little is known about the interactions between antibiotics and different ecological elements. In this study, the long-term influences of three representative antibiotics, i.e., tetracycline, erythromycin, and sulfamethoxazole, were investigated focusing on a simplified artificial freshwater system composed of amphibian tadpoles, gut and environmental bacterial and fungi communities, and water parameters. Results demonstrated that antibiotic exposure reduced tadpole's fitness with increased mortality and physiological abnormality, and altered the water quality, particularly the nitrogen homeostasis. Sequential analyses at organism, symbiont, and systematic levels revealed that antibiotics disrupted tadpole metabolome (e.g., tetrahydrobiopterin metabolism) directly by off-target effects. Antibiotics also reshaped the tadpole gut bacterial and fungi diversity and composition, which partly accounted for the tadpole's health condition. Moreover, changes of tadpole gut microbiome (i.e., Cyanobacteria and Basidiomycota OTUs) partly explained the variations of water parameters. In contrast, environmental microbiota and metagenome stayed relatively stable, and didn't contribute to the environmental variations. These results highlighted the pivotal role of gut microbiome in mediating the effects of antibiotics on the host and the environment, which would extend our understanding on the ecological outcomes caused by antibiotic pollution.

Pollution characterization of pharmaceutically active compounds (PhACs) in the northwest of Tai Lake Basin, China: Occurrence, temporal changes, riverine flux and risk assessment

PhACs have attracted great attentions of researchers because of their potential ecological and healthy risks. However, their long-term pollution tendency study is very scarce. In this study, 32 target PhACs from surface water, wastewater treatment plants, fishponds and livestock farms were investigated in Wujin, a city located in the northeast of Tai Lake, using grab sampling. The occurrence, spatiotemporal distribution characteristics, potential sources, riverine flux and risk assessment were systematically analyzed. It was found that non-antibiotics were the mainly PhACs category in Wujin and CF, SMX were the predominant non-antibiotics and antibiotics, respectively. Besides, the average concentrations of total PhACs were 586.6 ng L^-1 and 273.2 ng L^-1 in 2018 and 2019, respectively. This improvement could be mainly attributed to the closure of fishponds and livestock farms. Moreover, CF/CBZ ratios which was considered as an indicator to trace untreated wastewater decrease significantly in 2019, and this was also a main reason for the improvement. Riverine flux could be calculated through arranging control sampling sites in the boundary and the net riverine inflow flux of PhACs in Wujin was 264.3 kg/a. Finally, CF, SMX, EM were evaluated as the high risk contaminants based on a comprehensive risk assessment method.

Legacy and Emerging Pollutants in an Urban River Stretch and Effects on the Bacterioplankton Community

River contamination is due to a chemical mixture of point and diffuse pollution, which can compromise water quality. Polycyclic Aromatic Hydrocarbons (PAHs) and emerging compounds such as pharmaceuticals and antibiotics are frequently found in rivers flowing through big cities. This work evaluated the presence of fifteen priority PAHs, eight pharmaceuticals including the antibiotics ciprofloxacin (CIP) and sulfamethoxazole (SMX), together with their main antibiotic resistant genes (ARGs) and the structure of the natural bacterioplankton community, in an urbanized stretch of the river Danube. SMX and diclofenac were the most abundant chemicals found (up to 20 ng/L). ARGs were also found to be detected as ubiquitous contaminants. A principal component analysis of the overall microbiological and chemical data revealed which contaminants were correlated with the presence of certain bacterial groups. The highest concentrations of naphthalene were associated with Deltaproteobacteria and intI1 gene. Overall, the most contaminated site was inside the city and located immediately downstream of a wastewater treatment plant. However, both the sampling points before the river reached the city and in its southern suburban area were still affected by emerging and legacy contamination. The diffuse presence of antibiotics and ARGs causes particular concern because the river water is used for drinking purposes.

Distribution of pharmaceutical and personal care products (PPCPs) in aquatic environment in Hanoi and Metro Manila

Pharmaceutical and personal care products (PPCPs) recently defined as emerging pollutants that widespread in surface water all around the world. This study investigated the distribution, and ecological risk of PPCPs in urban rivers of Hanoi, Vietnam, and Metro Manila, the Philippines. Of the 56 investigated PPCPs, 48 and 33 compounds were detected in the river water in Hanoi and in Metro Manila, respectively. The individual PPCP concentrations ranged from a few ng L^-1 to thousands of ng L^-1_. The total concentration of PPCPs detected in water samples ranged from 7.5 to 20,789 ng L^-1 in Hanoi and 118 to 3,394 ng L^-1 in Manila. The predominant antibiotics was sulfamethoxazole detected in 27/28 samples with a maximum concentration up to 2,778 ng L^-1 in Hanoi and presented in all samples with a maximum concentration up to 261 ng L^-1 in Metro Manila. In Hanoi, the level of PPCPs in urban canals of Kim Nguu and To Lich Rivers was as high as that detected in domestic wastewater. The PPCP concentrations in tributaries and mainstream were lower than those found in urban canals. In rivers of both sites, PPCPs tended to increase along the stream. The concentration ratio of the labile marker caffeine to recalcitrant marker carbamazepine indicated that untreated domestic wastewater is the significant source of PPCPs in river water in Hanoi and Metro Manila. The ecological risk estimated by the risk quotient of the obtained maximum residue of PPCPs in investigated river water predicted a high risk of PPCPs to the aquatic organism in both Hanoi and Manila.

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.

Pollution characteristics and mixture risk prediction of phenolic environmental estrogens in rivers of the Beijing-Tianjin-Hebei urban agglomeration, China

Phenolic environmental estrogens (PEEs) are ubiquitous in most rivers worldwide and may cause potential endocrine-disrupting effects in aquatic organisms. Three typical PEEs (bisphenol A, BPA; 4-tert-octylphenol,4-t-OP; and nonylphenol, NP) were investigated in the rivers of the Beijing-Tianjin-Hebei urban agglomeration, which is the most urbanized and industrialized area in North China. The target PEEs were detected in 100% of river water samples, and the concentrations ranged from 23 to 255 ng L^-1. The concentrations of NP in most river sections were higher than those of BPA and 4-t-OP. The spatiotemporal variations in PEEs indicated that both domestic and industrial wastewater were main sources of PEEs in river water. In addition, rainfall runoff might be an important source of PEEs in the receiving waters, especially in the wet season. The ecotoxicological risk assessment of individual PEE revealed a moderate to high risk for aquatic organisms at most sampling sites. The mixture risk prediction based on the concentration addition method indicated a potential cumulative risk of PEEs in the study area, highlighting the importance of mixture risk assessment in the aquatic environment.

Environmental Risk Assessment of Active Human Pharmaceutical Ingredients in Urban Rivers in Japan

Active pharmaceutical ingredients (APIs) have become a public concern owing to their possible adverse effects on aquatic organisms. Ministry of Health, Labor and Welfare in Japan (MHLW) issued "Guidance on the Environmental Risk Assessment (ERA) in new pharmaceutical development" in 2016. To evaluate the validity of phase 1 in the MHLW's ERA guidance, we monitored the measured environmental concentrations (MECs) of approved APIs in urban rivers and sewage treatment plants (STPs) in Japan and compared these MECs with the predicted environmental concentration (PEC). We collected water samples from urban seven rivers and three STPs during each season. Fifty-one APIs for human and veterinary use and the artificial sweetener sucralose were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Forty-four APIs were observed in the rivers and 42 were found in the influent and effluent of STPs, with levels ranging from nanograms to micrograms per liter. The action limit in phase I of the MHLW's guidance was set to 10 ng/L, and there was no API except for ketoprofen, for which PEC of the MHLW's guidance (PECjapan) was lower than 10 ng/L and the maximum MEC (MECmax) was 10 ng/L or greater. Almost all APIs also had median MECs that were lower than those of the respective PECjapan. These results indicate that the PECjapan values in phase I of the MHLW's guidance were appropriate. However, some APIs had MECmax values that were greater than those of the respective PECjapan due to overestimation of the dilution factor of river water and/or underestimation of API production.

Manganese peroxidase mediated oxidation of sulfamethoxazole: Integrating the computational analysis to reveal the reaction kinetics, mechanistic insights, and oxidation pathway

In this study, manganese peroxidase (MnP) was applied to induce the in vitro oxidation of sulfamethoxazole (SMX). The results indicated that 87.04% of the SMX was transformed and followed first-order kinetics (k_obs=0.438 h^-1) within 6 h when 40 U L^-1 of MnP was added. The reaction kinetics were investigated under different conditions, including pH, MnP activity, and H₂O₂ concentration. The active species Mn³⁺ was responsible for the oxidation of SMX, and the Mn³⁺ production rate was monitored to reveal the interaction among MnP, Mn³⁺, and SMX. By integrating the characterizations analysis of the MnP/H₂O₂ system with the density functional theory (DFT) calculations, the proton-coupled electron transfer (PCET) process dominated the catalytic circle of MnP and the transformation of Mn³⁺. Additionally, possible oxidation pathways of SMX were proposed based on single-electron transfer mechanism, which primarily included the S-N bond cleavage, the C-S bond cleavage, and one electron loss without bond breakage. It was then transformed to hydrolysis, N-H oxidation, self-coupling, and carboxylic acid coupling products. This study provides insights into the atomic-level mechanism of MnP and the transformation pathways of sulfamethoxazole, which lays a significant foundation for the potential of MnP in wastewater treatment applications.

Seasonal occurrence and source analysis of pharmaceutically active compounds (PhACs) in aquatic environment in a small and medium-sized city, China

Pharmaceutically active compounds (PhACs) have been widely reported in most megacities in China but seldom in small and median-sized cities. The aim of this study is to investigate occurrence and distribution characteristics of PhACs in a typical small and medium-sized city in China and analyze their sources. 33 PhACs and 4 chiral drugs were selected for a four-season monitoring campaign in Wujin District, Jiangsu Province, a typical small and median-sized city, in 2018. PhACs concentration level in surface water, ranging from ng L^-1 to μg L^-1, was lower than in large-sized cities and areas in China. Impact from agricultural sources should be concerned in the study area: (1) Significant correlation between concentrations of antibiotics and NH₄-N in surface water indicated the potential impact from agricultural sources (fishponds and livestock farms); (2) Government regulating measures on livestock and poultry farms since January 2018 have effectively decreased macrolides and lincosamides emissions into surface water. As for source analysis, CF/CBZ (Caffeine/Carbamazepine) was a feasible indicator to trace untreated wastewater and enantiomeric fraction values of metoprolol (MTP) were also suggested to be helpful for identifying untreated wastewater. The results of both two indicators indicated more input of untreated wastewater to surface water in the northeast area and upstream of Wuyi Canal. To our best knowledge, this is the first study to systematically analyze PhACs in aquatic environment for a small and medium-sized city in China.

Intracellular organic matter from Chlorella vulgaris enhances the photodegradation of acetaminophen

Algae is able to accelerate the photodegradation rate of contaminants under sunlight irradiation, and this process can be attributed to algal substances, namely, intracellular organic matter (IOM) and extracellular organic matter (EOM). This study aimed to investigate the efficiencies and mechanisms of the photodegradation of three pharmaceuticals - acetaminophen (ACE), codeine (COD) and cephradine (CFD) - in the presence of Chlorella vulgaris and its algal substances. The result shows that a much higher photodegradation rate of acetaminophen was obtained in the presence of IOM (k_obs = 0.250 hr^-1) than in the presence of EOM (k_obs = 0.060 hr^-1). The photodegradation mechanisms of acetaminophen were demonstrated and verified by scavenger experiments and probe tests. The major reactive species for acetaminophen photodegradation was triplet-state IOM (³IOM∗), which contributed 93.52% of the photodegradation, while ⋅OH was the secondary contributor (5.60%), with ¹O₂ contributing the least (0.88%). Chlorella vulgaris also effectively enhanced the photodegradation of codeine and cephradine. However, the photodegradation behaviors of codeine and cephradine in the presence of algal substances were different from those of acetaminophen, indicating that the photodegradation mechanisms might depend on the type of compound. This study not only demonstrates the effectiveness of algal substances in the photodegradation of acetaminophen, codeine and cephradine under sunlight irradiation but also provides a comprehensive study on the photodegradation mechanisms of acetaminophen in the presence of algal substances.

A review of distribution and risk of pharmaceuticals and personal care products in the aquatic environment in China

Due to the extensive use and pseudo-persistence of pharmaceuticals and personal care products (PPCPs), they are frequently detected in the aqueous environment, which has attracted global attention. In this paper, accumulation data of 81 PPCPs in surface water or sediment in China were reported. In addition, 20 kinds of PPCPs with high frequency were selected and their ecological risk assessment was conducted by risk quotient (RQs). The results indicated that the concentration detected in surface water and sediment ranged from ng/L (ng/kg) to μg/L (μg/kg) in China, which was similar to concentrations reported globally. However, contamination by certain PPCPs, such as caffeine, oxytetracycline, and erythromycin, was relatively high with a maximum concentration of more than 2000 ng/L in surface water. RQs revealed that 14 kinds of PPCPs pose no significant risk or low risk to aquatic organisms, while 6 kinds of PPCPs pose a high risk. Additionally, the pollution characteristics of PPCPs in each watershed are different. The Haihe River watershed and the central and lower Yangtze River were the regions of high concern for erythromycin. Triclosan has potential risks in the Pearl River watershed. This study determined the occurrence and risk of PPCPs in China in the past decade, providing a scientific basis for PPCPs pollution control and risk prevention.

Occurrence and variations of pharmaceuticals and personal-care products in rural water bodies: A case study of the Taige Canal (2018-2019)

A systematic monitoring campaign of pharmaceuticals and personal-care products (PPCPs) was performed in the Taige Canal basin, which is located in a rural area of the Yangtze River Delta. A total of 55 out of 61 monitored PPCPs were detected, with concentrations up to 647 ng/L. The maximum concentrations of 75% of monitored antibiotics and 80% of non-antibiotics were above the median values of previously reported maximum concentrations in China, indicating that the basin is heavily contaminated. It is estimated that the PPCP mass flow of the Taige Canal (0.06-0.58 kg/day) entering into Lake Taihu is similar to that of the influent of a wastewater treatment plant. Analysis of the seasonal variation shows that, during the wet season, the average total concentration of sulfonamides was 8 and 11 times that of the normal season and dry season, respectively. The concentration of sulfachlorpyridazine accounted for 40.37% of total antibiotics, suggesting heavy pollution from the animal-breeding industry in this area. The PPCP mass flow rates observed in 2019 were lower than those of 2018 in the same season, and this interannual variation is mainly attributable to water pollution controls in the watershed. Combined analysis of ordination and clustering indicates that the distribution of PPCPs in the Taige Canal is affected by the confluence with Yong'an River and human activities such as water pollution control. Water-sediment distribution analysis demonstrates that the sediment-water distribution coefficients of quinolone and macrolide were higher than those of sulfonamide, lincosamide and chloramphenicol.

Contamination, source and potential risks of pharmaceuticals and personal products (PPCPs) in Baiyangdian Basin, an intensive human intervention area, China

The presence of pharmaceuticals and personal care products (PPCPs) has become a global concern, as it poses a threat to the environment, especially to the aquatic ecosystem. This study focused on 30 PPCPs found in the Baiyangdian basin of the Xiong'an New Area, in the core of Beijing-Tianjin-Hebei region, with intensive human interventions during two seasons. In general, 30 PPCPs were all frequently detected, ranging from 42.3 to 7710 ng/L in May and 48.9 to 1300 ng/L in November. Sulfamethoxazole, ofloxacin, anhydro-erythromycin, carbamazepine, caffeine, and were screened as the predominant PPCPs. The rivers input was an essential source of PPCPs. The source apportionment with a series of analytical methods revealed that domestic sewage was the primary source, and untreated water also crucial for PPCPs contamination. The risk assessment suggested carbamazepine, caffeine, ofloxacin, and anhydro-erythromycin exhibited relatively high ecological risks for protecting most species such as algae, fish, and flowers in the aquatic ecosystem, especially near the outlet of WWTPs. Thus, management strategies for such PPCPs will be needed. Intensive human interventions, including a prohibition of fish breeding, water diversion project, and wastewater treatment in villages, were having an effective role in alleviating PPCPs contamination.

The environmental risks of pharmaceuticals beyond traditional toxic effects: Chemical differences that can repel or entrap aquatic organisms

The aim of the present study was to assess the risks of four different pharmaceutical active compounds (PhACs; diazepam, metformin, omeprazole and simvastatin). Acute and chronic toxicities were studied using the bacterium Aliivibrio fischeri and the microalgae Pseudokirchneriella subcapitata; while the repellency and attractiveness were assessed by avoidance tests with juvenile Cypirinus carpio using a multi-compartmented exposure system. Omeprazole was found to be an acutely toxic drug (EC₅₀: 0.015 mg/L), while the other PhACs, except simvastatin, showed some chronic toxicity. Regarding avoidance, simvastatin and omeprazole induced an escape response for 50% of the fish population at 0.032 and 0.144 mg/L, respectively; contrarily, diazepam was attractive, even at lethal concentrations, representing a dangerous trap for organisms. The toxicity of the PhACs seemed not to be directly related to their repellency; and the mode of action seems to determine the repellency or attractiveness of the chemicals. Contamination by PhACs is of concern due to the environmental disturbance they might cause, either due to their acute and chronic toxicity (at the individual level), repellency (at the ecosystem level: loss of local biodiversity) or attraction to potentially lethal levels.

Multi-phase distribution, spatiotemporal variation and risk assessment of antibiotics in a typical urban-rural watershed

The widespread consumption and continuous discharge of antibiotics have threatened the ecological health of urban-rural watershed. In this study, multi-phase distribution, spatiotemporal variation and ecological risk of 18 antibiotics in rivers and lakes from Suzhou City were investigated based on urban-rural gradient. The total antibiotic concentration in surface water, suspended particulate matter (SPM) and sediments was 39.28-2578 ng/L, 6.16-171.09 ng/L and 12.67-2249 ng/g, respectively. High detection frequency (>76%) and concentration of antibiotics in multi-phase suggested universal pollution. Quinolones (QNs) and tetracycline (TCs) were the dominant antibiotics detected. The partitioning coefficient (K_P) value of SPM-water was 1.43-29.93 times larger than sediment-water, indicating that SPM can greatly affect the fate and distribution of antibiotics. Significant positive correlations between antibiotics and environmental parameters (e.g. TOC, TP and TN) revealed combined contamination and similar pollution sources. Antibiotic pollution exhibited evident spatiotemporal variation. For spatial variation, urban area showed more serious antibiotic pollution and greater ecological risk than rural and suburb areas, especially for sediments. Besides, antibiotic level and risk in rivers were higher than lakes. For seasonal variation, in case of surface water, rural area exhibited higher content in winter, while greater content was detected in autumn and spring in urban and suburb areas, respectively. The highest antibiotic content in SPM and sediments was all measured in winter owing to weak degradation ability. Ecological risk assessment based on risk quotients (RQs) indicated that norfloxacin (NFX), ciprofloxacin (CFX) and anhydroerythromycin (ETM-H₂O) in surface water presented medium to high risk throughout the entire year, while sulfadiazine (SDZ) and enrofloxacin (EFX) in sediments showed higher accumulation potential. Thus, these five antibiotics were selected as the priority antibiotics for pollution control. In short, this study improves the understanding of antibiotic fates in the urban-rural watershed and provides scientific basis for the authorities to regulate antibiotic pollution.

Enhanced micropollutants removal by nanofiltration and their environmental risks in wastewater reclamation: A pilot-scale study

The emerging contaminants, in particular pharmaceuticals and personal care products and environmental estrogens, have been received global concerns in recent years. Nanofiltration (NF) as an advanced tertiary treatment technology can be a reliable and potential tool for micropollutants removal. However, the influence of operation conditions of NF system to micropollutants rejections in an engineering application, is still lacking. Here, a pilot-scale NF system was set up to investigate its removal efficiencies to 49 micropollutants under different operation conditions by treating actual municipal wastewater. The results showed that the rejections of positively and neutrally charged micropollutants with molecular weight higher than 250 g mol^-1 were both higher than 80%. Besides, most negatively charged micropollutants were also rejected higher than 80% under different operation conditions. The rejections of most micropollutants increased with temperature decreased from 25 °C to 13 °C, which was primarily ascribed to decrease of pore size of NF membrane at low temperature. Compared with the water recovery rate of 80%, lower rejections of micropollutants were observed with lower water recovery rate of 60%. Except for sulfamethoxazole, the risk quotients of other detected 20 micropollutants in NF effluent were all lower than 1.0, showing medium or no risks to aquatic organisms. This study might aid understanding the performance of micropollutants rejections by NF in actual engineering application and could give guideline to the implementation of NF technology in future advanced treatment processes.

Evaluating surface water quality using water quality index in Beiyun River, China

The Beijing-Tianjin-Hebei urban agglomeration is one of the most water-scarce regions in China, because of the frequent human activities. Water scarcity and pollution have weakened the service functions of water ecosystems and hindered the regional economic development. As the "lifeline" of the economic development of Beijing-Tianjin-Hebei region, the water quality of Beiyun River has been widely concerned. River water quality assessment is one of the most important aspects to enhance water resources management plans. Water quality index (WQI), as one of the most frequently used evaluation tools, was used to comprehensively analyze the water quality in the Beiyun River. Between January 2017 and October 2018, we collected samples from 16 typical sampling sites along the main rivers of the watershed, covering four seasons. Seventeen water quality parameters, including temperature, pH, conductivity, dissolved oxygen (DO), chemical oxygen demand (COD), biochemical oxygen demand (BOD₅), ammonia nitrogen (NH₃-N), total phosphorus (TP), oil, volatile phenol (VP), fluoride, sulfide, surfactant, lead (Pb), copper (Cu), zinc (Zn), and arsenic (As), were used to calculate WQI. The average WQI values of Beiyun River in winter, spring, summer, and autumn were 88.15, 71.70, 78.92, and 90.12, respectively, explaining the water quality was "good" generally. There were significant differences in the spatial distribution of WQI values from Beiyun River, and water quality of upstream and downstream was better than that of midstream. In addition, correlation analysis was applied to explore the correlation between land use types and water quality. Water quality was significant negatively correlated with agriculture land and rural residential land, and a positive relationship between urban land and water quality. Generally, we believe that people's related activities on different land use are major elements impacting the water quality. Water environment improvement ought to increase the wastewater collection rate and sewage treatment capacity in rural areas, especially in the midstream of the Beiyun River. Graphical abstract.

Occurrence, spatiotemporal variation, and ecological risk of antibiotics in the water of the semi-enclosed urbanized Jiaozhou Bay in eastern China

The occurrence, temporal variation, and spatial variation of antibiotics in coastal bays and estuaries worldwide are not well documented or understood. Fifteen target antibiotics within the five classes of β-lactams, amphenicols, macrolides, fluoroquinolones, and sulfonamides were measured during the summer and winter in the water of Jiaozhou Bay in China, which is a semi-enclosed urbanized bay. Fourteen antibiotics (excluding tylosin) were detected, thus demonstrating the widespread occurrence of their residues in the bay. The total antibiotic concentration ranged from 71.8 ng L^-1 to 840 ng L^-1 for the estuarine water, which was significantly higher than that for the bay water (38.7-181 ng L^-1). The antibiotic classes in the bay water were dominated by fluoroquinolones and β-lactams, which accounted for nearly 90% of the total antibiotic concentration. In addition, amoxicillin contamination was the most prominent among the 14 detected antibiotics as it accounted for ~44% of the total antibiotic concentration. The concentrations of amoxicillin, leucomycin, enrofloxacin, and sulfamonomethoxine in the bay water were usually higher than those reported for coastal bays and estuaries worldwide. The average total antibiotic concentration in the bay water was 84.7 ng L^-1 during the summer, which was significantly lower than that during the winter (129.0 ng L^-1). This was mainly due to high dilution by runoff during the summer. The florfenicol concentration in the bay water was significantly higher during the summer than in winter due to its higher usage in aquaculture during the summer. Spatially, the total antibiotic concentration (both summer and winter) was higher in the water along the eastern coast of the bay, where the population and hospital densities are high. However, the sum of the veterinary antibiotic concentrations was higher in the northeastern aquaculture area of the bay during the summer. A risk assessment revealed that amoxicillin and enrofloxacin could pose high risks (risk quotient of > 1) to algae in the bay. The synergic effects of pharmaceutical mixtures and the bioaccumulation of antibiotics through the food web should be considered in future studies.