Priority screening of contaminant of emerging concern (CECs) in surface water from drinking water sources in the lower reaches of the Yangtze River based on exposure-activity ratios (EARs)

Magnetic relaxation switching sensor based on self-generated porous Fe3O4 with controllable apparent diffusion coefficient for highly sensitive detection of caffeine

Magnetic relaxation switch (MRS) sensors based on magnetic nanoparticles have received much attention in the field of environmental monitoring due to their rapid response and resistance to complex matrix interference. However, conventional MRS (cMRS) sensors constructed using magnetic nanoparticles have low sensitivity due to the lower relaxation rate of the magnetic probe. In this study, self-generated porous Fe3O4 were employed in the MRS sensors for detection of caffeine, and the regulation of transverse relaxation performance by porous structure has been explored. The abundant porous structure of self-generated porous Fe3O4 restricted the diffusion of the surrounding water molecules, and the controllable pore size can effectively adjust the apparent diffusion coefficient (ADC), as a result, improving the transverse relaxation properties. The developed MRS sensor exhibits a wide linear detection range from 0.5 to 100 ng/mL and a low limit of detection (LOD) of 0.047 ng/mL for caffeine. The LOD is 12 times lower than that of cMRS sensors. Consequently, the MRS sensor was further applied to the detection of caffeine in surface water samples. The results were consistent with those detected using high-performance liquid chromatography, demonstrating its superior anti-interference ability and the significant potential in environmental monitoring and food safety domains.

Spatial occurrence of emerging contaminants in rivers and wastewater. Analysis of environmental and human risks

This study assesses the occurrence of emerging contaminants (ECs) from agricultural and livestock production activities along the Salado River (Santa Fe province, Argentina). Of the 23 ECs studied, 8 were detected and quantified in river and wastewater samples, including ciprofloxacin, enrofloxacin, chlorpyrifos-methyl, albendazole, fenbendazole, levamisole, diazepam, and thiamethoxam. In river samples, the highest concentrations corresponded to ciprofloxacin, chlorpyrifos-methyl, and enrofloxacin. In wastewater samples, albendazole, fenbendazole, ciprofloxacin, enrofloxacin, and thiamethoxam were found. The detection frequency ranged from 4.2% to 54.2% in river samples and from 11.1% to 22.2% in wastewater samples. The spatial distribution of contaminants showed different concentrations, with higher levels often found near urban and agricultural areas, suggesting anthropogenic sources. Ecological risk assessments for different organisms were conducted. Ciprofloxacin posed the highest risk, especially affecting bacteria, cyanobacteria, and algae. Diazepam also was found to pose significant risks to algae, crustaceans, and fishes. Chlorpyrifos-methyl was identified as highly hazardous to multiple living organisms, which is in agreement with the fish mortality that occurred at the sampling sites. The risk assessment in humans showed differences among children, adolescents, and adults, with infants (6 months to 1 year) being at a higher risk than adults. Children may be at a higher daily intake of contaminants than adults, raising concerns about the long-term effects of exposure. This work underscores the critical need for monitoring and regulating ECs in aquatic environments. Further studies are necessary to fully understand their impact and to develop effective strategies for mitigating their presence in water systems.

Geospatial monitoring and human health risk assessment of pharmaceutical residues in groundwater and surface water in Kampala and Mbarara Districts, Uganda

This study investigated the occurrence, concentration and human health risks of five pharmaceutical residues-metronidazole, sulfamethoxazole, ciprofloxacin, carbamazepine, and caffeine-in groundwater and surface water samples from Kampala and Mbarara districts of Uganda. The present study also employed techniques of remote sensing and geographic information system (GIS); thereby, emphasizing the importance of thematic mapping, land use classification, and spatial buffering to evaluate pharmaceutical contaminants in an environmental setting. The risk quotient (RQ) approach was also employed to assess the risk of exposure to the pharmaceutical contaminants. Caffeine was found with the highest average concentration in groundwater (53.515 µg/L), whereas carbamazepine had the highest average concentration in surface water (48.635 µg/L) during the dry season. Ciprofloxacin consistently recorded the lowest average concentrations in both groundwater and surface water across all seasons. Overall, the data revealed high concentrations of pharmaceutical residues in surface water compared to groundwater during both seasons, except for caffeine which was not detected in surface water across the seasons. Notable seasonal changes were also observed in caffeine and metronidazole concentrations, indicating the role of human activities and environmental factors in influencing contamination patterns during specific seasons. The factor analysis revealed that consumption rate of pharmaceuticals and anthropogenic activities are the main factors responsible for the contamination of groundwater and surface water. Moreover, results revealed that the risk of adverse human health effects for carbamazepine and metronidazole during both seasons were high (RQ > 1), thereby highlighting the prioritization of frequent monitoring by the environmental protection agencies. Given that the combined risk of exposure for all the pharmaceuticals exceeded one, adopting stringent pharmaceutical disposal and control measures are essential for mitigating potential human health risks associated with their exposure. Further investigation into optimal and effective pharmaceutical remediation strategies for both groundwater and surface water are highly recommended.

Priority screening of contaminants of emerging concern (CECs) in surface water: Comparing cell-based bioassays and exposure-activity ratios (EARs)

In this study, we compared a wide range of cell-based bioassays to the use of chemical analysis followed by exposure-activity ratio (EAR) and Toxicological Prioritization index (ToxPi) for prioritizing chemicals, sites, and hazard concerns in water samples. Surface water samples were collected from nine sites in three Central Pennsylvania streams and analyzed for a forty-six contaminants of emerging concern (CECs), including pesticides, personal care products, and pharmaceuticals. Cell-based reporter assays evaluated human and zebrafish molecular initiating events (MIEs) in endocrine and metabolic disruption, altered lipid metabolism, and oxidative stress. Bioassays showed that 12 out of 40 assays had at least one site with activity over the effect-based trigger (EBT) values. The receptors that exhibited the highest number of samples above the EBT that would be expected to cause toxicity were Aryl hydrocarbon receptor (AhR, human and zebrafish), Pregnane X Receptor (PXR), Estrogen Receptor-beta (ERB), and Androgen Receptor (AR). Characterizing the collection sites by their bioactivity aligned closely with the stream in which samples were collected. The sum of all EARs for each chemical indicated that the pharmaceutical Carbamazepine and the pesticides Carbaryl and Atrazine posed the greatest concern. However, predicted activity and site prioritization based on individual chemical analysis and calculated EAR were different than those measured by bioassay, indicating that biologically active chemicals are present in the samples that were not included in the targeted analytes. Taken together, these data show that chemical analysis and EAR analysis are beneficial for prioritization of chemicals, whereas mechanism-based bioassays are more inclusive of known as well as unknown chemical contaminants and thus of more use for overall water quality analysis and site prioritization.

Occurrence, distribution, and fate evaluation of endocrine disrupting compounds in three wastewater treatment plants with different treatment technologies in Türkiye

Nowadays, two of the endocrine disrupting compounds (EDCs) in the group of alkylphenols (APs), nonylphenol (4-NP) and octylphenol (4-t-OP), have attracted great scientific and regulatory attention mainly due to concerns about their aquatic toxicity and endocrine disrupting activity. This paper investigated the occurrence, distribution behavior, fate, and removal of 4-NP and 4-t-OP in liquid and solid phases of three full-scale wastewater treatment plants (WWTPs) with different treatment technologies comparatively. In this context, (i) advanced biological WWTP, (ii) wastewater stabilization pond (WSP), and (iii) constructed wetland (CW) were utilized. In all three investigated WWTPs, the concentrations of 4-NP (219.9-19,354.4 ng/L) in raw wastewater were higher than those of 4-t-OP (13.9-2822.4 ng/L). Within the scope of annual average removal efficiencies, 4-NP was treated highly in advanced biological WWTP (93.5 %), while it was almost not treated in WSP (3.1 %) and treated with negative removal (<0 %) in CW. While 4-t-OP was treated at a similar removal rate (93.5 %) to 4-NP in advanced biological WWTP, it was treated moderately in WSP (52.5 %) and very poorly in CW (12.4 %). It has been determined that the most important removal mechanism of both 4-NP and 4-t-OP in WWTPs is biodegradation, followed by sorption onto sewage sludge. According to the mass balance performed in advanced biological WWTP, the biodegradation rates for 4-NP and 4-t-OP were found to be 70.4 % and 86.6 %, respectively, while the sorption onto sewage sludge were determined to be 23.3 % and 6.8 %. One of the critical findings obtained within the scope of the study is that while the concentrations of both metabolites, especially 4-NP, in wastewater and sewage sludge, decreased considerably under aerobic conditions, on the contrary, their concentrations increased significantly under anaerobic conditions. Both compounds were detected at higher concentrations in primary sludge compared to secondary sludge in advanced biological WWTP, while in WSP, they were determined at higher concentrations in anaerobic stabilization pond sludge compared to facultative stabilization pond sludge. Besides, it was also determined that the sorption behavior of these alkylphenols is much more dominant than desorption.

Occurrence of contaminants of emerging concern in surface and waste water from the Yangtze River chemical contiguous zone, China: Distribution, sources and ecological risk assessment

Limited knowledge exists regarding the occurrence, potential sources, and risks of contaminants of emerging concern (CECs) in surface and waste water from chemical contiguous zones. A total of 136 CECs were detected at 32 sampling sites along the Yangtze River, with concentrations ranging from 0.55 to 4.21 × 104 ng/L. Hydrocortisonacetate, cortisone, prednisone, enalapril and medroxyprogesterone were detected across all sampling sites. Hierarchical cluster analysis based on 47 core CECs yielded similar results compared with principal components analysis and identified two major clusters: wastewater sites and surface water sites. Distinct patterns of CECs were observed in wastewater from three industrial parks owing to variations in the industrial facilities and products within each park. Nineteen CECs were initially classified as presenting a high or medium risk to aquatic organisms. Further quantitative probabilistic risk assessment revealed that caffeine, trenbolone and norethindrone posed a threat to the most vulnerable aquatic species while high-risk sites mainly occurred downstream of the chemical industrial park. The joint ecological risk of high-risk CECs was evaluated using potentially affected fractions, which ranged from 0.44 % to 47.9 % with concentration addition and 0.33 % to 45.1 % with response addition. This suggests the need to consider the joint ecological risk of the detected compounds in future studies.

Applications of artificial intelligence for chemical analysis and monitoring of pharmaceutical and personal care products in water and wastewater: A review

Specifying and interpreting the occurrence of emerging pollutants is essential for assessing treatment processes and plants, conducting wastewater-based epidemiology, and advancing environmental toxicology research. In recent years, artificial intelligence (AI) has been increasingly applied to enhance chemical analysis and monitoring of contaminants in environmental water and wastewater. However, their specific roles targeting pharmaceuticals and personal care products (PPCPs) have not been reviewed sufficiently. This review aims to narrow the gap by highlighting, scoping, and discussing the incorporation of AI during the detection and quantification of PPCPs when utilising chemical analysis equipment and interpreting their monitoring data for the first time. In the chemical analysis of PPCPs, AI-assisted prediction of chromatographic retention times and collision cross-sections (CCS) in suspect and non-target screenings using high-resolution mass spectrometry (HRMS) enhances detection confidence, reduces analysis time, and lowers costs. AI also aids in interpreting spectroscopic analysis results. However, this approach still cannot be applied in all matrices, as it offers lower sensitivity than liquid chromatography coupled with tandem or HRMS. For the interpretation of monitoring of PPCPs, unsupervised AI methods have recently presented the capacity to survey regional or national community health and socioeconomic factors. Nevertheless, as a challenge, long-term monitoring data sources are not given in the literature, and more comparative AI studies are needed for both chemical analysis and monitoring. Finally, AI assistance anticipates more frequent applications of CCS prediction to enhance detection confidence and the use of AI methods in data processing for wastewater-based epidemiology and community health surveillance.

Spatiotemporal variations and priority ranking of emerging contaminants in nanwan reservoir: A case study from the agricultural region in huaihe river basin in China

The presence of emerging contaminants (ECs) in drinking water sources is an increasing concern, yet limited data exists on their occurrence and risk in the upper Huaihe River Basin, an important agricultural region in Central China. This study investigated 70 ECs, including pesticide and antibiotics in surface water from drinking water source areas in Nanwan Reservoir along the upper reaches of the Huaihe River Basin to prioritize the ECs based on ecological risk and health risk assessment. A total of 66 ECs were detected in the surface water at least once at the selected 38 sampling sites, with concentrations ranging from 0.04 to 2508 ng/L. Ecological risk assessment using the risk quotient (RQ) method revealed high risks (RQ > 1) from 7 ECs in the dry season and 15 ECs in the wet season, with triazine pesticides as the main contributors. Non-carcinogenic risks were below negligible levels, but carcinogenic risks from neonicotinoid and carbamate pesticides and macrolide antibiotics were concerning for teenagers. Ciprofloxacin exhibited a high level of resistance risk during the wet season. A multi-indicator prioritization approach integrating occurrence, risk, and chemical property data ranked 6 pesticides and 3 antibiotics as priority pollutants. The results highlight EC contamination of drinking water sources in this agriculturally-intensive region and the need for targeted monitoring and management to protect water quality.

Fingerprinting of emerging contaminants in L'Albufera natural park (Valencia, Spain): Implications for wetland ecosystem health

Wetlands are crucial ecosystems that are increasingly threatened by anthropogenic activities. L'Albufera Natural Park, the second-largest coastal wetland in Spain, faces significant pressures from surrounding agricultural lands, industrial activities, human settlements, and associated infrastructures, including treated wastewater inputs. This study aimed at (i) establishing pathways of emerging pollutants entering the natural wetland using both target and non-target screening (NTS) for management purposes, (ii) distinguishing specific contamination hotspots through Geographic Information System (GIS) and (iii) performing basic ecological risk assessment to evaluate ecosystem health. Two sampling campaigns were conducted in the spring and summer of 2019, coinciding with the start and end of the rice cultivation season, the region's primary agricultural activity. Each campaign involved the collection of 51 samples. High-resolution mass spectrometry (HRMS) was employed, using a simultaneous NTS approach with optimized gradients for pesticides and moderately polar compounds, along with complementary NTS methods for polar compounds, to identify additional contaminants of emerging concern (CECs). Quantitative analysis revealed that fungicides comprised a substantial portion of detected CECs, constituting approximately 50% of the total quantified pesticides. Tebuconazole emerged as the predominant fungicide, with the highest mean concentration (>16.9 μg L-1), followed by azoxystrobin and tricyclazole. NTS tentatively identified 16 pesticides, 43 pharmaceuticals and personal care products (PPCPs), 24 industrial compounds, and 12 other CECs with high confidence levels. Spatial distribution analysis demonstrated significant contamination predominantly in the southwestern region of the park, gradually diminishing towards the north-eastern outlet. The composition of contaminants varied between water and sediment samples, with pharmaceuticals predominating in water and industrial compounds in sediments. Risk assessment, evaluated through risk quotient calculations based on parent compound concentrations, revealed a decreasing trend towards the outlet, suggesting wetland degradation capacity. However, significant risk levels persist throughout much of the Natural Park, highlighting the urgent need for mitigation measures to safeguard the integrity of this vital ecosystem.

Quantitative Effects of Anthropogenic and Natural Factors on Heavy Metals Pollution and Spatial Distribution in Surface Drinking Water Sources in the Upper Huaihe River Basin in China

The water quality of sources in the Huaihe River Basin significantly affects the lives and health of approximately 16.7% of China's population. Identifying and quantifying pollution sources and risks is essential for effective water resource management. This study utilized Monte Carlo simulations and Geodetector to assess water quality and eutrophication, as well as to evaluate the sources of heavy metals and the associated health risks for both adults and children. The results showed that eutrophication of water sources in Huaihe River was severe, with an overall EI value of 37.92; 67.8% of the water sources were classified as mesotrophic and 32.2% classified as eutrophic. Water quality and eutrophication levels in the southern mountainous regions were better than those in the densely populated northern areas. Adults were found to have a higher carcinogenic risk than children, whereas children faced a higher noncarcinogenic risk than adults. Cr presented the highest carcinogenic risk, affecting more than 99.8% of both adults and children at levels above 1 × 10-6 but not exceeding 1 × 10-4. The noncarcinogenic risk from metals did not surpass a level of 1, except for Pb. As was primarily influenced by agricultural activities and transportation, whereas Cd, Cr, and Pb were mainly affected by industrial activities, particularly in local textile industries such as knitting and clothing manufacturing. The analysis demonstrated that the influence of anthropogenic factors on heavy metal distribution was significantly enhanced by indirect natural factors. For example, the explanatory power of Precipitation and Road Network Density on As was 0.362 and 0.189, respectively, whereas their interaction had an explanatory power as high as 0.673. This study indicates that the geodetector method is effective in elucidating the factors influencing heavy metal distribution in water, thereby providing valuable insights into pollution sources in global drinking water.

Health impact assessment of the surface water pollution in China

China suffers from severe surface water pollution. Health impact assessment could provide a novel and quantifiable metric for the health burden attributed to surface water pollution. This study establishes a health impact assessment method for surface water pollution based on classic frameworks, integrating the multi-pollutant city water quality index (CWQI), informative epidemiological findings, and benchmark public health information. A relative risk level assignment approach is proposed based on the CWQI, innovatively addressing the challenge in surface water-human exposure risk assessment. A case study assesses the surface water pollution-related health impact in 336 Chinese cities. The results show (1) between 2015 and 2022, total health impact decreased from 3980.42 thousand disability-adjusted life years (DALYs) (95 % Confidence Interval: 3242.67-4339.29) to 3260.10 thousand DALYs (95 % CI: 2475.88-3641.35), measured by total cancer. (2) The annual average health impacts of oesophageal, stomach, colorectal, gallbladder, and pancreatic cancers added up to 2621.20 thousand DALYs (95 % CI: 2095.58-3091.10), revealing the significant health impact of surface water pollution on digestive cancer. (3) In 2022, health impacts in the Beijing-Tianjin-Hebei and surroundings, the Yangtze River Delta, and the middle reaches of the Yangtze River added up to 1893.06 thousand DALYs (95 % CI: 1471.82-2097.88), showing a regional aggregating trend. (4) Surface water pollution control has been the primary driving factor to health impact improvement, contributing -3.49 % to the health impact change from 2015 to 2022. It is the first city-level health impact map for China's surface water pollution. The methods and findings will support the water management policymaking in China and other countries suffering from water pollution.

Research progress on the generation of NDMA by typical PPCPs in disinfection treatment of water environment in China: A review

The drugs and personal care products in water sources are potential threats to the ecological environment and drinking water quality. In recent years, the presence of PPCPs has been detected in multiple drinking water sources in China. PPCPs are usually stable and resistant to degradation in aquatic environments. During chlorination, chloramination, and ozonation disinfection processes, PPCPs can act as precursor substances to generate N-nitrosodimethylamine (NDMA) which is the most widely detected nitrosamine byproduct in drinking water. This review provides a comprehensive overview of the impact of PPCPs in China's water environment on the generation of NDMA during disinfection processes to better understand the correlation between PPCPs and NDMA generation. Chloramine is the most likely to form NDMA with different disinfection methods, so chloramine disinfection may be the main pathway for NDMA generation. Activated carbon adsorption and UV photolysis are widely used in the removal of NDMA and its precursor PPCPs, and biological treatment is found to be a low-cost and high removal rate method for controlling the generation of NDMA. However, there are still certain regional limitations in the investigation and research on PPCPs, and other nitrosamine by-products such as NMEA, NDEA and NDBA should also be studied to investigate the formation mechanism and removal methods.

Phenolic compounds in the freshwater environment in South Korea: Occurrence and tissue-specific distribution

In this study, we investigated the occurrence and distribution of phenolic compounds, including phenol, cresols, chlorophenols, nitrophenol, and bromophenols, in freshwater environments. We also focused on phenolic compounds in crucian carp (Carassius auratus) tissues, specifically the muscle, gills, brain, blood, liver, and gonads, to assess their potential bioaccumulation in fish and human health risks. Phenolic compounds were found to be widespread in various freshwater environments throughout South Korea. Phenol was predominant in all matrices, with median concentrations of 57.0 ng/L in freshwater, 54.3 ng/g dry weight (dw) in sediment, and ranging from 71 ng/g wet weight (ww) to 621 ng/g ww in crucian carp tissues. Cresols were the second most dominant compound, with m-cresol exhibiting the highest prevalence. Most of the compounds detected in crucian carp samples were also detected in freshwater and sediment, whereas pentachlorophenol and 2,4,6-tribromophenol were exclusively detected in crucian carp tissues. A high bioaccumulation potential in the liver was observed for most phenolic compounds [median log bioconcentration factor (BCF): 3.2-3.7]. Interestingly, only m-cresol showed high bioaccumulation potential in the gills (median log BCF: 3.1). The estimated daily intake of phenolic compounds suggested that it does not pose an immediate concern for human exposure owing to crucian carp consumption. These findings enhance our understanding of the exposure status, distribution, and bioaccumulation potency of phenolic compounds in aquatic ecosystems and emphasize the importance of ongoing monitoring and risk assessment efforts.

High resolution mass spectrometry (HRMS) determination of drugs in wastewater and wastewater based epidemiology in Cadiz Bay (Spain)

Multi-residue methods for the determination of the myriad of compounds of emerging concern (CECs) entering in the environment are key elements for further assessment on their distribution and fate. Here, we have developed an analytical protocol for the simultaneous analysis of 195 prescription, over-the-counter, and illicit drugs by using a combination of solid phase extraction (SPE) and determination by liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS). The method was applied to the analysis of influent sewage samples from 3 wastewater treatment plants (WWTPs) from Cadiz Bay (SW Spain), enabling the quantification of more than 100 pharmaceuticals, 19 of them at average concentrations higher than 1 μg L^-1, including caffeine (92 μg L^-1), paracetamol (72 μg L^-1), and ibuprofen (56 μg L^-1), as well as several illicit drugs (e.g., cocaine). Wastewater based epidemiology (WBE) was applied for 27 of the detected compounds to establish their consumption in the sampling area, which has been never attempted before. Caffeine, naproxen, and salicylic acid stood out because of their high consumption (638, 51, and 20 g d^-1·1000pop^-1, respectively). Regarding illicit drugs, cocaine showed the highest frequency of detection and we estimated an average consumption of 3683 mg d^-1·1000pop^-1 in Cadiz Bay. The combination of new HRMS methods, capable of discriminating thousands of chemicals, and WBE will allow for a more comprehensive characterization of chemical substances and their consumption in urban environments in the near future.