Seasonal dynamics, risk prioritization, and management implications for industrial chemicals, pesticides, and PPCPs in the Yangtze River Delta.

The rising detection of contaminants of emerging concern (CECs) in aquatic environments necessitates robust prioritization strategies to guide further testing and potential inclusion in monitoring programs. Existing CEC prioritization methods typically compare environmental concentrations to toxicity data (e.g., whole-organism or high-throughput assays) to identify "high-priority" chemicals, but integrating mechanistic insights into adverse effects remains limited. Here, a CEC prioritization framework which combined exposure-activity ratios (EARs) with adverse outcome pathways (AOPs) was developed and applied in the Yangtze River Basin in China. A total of 162 CECs across 9 categories in surface water samples from Yangtze River Basin were evaluated, and the most sensitive assay endpoints of these CECs were identified. Results showed that among all target CECs (nd-12,300 ng/L), 11 chemicals exhibited a 100% detection rate, with moclobemide (12,510 ng/L) and venlafaxine (12,300 ng/L) having the highest concentrations. Based on EAR and detection status, triisobutyl phosphate, aldicarb, methomyl, acetamiprid, perfluorodecanoic acid, nalidixic acid, and moclobemide were identified as "Level 1" priority chemicals. By linking high-exposure-activity ratio (high-EAR) molecular targets to validated AOPs, we connected analytical chemistry data with predictions of specific adverse outcomes, including endocrine-disruption-associated reproductive failure, porphyria-like metabolic disorders, and impairments in cognitive function and growth, which not only provide a mechanistic basis for analyzing the diverse biological effects induced by high-risk chemicals but also facilitate the screening-level prediction of potential associated ecological and human health risks.

Anthropogenic-induced ecological risks on marine ecosystems indicated by characterizing emerging pollutants in Pearl River Estuary, China

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

Comprehensive monitoring and prioritizing for contaminants of emerging concern in the Upper Yangtze River, China: An integrated approach

To better understand the composition of contaminants of emerging concern (CECs) in landfill leachate, fresh leachate from 19 landfills was sampled across the United States during 2011. The sampled network included 12 municipal and 7 private landfills with varying landfill waste compositions, geographic and climatic settings, ages of waste, waste loads, and leachate production. A total of 129 out of 202 CECs were detected during this study, including 62 prescription pharmaceuticals, 23 industrial chemicals, 18 nonprescription pharmaceuticals, 16 household chemicals, 6 steroid hormones, and 4 plant/animal sterols. CECs were detected in every leachate sample, with the total number of detected CECs in samples ranging from 6 to 82 (median = 31). Bisphenol A (BPA), cotinine, and N,N-diethyltoluamide (DEET) were the most frequently detected CECs, being found in 95% of the leachate samples, followed by lidocaine (89%) and camphor (84%). Other frequently detected CECs included benzophenone, naphthalene, and amphetamine, each detected in 79% of the leachate samples. CEC concentrations spanned six orders of magnitude, ranging from ng L(-1) to mg L(-1). Industrial and household chemicals were measured in the greatest concentrations, composing more than 82% of the total measured CEC concentrations. Maximum concentrations for three household and industrial chemicals, para-cresol (7 020 000 ng L(-1)), BPA (6 380 000 ng L(-1)), and phenol (1 550 000 ng L(-1)), were the largest measured, with these CECs composing 70% of the total measured CEC concentrations. Nonprescription pharmaceuticals represented 12%, plant/animal sterols 4%, prescription pharmaceuticals 1%, and steroid hormones <1% of the total measured CEC concentrations. Leachate from landfills in areas receiving greater amounts of precipitation had greater frequencies of CEC detections and concentrations in leachate than landfills receiving less precipitation.

Contaminants of emerging concern (CECs) is one of several reasons for the deterioration of surface water quality globally, even though the CECs occur in trace concentrations. This thesis produced new CEC data through a oneyear field study for substances which occur in Sweden’s three largest lakes and their associated rivers. The purpose was to investigate mass flows and seasonal variations of CECs, as well as estimate the potential ecotoxicological hazard posed by the CECs’ occurrence. It was found that numerous CECs occurred in all examined rivers, and that a continuous influx of CECs with suspected hazardous properties into the lakes occurred. Total mass loads of the investigated CECs were estimated from 0.51 to 5.6 kg/day in the influx to the lakes, and from 0.12 to 4.3 kg/day in the outflux from the lakes. Seasonal variations were observed in the aquatic environment for both individual and groups of CECs. This could be due to variations in consumption and environmental conditions. Some of the seasonal variations were being reported for the first time in the academic literature. Many of the CECs were suspected to have the combination of the hazardous properties of persistency, mobility, and toxicity (PMT). Of the 71 CECs detected far from any suspected input into the lakes, 20 had previously been suspected of having PMT properties. Within the remaining 51 CECs, multiple others also had suspected PMT properties. The thesis suggests that CECs with suspected PMT properties should be analysed closer with respect to these properties.

Reuse of treated wastewater is necessary to address water shortages in a changing climate. Sustainability of wastewater reuse requires reducing the environmental impacts of contaminants of emerging concern (CECs), but it is being questioned as CECs are not regulated in the assessment of effluent water quality for reuse both nationally in Sweden and at the broader European Union level. There is also a lack of details in this topic on which CECs to be addressed and methodologies to be used for assessing their environmental impacts. A better understanding of the ecological risks and health hazards of CECs associated with wastewater reuse will assist in the development of effective regulations on water reuse, (inter)nationally, as well as related treatment/monitoring guidelines. This review provides a list of specific chemical CECs that hinder sustainable wastewater reuse, and also demonstrates a holistic quantitative methodology for assessing, scoring and prioritizing their associated ecological risks and health hazards posed to the environment and humans. To achieve this, we compile information and concentrations of a wide range of CECs (∼15 000 data entries) identified in Swedish effluent wastewater from domestic (blackwater, greywater, mixture of both) and municipal settings, and further perform a meta-analysis of their potentials for 14 risk and hazard features, consisting of ecological risk, environmental hazard, and human health hazard. The features are then scored against defined criteria including guideline values, followed by score ranking for prioritization. This finally produces a unique list of chemical CECs from high to low priority based on risk- and hazard-evaluations. Out of the priority chemicals, 30, mainly pharmaceuticals, had risk quotient ≥ 1, indicating ecological risk, 16 had environmental hazard being persistent and mobile, and around 60 resulted in positive predictions for at least four human health hazards (particularly skin sensitization, developmental toxicity, hepatoxicity, and carcinogenicity). The 10 highest-priority chemicals (final score 2.3–3.0 out of 4.0) were venlafaxine, bicalutamide, desvenlafaxine, diclofenac, amoxicillin, clarithromycin, diethyltoluamide, genistein, azithromycin, and fexofenadine. Potential crop exposure to selected chemicals following one year of wastewater reuse for agricultural irrigation was also estimated, resulting in a range of 0.04 ng/kg (fluoxetine) to 1160 ng/kg (carbamazepine). Overall, our work will help focus efforts and costs on the critical chemicals in future (waste)water-related studies, such as, to evaluate removal efficiency of advanced treatment technologies and to study upstream source tracing (polluter-pays principle), and also in supporting policymakers to better regulate CECs for sustainable wastewater reuse in the future.

Ecological and human health risk of sulfonamides in surface water and groundwater of Huixian karst wetland in Guilin, China

Contaminants of emerging concern (CECs) are a concern in aquatic environments due to possible adverse effects on the environment and humans. This study assessed the occurrence and mass flows of CECs in Sweden's three largest lakes and 24 associated rivers. The occurrence and distribution of 105 CECs was investigated, comprising 71 pharmaceuticals, 13 perfluoroalkyl substances (PFASs), eight industrial chemicals, four personal care products (PCPs), three parabens, two pesticides, and four other CECs (mostly anthropogenic markers). This is the first systematic study of CECs in Sweden's main lakes and one of the first to report environmental concentrations of the industrial chemicals tributyl citrate acetate and 2,2′-dimorpholinyldiethyl-ether. The ∑CEC concentration was generally higher in river water (31–5200 ng/L; median 440 ng/L) than in lake water (36–900 ng/L; median 190 ng/L). At urban lake sites, seasonal variations were observed for PCPs and parabens, and also for antihistamines, antidiabetics, antineoplastic agents, antibiotics, and fungicides. The median mass CEC load in river water was 180 g/day (range 4.0–4300 g/day), with a total mass load of 5000 g/day to Lake Vänern, 510 g/day to Lake Vättern, and 5600 g/day to Lake Mälaren. All three lakes are used as drinking water reservoirs, so further investigations of the impact of CECs on the ecosystem and human health are needed.

There are potentially many thousands of municipally derived contaminants of emerging concern (CECs) present in discharged wastewaters that may cause adverse effects in receiving aquatic environments. Wastewater authorities, therefore, may face the momentous task of investigating these compounds with little or no prior CEC data for their sewage treatment plants (STPs). Such is the case for the Cleveland Bay Sewage Treatment Plant (CBSTP). To evaluate the potential environmental risk posed by municipal CECs, it is first necessary to understand which CECs are present in discharging wastewater, how they will be sampled and quantified, and which CECs are the most concerning regarding ecological risk. A Sampling Analysis and Quality Plan (SAQP) is a valuable tool that can be used to critically review and detail the strategy that will be adopted to achieve these outcomes. As such, this paper describes the development of a SAQP for screening wastewaters released from the CBSTP into Cleveland Bay as part of a preliminary CEC assessment. This paper describes the qualitative decision-making process employed to shortlist CECs into those perceived to pose the greatest ecological risk. In addition, the rationale and methods adopted to determine sampling locations and frequency are described.

Soil self-cleaning capacity: Removal of organic compounds during sub-surface irrigation with sewage effluent

Non-target screening of emerging contaminants in tropical island rivers: A case study of the Nandu River.

Advances in many analytical techniques allow the detection of compounds in water at very low concentrations (ng/L), which has facilitated the identification of many compounds in drinking water that went previously undetected. Some of these compounds are contaminants of emerging concern (CECs), which is broadly defined as any chemical or microorganism that is not currently being routinely monitored but has recently been identified as being present in the environment, and that may pose health or ecological risks. CECs can include pharmaceuticals, personal health care products and pesticides. Some CECs can act as endocrine disruptors, interfering with the normal functioning of the human endocrine system, potentially influencing foetal and child development. Although the level of many of these compounds are orders of magnitude below known acute toxicity levels, the health impact of long term exposure at low levels is mostly unknown. In this study, we present the results of a national survey over four seasons of potential CECs in the drinking water of major South African cities. The contaminants most often detected were the related herbicides atrazine and terbuthylazine, and the anticonvulsant and mood-stabilising drug, carbamazepine. The levels of these CECs were well below maximum levels proposed by the World Health Organization and the US Environmental Protection Agency. However, the range of CECs detected in drinking water, and seasonal and geographic variability in CECs levels, warrant a more frequent screening programme.

Occurrence, distribution, and seasonality of emerging contaminants in urban watersheds

This study investigates the occurrence, seasonal trends, and mass fluxes of 19 contaminants of emerging concern (CECs) in influents and effluents from four wastewater treatment plants (WWTPs) in Australia. A total of 352 triplicate 24-h composite samples were collected over seven days during autumn (May 2023) and spring (November 2023) and analysed using solid-phase extraction and LC-MS/MS. All CECs were detected in influents with >73% frequency, while detection in effluents was lower, indicating partial removal. Acetaminophen (1,610-26,600ng/L) and caffeine (716-9,720ng/L) were the most abundant in influent, irrespective of WWTP or season. Spatial and seasonal variations were evident; analgesics (codeine) and antibiotics (ofloxacin, sulfamethoxazole, trimethoprim) were higher in autumn, while psychiatric drugs (citalopram, desvenlafaxine) and DEET peaked in spring. Weekly trends revealed significant fluctuations (p<0.05) in ten compounds, with caffeine peaking midweek, while pharmaceuticals (fluoxetine, venlafaxine, sulfamethoxazole), pesticides (atrazine, piperonyl butoxide), and industrial chemicals (BBP, TCEP) peaked on Sundays. Removal efficiencies (RE) varied widely, from complete removal to elevated effluent levels for certain herbicides and psychiatric drugs. One WWTP consistently achieved >85% RE for most CECs. Risk Quotient assessment indicated low acute risks to algae and invertebrates, but moderate to high chronic risks to fish from venlafaxine, fluoxetine, citalopram, and carbamazepine (90th percentile). Median concentrations showed reduced risks, except for carbamazepine at W2. Invertebrates faced moderate chronic risks from acetaminophen and sulfamethoxazole. This assessment did not account for dilution in receiving waters and considered both peak and typical exposure levels.