Water Quality Criteria Research Articles

Progressive improvement of the water quality criteria of Lake Manzala, Egypt

Progressive improvement of the water quality criteria of Lake Manzala, Egypt

Impacts of urbanization on chloride and stream invertebrates: A 10-year citizen science field study of road salt in stormwater runoff.

The use of deicing agents during the winter months is one of many stressors that impact stream ecosystems in urban and urbanizing watersheds. In this study, a long-term data set collected by citizen scientists with the Missouri Stream Team was used to evaluate the relationships between watershed urbanization metrics and chloride metrics. Further, these data were used to explore the effects of elevated chloride concentrations on stream invertebrate communities using quantile regression. While the amount of road surface in a watershed was a dominant factor in predicting the maximum chloride measurement, the median chloride concentration was also strongly related to the amount of medium-to-high density development in the watershed, suggesting that nonmunicipal salt use is an important contributor to increases in base flow chloride concentrations. Additionally, chloride concentration appears to be one of the many factors that impact invertebrate density and diversity measurements, with decreases in invertebrate diversity corresponding with the US Environmental Protection Agency water quality criteria. Our findings suggest that the use of chloride-based road salt on municipal roads as well as on nonmunicipal settings is contributing to a loss of diversity and density of aquatic invertebrate communities in urban regions. Integr Environ Assess Manag 2022;18:1667-1677. © 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Evaluation of biological wastewater treatment in stabilization lagoons from Punta Carnero, Salinas – Ecuador

This research evaluated the wastewater treatment system of the Punta Carnero sector, in relation to pollutant efficiency load removal, final effluent quality and impact on the ecosystem, and finally to determine if the final discharge can be reused for agricultural irrigation. The research was based on the affluent and effluent characterization of the system, carried out in three phases: i) Taking of simple samples, analyzed in an accredited water laboratory and analysis of the contaminant loads efficiency; ii) Review of results compared to the Table of “Discharge limits to a freshwater receiving body”; iii) Examination of results based on the “Water Quality Criteria for Agricultural Irrigation” Table of the Ecuadorian regulation TULSMA (2015). BOD (62.42%), COD (62.41%) and FC (53.58%) removal efficiencies did not comply with current Ecuadorian regulations. The quality of the effluent with respect to the parameters evaluated for discharges to a freshwater receiving body denoted a non-optimal quality of final discharge, negatively impacting the ecosystem. Finally, the evaluation determined parameters that exceed the water quality criteria for agricultural irrigation allowed: Oils-Fats (5.65 mg/l), FC (62,900 NMP/100ml), Hg (0.00141 mg/l), OD (8.86 mg/l). After evaluating the wastewater treatment system, it was determined that the pollutant load removal efficiency and effluent quality is not optimal for discharge into a receiving water body, so it’s not suitable for reuse in agricultural irrigation.
 Keywords: affluent, effluent, water quality.

Reclaimed water reuse system on water quality, growth of irrigated crops, and impact of ecology: case study in Taiwan.

In rapidly urbanized regions, the development of sustainable and resilient urban agriculture is essential to reduce environmental pollution and ensure reusable resources. The purpose of this study was to design, implement, and analyze the effects of reclaimed water reuse systems on crop growth, water purification, and ecology. A simulated experimental field near the side of Li Tse Lake at MingDao University in Changhua County, Taiwan, was chosen as the research field. A reclaimed water reuse system was established to collect domestic sewage discharged from the student dormitory, and a soil filter bed and plants in the system were used to purify the sewage, so as to detect its effects on water quality, soil, plant growth, and ecology throughout the year. According to the results, the water purified by the reclaimed water reuse system met the agricultural irrigation water quality criteria. While the soil filter bed showed that the purified water was alkaline and had low electrical conductivity, this did not affect plant growth. In the reclaimed water reuse system, the cultivation of fruiting and leafy vegetables increased the habitats of a number of organisms, and a total of 49 families of arthropods in 13 orders were found. This study showed that the reclaimed water reuse system could not only purify water and promote water reuse but also improve the ecology and develop the potential for food production.

Principles and Technical Application of Mixing Zones for Wastewater Discharges to Freshwater and Marine Environments

A discharge mixing zone (DMZ) is a defined geographical area or volume of water in the receiving environment of a discharge where initial dilution of the effluent occurs and where exceedance of water quality criteria may be permitted. DMZs are essential to inform determination of discharge consent conditions and an important element of risk management frameworks to reduce any effects of the discharges on the environment and human health. In this review, we describe the principles and technical application of DMZs. We present an overview of the physical processes that govern the dispersion and dilution of wastewater discharges and the fate of contaminants in coastal environments and define key criteria for determining the size of DMZs. We summarize DMZ requirements in international legislation and guidance and exemplify their application to different types of discharges by means of case studies. The selected case studies illustrate different modelling tools for defining DMZs and different monitoring approaches to assess their effectiveness in achieving ecological and human health objectives.

From speciation to toxicity: Using a “Two-in-One” whole-cell bioreporter approach to assess harmful effects of Cd and Pb

Due to the sheer number of contaminated sites, bioavailability-based measurement and modeling of toxicity is used to triage response; despite advances, both remain relatively cumbersome. Cadmium (Cd) and lead (Pb) are two of the most toxic and globally prevalent pollutants, disproportionately impacting disadvantaged communities. Here we demonstrate the use of high throughput lights-on bioreporter technology to measure both speciation and toxicity. The organism's response is fit-for-purpose to parameterize the Biotic Ligand Model used in risk assessment of aquatic ecotoxicity and setting environmental Water Quality Criteria. Toxicity endpoints for analogous Cd and Pb models reported in literature average 71st and 44th rank-percentile sensitivity of Genus Mean Acute Values for acute toxicity (i.e., insensitive) in comparison to the bioreporter, the unique dual-mode measurement ability of which can predict toxicity endpoints from below the 5th percentile up to the 50th rank-percentile. These results are extensible to other reporters, paving the way to cost-efficient environmental risk assessment of aquatic ecotoxicity for a wide range of priority toxic pollutants.

A basis water quality monitoring plan for rehabilitation and protection

BACKGROUND AND OBJECTIVES: Safeguarding water resources became a major concern in many parts of the world as it aims to provide safe and healthy water for humans. Water quality monitoring is a popular tool in ensuring water quality is safe and within the allowable limits and standards for the health of the community. To provide interventions and strategies for the rehabilitation, a water quality monitoring plan was conducted to describe the water quality and the classification of the river.METHODS: This study conducted an environmental analysis to determine existing conditions and processes in the surrounding environment such as the land use, drainage pattern, reconnaissance survey of the river, and a key interview to describe the barangay profile and the community's water use and practices. The water quality monitoring covers the evaluation of ten water quality parameters: temperature, pH, dissolved oxygen, total dissolved solids, total suspended solids, phosphate, nitrate, oil and grease, chloride, and E. coli.FINDINGS: Results of the study presents the water quality against the ten water quality criteria. Phosphate measured on four stations ranges between 2.40-4.50 mg/L exceeding the allowable 0.50mg/L; the oil and grease exceeds the standards 2 mg/L with measured values of 2.40-4.60 mg/L in stations 2, 3, and 4; while measured chloride in all stations prove that the water is salty with values exceeding the freshwater requirement of 250mg/L; and the measured TSS in stations 2, 3 and 4 ranges from 32.30 to 49.3 mg/L exceeds the standards of 30mg/L. E. coli was also detected in water samples collected in all sampling stations. The computed water quality index of 39.02 described water as poor, always impaired, and threatened by the surrounding environment. CONCLUSION: The measured concentrations for phosphate, oil/ grease, chloride, and TSS exceeds the water quality requirement suggesting that the water is contaminated. The E. coli detected in all water samples, further recommends prohibition of recreational activities to avoid accidental intakes and skin contact on the polluted water. The existing activities in the surrounding residential, commercial and agricultural areas contributed to water contamination as aggravated by the unreliable drainage system, absence of proper sanitation facilities, and collection and disposal behavior of the community. From this, a scientific basis can be drawn on how the river can be rehabilitated and protected and serve as guide for policymakers and water managers on implementing strategies to achieve sustainable water resources.

Classic indicators and diel dissolved oxygen versus trend analysis in assessing eutrophication of potable-water reservoirs.

Potable source-water reservoirs are the main water supplies in many urbanizing regions, yet their long-term responses to cultural eutrophication are poorly documented in comparison with natural lakes, creating major management uncertainties. Here, long-term discrete data (June 2006-June 2018) for classical eutrophication water quality indicators, continuous depth-profile data for dissolved oxygen (DO), and an enhanced hybrid statistical trend analysis model were used to evaluate the eutrophication status of a potable source-water reservoir. Based on classical indicators (nitrogen, N and phosphorus, P concentrations and ratios; phytoplankton biomass as chlorophyll a, chl a; and trophic state indices), the reservoir was eutrophic to hypereutrophic and stoichiometrically imbalanced. Anoxia/hypoxia occurred for 7-8months annually systemwide, even throughout the water column for days to weeks in some years; and elevated total ammonia (up to ~900 μg tNH3 L-1 ) in surface waters from late summer/fall through late winter/early spring suggested substantial internal legacy nutrient loading. These surprising DO and tNH3 phenomena may characterize many reservoirs in urbanizing areas, and the associated cascade of negative impacts may increasingly affect them under global warming. Total organic carbon (TOC), seasonally influenced by phytoplankton biomass, commonly exceeded 6mg L-1 , which is problematic for potable-water treatment, and significantly trended up over time. Wet-year inflow dilution influenced an apparent decreasing trend in nutrients within the hypereutrophic upper reservoir, which receives most tributary inputs. Nevertheless, significant reservoirwide trends (increasing total phosphorus [TP], phytoplankton chl a, TOC) and mid- and/or lower region trends (increasing total nitrogen [TN], tNH3 , decreasing TN:TP ratios) suggest that water quality degradation from eutrophication has worsened over time. These findings support broadly applicable recommendations to strengthen protection of potable source-water reservoirs in urbanizing watersheds: (1) protective numeric water quality criteria are needed for TOC as well as TN, TP, and chl a; (2) continuous diel data capture more realistic DO conditions than traditional sampling, and can provide important insights for water treatment managers; and (3) assessment of reservoir eutrophication status to track management progress over time should emphasize classic indicators equally as statistical trends, which are highly sensitive to short-term meteorological forcing.

Assessment of ground water from some agrarian communities of South Eastern Nigeria

ABSTRACT Drinking water samples were collected from natural sources (groundwater and surface water) in rural villages in southeastern Nigeria, and the results were compared to WHO and Nigerian drinking water quality criteria. To meet the study’s goal, 21 drinking water samples were collected from sparsely populated rural settlements in Ebonyi State (Ugwulangu, Okposi, and Uburu). pH, temperature, turbidity, conductivity, salinity, total dissolved solids, total hardness, alkalinity, chlorides, nitrates, sulphates, phosphates, and metals were all measured in the water samples. This study looked at eight metals: Ca, Mg, Fe, Zn, Pb, Cr, Mn, and Ni. Except for turbidity, conductivity, alkalinity, Pb, and Ni, all metrics were found to be within allowed ranges. The metal concentrations followed the order: Ca > Mg > Pb > Fe > Zn > Ni > Mn > Cr. Metal index, degree of contamination, and hazard index were all calculated using the metal concentrations. The metal index and degree of contamination results showed that the water sources were safe to drink. The hazard index assessed children’s and adults’ chronic risk levels. By ingesting metals in water samples, the Hazard Index assessed the risk that users of water are prone to. Children are more at risk than adults from drinking untreated water from Ugwulangu, Okposi, and Uburu, according to the findings of a hazard index study. To safeguard children’s health, it is strongly advised that they be provided with alternative drinking water.

General Challenges and Recommendations for the Water Quality Criteria of Endocrine Disrupting Chemicals (EDCs).

Water quality criteria (WQC) play an important role in the environmental management of pollutants in different countries or institutions. It has been found that endocrine disrupting chemicals (EDCs) can potentially alter functions of the endocrine system and consequently cause adverse effects in aquatic organisms. Therefore, the complicated modes of action and mechanisms of EDCs should be carefully considered in WQC studies. For example, the research regarding the WQC derivation of EDCs should prioritize sensitive aquatic species in consideration of the WQC derivation. Second, the chronic toxicity of EDCs should be of utmost concern. In addition, the appropriate effects and endpoints of EDCs should be carefully selected for the WQC derivation. Moreover, it was pointed out that some new methods should be taken into consideration in the WQC studies of EDCs in the near future.

Assessment of the ecological state of the littoral zone of Lake Ladoga by the results of expedition research in 2019

Due to the fact that zones of ecological risk have appeared in Lake Ladoga since the increase in anthropogenic pressure in the 1970s, monitoring studies are currently needed to assess the ecological state of the littoral zone as the one that takes on the main anthropogenic load. The aim of the work was to assess the current ecological state of the waters in the littoral zone of Lake Ladoga in terms of toxicological and hydrochemical characteristics, and indicators of phytoplankton development, and to identify the most problematic zones of deterioration in water quality as a habitat for aquatic organisms. To assess the ecological state of the littoral zone, we used the following water quality criteria for water bodies of fishery importance: maximum permissible concentrations of heavy metals, petroleum hydrocarbons, pH, redox potential, indicators of phytoplankton development, trophic level, and toxicity indicators. It is shown that the areas of the most pressing environmental risk, as determined by the selected criteria, currently are: in the northern region – water areas near Impilahti Bay, Cape Umoppiumi, Kojonsaari, and Putsaari Islands; among eastern coast water – Uksunlahti Bay and Andrusovskaya Bay; among waters in the southern region – Volkhov Bay; among western coast waters – Taipolovsky Bay, Dalyokaya Bay, and Shchuchiy Bay. These water areas should be mandatory observation areas within the environmental monitoring system of Lake Ladoga with annual monitoring of toxicological, hydrochemical, and hydrobiological parameters. Considering the trophic scales used, the littoral zone of the western and southern regions of Lake Ladoga in 2019 can be characterized as weakly mesotrophic, the area along the eastern coast as mesotrophic-eutrophic, and the northern skerries region as mesotrophic. In general, according to the data obtained, the ecological state of the littoral zone of Lake Ladoga in 2019 can be said to have improved since 13 years ago (in 2006)

Development of optimal water distribution system design and operation approach considering hydraulic and water quality criteria in many-objective optimization framework

Abstract Water distribution systems (WDSs) are major infrastructure, and it needs to consider economic, hydraulic stability, and water quality safety to optimal design and operation of WDSs. However, the previous studies related to WDS design and operation were focused on each field (i.e. design: optimal pipe diameter, pump sizing, and valve location; operation: optimal pump scheduling, etc.) even though the WDS design and operation have a correlation. Therefore, to achieve economic feasibility, hydraulic stability, and water quality safety under WDS design and operation process, this study develops an optimal WDS design and operation approach considering hydraulic and water quality criteria in the many-objective optimization framework. To consider design and operation, this study applies three objective functions to minimize the total design and operation cost (i.e. the pipe cost, pump construction, and pump operation cost), maximize system robustness, and minimize the amount of chlorine requisition simultaneously under the hydraulic and quality constraints. The proposed optimal WDS design and operation model was applied to the two-stage optimization procedures. The first process determined the optimal pipe diameter set. The second process determined the optimal pump construction and scheduling considering three objective functions such as the total pump cost, the system robustness, and the quantity of the required residual chlorine for determining optimally the available number of pumps, capacity, and scheduling. For the optimization, the self-adaptive multi-objective harmony search is used and a famous benchmark network for the optimal design and pump operation of WDSs is applied to verify the proposed approach. This study can provide a new perspective on WDS design and operation technique considering the essential design factors to the water utility.

Stream Mesocosm Experiments Show no Protective Effects of Calcium on Copper Toxicity to Macroinvertebrates.

Although the concept and modeling of metal bioavailability and toxicity have been well developed based largely on laboratory experiments with standard test species, additional evidence is required to demonstrate their applicability for macroinvertebrates typically found in natural lotic ecosystems. We conducted 10‐day stream mesocosm experiments to test the hypothesis that increased water hardness (in the present study, the calcium [Ca] concentration was increased by adding CaCl2) would mitigate the effects of copper (Cu) on natural benthic macroinvertebrate communities. Exposure of macroinvertebrate communities to 25 μg/L Cu for 10 days in stream mesocosm experiments resulted in significant decreases in total abundance, in number of taxa, and in abundance of many macroinvertebrate taxa. However, the addition of Ca to stream mesocosms and the associated increase in water hardness up to 250 mg/L CaCO3 did not mitigate these effects of Cu on macroinvertebrate communities. The results showed that the hardness‐based water quality criteria for Cu of the US Environmental Protection Agency were not protective under the conditions of relatively high hardness, low alkalinity, and circumneutral pH. In contrast, the water quality criteria based on the biotic ligand model predicted little protective effects of Ca on Cu toxicity, which is consistent with our results. Additional experiments are required to understand the influence of modifying factors on the toxicity of metals to macroinvertebrate communities. Environ Toxicol Chem 2022;41:1304–1310. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Prediction of irrigation water quality indices based on machine learning and regression models

Assessing irrigation water quality is one of the most critical challenges in improving water resource management strategies. The objective of this work was to predict the irrigation water quality index of the Bahr El-Baqr, Egypt, based on non-expensive approaches that requires simple parameters. To achieve this goal, three artificial intelligence (AI) models (Support vector machine, SVM; extreme gradient boosting, XGB; Random Forest, RF) and four multiple regression models (Stepwise Regression, SW; Principal Components Regression, PCR; Partial least squares regression, PLS; Ordinary least squares regression, OLS) were applied and validated for predicting six irrigation water quality criteria (soluble sodium percentage, SSP; sodium adsorption ratio, SAR; residual sodium carbonate, RSC; potential of salinity, PS; permeability index, PI; Kelly’s ratio, KR). Electrical conductivity (EC), sodium (Na+), calcium (Ca2+) and bicarbonate (HCO3−) were used as input exploratory variables for the models. The results indicated the water source is not suitable for irrigation without treatment. A good soil drainage system and salinity control measures are required to avoid salt accumulation within the soil. Based on the performance statistics of the root mean square error (RMSE) and the scatter index (SI), SW emerged as the best (0.21% and 0.03%) followed by PCR and PLS with RMSE 0.22% and 0.21% for SAR, respectively. Based on the classification of the SI, all models applied having values less than 0.1 indicate good prediction performance for all the indices except RSC. These results highlight potential of using multiple regressions and the developed machine learning methods in predicting the index of irrigation water quality, and can be rapid decision tools for modelling irrigation water quality.

The Optimization of Silica-Based Composite Membrane from Volcanic Ash of Mount Sinabung, Titanium Dioxide, and Polyvinyl Alcohol for River Water Treatment through Photocatalyst Process

The application of composite membranes consisting of SiO2 from the volcanic ash of Mount Sinabung, TiO2, and PVA on a laboratory scale has been investigated to improve the Silau River’s water quality in Asahan Regency. The purpose of this study is to determine the optimal combination of SiO2, TiO2, and PVA for treating river water to minimize its heavy metal content and color intensity to achieve clean water requirements. The membranes were prepared by drop-casting with varied compositions of PVA/40TiO2/60SiO2, PVA/60TiO2/40SiO2, PVA/80TiO2/20SiO2, and PVA/100TiO2/0SiO2. PVA was dissolved in aquadest, mixed with SiO2 and TiO2, then imprinted and dried for 24 h at 50 °C. A photocatalyst test was performed on each composition variation to see how the Silau River water’s color changed over time. The PVA/80TiO2/20SiO2 membrane’s composition fluctuated the highest during photocatalyst testing, with 45.95% degradation. The parameter results on the Silau River water test, namely turbidity, color, and chromium values, were reduced by photocatalysis of a PVA/80TiO2/20SiO2 composite membrane to 16 NTU, 30 TCU, and 0.013 mg/L, respectively. These results met the clean water quality criteria specified by Minister of Health of the Republic of Indonesia Decree No. 416/MENKES/PER/IX/1990.

Spatiotemporal estimation of heavy metals pollution in the Mediterranean Sea from Volturno River, southern Italy: distribution, risk assessment and loads

ABSTRACT With the aim of assess the pollutant load from the Volturno River into the Mediterranean Sea, the amount of some heavy metals (As, Hg, Cd, Cr, Cu, Ni, Pb and Zn) was determined in water dissolved phase (DP), suspended particulate matter (SPM) and sediment samples. Total heavy metal concentrations were in the range 0.20–65.67 μg L−1 (mean value of 12.95 μg L−1) for DP, 1.37–601.77 μg L−1 (mean value of 105.39 μg L−1) for SPM and 14.62–157.33 mg kg−1 (mean value of 55.24 mg kg−1) for sediments. The total heavy metals input are evaluated in about 620.39 kg year−1, suggesting that the river could be an important source of heavy metals in the Tyrrhenian Sea. The ecological risk characterisation was assessed based on the National Water Quality Criteria, by comparison with criterion concentration for chronic and acute toxicity (CCC and CMC), and sediment quality guidelines. Hg and Cd showed higher values than CMC and CCC for most water samples. The Index of Geoaccumulation (I geo), Contamination Factor, Contamination degree, Pollution Load Index (PLI) and Potential Ecological Risk Index were evaluated. According to I geo and PLI, the Volturno River was uncontaminated or moderately polluted by heavy metals.

Applying Generic Water Quality Criteria to Cu and Zn in a Dynamic Aquatic Environment—The Case of the Brackish Water Formation Strömmen-Saltsjön

The EU Water Framework Directive stipulates that all EU waterways shall have good chemical and ecological status by 2027. Methodologies are described for how to assess and classify waterbodies and make 7-year management plans. Aquatic risk assessment methodologies and environmental quality standards are defined and a biotic ligand model methodology is available to assess the influence of water chemistry on the ability of aquatic organisms to take up metals. Aquatic status classification practices of naturally occurring river basin-specific metals are discussed, specifically how Cu and Zn water quality criteria guideline values have been adopted and defined for Swedish coastal and estuarine waters and how well they represent possible ecological risks. Calculations of bioavailability and ecotoxicity are conducted using recognised models for the Strömmen-Saltsjön water body in Stockholm, in which naturally occurring metals, especially Cu, have among the highest background concentrations of Sweden. Proposals are made to improve risk assessment methodologies to better reflect the vitality of living organisms, and to what extent current levels of these metals in Swedish waterways may influence their welfare. The study concludes that a more local assessment including, e.g., studies of the benthic fauna would be relevant for ecological status classification.

Derivation of water quality criteria for glyphosate and its formulations to protect aquatic life in China.

Extensive use of the herbicide glyphosate leads to a high detection rate in the environment and potential risks to nontarget aquatic life. China ranks first globally in the production and consumption of glyphosate, but there are no glyphosate water quality criteria (WQCs) for protecting aquatic life. Here, data on the acute and chronic toxicity of glyphosate and glyphosate-based formulations (GBFs) to freshwater aquatic life were collected and screened. Significant differences in species sensitivity distributions (SSDs) and toxicity values for acute or chronic toxicity were found between glyphosate and GBFs. The hazardous concentrations for 5% of species (HC5) of glyphosate or GBFs between native and nonnative species were different, and native species were found to be more sensitive to the toxicity of glyphosate. The acute and chronic WQCs derived with the SSD method for glyphosate based on the toxicity data for native species in China were 3.35 and 0.26mg/L, respectively, and those found for GBFs were 0.21 and 0.005mg/L, respectively. The WQCs in this study were quite different from those estimated using similar statistical extrapolation methods in other countries, which reflects the differences in species sensitivity to glyphosate toxicity in different regions. The hazard quotients (HQs) were calculated based on the WQCs and concentrations of glyphosate in some surface waters in China and indicated that glyphosate exhibits medium or high hazard risk in some samples of Tai Lake, surface water in Guiyang, fishpond water in Chongqing, rural drinking water, and surface water and reservoir water in Henan Province. The WQCs of glyphosate and GBFs have scientific significance for the exposure and pollution control of herbicide formulations and the protection of aquatic life in China.

Data and Diversity in the Development of Acute Water Quality Criteria in the United States.

The US Environmental Protection Agency (USEPA) is responsible for the development of water quality criteria, regulatory standards that protect aquatic organisms from harmful chemical exposure. Although these criteria are intended to be broadly protective of aquatic life, the data used to derive criteria do not necessarily reflect the actual diversity of natural communities nor are they available for most chemicals. In addition, although the USEPA's current procedures emphasize using toxicity data with a certain minimum amount of biological diversity, the quantitative impact of such diversity on criteria is unclear. In the present study we assessed the changes to acute toxicity data over time, determined the prevalence of significant taxonomic differences in sensitivity, and investigated the effect of biological diversity on criteria. We found major gaps in existing toxicity data that we hypothesize have contributed to the absence of acute criteria for the majority of chemical pollutants. Taxonomic patterns of sensitivity in these data are abundant, although the resolution of the patterns is relatively poor. In addition, we found that the amount of biological diversity in a toxicity data set and the data set's taxonomic composition does not quantitatively affect criteria in most cases. Because the USEPA has published acute criteria for fewer than 20% of priority pollutants and the persistence of major gaps in toxicity data over the last 37 years, we recommend that the USEPA consider revisions to their water quality criteria guidelines that will expedite the criteria development process and advance the responsible management of pollutants in the aquatic environment. Environ Toxicol Chem 2022;41:1333-1343. © 2022 SETAC.

Risk-Based Prioritization of Organic Chemicals and Locations of Ecological Concern in Sediment From Great Lakes Tributaries.

With improved analytical techniques, environmental monitoring studies are increasingly able to report the occurrence of tens or hundreds of chemicals per site, making it difficult to identify the most relevant chemicals from a biological standpoint. For the present study, organic chemical occurrence was examined, individually and as mixtures, in the context of potential biological effects. Sediment was collected at 71 Great Lakes (USA/Canada) tributary sites and analyzed for 87 chemicals. Multiple risk‐based lines of evidence were used to prioritize chemicals and locations, including comparing sediment concentrations and estimated porewater concentrations with established whole‐organism benchmarks (i.e., sediment and water quality criteria and screening values) and with high‐throughput toxicity screening data from the US Environmental Protection Agency's ToxCast database, estimating additive effects of chemical mixtures on common ToxCast endpoints, and estimating toxic equivalencies for mixtures of alkylphenols and polycyclic aromatic hydrocarbons (PAHs). This multiple‐lines‐of‐evidence approach enabled the screening of more chemicals, mitigated the uncertainties of individual approaches, and strengthened common conclusions. Collectively, at least one benchmark/screening value was exceeded for 54 of the 87 chemicals, with exceedances observed at all 71 of the monitoring sites. Chemicals with the greatest potential for biological effects, both individually and as mixture components, were bisphenol A, 4‐nonylphenol, indole, carbazole, and several PAHs. Potential adverse outcomes based on ToxCast gene targets and putative adverse outcome pathways relevant to individual chemicals and chemical mixtures included tumors, skewed sex ratios, reproductive dysfunction, hepatic steatosis, and early mortality, among others. The results provide a screening‐level prioritization of chemicals with the greatest potential for adverse biological effects and an indication of sites where they are most likely to occur. Environ Toxicol Chem 2022;41:1016–1041. Published 2022. This article is a U.S. Government work and is in the public domain in the USA. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.