Risk Of Cu Research Articles

Risk of chronic non-carcinogenic and internal respiratory exposure to Cu and Zn from particulate matter 2.5 in different microenvironments

This study investigated the respiratory exposure characteristics and health risks of Cu and Zn from particles with aerodynamic diameters smaller than 2.5 μm (PM2.5) in five microenvironments by using an chronic non-carcinogenic risk index and a physiologically based pharmacokinetic (PBPK) model. The results indicated that taxis and the outdoor environment had the highest Cu concentration and that the outdoor environment had the highest Zn concentration. In offices, buses, taxis, and the outdoor environment, the concentrations of Cu and Zn were higher in winter than in summer. In residential buildings, the concentrations of Cu and Zn were higher in summer than in winter. Acceptable levels of health risk due to respiratory exposure to Cu and Zn from PM2.5 were observed for nonelderly and elderly adults in the five microenvironments. The chronic non-carcinogenic risk index values derived for the nonelderly adults were higher than those derived for the elderly adults in residential buildings, buses, and taxis but lower than those derived for the elderly adults in the outdoor environment. The results of exposure assessment based on the PBPK model indicated that the concentrations of Cu and Zn from PM2.5 were high in the liver and kidney but low in arterial and venous blood. After respiratory exposure was stopped and the pollutant concentrations reached a steady state, the highest concentrations of Cu and Zn were found in muscles. The muscles and brain exhibited the highest internal exposure risk index values for Cu and Zn. According to these results, the simulation of continuous exposure in multiple microenvironments (rather than a single environment) can accurately reflect the exposure concentration and exposure risk index for people in such environments. Hence, during the execution of human exposure risk assessment for various contaminants, internal exposure risk assessment should be preferred over chronic non-carcinogenic risk assessment.

Following the evidence and using the appropriate regulatory tools: A European-wide risk assessment of copper in freshwaters.

The ecological risks of copper (Cu) in freshwaters have been the focus of regulatory assessments for several decades. Recently, it has been suggested by the European Commission that Cu represents a continent-wide risk to freshwaters. We assessed to what extent this suggestion is supported by the available evidence if Cu bioavailability is considered in the assessment of risk. We used several evidence-driven metrics to assess the continental-wide risks of Cu to European freshwaters. Such an approach is recommended and readily applicable where comprehensive data sets are available. We confirmed the validity of a bioavailability-based Environmental Quality Standard of 1 µg L-1 for Cu and used this to characterize the risks of Cu in 286 185 regulatory monitoring samples from 17 307 sites across 19 European countries between 2006 and 2021. These data show that risks, based on site averages and accounting for bioavailability, were identified in only two countries (Spain and Portugal). Investigation of these risks showed them to be highly localized to a single region in Spain and not reflective of the country-wide risks for either country. The 95th percentile of all the risk quotients for the continent-wide data set is 0.35. The relatively low levels of risk associated with Cu are supported by long-term trend data from sites on two large European rivers (Rhine and Meuse), where highly significant (p < 0.001) decreases in Cu concentrations over the last 40 years can be observed. We conclude that it is critical to consider metal bioavailability in both effects and exposures in assessments of potential risk to ensure ecological relevance. Integr Environ Assess Manag 2023;19:1570-1580. © 2023 WCA Environment Ltd. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Geochemical fractionation, bioavailability, ecological and human health risk assessment of metals in topsoils of an emerging industrial cluster near New Delhi.

Urban spaces have become sink for metal-rich waste, particularly in unorganized industrial clusters and metro-cities. Geochemical distribution of metals in different forms and their mobility and bioavailability in topsoils of Bhiwadi Industrial Cluster (BIC) near New Delhi are studies following m-BCR-SEP. Contamination factor (Cf), risk assessment code (RAC), ecological risk assessment (Er), and carcinogenic and non-carcinogenic health risk (HRA) were calculated to assess health and environmental risks. Residual fraction (F4) contained considerable amounts of Cd (57.2%), Cr (81.5%), Fe (86.1%), Mn (62.5%), Ni (58.3%), and V (71.4%). Pb was present in reducible fraction (F2; 52.8%), whereas Cu was distributed in F2 (33.3%) and F4 (31.6%). Zn showed equal distribution in acid exchangeable (F1; 33.9%) and oxidizable fraction (F3; 32.5%). High Cf was observed for Zn (0.9-20.9), Cu (0.46-17) and Pb (0.2-9.9). RAC indicated high risk of Cd, Cu, Mn, Ni, and Zn due to their high mobility and toxicity. High potential bioavailability of Cu, Pb, and Zn (> 65%) was found in samples collected near to metal casting, electroplating, and automobile part manufacturing industries. Considerable to extremely high ecological risk was observed for Cd, low to high risk for Cu, low risk to moderate risk for Cr, Mn, Ni, Zn, and Pb. All topsoil samples were in low to very high-risk range for metals. Ingestion was major pathway of metals followed by dermal and inhalation. Children were more prone to non-carcinogenic risks (hazardous index: 3.6). Topsoils had high carcinogenic risk to exposed population for Cd, Cr, Ni, and Pb.

Positive effect of Ca addition on the risk of Cu and Zn in digestate as biofertilizer

The addition of Ca in anaerobic digestion will passivate the heavy metals in digestate. The effects of CaCl2, Ca(OH)2 and CaCO3 addition on the anaerobic digestion process and the speciation changes of Cu and Zn in solid fraction of anaerobic digestate (SFD) after digestion were studied. Then the effects of Ca-containing solid fraction digestate (SFD-Ca) application on the speciation changes of Cu and Zn in soil and the effects of ryegrass on the enrichment of Cu and Zn were also explored through pot experiments. The results indicated that: The addition of Ca(OH)2 was beneficial to the transfer of Cu and Zn from the liquid fraction of anaerobic digestate (LFD) to SFD, and the transfer effect was the best. The transfer amount of Cu and Zn increased by about 10.0% and 4.2%, respectively, compared with the blank group. The SFD-Ca promoted the increase of biomass, inhibited the enrichment of Cu and Zn by ryegrass, and the effect of a high concentration of Ca(OH)2 was the best. Ryegrass biomass increased by 19.7%, and the enrichment of Cu and Zn decreased by 39.3% and 31.1%, respectively. High concentration of Ca(OH)2-containing solid fraction digestate (SFD-Ca(OH)2) had the best passivation effect on Cu and Zn in soil, the residual state of Cu and Zn in soil increased by 4.3% and 7.8%, respectively. Adding a high concentration of Ca(OH)2 had a positive effect on ryegrass biomass and reduced the risk of Cu and Zn when SFD was used as biofertilizer.

Co-pyrolysis with pine sawdust reduces the environmental risks of copper and zinc in dredged sediment and improves its adsorption capacity for cadmium

Proper treatment of heavy metal-contaminated dredged sediment (DS) is crucial to avoid secondary pollution. Effective and sustainable technologies are desired for the treatment of Zn- and Cu-contaminated DS. Due to the advantages of low energy consumption and time saving, co-pyrolysis technology was innovatively applied to treat Cu- and Zn-polluted DS in this study, and the effects of the co-pyrolysis conditions on Cu and Zn stabilization efficiencies, potential stabilization mechanisms, and the possibility for resource utilization of co-pyrolysis product were also investigated. The results showed that pine sawdust is an appropriate co-pyrolysis biomass for the stabilization of Cu and Zn based on the leaching toxicity analysis. The ecological risks of Cu and Zn in DS were reduced after co-pyrolysis treatment. The total concentrations of Zn and Cu in co-pyrolysis products were decreased by 5.87%–53.45% and 8.61%–57.45% of that in DS before co-pyrolysis. However, the total concentrations of Zn and Cu in DS remained basically unchanged after co-pyrolysis, which indicating the decreases in total concentrations of Zn and Cu in co-pyrolysis products were mainly related to dilution effect. Fraction analysis indicated that co-pyrolysis treatment contributed to transforming weakly bound Cu and Zn into stable fractions. The co-pyrolysis temperature and mass ratio of pine sawdust/DS had a greater influence than co-pyrolysis time on the fraction transformation of Cu and Zn. The leaching toxicity of Zn and Cu from the co-pyrolysis products was eliminated when the co-pyrolysis temperature reached 600 and 800 °C, respectively. Analysis of the X-ray photoelectron spectroscopy and X-ray diffraction results demonstrated that co-pyrolysis treatment could transform mobile Cu and Zn in DS into metal oxides, metal sulfides, phosphate compounds, etc. Batch adsorption procedures suggested that the co-pyrolysis product possessed a high adsorption capacity for Cd (95.70 mg/g at 318 K). The formation of CdCO3 precipitates and the complexation effects of oxygen-containing functional groups were the principal adsorption mechanisms of the co-pyrolysis product. Overall, this study provides new insights into sustainable disposal and resource utilization for heavy metal-contaminated DS.

Study on the reduction of chlorine and heavy metals in municipal solid waste incineration fly ash by organic acid and microwave treatment and the variation of environmental risk of heavy metals

Municipal solid waste incineration (MSWI) fly ash usually needs to undergo dechlorination or heavy metal stabilization pretreatment for further treatment, recycling or disposal. In this paper, the removal effect of chlorine in fly ash by water washing, lactic acid, citric acid and microwave treatment was studied, and XANES was used to analyze chlorine chemical form in fly ash. In addition, the heavy metals in fly ash were also checked. The results indicated that double washing and triple washing could remove 88.0 % and 95.5 % of chlorine from fly ash respectively. The “double water washing + microwave/organic acid” could remove about 96.6 % of chlorine, and 42.9 % and 47.2 % of insoluble chloride respectively. The microwave treatment could maximize the stabilization of heavy metals with a BI value of 39.1 %, 0.11 %, 1.65 %, 15.4 % and 3.98 % for Cd, Cr, Cu, Pb and Zn. The elution of heavy metals by citric acid was obvious. “Double water washing + citric acid” removed 87.0 % of Cd, 17.2 % of Cr, 11.9 % of Cu, 39.6 % of Pb and 43.6 % of Zn, but the environmental risk of Cu and Cr increased about 2–3 % after the treatment. The results of this study provide guidance for the pretreatment of fly ash before resource utilization.

Iron (oxyhydr)oxides are responsible for the stabilization of Cu and Zn in AMD after treatment with limestone.

The formation and transformation of secondary iron (oxyhydr)oxides and their role in the stabilization of copper (Cu) and zinc (Zn) in acid mine drainage (AMD) after limestone treatment are worth studying to better understand the impacts of limestone AMD treatment. In this study, the wastewater from a copper mine ditch was sampled. Two different doses of limestone (S: 5.33 g L-1 and SS: 8.00 g L-1) were applied to adjust the pH range of the sampled AMD. The concentrations of Fe, Cu and Zn in the supernatant and the levels of iron (oxyhydr)oxides and heavy metals in AMD sediments were dynamically monitored for 300 days to analyze the transformation of the secondary iron mineral phase and the role iron (oxyhydr)oxides play in the removal and stabilization of Cu and Zn. The results showed that the pH rose rapidly to 6.82, decreased to 5.82 on the 150th day, and finally decreased to approximately 4.63 by the 300th day, when the dosage of limestone (S) was 5.33 g L-1. Goethite was the main form of iron oxides in the sediments. As the incubation time increased, so did the content of crystalline Fe (oxyhydr)oxides. In addition, the Cu and Zn content in the fraction of crystalline Fe (oxyhydr)oxides increased as the corresponding iron (oxyhydr)oxide increased. When the high dosage of limestone (8.00 g L-1 or SS) was applied, the pH remained at approximately at 7.46 during the whole period and goethite and lepidocrocite were present in the sediment. Amorphous/ poorly crystalline Fe-oxyhydroxide was the main product after SS limestone dosage, indicating that the risk of Cu and Zn reactivation in the sediment was higher with a higher limestone treatment dosage.

Cell cycle-dependent Cu uptake explained the heterogenous responses of Chlamydomonas to Cu exposure

Growing evidence suggested that microorganisms exhibited heterogeneous sensitivity to toxicants, but their underlying mechanisms remain largely unknown. The asynchronous cell cycle progression in natural population implies the connection between cell cycle and heterogeneity. Here, the heterogenous responses of Chlamydomonas reinhardtii upon Cu stress were confirmed with the aid of a fluorometric probe for imaging Cu(I), implying the connection with cell cycle. Our results further indicated that the increase of labile Cu(I) was related to the cell division, leading to the fluctuation of labile Cu(I) with diurnal cycle and cell cycle, respectively. However, lack of Cu mainly influenced the cell division. We demonstrated that G2/M phase was the critical stage requiring high Cu quota during cell division. Specifically, algae at G2/M phase required 10-fold of Cu quota compared with that at G1 phase, which was related to the mitochondrial replication. Eventually, the heterogeneous Cu uptake ability of algae at different cell phases led to the heterogeneous responses to Cu exposure. Overall, Cu could influence the cell cycle through mediating the cell division, and in turn algae at different cell phases exhibited different Cu sensitivities. This study firstly uncovered the underlying mechanisms of heterogeneous Cu sensitivity for phytoplankton, which could help to evaluate the potential ecological risks of Cu.

The rationale behind the NIA‐AA research framework definition of Alzheimer's disease

AbstractBackgroundThe NIA‐AA research framework group and the IWG both agree that abnormal AD biomarkers are necessary for the diagnosis of AD; however, the groups disagree on the appropriate definition of Alzheimer’s disease. The NIA‐AA framework argues that a CU A+T+ individual has AD pathology and therefore has the disease. The IWG argues that such an individual should be labeled “at risk for AD” because both abnormal biomarkers and clinically significant impairment are required for an AD diagnosis.MethodThe major IWG argument against a biological‐only definition of AD is that some CU A+T+ individuals will die of other causes without experiencing overt symptoms (MCI or dementia) in their lifetime. However, the same statement can be made about any other disease in medicine. The question therefore must be how often will CU A+T+ individuals die without experiencing dementia.ResultMany studies have examined rates of cognitive decline in CU A+ relative to CU A‐ (fewer studies in CU A+T+ vs CU A‐T‐). Studies have examined the risk of incident MCI/dementia in CU A+ relative to CU A‐ (fewer in CU A+T+ vs CU A‐T‐). Relative risk indicates likelihood of an outcome in a particular risk group relative to a reference group; it does not indicate the likelihood in percentage terms that an individual will experience an outcome in their lifetime. It is lifetime risk (i.e., absolute risk) that is needed to address the current controversy and to our knowledge only 2 published studies have estimated lifetime risk associated with AD biomarkers. A recent Mayo Clinic Study of Aging analysis examined lifetime risk of dementia associated with varying levels of amyloid PET, APOE and sex. Among APOE ε4 carriers with high amyloid PET SUVR, remaining lifetime risk of dementia at age 75 years was 76% for women and 64% for men. Lifetime risk of CU A+T+ remains to be determined, however.ConclusionThe major discordance between the NIA‐AA framework and the IWG (the definition of AD) points to the question, how risky is the CU A+T+ state? Accurate estimates of lifetime risk from population‐based studies are needed to address this question.

Water quality criteria and ecological risk assessment for copper in Liaodong Bay, China.

The establishment of water quality criteria (WQC) for copper (Cu) was used as the basis for an ecological risk assessment of marine Cu pollution in Liaodong Bay, China. Published ecotoxicity data for Cu were obtained and supplemented with the results of acute Cu toxicity tests. The marine WQC for Cu in Liaodong Bay was developed using a species sensitivity distribution method with a safety factor of 2.0 and the USEPA acute-to-chronic ratio method. The ecological risk of Cu in Liaodong Bay was assessed by comparing the seawater Cu concentrations with the developed WQC. The results of this study showed that the acute and chronic Cu concentrations in Liaodong Bay were 3.31 and 2.18 μg/L, respectively. Comparison of the WQC to Cu concentrations in the bay resulted in risk quotients slightly >1.0 and typically ≤2.0. These data suggest that certain organisms in Liaodong Bay are at risk. These results can assist in the development of a pollution control management approach for the bay.

Aggregation, Sedimentation and Dissolution of Cu(OH)2-Nanorods-Based Nanopesticide in Soil Solutions.

Along with the development of nanotechnology, nanomaterials have been gradually applied to agriculture in recent years, such as Cu(OH)2-nanorods-based nanopesticide, an antibacterial agrochemical with a high efficacy. Nevertheless, knowledge about physical stability of Cu(OH)2 nanopesticide in soil solutions is currently scarce, restricting comprehensive understanding of the fate and risk of Cu(OH)2 nanopesticide in the soil environment. Herein we investigated aggregation, sedimentation and dissolution of Cu(OH)2 nanopesticide in soil solutions extracted from three different soil samples, wherein commercial Cu(OH)2 nanopesticide formulation (NPF), as well as its active ingredient (AI) and laboratory-prepared Cu(OH)2 nanorods (NR) with similar morphology as AI, were used as model Cu(OH)2 nanopesticides. We found that NPF compared to AI showed less extents of aggregation in ultrapure water due to the presence of dispersing agent in NPF. Yet, moderated aggregation and sedimentation were observed for Cu(OH)2 nanopesticide irrespective of NPF, AI or NR when soil solutions were used instead of ultrapure water. The sedimentation rate constants of AI and NPF were 0.023 min-1 and 0.010 min-1 in the ultrapure water, whereas the rate constants of 0.003-0.021 min-1 and 0.002-0.007 min-1 were observed for AI and NPF in soil solutions, respectively. Besides aggregation and sedimentation, dissolution of Cu(OH)2 nanopesticide in soil solutions was highly dependent on soil type, wherein pH and organic matter played important roles in dissolution. Although the final concentrations of dissolved copper (1.08-1.37 mg/L) were comparable among different soil solutions incubating 48 mg/L of AI, NPF or NR for 96 h, a gradual increase followed by an equilibrium was only observed in the soil solution from acidic soil (pH 5.16) with the low content of organic matter (1.20 g/kg). This work would shed light on the fate of Cu(OH)2 nanopesticide in the soil environment, which is necessary for risk assessment of the nanomaterials-based agrochemical.

Seasonal variation of heavy metal contents in road dust from residential, industrial and rural areas of Hong Kong

Heavy metal contents in road dust have been an important indicator of heavy metal pollution arising from traffic-related activities. In this study, 108 road dust samples were collected from four locations of Hong Kong, namely Kwai Hing (industrial area), Sau Mau Ping (residential area), Sai Kung and Tai Lam (rural area), over a one-year period and analysed for zinc (Zn), nickel (Ni), copper (Cu), lead (Pb), chromium (Cr), cadmium (Cd), and arsenic (As). The geo-accumulation indices (Igeo) and contamination factors indicated zinc, copper, chromium, to a lesser extent, nickel, and cadmium pollution of road dust in industrial and residential areas. The potential ecological risks of Cu were found to be particularly high in both areas. Residential and industrial areas are prone to considerable and very high risks, respectively, based on the risk indices (RI). The sources of heavy metals may vary slightly between the areas based on Pearson's correlation analysis. It was found that the metal contents in the road dust samples vary differently between the dry and wet seasons. The concentrations of Zn were higher in the dry season while those of Cu, Cr and Ni were generally higher in the wet season.

Association between Chronic Urticaria and Helicobacter Pylori Infection in Patients Visiting a Tertiary Hospital

Objective: This study aims to demonstrate the association between chronic urticaria and H.pylori infection for effective management of chronic urticaria. Methodology: A case-control study was conducted in the Dermatology Department of Bakhtawar Amin Trust Hospital Multan from 30th Jan 2020 to 30th Jan 2021. The patients who recently visited the inpatient or outpatient ward of the hospital were a part of the study whereas the patients who were administered proton pump inhibitors or any antibiotics in the last 1 month were excluded from the study. The patients diagnosed with chronic urticaria were asked to collect one gram of stool and submit the sample. The sample was stored at -20 Celsius and tested for H.pylori infection. The strength of association between chronic urticaria and H.pylori infection was measured by conditional logistic regression. Two-tailed p values were noted and p&lt;0.05 was regarded as statistically significant Results: The study included 80 patients (40 controls and 40 cases). The median age was 32 years in controls while 35 years in cases. Both groups had a majority (n=56, 70%) of females. More than one half (n=23, 57%) of cases and controls (n=27, 67%) lived in urban region. There was a significant difference between the percentage of those who tested H.Pylori positive and had CU and those who were H.Pylori positive but did not have CU. In subjects infected with H.Pylori risk of CU is six times higher than those not infected Conclusion: Relation between H.Pylori and Chronic urticaria is significant, which indicates H.Pylori tests for diagnosis of CU. Keywords: Chronic Urticaria, H.Pylori, Stool antigen test

Ecological Risk Evaluation of Baihetan Dam Based on Fuzzy Hazard Quotient Model

To evaluate the variation in ecological risk induced by pollutants from the construction of Baihetan Dam, the largest hydropower station under construction in the world, this study proposes a fuzzy hazard quotient (HQ) model designed on the basis of triangular fuzzy number (TFN) theory. The fuzzy HQ model uses hazardous TFN to evaluate the ecological risk including uncertain observation data, and the transition TFN to analyze the variation in ecological risk before and after the dam construction. The results show the following: (i) The ecological risk of ammonia nitrogen (NH3-N) showed a marked increasing trend after the construction of the dam because this activity weakened the degradation ability of the water body. The chronic hazard of NH3-N was classified as “medium” grade and its acute hazard was “low” grade. (ii) The crucial acute hazard factor for the local aquatic ecosystem was copper (Cu) and the key chronic hazard factor was lead (Pb). (iii) After the construction of Baihetan Dam, both the long-term and short-term hazardous TFNs of Cu were classified as “medium” grade. The acute hazard of Pb belonged to “low” grade with high certainty, whereas its chronic hazard classification had uncertainties. Its long-term hazardous vectors upstream were {0.000, 0.928, 0.072}, whereas its long-term hazardous vectors downstream were {0.000, 0.108, 0.892}. (iv) Both of the ecological risks of Cu and Pb showed substantial decreasing trends after the construction of Baihetan Dam because the impounding effect of Baihetan Dam promoted the settlement of heavy metals with sediment. (v) The hazardous TFN method can be applied to perform an ecological risk evaluation that accounts for uncertainties in the observation data set, and the transition TFN method can analyze the variation in ecological risk with a small sample size. Therefore, the fuzzy HQ model is effective for the evaluation of ecological risk induced by dam construction.

Co-hydrothermal carbonization of sewage sludge and swine manure: Hydrochar properties and heavy metal chemical speciation

Alleviating the risk of heavy metals while improving fuel properties is one of the important challenges of sewage sludge (SS) disposal. In this work, ferric chloride (FeCl3) was chosen as a typical additive (0.005–0.02 mol) to analyse its effect on the co-hydrothermal carbonation (co-HTC) of SS and swine manure (SM). During co-HTC, SS was converted into hydrochar with SM at different mixing ratio (30–70 %) at 230 °C. Chemical speciation of heavy metals (HMs) in hydrochars, along with fuel properties, were evaluated. The results showed that co-HTC was beneficial for the decline of weakly fractions of Cr, Ni, Mn, and Zn. Furthermore, FeCl3 further decreased the risk of Mn and Zn without significantly expanding the pollution of Ni. More importantly, the risk of Cu was dramatically alleviated by the addition of 0.02 mol FeCl3. Compared with the hydrochar produced from SS, the fuel ratio, higher heating values (9.75–13.09 MJ/kg), and combustion behavior of the hydrochar derived from co-HTC were upgraded and improved. The FeCl3 could notably promoted the dehydration and decarboxylation reaction and prevented the reservation of N content. This study suggested that co-HTC with FeCl3 was a promising strategy to produce superior solid fuel with lower risk of HMs.

Multi-elements characteristic and potential risk of heavy metals in MOUTAN CORTEX from Anhui Province, China.

To ensure the quality and safety of herbs, the content of 54 elements in MOUTAN CORTEX (MC) was determined by the ICP-AES and ICP-MS, and the health risks of Cu, As, Cd, Pb, Hg and rare earth elements (REEs) were assessed. These herbs were collected from 5 producing areas in Anhui Province, China, namely Wuhu, Tongling, Bozhou, Xuancheng and Chizhou. The multi-elements fingerprint identification of MC in Anhui Province was established. The total amount of macro-elements from Wuhu and Tongling is significantly lower than Bozhou. Among all MC from 5 producing areas, the highest content is Ca. Except for Bozhou, the content of macro-elements and REES in the other 4 origins of MC is from highest to lowest: Ca > K > Mg > Al > Fe > Na and Ce > La > Nd > Y > Pr > Er > Yb > Eu > Ho > Tb > Tm > Lu. The chemical forms of Cd in MC from Bozhou with the highest percentage were PH2O of high toxicity and migration, while the other 4 regions were PNaCl of low activity and mobility. There was a great difference in the content of inorganic elements and chemical forms of Cd between the MC produced from the plain (Bozhou) and the hilly areas (Wuhu, Tongling, Chizhou and Xuancheng). Except for Cd, the content of Cu, As, Pb and Hg in MC did not exceed the limit. The results of PTWIFact and ADI for Cd and REEs showed that MC herbs did not pose a risk to human health.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13762-022-04402-6.

Investigating the mechanisms of dissolved organic matter protection against copper toxicity in fish of Amazon's black waters

We investigated how natural dissolved organic matter (DOM) of the Rio Negro (Amazon) affects acute copper (Cu) toxicity to local fish: the cardinal tetra (Paracheirodon axelrodi) and the dwarf cichlid (Apistogramma agassizii). It is established that Cu2+ complexation with DOM decreases Cu bioavailability (and thus toxicity) to aquatic organisms, as conceptualized by the Biotic Ligand Model (BLM). However, we also know that Rio Negro's DOM can interact with fish gills and have a beneficial effect on Na+ homeostasis, the main target of acute Cu toxicity in freshwater animals. We aimed to tease apart these potential protective effects of DOM against Cu-induced Na+ imbalances in fish. In the laboratory, we acclimated fish to Rio Negro water (10 mg L−1 DOC) and to a low-DOM water (1.4 mg L−1 DOC) with similar ion composition and pH (5.9). We measured 3-h Cu uptake in gills and unidirectional and net Na+ physiological fluxes across a range of Cu concentrations in both waters. Various DOM pre-acclimation times (0, 1 and 5 days) were evaluated in experiments with P. axelrodi. Copper exposure led to similar levels of net Na+ loss in the two fish, but with distinct effects on Na+ influx and efflux rates reflecting their different ionoregulation strategies. Rio Negro DOM protected against Cu uptake and toxicity in the two fish species. Both Cu uptake in fish gills and Na+ regulation disturbances were relatively well predicted by the modelled aqueous free Cu2+ ion concentration. These findings suggest that protection by DOM occurs mainly from Cu complexation under the tested conditions. The prevalence of this geochemical-type protection over a physiological-type protection agrees with the BLM conceptual framework, supporting the use of the BLM to assess the risk of Cu in these Amazonian waters.

Ecological–Health Risk Assessments of Copper in the Sediments: A Review and Synthesis

The ecological and children’s Health Risk Assessments (HRA) of Copper (Cu) in aquatic bodies ranging from rivers, mangrove, estuaries, and offshore areas were studied using the Cited Cu Data in The Sediments (CCDITS) from 125 randomly selected papers published from 1980 to 2022. The ecological and children’s HRA were assessed in all CCDITS. Generally, local point Cu sources (8%) and lithogenic sources were the main controlling factors of Cu concentrations. The present review revealed three interesting points. First, there were 11 papers (8%) documenting Cu levels of more than 500 mg/kg dw while China was the country with the highest number (26%) of papers published between 1980 and 2022, out of 37 countries. Second, with the Cu data cited from the literature not normally distributed, the maximum Cu level was higher than all the established guidelines. However, the median Cu concentration was lower than most of the established guidelines. The median values of the geoaccumulation index (Igeo) indicated a status of ‘unpolluted‘ and ‘moderate contamination’ for the contamination factor (CF), and ‘low potential ecological risk’ for the ecological risk (ER) of Cu. However, the Cu ER could be based at present on the above mentioned 8% of the literature in the present study. Third, the calculated hazard index (HI) values were found to be below 1, indicating no potential chance of Cu non–carcinogenic effects in both adults and children, except for children’s HI values from Lake Pamvotis of Greece, and Victoria Harbor in Hong Kong. Thus, regular monitoring (every 2 years), depending upon the available resources, is recommended to assess the ecological–health risk of Cu pollution in aquatic bodies to abate the risk of Cu exposure to children’s health and avoid injurious impacts on the biota. It can be concluded that there is always a need for the mitigation and management of a Cu exposure risk assessment that can be used successfully for screening purposes to detect important human health exposure routes. Consequently, any sediments contaminated with Cu require rapid sediment remediation techniques.

Potentially Toxic Elements (PTEs) contamination and ecological risk of sediment in the upper course of the Ankobra River, Ghana

Metals, when introduced into a high pH aquatic environment, generally sink into bottom sediments and can pose a direct and indirect threat to aquatic organisms as well as humans. The concentrations of ten heavy metals (Mn, Fe, Cd, Cu, Cr, Pb, Hg, As, Zn, and Al) in the surface sediment samples from the upper part of the Ankobra, which is an illegal mining (Galamsey) prone area, were assessed in both the dry and wet seasons. To ascertain the quality of sediments, sediment quality indices, including enrichment factor (EF), index of geo-accumulation (I-geo), and modified pollution index (MPI), were employed. A comprehensive potential ecological risk assessment was also carried out using the consensus-based sediment quality guideline (CBSQG) as well as the modified potential ecological risk index (MPERI). In general, the sediment is considered to be "slightly" to "moderately" polluted in the dry season as well as "moderately" to "heavily'' polluted in the wet season. The potential ecological risk of the metals in the sediments was within the considerable to high-risk grade for Hg, moderate to considerable risk for Cd, low to moderate risk for As, and low risk for Cu, Cr, Pb, and Zn. The order of decreasing potential ecological risk for the metals is Hg > Cd > As > Cu > Pb > Cr > Zn and the risk in the wet season was higher than that in the dry season.

Insight into the effects of biological treatment on the binding properties of copper onto dissolved organic matter derived from coking wastewater

Biological treatment can remove more than 89.8% of total organic carbon (TOC) and 94.4% of fluorescent dissolved organic matter (DOM) in the coking wastewater, thereby affecting the migration, transformation and bioavailability and binding characteristics of heavy metals (HMs). The results of parallel factor analysis (PARAFAC) show that protein-like materials accounted for 97.53% in the coking wastewater DOM, a large number of humic-like substances are produced and accounted for more than 55.40% after biological treatment. A new spectral data processing method, the 1/n-th power transformation after two-dimensional correlated spectroscopy (2D-COS) in combination with synchronous fluorescence spectra (SFS), can identify small features obscured by strong peaks, and reveal more binding sites as well as preserve the sequential order information. The result indicates that the preferential bonding of Cu(II) is at 306 nm (protein-like) for coking wastewater DOM, and at 514 nm (humic-like) for effluent DOM. The C−O group of esters and alcohols can preferentially complexate with Cu(II) in the coking wastewater and effluent DOM. The log KM values of PARAFAC components with Cu(II) are in the range of 3.59–5.06 for coking wastewater DOM, and in the range of 4.80–5.64 for the effluent DOM. Log KM values for protein-like materials with Cu(II) are higher than these for fulvic- and humic-like substances. Humic-like substances can form more stable complexes with Cu(II) in the effluent DOM. Biological treatment increases the chemical stability of DOM-Cu(II) complexes, thereby further reducing the environmental risk of Cu(II).