Both polychlorinated biphenyls (PCBs) and cadmium (Cd) can be frequently found in marine ecosystems and have detrimental effects on marine organisms, especially on filter-feeding marine mussels. Although biological responses to single metal or PCB exposure in mussels have been well-studied, information about oxidative stress is still limited, especially in different tissues in mussels. Considering the variety of contaminants existing in the actual marine environment, the exposures of the marine mussel Mytilus coruscus to Cd²⁺ alone (0.194, 0.388, and 0.775 mg/L) and Aroclor 1254 alone (0.005, 0.010, and 0.050 mg/L) and the co-exposures of the marine mussel Mytilus coruscus to Cd²⁺ (0.194 and 0.388 mg/L) and Aroclor 1254 (0.005 and 0.010 mg/L) were tested in an 8-day exposure experiment followed by a 7-day acclimation experiment. The alterations in superoxide dismutase, catalase, glutathione peroxidase, and malondialdehyde levels in the gills of the mussels were assessed. The effects of the depressed antioxidant were induced by the exposures of Cd²⁺ and Aroclor 1254 and their co-exposures. All exposures resulted in an initial increase and then a reduction in antioxidant enzyme activities. The range and rate of the antioxidant enzyme activities were positively correlated with stress duration and the concentration of the stress material. The effect of combined stress was stronger than that of each individual stressor. The valuable information for future investigations of stress response mechanisms, especially in relation to tissue functions in marine organisms, has been provided by the results and experimental model. The study of combined pollution effects has more scientific significance for marine pollution monitoring.

The aim of this research was the investigation of the effectiveness of several extractants as possible assessment of pseudo-total As, Pb and Cu concentrations in moderately contaminated soils of Central Greece. In soils of 3 different land uses (forest, agricultural and industrial), various extraction procedures were performed using simple and low-cost extraction solutions, i.e. inorganic acids (HCl and H₃PO₄), salts (NH₄NO₃ and CH₃COONH₄), organic chelating agents (as ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA)) and an alkaline agent (NaOH). The findings were reported as percentages to their pseudo-total concentrations obtained using Aqua Regia. The species of As (III), As (V) and total As(T) were extracted. Higher percentages of As concentrations were extracted using H₃PO₄ concluding that this may be the most effective of the extractants used. On the other hand, the percentages of the EDTA-extracted Pb and Cu, in forest soils with high organic matter content, were the highest. In forest soils, also, satisfactory correlations between EDTA-extracted Pb and Cu versus their pseudo-total content were observed. Finally, significant correlations among As, Pb and Cu concentrations in some soil extracts and soil physicochemical parameters were obtained, suggesting that the extractability of As, Pb and Cu may depend upon soil characteristics in the study area.

Exposure to organophosphate pesticides (OP) has been associated with the inhibition of cholinesterase enzymatic activity, such as butyrylcholinesterase (BuChE). Changes in BuChE activity have been associated with obesity, diabetes, hyperthyroidism, and metabolic syndrome. However, few studies have evaluated the effects of pesticides on both BuChE and lipid parameters. The aim of this study was to evaluate lipid parameters in urban sprayers and their association with BuChE activity. An analytical cross-sectional study was conducted in workers exposed to pesticides. The pesticide exposures were evaluated by the measurement of urinary dialkylphosphates. BuChE activity was determined spectrophotometrically in serum, and biochemical parameters were determined at a certified laboratory. Information regarding general characteristics, lifestyle, and other aspects was obtained from a structured questionnaire. The results showed variations in glucose, cholesterol, albumin, atherogenic index, creatinine, LDL, VLDL, triglycerides, and total lipids according to the level of exposure to pesticides in individuals with overweight and obesity. Furthermore, positive correlations between BuChE activity and lipid parameters were observed; these effects were associated with the body mass index. More studies are needed in human population to better elucidate the role of BuChE in lipid metabolism.

Cu-based copper nanoclusters have generated a great deal of interest based on for their fluorescent and catalytic properties. However, as heterogeneous catalysts, little attention has been given to the degradation of organic pollutants in Fenton-like reaction systems. Here, flower-like copper nanoclusters/flower carbon heterostructured microspheres were prepared by a one-pot mixing template-based method. With Cu-based copper nanoclusters/carbon (CuNCs/C) composite as a Fenton-like catalyst, a CuNCs/C-H₂O₂ system was used to degrade Amido Black 10B (AB-10B). The effects of different factors on the degradation rate of AB-10B were studied. A 98.6% degradation ratio of AB-10B was reached for the CuNCs/C -H₂O₂ based Fenton-like reaction within 180 min under optimal experimental conditions. The CuNCs/C concentration was 0.06 g/L, the dosage of H₂O₂ was 25 mmol/L, the mass ratio of CuNCs and the carbon was 1:2, pH = 6.0, and the reaction temperature was 40.0 °C. The removal rate of AB-10B on CuNCs/C decreased by less than 10% even after 6 catalytic cycles, which showed a remarkable reusability characteristic and high catalytic activity. Cu⁰ and Cu⁺ were found to co-exist in the catalysts and presented a high degradation effective for intermediates that were identified by liquid chromatography-mass spectrometry (LC-MS). These results indicated that the catalysts can be used as highly efficient Fenton-like catalyst for the degradation of toxic organic pollutants in wastewater. Graphical Abstract

Fourteen pesticides were screened and determined through quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction process combined with GC-MS/MS in arid agriculture soil. The aims of the current investigation were to account the occurrence of organochlorine (OCP) and organophosphates (OPP) pesticide residues as well as other groups of pyrethroids (PYRs), carbamates, and biopesticides using a combined of QuEChERS and GC-MS/MS techniques in agriculture soils at Al-Kharj region, Saudi Arabia, and to investigate correlation between pesticide losses in soils and some physicochemical characteristics of pesticides including an octanol-water coefficient partition (Kₒw) and the vapor pressure (Vp). Prediction of pesticide fate by considering both pesticide and soil physio-chemical properties will facilitate the management of pesticide application and minimize the hazards of environmental pollution. The fate of pesticide residue in soils is generally controlled by soil/air exchange, water interaction, and biodegradation. The results indicated that 14 pesticide residues were measured in collected samples of various soils, spinosad, chlorpyrifos methyl, dimethoate, chlorpyrifos, lindane (γ-HCH), permethrin, and methomyl which were the most abundant sources of contamination in the studied region. p,p-DDT, o,p-DDT, bifenthion, β-cyfluthrin, and methidathion were less commonly detected. Single parameter least squares regression equations (sp-LSRE) for Vp and Kₒw against the loss of each pesticide residue showed a significant change in concentration levels (p < 0.05) between the two seasons. The results showed that vapor pressure and octanol-water partition coefficient data are not enough to model pesticide residue losses in arid low organic carbon soil. More soil-related data is needed to describe the dissipation mechanisms of these pesticide residues in the region.

The reaeration coefficient (Kₐ₂₀) is one of the main indicators of dissolved O₂ movement to and from aquatic systems via the atmosphere. Direct gas tracer measurements, physical models, and models of O₂ dynamics have been used for Kₐ₂₀ estimation, especially in temperate aquatic ecosystems, with fewer examples in their tropical counterparts. Here we investigate a less commonly employed soluble floating probe (SFP) method, based on the dissolution rate of a soluble solid (VS₂₀) as an auxiliary variable for Kₐ₂₀ estimation. Our objectives were to test the SFP method for estimating Kₐ₂₀, validate such estimates through the traditional gas tracer method, and develop empirical models for Kₐ₂₀ prediction using VS₂₀ and additional physical variables. Five reaches (with lengths from 20 to 250 m) of four tropical headwater streams were selected, and their main physical, hydrological, and hydraulic variables were measured in eight sampling periods. The gas tracer (using NaCl and SF₆ tracers) and the SFP (spherical format made with oxalic acid dihydrate) methods were carried out in each reach. The Kₐ₂₀ values ​​ranged from 16.94 to 373.79 days⁻ ¹ and the VS₂₀ ranged from 0.079 to 0.778 mm min⁻ ¹. We observed a significant linear relationship between Kₐ₂₀ and VS₂₀. The best model (R² = 0.78) combined the variables depth, Froude number, and VS₂₀. Our study highlighted that models developed for temperate aquatic systems can underestimate Kₐ₂₀ in tropical streams, bringing uncertainties for modeling metabolic rates, self-depuration capacity, or any other processes that depend on reaeration.

This paper investigates the elasticity of substitution between four inputs—capital, labor, energy, and material—with the translog cost approach for a wide range of industries in Germany by incorporating the slow adjustment process in factor substitution. To this end, we take advantage of EU KLEMS database covering a wide range of industries and consider two models. The first is the static model, in which instantaneous and complete substitution adjustments are assumed. The other model, referred to as dynamic, takes into account the slow adjustment process and applies this to the cost share equations which are estimated using Zellner’s seemingly unrelated regression. The empirical results suggest that (i) the dynamic models have greater explanatory power than the static models; (ii) the production process at the national or industry level in Germany is mainly characterized by a complementarity or weak substitutability between energy and other inputs, which limits German government’s ability to reduce energy use through factor substitution; (iii) among four factor prices, energy demand seems to be more sensitive to changes in the price of material, followed by labor. Hence, an increase in energy prices can be efficient to some extent in order to reduce energy use; (iv) there is a substantial industry heterogeneity in Germany in terms of both input substitution and its adjustment process. Therefore, strategies to mitigate CO₂ emissions through input substitution channel should be designed at the industry level based on the industry-specific needs and peculiarities. It is because well-designed comprehensive policies that consider different structures of industries could help to achieve a carbon-neutral economy for Germany.

Dietary composition and husbandry practices largely determine the essential trace element status and the toxic metal exposure of livestock and consequently their concentrations in animal products. The main objective of this study was to determine the real contamination of selected areas of Slovakia compared with existing Environmental regionalization of the Slovak Republic (SR) created by the Ministry of the Environment SR. Another aim of this study was to determine the content of essential and toxic metals in feed and milk of dairy cows on selected farms in Slovakia referred to the suitability of the use of milk from these areas to other food processing. This article deals with the analysis of the content of selected elements in feed and milk of dairy cows in the area of Novoť (Northern Slovakia; area with undisturbed environment) and Čečejovce (Eastern Slovakia; highly disturbed environment). Eleven elements have been analyzed (essential elements: calcium, zinc, magnesium, selenium, iron, copper; toxic elements: arsenic, cadmium, mercury, lead, nickel). Samples of feed and milk were collected five times during the spring season and five times during the autumn season in 2016. Analysis of samples was performed in Eurofins Bel/Novamann (Nové Zámky, Slovak Republic). Analyses were performed by atomic absorption spectroscopy and atomic emission spectrometry. The obtained values of the individual elements in the feed and milk were evaluated by Student’s t test. Significantly higher contents of essential elements Ca, Zn, Fe, Mg, and Cu were found in the feed of dairy cows in Čečejovce (P < 0.001). Significantly higher (P < 0.001) As and Ni content in feed in Čečejovce in autumn season was also recorded. However, the content of these elements in feed did not affect their milk content. The content of Ca, Zn, and Mg in milk was significantly (P < 0.001) higher in Novoť in both investigated seasons. Some essential elements and toxic elements in feed and milk were below the LOQ (limit of quantification). Reduced content of Ca and Zn in milk in both farms compared with optimal limits, decreased Ca and Mg content in feed in Novoť, and a significant increase of Ca and Mg in feed in Čečejovce in autumn season were found. It can be concluded, due to the low content of toxic elements on these farms, that the use of milk of dairy cows from these areas for direct use or for dairy product processing is appropriate and poses no health risk to the consumers.

As observed among residents in electronic waste (e-waste) recycling areas, dioxins can disrupt the homeostasis of endocrine hormones and the balance of thyroid hormones. Few studies, however, have examined whether e-waste recycling activities influence steroid hormone equilibrium in the general adult male population. This study evaluated the association between steroid hormones and the physical burdens of dioxins in the general adult male population residing in an e-waste region. In September 2017, 74 adult males residing in an e-waste dismantling region were enrolled in the current study. Approximately 10 mL of blood was collected from each adult male, and the serum samples were separated through centrifugation. Then, the levels of dioxin and steroid hormones in the serum of the participants were measured. We treated dioxin levels as categorical variables in the general linear model according to quartiles (25, 50, and 75 percentile). Comparing the findings with a reference group (< 25th percentile), we noted significantly higher dehydroepiandrosterone (DHEA) level in men with low serum polychlorinated dibenzofuran-toxic equivalent (PCDFs-TEQ) level between 3.80 and 6.31 pg/g lipid (1933 vs. 1447 pg/ml) and low polychlorinated dibenzo-p-dioxins and dibenzofurans-TEQ (PCDD/PCDFs-TEQ) between 8.57 and 15.11 pg/g lipid (1996 vs. 1360 pg/ml). Moreover, a significantly higher androstenedione (A-dione) level was found in men whose serum PCDFs-TEQ ≥ 11.34 pg/g lipd (2404 vs. 1848). What’s more, there were significantly higher 3β-hydroxysteroid dehydrogenase (3β-HSD) concentrations in low- and high-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) groups (1.30–1.67 and ≥ 2.64 pg-TEQ/g lipid, respectively with 719 and 807 vs. 496, respectively). Our findings suggest that specific dioxin exposure may disturb normal DHEA, A-dione levels, and enzyme activity in the general adult male population in an e-waste region of China.

As eco-compensation is considered an effective economic instrument for controlling the industrial water pollution in transboundary basin, this study aims to explore a transboundary eco-compensation mechanism for Songhua River Basin that is one of the seven major drainage basins in China. Using a panel dataset of eleven cities in this basin tracked from 1992 to 2016, we empirically examined the environmental Kuznets curve (EKC) hypothesis by analyzing the relationship between economic development and industrial water pollution. Then, we developed two econometric models to quantify the wastewater discharge allowance and eco-compensation of investigated cities, respectively. The results specifically reveal the inverted U-curve effects of GRP (gross regional product) on industrial wastewater discharge, which displays an evidence of EKC in the field of transboundary water pollution in China. Moreover, our results verify the polluter pays principle that polluter should be responsible for its pollution behavior through paying of eco-compensation. Our results further interpret that the emissions trading program can help protect the ecosystem by allowing the wastewater discharge allowance to trading market.