The contribution of veterinary growth promoters (VGP) to the environmental burden of endocrine-disrupting chemicals (EDCs) is largely unknown. At cattle feedlots, the excrement of cattle may contain VGPs, which can contaminate aquatic systems and pose reproductive health risks. The study identifies VGPs used at cattle feedlots in South Africa and confirms associated estrogenic activity in feedlot runoff water. Using a rat model, we investigate the potential reproductive health effects and thyroid function of an environmentally relevant mixture of VGPs. Collected water samples had low levels of selected VGPs, and estrogenic activity was detected in the T47D-KBluc bioassay. Rats exposed to VGP had significant adverse effects on male reproductive health, including shortened anogenital distance, lowered sperm counts, disorganized seminiferous tubules, and thyroid parameters. In conclusion, VGP can contribute to complex environmental EDC mixtures and may adversely affect the reproductive and thyroid health of both humans and wildlife. The varied topography of individual cattle feedlots will govern the rate and extent of effluent runoff, thus continuous monitoring of VGPs in aquatic systems surrounding cattle feedlots is necessary.

A series of highly active amorphous manganese oxide catalysts for soot combustion were synthesized using colloidal solution combustion synthesis (CSCS) method. The surface morphological and structural properties were systematically tested via various techniques: X-ray diffraction, N₂ adsorption-desorption, temperature-programmed reduction, scanning electron microscopy, and X-ray photoelectron spectroscopy. Manganese precursors and calcination temperatures affect the crystal structure, redox properties, and surface properties of MnOx. With the calcination temperature increasing from 550 to 850 °C, the crystalline structure of manganese oxides changed from amorphous phase to crystal phase. In general, the amorphous MnOx with a hierarchical porous structure showed better catalytic activity for soot oxidation than the crystal ones (T₁₀ as indicator), which can be ascribed to the improved low-temperature reducibility, more surface active oxygen species, and abundant surface Mn⁴⁺ ions. The presence of NO in O₂ also promoted soot oxidation which follows the NO₂-assisted mechanism. Our work may provide a rational comparison between high-efficient amorphous and crystal MnOx catalysts for soot oxidation.

Vanadium (V) pollution in soil has been widely noted, while knowledge about the effect of soil colloid on migration of V is scarce. Batch adsorption-desorption and transportation of the colloid-adsorbed V in columns packed with quartz sand under various environment conditions were carried out to explore the retention and transportation of V by colloidal kaolinite. Batch adsorption-desorption studies show that the adsorption of V by the colloidal kaolinite was mainly specific adsorption and redox played a limited role in the adsorption process. The maximum adsorption capacity of the colloidal kaolinite was 712.4 mg g⁻¹, and about 5.9–8.7% of the adsorbed V could be desorbed. Both the adsorption-desorption and migration of V with colloidal kaolinite were highly ambient condition dependent. The column studies show that V was highly mobile in the saturated porous media. An easier transfer of V with an increase in pH, IS, and velocity of flow was noted. However, the increase of IS lead to the blockage of the colloidal kaolinite transportation. The recovery rate of the colloidal kaolinite at pH 7 and 9 was 2.0 and 2.1 times that at pH 5, respectively. The migration of colloidal-adsorbed V in sand column preceded that of V ion, but more colloidal-bound V than V ion remained in the column. Lack of consideration of the combination and co-transportation of V and colloidal kaolinite will lead to an overestimation of the risk of V to deeper soil profiles and groundwater. Graphical abstract

Feldspathic sandstone is a type of sandstone that is severely eroded by wind, rainfall, and gravity forces. The land surface in feldspathic area is degraded and covered with extremely low vegetation coverage. In this study, we propose a type of hydrophilic polyurethane (W-OH) to control its erosion and conduct the experiment to evaluate the consolidation performances. The results showed that the cementing materials (such as montmorillonite) are the main reason for the vulnerability of feldspathic sandstone to erosion, which expands by absorbing water. Additionally, the organic content is extremely low and is not suitable for vegetation growth. However, when the different concentrations of W-OH solution were sprayed on the feldspathic sandstone surface, the solution could penetrate in several minutes and form a flexible and porous consolidation layer. The anti-scourability index (K) of the layer could increase from approximately 0.2 to 1.0 which significantly increased the water resistance. The water retention benefit increased by 50%. In the simulated rainfall test, the sediment yield reduction in the treated slopes sprayed with the W-OH solution could reach 99% compared with that on the control slopes. The SEM images indicated that the W-OH solution enveloped the feldspathic sandstone particles and connected them tightly together. Therefore, the consolidation layer could decrease water erosion rate and reduce evaporation.

The study proposes an empirical model (based on stimulus-organism-response as conceptual framework) to analyse sojourners’ intention to adopt green practices (i.e., electronic consumption behaviour). Specifically, the proposed model comprises ethical, ecological and economic concerns as stimuli while mapping sojourners’ altruistic traits and beliefs in climate change, which further lead to their green behaviour. The study investigates a sample of 1184 sojourners in China. Results highlight that sojourners’ perceived concerns (stimuli) are partially mediated by sojourners’ altruistic traits and beliefs in climate change while defining their green behaviour. The novel contributions of the current study include determining sojourners’ green behaviour, the role of scientific literacy and regulatory policy in green behaviour and generalising and proposing the concept of sojourner leakage (adapted from tourism leakage). The study emphasises that sojourners can be strategic stakeholders by involving them in designing, implementing and communicating green policies and reforms in diverse societies.

Nitrosodipropylamine (NDPA) and nitrosodibutylamine (NDBA), two highly toxics and carcinogenic disinfection by-products, cannot be efficiently removed by conventional water treatment processes, while the ultrasound treatment was developed as a promising alternative. In this work, nitrosodipropylamine (NDPA) and nitrosodibutylamine (NDBA) are degraded by ultrasound treatment. Greater than 99% of NDPA and NDBA mixing solution could be decomposed within 60 min at neutral pH under optimal ultrasound power and frequency settings of 100 W and 600 kHz, respectively. Free radical reactions (OH•) played a significant role and the reaction sites were predominately at the bubble interface. The degradation of both NDPA and NDBA exhibited pseudo-first-order degradation kinetics, and the rate constant kₐₚₚ was influenced by a number of factors including ultrasonic frequency, power, initial concentration, initial pH, various anions and cations frequently present in drinking water, hydroxyl radical scavengers, and water matrices, especially the promoting effect of various anions and cations and water matrices. The results of this study suggest the potential for ultrasound treatment as a method for removing NAms from water.

Mercury and cadmium are highly dangerous metals that can lead to disastrous effects in animals and humans. The aim of the current research was to elucidate the poisonous effects of mercuric chloride and cadmium chloride individually and in combination on biochemical profiles of plasma and their accumulation in heart. The therapeutic effect of vitamin C against these metals in rabbits was also studied. Mercuric chloride (1.2 μg/g), cadmium chloride (1.5 μg/g), and vitamin C (150 μg/g of body weight) were orally given to treatment groups of the rabbits (1—control; 2—vitamin; 3—CdCl₂; 4—HgCl₂; 5—vitamin + CdCl₂; 6—vitamin + HgCl₂; 7—CdCl₂ + HgCl₂, and 8—vitamin + CdCl₂ + HgCl₂. After the biometric determination of all intoxicated rabbits, biochemical parameters, viz low-density lipoproteins (LDL), high-density lipoproteins (HDL), cholesterol, creatine kinase, and troponin T (TnT) were analyzed using available kits. Levels of cholesterol (0.7 ± 0.1 mmol/l), creatine kinase (2985.2 ± 11 IU/L), LDL (20.35 ± 1.31 mg/dl), and troponin T (1.22 ± 0.03 μg/l) were significantly (P < 0.05) increased. HDL (84.78 ± 4.30 mg/dl) was significantly (P < 0.05) decreased, while supplementation of vitamin C decreased the adverse effects of CdCl₂ and HgCl₂ on biochemical parameters in all metal-exposed groups. A similar trend was also seen in rabbits treated with CdCl₂ + vitamin and vitamin + CdCl₂ + HgCl₂. Accumulation of Cd and Hg was higher in heart tissues. This study, therefore, provides awareness on the cardiac toxicity of mercury and cadmium chlorides in the rabbits and the possible protective role of vitamin C against the perturbations induced by metals.

The present study aimed to evaluate the biochemical status of Venerupis decussata collected seasonally from two Tunisian coastline lagoons (Ghar El Melh and Boughrara) submitted to different anthropogenic levels. Trace elements were significantly higher in clams from Boughrara, especially during the warm season. Fatty acids, proximate compositions, and nutritional value of both clam populations were higher, appearing to be the best for human consumption principally during the spring season. The principal component analysis was determined, including phospholipids and reserve lipids, revealing a great variation with the exogenous and endogenous factors. Generally, clams from Boughrara had a significant alteration in biochemical composition principally due to the anthropogenic levels and physicochemical fluctuation of this lagoon. Our results reflected the healthy benefit of clam consumption and the use of energy reserves and essential fatty acids as a great biomarker to assess ecological risk in lagoons and other coastal ecosystems.

Some studies have shown that exposure to polycyclic aromatic hydrocarbons (PAHs) is a dangerous factor for attention deficit hyperactivity disorder (ADHD). This systematic review and meta-analysis aimed to clarify this relationship, and to collect and analyze all the relevant evidences in published reports of epidemiologic studies. PubMed, Science Direct, Web of Science, Scopus, and Google Scholar databases were searched through September 31, 2018. The study quality was evaluated using the Newcastle-Ottawa Scale. Moreover, fixed- and random-effect models were used. The data in this meta-analysis were presented as adjusted odds ratio (AOR). From 959 articles, six articles were included in the systematic review, and for meta-analysis, one study (that was not AOR) was excluded. The participants included in the studies were 2799 with the age range of 5–15 years old, and 93.6% were living in America. Four of the studies were placed in one group, due to having a common author (Perera). Moreover, a significant association was found between PAH exposure and ADHD in these studies (odds ratio = 2.57, 95% CI = 1.75–3.78); however, in all studies, there was no significant association between PAH exposure and ADHD for children (overall odds ratio = 1.99, 95% CI = 0.96–4.11) with low heterogeneity (I² = 28.73%; P value < 0.001). This study provided a systematic review and meta-analytic evidence for the association between PAH exposure and ADHD by a small number of studies. Further research study can be conducted in various countries. Graphical Abstract

Hazardous waste landfill leachate (HWLL) with high concentrations of salt and pollutants has created a bottleneck at hazardous waste landfills. This study applied a cement-based curing method to the disposal of HWLL. The highest contaminant fixing rate was achieved by adjusting the composition and proportion of the curing base, the content of additives, and the liquid-solid (L/S) ratio of the leachate to the curing base. The fixing rates for chemical oxygen demand and salt content in HWLL reached the highest values of 95.1% and 86.1%, respectively, when the Portland cement to metakaolin ratio was 3:2; the L/S was 1; and diatomite and activated carbon were added at 0.5% and 0.25%, respectively. The addition of glass fiber to the curing base improved the crack resistance of the solidified product. A simulated landfill experiment further indicated that after 116 days of leaching, the leachate effluent pollutant concentrations of the landfill column were lower than the effluent standard. Solidification is a feasible method for HWLL disposal.