Microplastics and Nanoplastics in Atheromas and Cardiovascular Events.

BACKGROUND: Microplastics and nanoplastics (MNPs) are emerging as a potential risk factor for cardiovascular disease in preclinical studies. Direct evidence that this risk extends to humans is lacking. METHODS: We conducted a prospective, multicenter, observational study involving patients who were undergoing carotid endarterectomy for asymptomatic carotid artery disease. The excised carotid plaque specimens were analyzed for the presence of MNPs with the use of pyrolysis-gas chromatography-mass spectrometry, stable isotope analysis, and electron microscopy. Inflammatory biomarkers were assessed with enzyme-linked immunosorbent assay and immunohistochemical assay. The primary end point was a composite of myocardial infarction, stroke, or death from any cause among patients who had evidence of MNPs in plaque as compared with patients with plaque that showed no evidence of MNPs. RESULTS: A total of 304 patients were enrolled in the study, and 257 completed a mean (±SD) follow-up of 33.7±6.9 months. Polyethylene was detected in carotid artery plaque of 150 patients (58.4%), with a mean level of 21.7±24.5 µg per milligram of plaque; 31 patients (12.1%) also had measurable amounts of polyvinyl chloride, with a mean level of 5.2±2.4 µg per milligram of plaque. Electron microscopy revealed visible, jagged-edged foreign particles among plaque macrophages and scattered in the external debris. Radiographic examination showed that some of these particles included chlorine. Patients in whom MNPs were detected within the atheroma were at higher risk for a primary end-point event than those in whom these substances were not detected (hazard ratio, 4.53; 95% confidence interval, 2.00 to 10.27; P<0.001). CONCLUSIONS: In this study, patients with carotid artery plaque in which MNPs were detected had a higher risk of a composite of myocardial infarction, stroke, or death from any cause at 34 months of follow-up than those in whom MNPs were not detected. (Funded by Programmi di Ricerca Scientifica di Rilevante Interesse Nazionale and others; ClinicalTrials.gov number, NCT05900947.).

Electrochemical Removal of Nitrogen Compounds from a Simulated Saline Wastewater.

In the last few years, many industrial sectors have generated and discharged large volumes of saline wastewater into the environment. In the present work, the electrochemical removal of nitrogen compounds from synthetic saline wastewater was investigated through a lab-scale experimental reactor. Experiments were carried out to examine the impacts of the operational parameters, such as electrolyte composition and concentration, applied current intensity, and initial ammoniacal nitrogen concentration, on the total nitrogen removal efficiency. Using NaCl as an electrolyte, the NTOT removal was higher than Na2SO4 and NaClO4; however, increasing the initial NaCl concentration over 250 mg·L-1 resulted in no benefits for the NTOT removal efficiency. A rise in the current intensity from 0.05 A to 0.15 A resulted in an improvement in NTOT removal. Nevertheless, a further increase to 0.25 A led to basically no enhancement of the efficiency. A lower initial ammoniacal nitrogen concentration resulted in higher removal efficiency. The highest NTOT removal (about 75%) was achieved after 90 min of treatment operating with a NaCl concentration of 250 mg·L-1 at an applied current intensity of 0.15 A and with an initial ammoniacal nitrogen concentration of 13 mg·L-1. The nitrogen degradation mechanism proposed assumes a series-parallel reaction system, with a first step in which NH4+ is in equilibrium with NH3. Moreover, the nitrogen molar balance showed that the main product of nitrogen oxidation was N2, but NO3- was also detected. Collectively, electrochemical treatment is a promising approach for the removal of nitrogen compounds from impacted saline wastewater.

Application of Electrochemical Oxidation for Water and Wastewater Treatment: An Overview.

In recent years, the discharge of various emerging pollutants, chemicals, and dyes in water and wastewater has represented one of the prominent human problems. Since water pollution is directly related to human health, highly resistant and emerging compounds in aquatic environments will pose many potential risks to the health of all living beings. Therefore, water pollution is a very acute problem that has constantly increased in recent years with the expansion of various industries. Consequently, choosing efficient and innovative wastewater treatment methods to remove contaminants is crucial. Among advanced oxidation processes, electrochemical oxidation (EO) is the most common and effective method for removing persistent pollutants from municipal and industrial wastewater. However, despite the great progress in using EO to treat real wastewater, there are still many gaps. This is due to the lack of comprehensive information on the operating parameters which affect the process and its operating costs. In this paper, among various scientific articles, the impact of operational parameters on the EO performances, a comparison between different electrochemical reactor configurations, and a report on general mechanisms of electrochemical oxidation of organic pollutants have been reported. Moreover, an evaluation of cost analysis and energy consumption requirements have also been discussed. Finally, the combination process between EO and photocatalysis (PC), called photoelectrocatalysis (PEC), has been discussed and reviewed briefly. This article shows that there is a direct relationship between important operating parameters with the amount of costs and the final removal efficiency of emerging pollutants. Optimal operating conditions can be achieved by paying special attention to reactor design, which can lead to higher efficiency and more efficient treatment. The rapid development of EO for removing emerging pollutants from impacted water and its combination with other green methods can result in more efficient approaches to face the pressing water pollution challenge. PEC proved to be a promising pollutants degradation technology, in which renewable energy sources can be adopted as a primer to perform an environmentally friendly water treatment.

Sorption of Organic Pollutants by Humic Acids: A Review.

Humic acids (HA) are promising green materials for water and wastewater treatment. They show a strong ability to sorb cationic and hydrophobic organic pollutants. Cationic compounds interact mainly by electrostatic interaction with the deprotonated carboxylic groups of HA. Other functional groups of HA such as quinones, may form covalent bonds with aromatic ammines or similar organic compounds. Computational and experimental works show that the interaction of HA with hydrophobic organics is mainly due to π-π interactions, hydrophobic effect and hydrogen bonding. Several works report that sorbing efficiency is related to the hydrophobicity of the sorbate. Papers about the interaction between organic pollutants and humic acids dissolved in solution, in the solid state and adsorbed onto solid particles, like aluminosilicates and magnetic materials, are reviewed and discussed. A short discussion of the thermodynamics and kinetics of the sorption process, with indication of the main mistakes reported in literature, is also given.

Unscrambling why plastics aren't detectable in chicken eggs.

Several food groups have been reported to contain varying concentrations of plastics. This study was designed to quantitatively investigate for the first time in Australia the presence of plastics in store-bought chicken eggs. Three commonly consumed brands of free-range, free-range organic, barn-laid and backyard (home-laid) chicken egg samples were analyzed for seven common polymers (i.e., polypropylene, polyethylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, poly-(methylmethacrylate) and polycarbonate)). Samples were extracted by enzyme digestion and pressurized liquid extraction, followed by quantitative analysis through double-shot microfurnace pyrolysis coupled to gas chromatography-mass spectrometry. No plastics were detected at concentrations >limit of detection (LOD) (from 0.04 µg/g for PS to 0.22 µg/g for PVC) in the egg samples analyzed, regardless of brand and category, suggesting limited exposure of Australians to plastics from consuming eggs This study provides valuable baseline data and underscores the importance of continued monitoring to ensure the safety and integrity of food supplies in the face of rising environmental plastic pollution.

Efficient electrochemical removal of ammoniacal nitrogen from livestock wastewater: The role of the electrode material.

Wastewater from livestock farms contains high concentrations of suspended solids, organic contaminants, and nitrogen compounds, such as ammoniacal nitrogen. Discharging livestock effluents into water bodies without appropriate treatment leads to severe environmental pollution. Compared to conventional treatment methods, electrochemical oxidation exhibits higher nitrogen removal efficiencies. In the present work, the electrochemical removal of ammoniacal nitrogen from real livestock wastewater was investigated through a lab-scale reactor. Preliminary experiments were carried out to investigate the effects of different anode materials, including boron-doped diamond and iridium/ruthenium-coated titanium, on the total nitrogen removal efficiency using synthetic wastewater. Boron-doped diamond, a well-known non-active electrode, allowed to obtain 63.7 ± 1.21 % of total nitrogen degradation efficiency. However, the iridium/ruthenium-coated titanium electrode, belonging to the class of active anodes, showed a higher performance, achieving 78.8 ± 0.76 % contaminant degradation. Coupling iridium/ruthenium-coated titanium anode with a stainless-steel cathode improved the performance of the system, achieving even 96.2 ± 2.73 % of total nitrogen removal. The optimized cell configuration was used to treat livestock wastewater, resulting in the degradation of 67.0 ± 2.25 % of total nitrogen and 37.3 ± 0.68 % of total organic carbon when sodium chloride was added. At the end of the process, the ammonium content was completely removed, and only 17.7 ± 0.51 % of the initial nitrogen turned into nitrate. The results show that the proposed system is a promising approach to treating livestock wastewater by coupling high contaminant removal efficiencies with low operational costs. Anyway, further studies on process optimization with an emphasis on power requirements and electrode costs need to be carried out.