Acrylamide (AA) has been identified as probably carcinogenic to humans and thus represents a potential public health threat. This study aimed to determine the urinary concentrations of AA and N-acetyl-S-(2-carbamoylethyl)-L-cysteine (AAMA) in a nationally representative sample (n = 1025) of children and adolescents (age range 3–18 years) in South Korea. The AA and AAMA detection rates and geometric mean concentrations were 97%, 19.1 ng/mL, and 98.7%, 26.4 ng/mL, respectively. Although urinary AA levels did not vary widely by age (17.2 ng/mL at 3–6 years, 19.9 ng/mL at 7–18 years), the urinary concentration of AAMA increased with age (18.3 ng/mL at 3–6 years, 30.4 ng/mL at 7–18 years). A multiple linear regression analysis revealed that the urinary levels of AA and AAMA varied significantly by sex, with the adjusted proportional changes indicating rates of 1.47- to 1.48-fold higher at 3–6 years and 1.36- to 1.68-fold higher at 7–18 years among males relative to females. Furthermore, the urinary levels of AA and AAMA correlated with the consumption of certain foods (doughnuts, hotdogs, popcorn, and nachos) among male subjects aged 7–18 years. The urinary concentrations of AA and AAMA increased significantly with the smoking status and passive smoking exposure, with adjusted proportional changes of 1.51 to 1.71-fold higher among smokers relative to non-smokers in the age range of 7–18 years. Exposure to smoking for > 30 min led to adjusted proportional increases in AA and AAMA of 1.51 and 1.77 times in the non-smoking group aged 3–6 years and a 1.52-fold increase in AAMA in the non-smoking group aged 7–18 years. In conclusion, the urinary levels of AA and AAMA were found to associate with age, sex, smoking, and food consumption in a population of Korean children and adolescents.

A new set up of the integral mechanistic BIO_ALGAE model that describes the complex interactions in mixed algal-bacterial systems was developed to overcome some restrictions of the model. BIO_ALGAE 2 includes new sub-models that take into account the variation of microalgae and bacteria performance as a function of culture conditions prevailing in microalgae cultures (pH, temperature, dissolved oxygen) over daily and seasonal cycles and the implementation of on-demand dioxide carbon injection for pH control. Moreover, another aim of this work was to study a correlation between the mass transfer coefficient and the hydrodynamics of reactor. The model was calibrated using real data from a laboratory reactor fed with real wastewater. Moreover, the model was used to simulate daily variations of different components in the pond (dissolved oxygen, pH, and CO₂ injection) and to predict microalgae (XALG) and bacteria (XH) proportions and to estimate daily biomass production (Cb). The effect of CO₂ injection and the influence of wastewater composition on treatment performance were investigated through practical study cases. XALG decreased by 38%, and XH increased by 35% with respect to the system under pH control while microalgae and bacteria proportions are completely different as a function of influent wastewater composition. Model simulations have indicated that Cb production (~ 100 gTSS m⁻³ day⁻¹ for manure and centrate) resulted lower than Cb production obtained using primary influent wastewater (155 gTSS m⁻³ day⁻¹).

The degradation of roxithromycin (ROX) by hydroxyl radical (·OH) generated by UV/H₂O₂ was systematically investigated in terms of degradation kinetics, effects of water chemistry parameters, oxidation products, as well as toxicity evaluation. The degradation of ROX by UV/H₂O₂ with varying light irradiation intensity, initial ROX concentration, and H₂O₂ concentration in pure water and wastewater all followed pseudo-first-order kinetics. The second-order rate constant for reaction between ROX and ·OH is 5.68 ± 0.34 × 10⁹/M/s. The degradation rate of ROX increased with the pH; for instance, the apparent degradation rates were 0.0162 and 0.0309/min for pH 4 and pH 9, respectively. The presence of natural organic matter (NOM) at its concentrations up to 10 mg C/L did not significantly affect the removal of ROX. NO₃⁻ and NO₂⁻ anions inhibited the degradation of ROX due to the consumption of ·OH in reactions with these ions. Fe³⁺, Cu²⁺, and Mg²⁺ cations inhibited the degradation of ROX, probably because of the formation of ROX-metal chelates. A total of ten degradation products were tentatively identified by HPLC/LTQ-Orbitrap XL MS, which mainly derived from the attack on the oxygen linking the lactone ring and the cladinose moiety, tertiary amine and oxime side chain moiety by ·OH. The toxicity evaluation revealed that UV/H₂O₂ treatment of ROX induced the toxicity to bioluminescent bacteria increased.

Waste electrical and electronic equipment (WEEE) contains both toxic and valuable materials. Due to rapid development of information and communication technologies (ICT), a large amount of WEEE have been produced, leading to increasing academic efforts in this field. This study aims to depict the trends and features of WEEE-related studies through a bibliometric analysis. The results show that the total number of WEEE-related publications had sharply increased, with China as the leading country. University of Chinese Academy of Sciences is the most productive WEEE-related research institution, while Mai BX is the most productive author. As such, Waste Management, Journal of Cleaner Production, and Environmental Science & Technology are the most influential journals. The research hotspots of WEEE mainly focus on the recycling and treatment technologies, environmental impacts, and relevant policies of WEEE. By tracing the evolutionary pathway of WEEE research, it is clear that the research frontiers have switched from electronic equipment, extended producer responsibility, sediment, environment and design, risk assessment to life cycle assessment, mobile phone, and behaviors. This study provides valuable insights to those WEEE-related scholars so that they can identify their own research topics and partners. This paper is one of the first studies in WEEE research field that offers critical discussions and suggestions related to research development and future trends, and used visualized tools to present the holistic picture of this field.

There are a limited number of studies on the estimation of environmental Kuznets curve (EKC) hypothesis for nitrous oxide (N₂O) emissions, though it is one of the most harmful greenhouse gases (GHGs) present in ambient atmosphere. In the wake of industrialization, it is necessary to understand the impact of energy consumption pattern on N₂O emissions and revise the energy policies accordingly. In this study, we have analyzed the impact of renewable and fossil fuel energy consumptions on N₂O emissions for APEC countries over the period of 1990–2015, and the analysis has been carried out following the EKC hypothesis framework. The results obtained from the study indicate the efficacy of the renewable energy solutions in having positive impact on environmental quality by helping to reduce the level of N₂O emissions. The policy implications derived from the results are designed while keeping the objectives of sustainable development goals (SDGs) in mind, so that the energy policies can bring forth sustainability in the economic systems in these nations.

Schizophyllum commune is a filamentous basidiomycete which can degrade complex organic macromolecules like lignin by the secretion of a large repertoire of enzymes. One of these white rot enzymes, laccase, exhibits a broad substrate specificity and is able to oxidize a variety of substances including carbonaceous rocks. To investigate the role of laccase in bioweathering, laccase gene lcc2 was overexpressed, and the influence on weathering of black slate, originating from a former alum mine in Schmiedefeld, Germany, was examined. The metal release from the rock material was enhanced, associated with a partial metal accumulation into the mycelium. A sequestration of metals could be shown with fluorescent staining methods, and an accumulation of Zn, Cd, and Pb was visualized in different cell organelles. Additionally, we could show an increased metal resistance of the laccase overexpressing strain.

This paper determines the impact of two clay minerals (kaolinite and montmorillonite) and three oxides (goethite, δ-MnO₂, and bayerite) on the elemental composition and FTIR spectra of humic-like acid (HLA) extracted from microbial-mineral residue formed from the microbial utilization of lignin in liquid shake flask cultivation. Goethite, bayerite, and δ-MnO₂ showed higher enrichment capabilities of C and O + S in the HLA than kaolinite and montmorillonite. Goethite showed the highest retention of organic C, followed by bayerite, but kaolinite exhibited the least exchangeability. Kaolinite and montmorillonite enhanced microbial consumption of N, resulting in the absence of N in HLA. A few aliphatic fractions were preferentially gathered on the surfaces of kaolinite and montmorillonite, making the H/C ratios of HLA from the clay mineral treatments higher than those of HLA from the oxide treatments. δ-MnO₂ was considered the most effective catalyst for abiotic humification, and goethite and bayerite ranked second and third in this regard. This trend was proportional to their specific surface areas (SSAs). However, comparing the effects of different treatments on the promotion of HLA condensation by relying solely on the SSA of minerals was not sufficient, and other influencing mechanisms had to be considered as well. Additionally, Si–O–Al and Si–O of kaolinite participated in HLA formation, and Si–OH, Si–O, and Si–O–Al of montmorillonite also contributed to this biological process. Fe–O and phenolic –OH of goethite, Mn–O of δ-MnO₂, and Al–O of bayerite were all involved in HLA formation through ligand exchange and cation bridges. Lignin was better protected from microbial decomposition by the kaolinite, bayerite, and δ-MnO₂ treatments, which caused lignin-like humus (HS) formation. Under the treatments of δ-MnO₂, goethite, and bayerite, HLA showed a greater degree of condensation compared to HLA precipitated by kaolinite and montmorillonite. Contributions from Si–O, and Si–O–Al of clay minerals, and Fe–O, Mn–O, and Al–O of oxides were the mechanisms by which minerals catalyzed the formation of HS from lignin.

Mining tailing areas may contain metal minerals such as Cu, Pb, Zn, Cr, and Cd at high concentrations and low nutrients for the growth of plants. This kind of conditions of the area, as well as lack of tailing structure, may limit the development of plants on these areas. Thus, the present study determined the metal, macronutrient, and micronutrient concentrations in the tissues of the roots and shoots of the Solanum viarum Dunal species as well as it evaluated the potential use of the plant for phytoremediation of mining tailing areas contaminated with heavy metals. The macronutrients, micronutrients, and heavy metals in the roots and shoots were determined by the digestion method with nitric and perchloric acid (HNO₃-HClO₄) and quantified by the ICP-OES. In S. viarum, the average concentrations of the metals presented in the dry biomass varied between the shoots and roots, being higher in the roots for metals such as Cu (229 mg kg⁻¹), Zn (232 mg kg⁻¹), Mn (251 mg kg⁻¹), Cr (382 mg kg⁻¹), Ni (178 mg kg⁻¹), Pb (33 mg kg⁻¹), and Ba (1123 mg kg⁻¹). S. viarum indicates the possibility of a potential application in phytoremediation and treatment of areas contaminated with heavy metals.

Milk can be considered as an indicator of the degree of environmental contamination of the place where it is produced and this is especially important when assessing its content in toxic metals. Therefore, 36 bovine milk samples from 7 farms with a semi-extensive grazing system were analysed, located in Asturias (Spain), in an area with high probability of being highly contaminated due to a mining zone, with important industrial activity and near high-density highway traffic. The samples were lyophilised to achieve total dehydration, further analysed using inductively coupled plasma mass spectrometry (ICP-MS). The metals titrated were aluminium (Al), arsenic (As), molybdenum (Mo) and mercury (Hg) in the lyophilised samples and subsequently extrapolated their values to whole milk. All samples analysed showed levels of Al and Mo above the limit of detection, with mean values of Al of 140.89 ± 157.07 in liquid milk and 1065.76 ± 1073.45 in lyophilised milk and Mo of 20.72 ± 14.61 μg/kg and 152.26 ± 96.82 μg/kg in whole and lyophilised milk. Only As was detected in four samples with mean values of 18.45 ± 6.89 and 166.45 ± 42.30 μg/kg in liquid and lyophilised milk, respectively, and no Hg was found in any of them. In no case do the values found indicate a significant hazard to the population and are in agreement with those found in other investigations. Although the various anthropogenic activities of the area (industrial, mining, traffic density) could, a priori, indicate a possibly contaminated area.

The consequence of carcinogenic and non-carcinogenic health risks of the heavy metal concentrations in street dust of North Cyprus is yet to be reported. This study is aimed at investigating the concentration of six different heavy metals’ concentration explicitly: As, Cu, Zn, Ni, Cr, and Pb, along leading highways in Nicosia. The result obtained was analyzed using an X-ray fluorescent machine. Multivariate and statistical methods were applied for the data analysis using xlstat MS-excel; furthermore, index of geo-accumulation (Igeo) and human health risk assessment using exposure pathways as defined by United State Environmental Protection Agency (USEPA) pollution mode were also used for level assessment and health risk implications. The average (M ± SD) concentrations of the metals in the dust are as follows: As (17.48 ± 1.53 mg/kg), Cu (51.86 ± 8.60 mg/kg), Cr (321.14 ± 8.20 mg/kg), Pb (35.62 ± 8.54 mg/kg), Ni (64.79 ± 8.72 mg/kg), and Zn (136.13 ± 30.85 mg/kg). Variation coefficient, Vc, and principle component analysis (PCA) suggested that As, Cr, Ni, and Pb have same source of pollution emission from both natural and anthropogenic activities, Zn from traffic emission while Cu from natural source. However, the result was compared with other nearby towns bordering North Cyprus; all the metal shows similar pattern of pollution with the exception of Cr which is 5 and 11 times higher than street dust of Amman (Jordan) and Tokat (Turkey), respectively. Additionally, Igeo result has the following decreasing order: Zn > Cr > Pb > Ni > Cu > As and also revealed that the As, Cu, and Ni have originated from natural source. Cr has mix source: one from traffic and the other one from atmospheric deposition. Also, Pb is emitted from industrial pollution, whereas 80% of Zn are from traffic-related emissions. The non-carcinogenic health risk (hazard quotient (HQ) and hazard index (HI)) follows the order Cr > As>Ni > Pb > Zn > Cu for children and adults. It is found that the HI of As, Cu, Ni, Pb, and Zn is less one; hence, the street dust does not exhibit non-carcinogenic health risk. But that of Cr content is greater than one, with HI values of Cr 1.44E+02 and 1.55E+01 for children and adults, respectively. The result for carcinogenic health risk (total cancer risk (TCR)) has the following order: Pb (1.42E−05) > Cr (4.81E−09) > (Ni 1.35E−09) > As (1.96E−10). With all the values less than threshed hole limit of TCR ≥ 10⁻⁴, street dust does not possess carcinogenic health risk for the entire values of six heavy metals considered in this work.