Methane (CH₄) production from anaerobic digestion of solid and liquid agro-industrial wastes is an attractive strategy to meet the growing need for renewable energy sources and promote environmentally appropriate disposal of organic wastes. This work aimed at determining the CH₄ production potential of six agro-industrial wastewaters (AWW), evaluating the most promising for methanization purposes. It also aims to provide kinetic parameters and stoichiometric coefficients of CH₄ production and define which kinetic models are most suitable for simulating the CH₄ production of the evaluated substrates. The AWW studied were swine wastewater (SW), slaughterhouse wastewater (SHW), dairy wastewater (DW), brewery wastewater (BW), fruit processing wastewater (FPW), and residual glycerol (RG) of biodiesel production. RG was the substrate that showed the highest methanization potential. Exponential kinetic models can be efficiently applied for describing CH₄ production of more soluble substrates. On the other hand, logistic models were more suitable to predict the CH₄ production of more complex substrates.

Contamination status, potential emission sources, environmental fate, and human exposure risk of polybrominated diphenyl ethers (PBDEs) are reviewed for indoor and outdoor dust from Southeast Asian countries, under an international comparison point of view. PBDEs have been widely detected in house, workplace, car, and road dust samples collected from Indonesia, Philippines, Singapore, Thailand, and Vietnam. The highest PBDE levels up to hundreds of μg/g were found in settled dust from some e-waste processing areas in Thailand and Vietnam. Concentrations of PBDEs in house, car, and road dust from this region were generally lower than those reported in China and Western developed countries. BDE-209 was the most predominant congener in almost all analyzed samples, reflecting the widespread application of materials and products treated with commercial deca-BDE mixtures in this region. The market demand and application rate of commercial PBDE mixtures in Southeast Asia were lower than those documented for other regions in the world. As a result, PBDE contamination levels in the environments (e.g., indoor and outdoor dust) and associated risks in these countries were not significantly high. However, more attention should be paid to informal processing activities and management strategies for modern wastes such as e-waste, plastics, and end-of-life vehicles. There exist several knowledge gaps about spatiotemporal trends, potential sources, risk assessment, inventory, management, and legislation regarding PBDEs in dust from this region, which should be filled by additional comprehensive, detailed studies with relevant inter-country/regional monitoring schemes.

Pyriproxyfen is a juvenile hormone analogue insecticide used worldwide. At present, the potential threat of pyriproxyfen to aquatic organism has not been well explored. In this work, the bioaccumulation, metabolic profile and toxicity of pyriproxyfen and its metabolites to zebrafish were studied, and the enantioselectivity of pyriproxyfen and the major chiral metabolites were also determined. Sixteen metabolites of pyriproxyfen in zebrafish were identified. Hydroxylation, ether linkage cleavage and oxidation in phase I metabolism, followed by sulfate and glucuronic acid conjugation. The bioconcentration factors ranged from 1175 to 1246. Hydroxylation metabolites of pyriproxyfen showed enantioselective behavior in zebrafish with enantiomer fractions (EFs) of 4′–OH– pyriproxyfen and 5″–OH– pyriproxyfen ranged from 0.50 to 0.71. Toxicological indexes including acute toxicity, joint toxicity and oxidative stress were tested. Among all the metabolites, 4′–OH– pyriproxyfen was found 2 folds more toxic to zebrafish than pyriproxyfen. (−)-Pyriproxyfen was found 2 folds more toxic than rac- and (+)-pyriproxyfen. Antagonistic effects were found in binary joint toxicity of pyriproxyfen and its hydroxylated metabolites. Pyriproxyfen and its metabolites also showed oxidative stress damage by inhibiting the activity of CAT and SOD and increasing MDA. This work provided deep insight into the metabolism and the potential risks of pyriproxyfen to aquatic organisms.

Potential suppression of fertility due to mobile phone radiation remains a focus of researchers. We conducted meta-analyses on the effects of mobile phone radiation on sperm quality using recent evidence and propose some perspectives on this issue. Using the MEDLINE/PubMed, Embase, WOS, CENTRAL, and ClinicalTrials.gov databases, we retrieved and screened studies published before December 2020 on the effects of mobile phone use/mobile phone RF-EMR on sperm quality. Thirty-nine studies were included. Data quality and general information of the studies were evaluated and recorded. Sperm quality data (density, motility, viability, morphology, and DFI) were compiled for further analyses, and we conducted subgroup, sensitivity, and publication bias analyses. The pooled results of human cross-sectional studies did not support an association of mobile phone use and a decline in sperm quality. Different study areas contributed to the heterogeneity of the studies. In East Europe and West Asia, mobile phone use was correlated with a decline in sperm density and motility. Mobile phone RF-EMR exposure could decrease the motility and viability of mature human sperm in vitro. The pooled results of animal studies showed that mobile phone RF-EMR exposure could suppress sperm motility and viability. Furthermore, it reduced sperm density in mice, in rats older than 10 weeks, and in rats restrained during exposure. Differences regarding age, modeling method, exposure device, and exposure time contributed to the heterogeneity of animal studies. Previous studies have extensively investigated and demonstrated the adverse effects of mobile phone radiation on sperm. In the future, new standardized criteria should be applied to evaluate potential effects of mobile phone RF-EMR dosages. Further sperm-related parameters at the functional and molecular levels as well as changes in biological characteristics of germ cells should be evaluated. Moreover, the impact of mobile phone RF-EMR on individual organs should also be examined.

Ambient fine particulate matter (PM₂.₅) is a worldwide environmental problem and is posing a serious threat to human health. Until now, the molecular toxicological mechanisms and the crucial toxic components of PM₂.₅ remain to be clarified. This study investigated the whole transcriptomic changes in THP-1 derived macrophages treated with different types of PM₂.₅ extracts using RNA sequencing technique. Bioinformatics analyses covering biological functions, signal pathways, protein networks and node genes were performed to explore the candidate pathways and critical genes, and to find the potential molecular mechanisms. Results of Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes pathway (KEGG), and protein-protein interaction (PPI) networks revealed that water extracts (WEs) of PM₂.₅ obviously influenced genes and molecular pathways responded to oxidative stress and inflammation. Dichloromethane extracts (DEs) specifically affected genes and signal cascades related to cell cycle progress process. Furthermore, compared with WEs collected in heating season, non-heating season WEs induced much higher expression levels of Ca-associated genes (including phosphodiesterase 4B and cyclooxygenase-2), which may consequently result in more severe inflammatory responses. While, for DEs exposure, the heating season (DH) group showed extensive induction of deferentially expressed genes (DEGs) related to cell cycle pathway, which may be caused by the higher polycyclic aromatic hydrocarbons (PAHs) contents in DH samples than those from non-heating season. In conclusion, the oxidative stress and inflammation response are closely correlated with cellular responses in THP-1 derived macrophages induced by water soluble components of PM₂.₅, and cell cycle dysregulation may play an important role in biological effects induced by organic components. The different transcriptomic changes induced by seasonal PM₂.₅ extracts may partially depend on the contents of PAHs and metal ions, respectively.

In many countries, including Morocco, groundwater contamination with pesticides such as globally banned organochlorides (e.g., dichlorodiphenyltrichloroethane (DDT)) and some accredited organophosphates and pyrethroids poses ecological and human health risks. To assess these risks, we herein monitored pesticides in Saïss plain groundwater (Morocco) during the summer of 2017 and the winter of 2018 using polar organic chemical integrative samplers. The two types of passive samplers were deployed in 22 traditional wells for 14–20 days and subjected to solid-phase extraction. The extracts were analyzed by gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry using a multiresidue method, and 27 pesticides were detected in total. In the summer campaign, 22 pesticides with individual concentrations ranging from <limit of quantitation (LOQ) to 243.1 ng L⁻¹ were identified, whereas 17 compounds with concentrations ranging from <LOQ to 53.8 ng L⁻¹ were detected in the winter campaign. In the summer period, the maximum individual concentrations of chlorothalonil, DDT, and α-hexachlorocyclohexane (α-HCH) equaled 111.7, 36.1, and 22.3 ng L⁻¹, respectively, with the respective values for the winter period equaling 18.14, 16.62, and 22.2 ng L⁻¹. Health risk assessment indicated that the carcinogenic α-HCH, β-HCH, DDT, and dichlorodiphenyldichloroethylene present in groundwater may also contaminate drinking water and thus pose a threat to human health, particularly to that of infants and children. Further analysis revealed that the Saïss aquifer presents a high ecological risk. Thus, the monitoring of pesticides in groundwater by passive sampling was effective and could be combined with human health and ecological risk assessment to develop ways of reducing human and environmental exposure to pesticides.

A total of 106 24-h PM₂.₅ aerosol samples were collected in an urban area (Shijiazhuang, SJZ) and a suburban area (Liulihe, LLH, Fangshan County, Beijing) in the Beijing-Tianjin-Hebei (BTH) region in 2 periods: the first is from 10 July to 10 August, which is before Sept. Third Parade (Period I); the second is from 20 Aug. to 6 Sept. 2015, which is during Sept. Third Parade (Period II). Polar organic tracers, including isoprene, α-pinene, β-caryophyllene and toluene oxidation products, as well as sugars and carboxylic acids were measured. In Period II, rigorous emission-reduction measures were taken in the BTH region. With the anthropogenic emission being cut down significantly, the average concentrations of isoprene, α-pinene, β-caryophyllene and toluene oxidation products and all carboxylic acids (except tetradecanoic, palmitic, and stearic acids), were lower in Period II than those in Period I in LLH, indicating that the SOA tracers were decreased with precursor emission volumes and yields in the atmosphere. Moreover, sugar compounds were shown with comparable levels during the two periods in LLH, suggesting that no measures were taken to reduce the intensities of the biogenic sources. On the contrary, tetradecanoic, palmitic, and stearic acids were shown with obviously higher concentrations in Period II than those in Period I, demonstrating that cooking fumes increased during Sept. Third Parade period.The positive matrix factorization (PMF) model combining with tracer-based method was applied to explore the sources of secondary organic carbon (SOC). It reveals that the sources of SOC include isoprene, α-pinene, β-caryophyllene and toluene oxidation products, fossil fuel combustion, cooking fumes and regionally transferred aged aerosols. These sources accounted for 11.3%, 9.0%, 15.5%, 10.9%, 29.2%, 2.9%, 21.1% of SOC for SJZ, and 12.7%, 11.2%, 9.7%, 14.4%, 25.3%, 0%, 26.7% of SOC for LLH, during the whole sampling periods respectively.

Facile modification is a common, but effective, option to improve the uptake removal capacity of of activated carbon (AC) against diverse target volatile organic compounds (VOCs; e.g., benzene) in gaseous streams. To help design the routes for such modification, this research built strategies to generate three types of modified ACs by incorporating amine/sulfur/amino-silane groups under solvothermal or microwave (MW) thermal conditions. The adsorption performance has been tested using a total of six types of AC sorbents (three modified + three pristine forms) for the capture of 1 Pa benzene (1 atm and 298 K). The obtained results are evaluated in relation to their textural properties and surface functionalities. Accordingly, the enhancement of AC surface basicity (e.g., point of zero charge (PZC) = 10.25), attained via the silylation process, is accompanied by the reduced adsorption of benzene (a weak base). In contrast, ACs amended with amine/sulfur (electron-donating) groups using the MW technique are found to acquire high surface acidity (PZC of 5.99–6.05) to exhibit significantly improved benzene capturing capability (relative to all others). Their uplifted performance is demonstrated in terms of key performance metrics such as breakthrough volume (BTV10%: 163 → 443 L g⁻¹), adsorption capacity (Q10%: 4.82 → 13.6 mg g⁻¹), and partition coefficient (PC10%: 0.516 → 1.67 mol kg⁻¹ Pa⁻¹). Based on the kinetic analysis, the overall adsorption process is found to be governed by pore diffusion as the main rate-determining step, along with surface interaction mechanisms. The results of this research clearly support the critical role of surface chemistry of AC adsorbents and their textural properties in upgrading air/gas purification systems.

To control the spread of the 2019 novel coronavirus (COVID-19), China imposed rigorous restrictions, which resulted in great reductions in pollutant emissions. This study examines the characteristics of air pollutants, including PM₂.₅ (particles with aerodynamic diameters < 2.5 μm), gas pollutants, water-soluble ions (WSIs), black carbon (BC) and elements, as well as the source apportionment of PM₂.₅ in Suzhou before, during and after the Chinese New Year (CNY) holiday of 2020 (when China was under an unprecedented state of lockdown to restrict the COVID-19 outbreak). Compared to those before CNY, PM₂.₅, BC, SNA (sulfate, nitrate and ammonium), other ions, elements, and NO₂ and CO mass concentrations decreased by 9.9%–64.0% during CNY. The lockdown policy had strong (weak) effects on the diurnal variations in aerosol chemical compositions (gas pollutants). Compared to those before CNY, source concentrations and contributions of vehicle exhaust during CNY decreased by 72.9% and 21.7%, respectively. In contrast, increased contributions from coal combustion and industry were observed during CNY, which were recorded to be 2.9 and 1.7 times higher than those before CNY, respectively. This study highlights that the lockdown policy that was imposed in Suzhou during CNY not only reduced the mass concentrations of air pollutants but also modified their diurnal variations and the source contributions of PM₂.₅, which revealed the complex responses of PM₂.₅ sources to the rare, low emissions of anthropogenic pollutants that occurred during the COVID-19 lockdown.

Fish Embryo Acute Toxicity (FET) test was proposed as an alternative to the traditional test methods using larval or adult fish. However, whether fathead minnow (Pimephales promelas) embryo is appropriate for FET remains uncertain. In the present study, ecological threshold of toxicological concern (ecoTTC) values and uncertainty factors (UFs) for each Verhaar et al. category in P. promelas were identified by employing probabilistic ecological risk assessment (PERA) approach with chemical toxicity distributions (CTDs). The sensitivity among different life stages and toxicity among different mode of actions (MOAs) classes were comprehensively compared by CTD comparisons. The results showed that embryo exhibited the less or similar sensitivity compared to larva or adult for Verhaar et al. MOA classes (1-4) while adults were more sensitive, followed by embryo than larval for non-classified chemicals. Considering growth effect as endpoint to class 1, class 3, and non-classified chemicals on P. promelas embryo and larva was more sensitive than mortality. Non-classified chemicals especially inorganic compounds were most toxic to P. promelas embryo for the four concerned Verharr et al. MOA-specific chemical classes. This study also derived uncertainty factors (UFs) as 26.5 (9.8, 109) for embryo-to-larva, 6.26 (3.94, 11.0) for embryo-to-adult, 15.6 (10.1, 36.1) for mortality-to-growth, and 3.03 (1.86, 7.08) for mortality-to-reproduction, which can be applied for extrapolations of life stage-to-life stage and effect-to-effect to reduce the underestimating and overestimating risk by the use of default UF such as 10, 100 or 1000. Our findings are vital for feasibility of FET test of P. promelas for ecotoxicity testing and ecological risk assessment for chemicals with different MOAs.