Assessing the Release of Microplastics and Nanoplastics from Plastic Containers and Reusable Food Pouches: Implications for Human Health.

This study investigated the release of microplastics and nanoplastics from plastic containers and reusable food pouches under different usage scenarios, using DI water and 3% acetic acid as food simulants for aqueous foods and acidic foods. The results indicated that microwave heating caused the highest release of microplastics and nanoplastics into food compared to other usage scenarios, such as refrigeration or room-temperature storage. It was found that some containers could release as many as 4.22 million microplastic and 2.11 billion nanoplastic particles from only one square centimeter of plastic area within 3 min of microwave heating. Refrigeration and room-temperature storage for over six months can also release millions to billions of microplastics and nanoplastics. Additionally, the polyethylene-based food pouch released more particles than polypropylene-based plastic containers. Exposure modeling results suggested that the highest estimated daily intake was 20.3 ng/kg·day for infants drinking microwaved water and 22.1 ng/kg·day for toddlers consuming microwaved dairy products from polypropylene containers. Furthermore, an in vitro study conducted to assess the cell viability showed that the extracted microplastics and nanoplastics released from the plastic container can cause the death of 76.70 and 77.18% of human embryonic kidney cells (HEK293T) at 1000 µg/mL concentration after exposure of 48 and 72 h, respectively.

Impacts of Future Climate Variability on Atrazine Accumulation and Transport in Corn Production Areas in the Midwestern United States.

Atrazine is one of the most prevalent herbicides that has been widely applied to agricultural lands in the U.S. Understanding the transport and accumulation of atrazine in the subsurface under future climate scenarios is essential for future agriculture and water management. Here, we predict atrazine transport and accumulation under an intensive corn production land based on 20 projected global climate model (GCM) realizations, while considering uncertainties of transport parameters. Our study predicted continuous groundwater table declination and atrazine mass accumulation on the study site. We show that atrazine mass accumulation in corn production areas is subject to total precipitation in the atrazine application season, whereas atrazine plume movement is controlled by the sequence of annual precipitation. Atrazine mass transport and accumulation are more sensitive to climate variation on the field sites with low sorption and atrazine degradation rate. Under the extreme condition, the atrazine plume can migrate as far as five meters from the ground surface in only three years. While annual mean precipitation in the Midwestern U.S. is projected to increase in the future, groundwater vulnerability to atrazine and associated water quality impacts may rise in the U.S. Corn Belt, especially in sites with low atrazine degradation and sorption.

Toxicity assessment of p-choroaniline on Platymonas subcordiformis and its biodegradation.

The use of p-chloroaniline (PCA) in various aspects leads to its existence and accumulation in the environment. Relevant researches showed that PCA was a prime toxic pollutant that had imposed a serious risk to public health and the environment. This paper investigated the toxicity effects of PCA on Platymonas subcordiformis (P. subcordiformis) and the biodegradation of PCA by the marine microalga. In the toxicity experiments, the EC50 of PCA on P. subcordiformis at 24 h, 48 h, 72 h and 96 h was 41.42, 24.04, 17.15 and 13.05 mg L-1, respectively. The pigment parameters including chlorophyll a, chlorophyll b, carotenoids, photosynthetic O2 release rate, respiration O2 consumption rate and the chlorophyll fluorescence parameters including Fv/Fm, ETR and qP decreased greatly while antioxidant enzyme activities (SOD, CAT) and the chlorophyll fluorescence parameter NPQ increased when P. subcordiformis exposed to PCA compared with the control group. Fv/Fm would be a suitable indicator for assessing the toxicity of PCA in marine environment based on the analysis of Pearson's correlation coefficient and Integrated Biomarker Response (IBR). The degradation assay in P. subcordiformis indicated that the green marine microalga had the ability to remove and degrade PCA, and the order of removal and degradation proportion of PCA was 2 mg L-1 > 5 mg L-1>10 mg L-1. The maximum removal and biodegradation percentage was 54% and 34%, respectively.

MiR-143 regulates the proliferation and migration of osteosarcoma cells through targeting MAPK7.

Accumulating documents have been suggested that microRNA-143 (miR-143) function as a tumor suppressor, involved in many biological processes including tumor initiation and progression. However, the biological function and molecular mechanism of miR-143 in Osteosarcoma (OS) still remains to be further investigated. Despite many efforts have been made, the prognosis of OS is still unsatisfied. Thus, exploring the underlying mechanism of OS and finding new treatment targets is essential for improving the survival rate of OS patients. In our study, we determined the level of miR-143 in clinical OS tissues and cells, and explored its function and underlying mechanisms in the tumorigenesis of OS. Our findings revealed that miR-143 expression was significantly downregulated in OS tissues and cell lines. Gain-of-function assays indicated that forced expression of miR-143 in OS cells inhibited cell proliferation and migration/invasion. Bioinformatics and luciferase reporter assays confirmed that MAPK7 was targets gene of miR-143. The results of the present study indicated that miR-143 could be a potential target for treating OS.

Precipitation, temperature, and landcovers drive spatiotemporal variability of groundwater nitrate concentration across the Continental United States.

Groundwater nitrate contamination, especially in agriculturally active regions, is a well-recognized environmental concern. Understanding how this contamination evolves across the continental USA (CONUS) and through time is important to designing effective mitigation strategies. Despite extensive research on nitrate contamination, no existing studies can accurately predict changes in groundwater nitrate concentrations over time across the CONUS. To bridge this gap, we compiled a comprehensive dataset for a systematic evaluation of the potential influence of climate dynamics, landcover changes, and crucial soil and geological properties on groundwater contamination. We employed an interpretable machine learning approach, using 293,775 groundwater nitrate observations and 12 independent variables, to estimate annual groundwater nitrate concentrations at the county level from 2001 to 2020. Our model is the first one capable of accurately forecasting temporal changes in groundwater nitrate concentration across the entire CONUS. Our analysis reveals county level groundwater nitrate concentration changes occurred over the past two decades, particularly in regions initially with high concentrations in 2001, ranging from -16.2 mg/L-N to +6.5 mg/L-N between 2001 and 2020. 27 counties in the country appeared to have new concentrations greater than or equal to the maximum concentration level (MCL) at least once during this period. We revealed direct relationships between groundwater nitrate concentrations and climate factors, including that temperature and precipitation dominate the interannual variability in groundwater nitrate concentration in 75.2 % of counties. Notably, we have established a clear correlation between groundwater nitrate concentration and precipitation. Specifically, when annual precipitation falls below a threshold of about 748 mm, an increase of precipitation can directly result in elevated nitrate concentrations in groundwater, indicating heightened vulnerability to contamination due to climate change. This study forms a pivotal foundation for forecasting groundwater nitrate concentration changes across the continent and assessing the potential impact of climate change on future groundwater nitrate concentrations.

Transport and retention of colloids in porous media: does shape really matter?

The effect of particle shape on its transport and retention in porous media was evaluated by stretching carboxylate-modified fluorescent polystyrene spheres into rod shapes with aspect ratios of 2:1 and 4:1. Quartz crystal microbalance with dissipation (QCM-D) experiments were conducted to measure the deposition rates of spherical and rod-shaped nanoparticles to the collector (poly-l-lysine coated silica sensor) surface under favorable conditions. The spherical particles displayed a significantly higher deposition rate compared with that of the rod-shaped particles. Theoretical analysis based on Smoluchowski-Levich approximation indicated that the rod-shaped particles largely counterbalance the attractive energies due to higher hydrodynamic forces and torques experienced during their transport and rotation. Under unfavorable conditions, the retention of nanoparticles in a microfluidic flow cell packed with glass beads was studied with the use of laser scanning cytometry (LSC). Significantly more attachment was observed for rod-shaped particles than spherical particles, and the attachment rate of the rod-shaped particles showed an increasing trend with the increase in injection volume. Rod-shaped particles were found to be less sensitive to the surface charge heterogeneity change than spherical particles. Increased attachment rate of rod-shaped particles was attributed to surface heterogeneity and possibly enhanced hydrophobicity during the stretching process.

Improving the sweeping efficiency of permanganate into low permeable zones to treat TCE: experimental results and model development.

The residual buildup and treatment of dissolved contaminants in low permeable zones (LPZs) is a particularly challenging issue for injection-based remedial treatments. Our objective was to improve the sweeping efficiency of permanganate into LPZs to treat dissolved-phase TCE. This was accomplished by conducting transport experiments that quantified the ability of xanthan-MnO4(-) solutions to penetrate and cover (i.e., sweep) an LPZ that was surrounded by transmissive sands. By incorporating the non-Newtonian fluid xanthan with MnO4(-), penetration of MnO4(-) into the LPZ improved dramatically and sweeping efficiency reached 100% in fewer pore volumes. To quantify how xanthan improved TCE removal, we spiked the LPZ and surrounding sands with (14)C-lableled TCE and used a multistep flooding procedure that quantified the mass of (14)C-TCE oxidized and bypassed during treatment. Results showed that TCE mass removal was 1.4 times greater in experiments where xanthan was employed. Combining xanthan with MnO4(-) also reduced the mass of TCE in the LPZ that was potentially available for rebound. By coupling a multiple species reactive transport model with the Brinkman equation for non-Newtonian flow, the simulated amount of (14)C-TCE oxidized during transport matched experimental results. These observations support the use of xanthan as a means of enhancing MnO4(-) delivery into LPZs for the treatment of dissolved-phase TCE.

The Effect of Energy Use Rights Trading Policy on Environmental Performance: Evidence from Chinese 262 Cities.

This study provides empirical evidence and policy inspiration for China to implement the energy use rights trading policy. Using 262 cities in China from 2005 to 2019 as samples, we employed the double difference method and mediation analysis to empirically measure the impact of energy use rights trading policy on environmental performance. First, energy use rights trading policy can improve urban environmental performance. This conclusion is valid as per the endogeneity test, parallel trend test, PSM-DID test, placebo test, and triple difference method. Second, heterogeneity analysis shows that the effect of the energy use rights trading policy on urban environmental performance will be different by the size of population. Energy use rights trading policy has the greatest effect on the environmental performance of resource-based cities. Meanwhile, compared to non-industrial base, the effect of the energy use rights trading policy on environmental performance is more pronounced in cities with older industrial base. Third, the mechanism test using the mediation effect model proved that the impact of energy use rights trading policy on environmental performance is achieved by improving the level of marketization and technological innovation.

Application of machine learning in groundwater quality modeling - A comprehensive review.

Groundwater is a crucial resource across agricultural, civil, and industrial sectors. The prediction of groundwater pollution due to various chemical components is vital for planning, policymaking, and management of groundwater resources. In the last two decades, the application of machine learning (ML) techniques for groundwater quality (GWQ) modeling has grown exponentially. This review assesses all supervised, semi-supervised, unsupervised, and ensemble ML models implemented to predict any groundwater quality parameter, making this the most extensive modern review on this topic. Neural networks are the most used ML model in GWQ modeling. Their usage has declined in recent years, giving rise to more accurate or advanced techniques such as deep learning or unsupervised algorithms. Iran and the United States lead the world in areas modeled, with a wealth of historical data available. Nitrate has been modeled most exhaustively, targeted by nearly half of all studies. Advancements in future work will be made with further implementation of deep learning and explainable artificial intelligence or other cutting-edge techniques, application of these techniques for sparsely studied variables, the modeling of new or unique study areas, and the implementation of ML techniques for groundwater quality management.

Pore-scale investigation of nanoparticle transport in saturated porous media using laser scanning cytometry.

Knowledge of nanoparticle transport and retention mechanisms is essential for both the risk assessment and environmental application of engineered nanomaterials. Laser scanning cytometry, an emerging technology, was used for the first time to investigate the transport of fluorescent nanoparticles in a microfluidic flow cell packed with glass beads. The laser scanning cytometer (LSC) was able to provide the spatial distribution of 64 nm fluorescent nanoparticles attached in a domain of 12 mm long and 5 mm wide. After 40 pV of injection at a lower ionic strength condition (3 mM NaCl, pH 7.0), fewer fluorescent nanoparticles were attached to the center of the flow cell, where the pore-scale velocity is relatively higher. After a longer injection period (300 PV), more were attached to the center of the flow cell, and particles were attached to both the upstream and downstream sides of a glass bead. Nanoparticles attached under a higher ionic strength condition (100 mM NaCl, pH 7.0) were found to be mobilized when flushed with DI water. The mobilized particles were later reattached to some favorable sites. The attachment efficiency factor was found to reduce with an increase in flow velocity. However, torque analysis based on the secondary energy minimum could not explain the observed hydrodynamic effect on the attachment efficiency factor.

Enhanced mobility of fullerene (C60) nanoparticles in the presence of stabilizing agents.

Experimental and mathematical modeling studies were performed to examine the effects of stabilizing agents on the transport and retention of fullerene nanoparticles (nC(60)) in water-saturated quartz sand. Three stabilizing systems were considered: naturally occurring compounds known to stabilize nanoparticles (Suwannee river humic acid (SRHA) and fulvic acid (SRFA)), synthetic additives used to enhance nanoparticle stability (Tween 80, a nonionic surfactant), and residual contaminants resulting from the manufacturing process (tetrahydrofuran (THF)). The results of column experiments demonstrated that the presence of THF, at concentrations up to 44.5 mg/L, did not alter nC(60) transport and retention behavior, whereas addition of SRHA (20 mg C/L), SRFA (20 mg C/L), or Tween 80 (1000 mg/L) to the influent nC(60) suspensions dramatically increased the mobility of nC(60), as demonstrated by coincidental nanoparticle and nonreactive tracer effluent breakthrough curves (BTCs) and minimal nC(60) retention. When columns were preflushed with surfactant, nC(60) transport was significantly enhanced compared to that in the absence of a stabilizing agent. The presence of adsorbed Tween 80 resulted in nC(60) BTCs characterized by a declining plateau and retention profiles that exhibited hyperexponential decay. The observed nC(60) transport and retention behavior was accurately captured by a mathematical model that accounted for coupled surfactant adsorption-desorption dynamics, surfactant-nanoparticle interactions, and particle attachment kinetics.

Does air quality improvement promote enterprise productivity increase? Based on the spatial spillover effect of 242 cities in China.

Introduction: Air pollution not only harms people's health, but also impedes urban economic development. This study aims to analyze how air quality improvement affects enterprise productivity. And then from regional and time heterogeneities' aspects to investigate if the air quality improvement increase enterprise productivity. Methods: The data were obtained from China Industrial Enterprise Database and China Patent Database,and this study used Spatial Durbin Model to analyze how air quality improvement affects enterprise productivity. Results: The results show that: (1) air quality improvement and its spatial spillover effect can significantly increase enterprise productivity in adjacent areas. (2) After 2010, the government implemented more stringent measures to prevent and control air pollution, which made the air quality improvement promote enterprise productivity increase more obviously. The air quality improvement in eastern and central regions was less obvious than in western regions. (3) Air quality improvement can increase enterprise productivity by improving enterprise innovation quality, ensuring the health of urban residents, and increasing the stock of urban human capital. Conclusion: Air quality improvement and its spatial spillover effect can significantly increase enterprise productivity in adjacent areas. So this study puts forward some policy enlightenment, such as establishing an air pollution detection system, using an intelligent network supervision platform, and implementing a coordinated defense and governance system.

Down-regulation of GAS5 has diagnostic value for tuberculosis and regulates the inflammatory response in mycobacterium tuberculosis infected THP-1 cells.

OBJECTIVE: This study aimed to investigate the expression of long non-coding RNA (lncRNA) growth arrest-special transcript 5 (GAS5) in the serum of tuberculosis (TB) patients and discuss the mechanism of GAS5 in TB by establishing an in-vitro TB cell model. METHODS: Serum expressions of GAS5 and miR-18a-5p were determined by quantitative real-time PCR (qRT-PCR). The effects of GAS5 on macrophage cell viability and the inflammatory response after MTB infection were assessed by CCK-8 and ELISA. Luciferase reporter gene assay was applied to delve into the potential target gene of GAS5. RESULTS: The expression of GAS5 in TB patients was down-regulated, while miR-18a-5p was up-regulated, and the serum inflammatory factors were negatively correlated with the expression level of GAS5. MTB infection induced significant upregulation on the cell viability and inflammatory response but the acceleration effect could be rescued by GAS5-overexpression. Meanwhile, miR-18a-5p was recognized as the target gene of GAS5. CONCLUSION: This study indicated that the expression level of GAS5 in the serum of TB patients was decreased, while in the cells infected with MTB, the down-regulated GAS5 might develop a role in facilitating the cell vitality and the inflammatory response by adsorbing miR-18a-5p in the form of molecular sponge.

Modeling the release and spreading of permanganate from aerated slow-release oxidants in a laboratory flow tank.

Aerated, slow-release oxidants are a relatively new technology for treating contaminated aquifers. A critical need for advancing this technology is developing a reliable method for predicting the radius of influence (ROI) around each drive point. In this work, we report a series of laboratory flow tank experiments and numerical modeling efforts designed to predict the release and spreading of permanganate from aerated oxidant candles (oxidant-wax composites). To mimic the design of the oxidant delivery system used in the field, a double screen was used in a series of flow tank experiments where the oxidant was placed inside the inner screen and air was bubbled upward in the gap between the screens. This airflow pattern creates an airlift pump that causes water and oxidant to be dispersed from the top of the outer screen and drawn in at the bottom. Using this design, we observed that permanganate spreading and ROI increased with aeration and decreased with advection. A coupled bubble flow and transport model was able to successfully reproduce observed results by mimicking the upward shape and spreading of permanganate under various aeration and advection rates.

Modeling the impact of evolving biofilms on flow in porous media inside a microfluidic channel.

This study integrates microfluidic experiments and mathematical modeling to study the impacts of biofilms on flow in porous media and to explore approaches to simplify modeling permeability with complicated biofilm geometries. E. coli biofilms were grown in a microfluidic channel packed with a single layer of glass beads to reach three biofilm levels: low, intermediate, and high, with biofilm ratios (ßr) of 2.7%, 17.6%, and 55.2%, respectively. Two-dimensional biofilm structures and distributions in the porous medium were modeled by digitizing confocal images and considering broad ranges of biofilm permeability (kb) (from 10-15 m2 to 10-7 m2) and biofilm porosity (εb) (from 0.2 to 0.8). The overall permeability of the porous medium (k), the flow pathways and the overall/local pressure gradients were found to be highly dependent on ßr and kb but were moderately impacted by εb when the biofilm levels were high and intermediate with kb>10-11 m2. When biofilm structures are well developed, simplified biofilm geometries, such as uniform coating and symmetric contact filling, can provide reasonable approximations of k.

Modeling the vertical transport of antibiotic resistance genes in agricultural soils following manure application.

Antibiotic resistance genes (ARGs) may be introduced to agricultural soil through the land application of cattle manure. During a rainfall event, manure-borne ARGs may infiltrate into subsurface soil and leach into groundwater. The objective of this study was to characterize and model the vertical transport of manure-borne ARGs through soil following the land application of beef cattle manure on soil surface. In this study, soil column experiments were conducted to evaluate the influence of manure application on subsurface transport of four ARGs: erm(C), erm(F), tet(O) and tet(Q). An attachment-detachment model with the decay of ARGs in the soil was used to simulate the breakthrough of ARGs in leachates from the control column (without manure) and treatment (with manure) soil columns. Results showed that the first-order attachment coefficient (ka) was five to six orders of magnitude higher in the treatment column than in the control column. Conversely, the first-order detachment and decay coefficients (kd and µs) were not significantly changed due to manure application. These findings suggest that in areas where manure is land-applied, some manure-borne bacteria-associated ARGs will be attached to the soil, instead of leaching to groundwater in near terms.

Characterization of dissolved organic matter derived from coal gangue packed in underground reservoirs of coal mines using fluorescence and absorbance spectroscopy.

Organic and nitrogen pollutants in mine water could be removed effectively during the storage and transport of water in a coal mine underground reservoir packed with coal gangue through various water-rock interactions. However, little is known about the effect of the released dissolved organic matter (DOM) derived from the packed matrix on their removal. Column experiments were performed at a Darcy flux of 1.56 cm·h-1 at 25 °C to investigate the characteristics of DOM derived from Jurassic and Permian coal gangue individually packed in underground reservoirs of Bulianta (BL1) and Baode (BD2) coal mines. Chemical characteristics of the DOM were analyzed by using the ultraviolet and visible (UV-Vis) absorbance and fluorescence spectroscopy techniques. Results showed that the values of dissolved organic carbon (DOC) and electricity (EC) in the outlet of column packed with BL1 were obviously higher than those from BD2 due to the higher permeability of BL1 with more complex mineralogical and chemical compositions. The parallel factor analysis (PARAFAC) indicated that the fluorescence components in the DOM derived from BL1 and BD2 were individually dominated by the humic-like and tryptophan-like substances. Thus, the higher aromaticity, hydrophobicity, and humification indicated by the specific ultraviolet absorbance at 254 nm (SUVA254) and 260 nm (SUVA260) and humification index (HIX) were observed in the DOM from the younger Jurassic BL1, implying that the DOM may contain more plant-derived precursors. Meanwhile, the higher values of fluorescence index (FI) and biological/autochthonous index (BIX) confirmed the stronger autochthonous characterization of DOM originated from the earlier Permian BD2. The observed characterization of DOM will further extend the understanding of purification mechanism of mine water during its storage and transport in coal mine underground reservoirs packed with coal gangue of different geologic ages.

Toxic effect of p-chloroaniline and butyl acrylateon Nannochloropsis oculata based on water samples from two sea areas.

To compare the influence of water samples collected from various areas on toxic effect of HNS, we examined the toxic effect of two commonly found HNS: p-chloroaniline and butyl acrylate, on Nannochloropsis oculata cultured in seawater collected from Laizhou bay and Jiaozhou bay (China). The results showed that both p-chloroaniline and butyl acrylate had significant toxic effect on N. oculata cultured in both water samples. P-chloroaniline inhibited its net oxygenation rate and oxygen consumption rate. Butyl acrylate inhibited the net oxygenation rate whereas significantly stimulated oxygen consumption rate. Performance of N. oculata changed between two water samples under same level of p-chloroaniline and butyl acrylate. The net oxygenation rate of N. oculata cultured in the seawater from the Jiaozhou bay increased by 11.60 %, the oxygen consumption rate increased by 26.91 %, algae cell growth decreased by 16.83 %, compared to those from Laizhou bay. The Fv/Fm of N. oculata cultured in Jiaozhou bay was more significantly inhibited at 0.5 and 2.0 mg L-1 p-chloroaniline, while it was significantly inhibited at 5. 0 mg L-1 of butyl acrylate, compared to those from Laizhou bay. Moreover, the toxic effect of both HNS on net oxygenation rate and oxygen consumption rate were significantly attenuated as the concentration increased. The growth inhibition of microalgae cultured in two seawater samples was more evident at 0.5 and 5.0 mg L-1 p-chloroaniline than at 2.0 mg L-1 p-chloroaniline,and the growth inhibition of microalgae cultured in two seawater samples was more evident at 2.0 and 5.0 mg L-1 butyl acrylate than at 0.5 mg L-1 butyl acrylate. These results indicated that toxic effect of p-chloroaniline and butyl acrylate on the growth of N. oculata was influenced by the pollutants in the two water samples. Consequently, a corresponding research on water sample is required in advance to increase accuracy of future ecological risk assessment of HNS.

Transport and retention of fullerene nanoparticles in natural soils.

Commercial production and use of fullerene (C60) nanomaterials will inevitably lead to their release into the environment, where knowledge of C60 fate and transport is limited. In this study, a series of one-dimensional column experiments was conducted to assess the transport and retention of nanoscale fullerene aggregates (nC60) in water-saturated soils. Under the experimental conditions, complete retention of nC60 was observed in columns (2.5 cm inside diameter x 11 cm length) packed with Appling or Webster soil, which contain 0.75 and 3.33% organic carbon by weight, respectively. When the volume of aqueous nC60 suspension (approximately 4.5 mg L(-1)) applied to Appling soil was increased from 5 to 65 pore volumes, the travel distance increased from 3 to 8 cm, and the retention capacity approached a limiting value of 130 microg g(-1), although nC60 was not detected in the column effluent. The addition of 20 mg C L(-1) Suwannee River humic acid to the influent suspension increased the nC60 transport in Appling soil but did not resul in breakthrough. Attempts to simulate the experimental data using clean-bed filtration theory were not satisfactory, yielding retention profiles that failed to match observed data. Subsequent incorporation of a limiting retention capacity expression into the mathematical model resulted in accurate predictions of the measured nC60 retention profiles and transport behavior. The sizable retention capacities observed in this study suggest that transport of nC60 is limited in relatively fine-textured soils containing appreciable amounts of clay minerals and organic matter, with substantial accumulation of nC60 aggregates near the point of release.