Impacts of particulate matter (PM2.5) on the behavior of freshwater snail Parafossarulus striatulus

Toxic responses of environmental concentrations of bifenthrin in larval freshwater snail Bellamya aeruginosa

Bifenthrin (BF) is ubiquitous in aquatic environments, and studies have indicated that environmental concentrations of BF could cause neurotoxicity and oxidative damage in fish and decrease the abundance of aquatic insects. However, little information is available on the toxicity of BF in freshwater benthic mollusks. Bellamya aeruginosa (B. aeruginosa) is a key benthic fauna species in aquatic ecosystems, and has extremely high economic and ecological values. In this study, larval B. aeruginosa within 24 h of birth were exposed to 0, 30 or 300 ng/L of BF for 30 days, and then the toxic effects from molecular to individual levels were comprehensively evaluated in all the three treatment groups. It was found that BF at 300 ng/L caused the mortality of snails. Furthermore, BF affected snail behaviors, evidenced by reduced crawling distance and crawling speed. The hepatopancreas of snails in the two BF exposure groups showed significant pathological changes, including increase in the number of yellow granules and occurrence of hemocyte infiltration, epithelial cell thinning, and necrosis. The levels of ROS and MDA were significantly increased after exposure to 300 ng/L BF, and the activities of two antioxidant enzymes SOD and CAT were increased significantly. GSH content decreased significantly after BF exposure, indicating the occurrence of oxidative damage in snails. Transcriptomic results showed that differentially expressed genes (DEGs) were significantly enriched in pathways related to metabolism and neurotoxicity (e.g., oxidative phosphorylation and Parkinson disease), and these results were consistent with those in individual and biochemical levels above. The study indicates that environmental concentration of BF results in decreased survival rates, sluggish behavior, histopathological lesions, oxidative damage, and transcriptomic changes in the larvae of B. aeruginosa. Thus, exposure of larval snails to BF in the wild at concentrations similar to those used in this study might have adverse consequences at the population level. These findings provide a theoretical basis for further assessing the ecological risk of BF to aquatic gastropods.

Oxidative stress and neurotoxicity induced by exposure to settleable atmospheric particulate matter in bullfrog tadpoles, Aquarana catesbeiana, (Shaw, 1802)

Bullfrog tadpoles, Aquarana catesbeiana, were exposed to settleable particulate matter (SePM), (1 g L-1, 96 h) and their organs were collected for analysis of metal/metalloid, oxidative stress and neurotoxicity in liver, muscle, kidney and brain. The SePM water of the exposed groups contained 18 of the 28 metals/metalloids detected in ambient particulate matter (APM). Fe56 and Al were those that presented the highest concentrations, Cr, Mn, Pb and Cu increased from 10 to 20 times and Ti, V, Sr, Rb, Cd, Sn and Ni increased from 1 to 3 times compared to the control. Bioaccumulation of metals/metalloids in the exposure water varied significantly between organs, with the muscle and liver showing the highest concentrations of metals, followed by the brain. Lipoperoxidation and malondialdehyde increased only in muscle, while carbonyl proteins increased only in the liver and brain. Regarding nitric oxide synthase, there was an increase in the liver and brain in the group exposed to SePM. Catalase activity decreased in the liver and muscle, while the activity of glutathione peroxidase, increased in the liver and kidney and decreased in muscle. Glutathione S-transferase, which is mainly responsible for detoxification, increased in the liver and decreased in muscle and the kidney. Cholinesterase activity increased only in the muscle. The results indicate oxidative stress, due to oxidation catalyzed by metals, components of SePM. Thus, the results contribute to the understanding that SePM has a deleterious effect on the aquatic environment, negatively affecting bullfrog tadpoles, in different ways and levels in relation to the analyzed organs.

Global economic structure transition boosts PM2.5-related human health impact in Belt and Road Initiative

The Belt and Road Initiative (BRI) is an open platform for international cooperation proposed by China to promote common global development and prosperity. The BRI can promote the optimal allocation of resources and promote in-depth cooperation in international trade. Meanwhile, it can establish a green supply chain cooperation network to help BRI countries achieve green transformation. BRI has made a notable contribution to the rapid growth of cross-border trade. However, it has also brought environmental impacts. Given that little attention has been paid to the trade-embodied particulate matter 2.5 related human health impacts (PM2.5-HHI) throughout the BRI, this study accounts for and traces the embodied PM2.5-HHI flows between the BRI countries and non-Belt and Road Initiative (non-BRI) countries. Moreover, this study also uncovers the critical socioeconomic drivers of PM2.5-HHI changes in BRI countries during 1990-2015, based on the multi-regional input-output based structural decomposition analysis (MRIO-SDA). Results show that, firstly, BRI countries had significantly increased their economic added value by exporting products to the non-BRI countries. They also have brought PM2.5-HHI to themselves. Secondly, the final demand of BRI countries was the largest potential driving force of PM2.5-HHI of BRI countries. Thirdly, the emission intensity change of BRI is the key socioeconomic factor for reducing PM2.5-HHI. While per capita final demand level change of BRI and production structure change of non-BRI are the key socioeconomic factors for increasing PM2.5-HHI. The study's findings on the one hand can help reduce the PM2.5-HHI and impacts of environmental pollution of BRI countries from a global perspective by providing scientific support. On the other hand, they can help provide relevant policy recommendations for the green transformation of BRI and the construction of green BRI.

Spatial variation and chemical reactivity of dusts from open-pit bitumen mining using trace elements in snow

The chemical reactivity of trace elements (TEs) in dusts from bitumen mining, upgrading and related industrial activities in the Athabasca Bituminous Sands region (ABS), Alberta, Canada, was evaluated using the acid-soluble fraction of snow. Samples were collected at 14 sites along the Athabasca River (AR) and its tributaries, and at 3 remote locations. Following metal-free, ultra-clean procedures for processing and analysis, samples were leached with nitric acid (pH < 1), filtered (<0.45 μm), and analyzed using ICP-MS. Insoluble particles (>0.45 μm) were examined using SEM-EDS. Along the river, acid-soluble concentrations of TEs varied by 6 orders of magnitude, from 1 mg/L (Al) to less than 1 ng/L (Tl). Conservative (Al, Y, La, Th) and mobile (Li, Be, Cs, Sr) lithophile elements, those enriched in bitumen (V, Ni, Mo), and potentially toxic chalcophile elements (As, Cd, Pb, Sb, Tl) showed considerable spatial variation. Normalizing the concentrations of TEs in samples collected near industry to the corresponding concentrations in snow from the reference site (UTK), resulted in enrichments of V and most of the lithophile elements. Dust reactivity, quantified as the ratio of acid-soluble to total concentrations, was less than 50% suggesting limited bioaccessibility. The large differences in behaviour between Cd and Pb versus Ni and V could be due to the occurrence of the former pair in carbonate or sulfide minerals, versus acid-insoluble petcoke particles for the latter couple. Spatial variations in the reactivity of TEs most likely reflect the range in diversity and chemical stability of dust particles, and variations in their abundance in primary source areas. The leaching conditions employed here are extreme (pH < 1) and intended to identify an upper limit of chemical reactivity, with far less dust dissolution expected when these dusts encounter natural waters of the area which range in pH from 4 to 8.

Assessing the ecological risk induced by PM2.5 pollution in a fast developing urban agglomeration of southeastern China

High PM_2.5 concentration threats ecosystem functions but limited quantitative studies have recognized PM_2.5 pollution as an individual stressor in evaluating ecological risk. In this study, we applied a machine-learning-based simulation model incorporating full-coverage satellite-driven PM_2.5 dataset to estimate high-resolution ground PM_2.5 concentration for the Golden Triangle of Southern Fujian Province, China (GTSF) in 2030 under two Representative Concentration Pathways (RCPs). Based on the simulation output, the ecological risk's spatiotemporal change and the risk for different land cover types, which were caused by PM_2.5 pollution, were assessed. We found that the PM_2.5 levels and ecological risk in the GTSF under RCP 4.5 would be reduced while those under RCP 8.5 would continue to increase. The regions with the highest ecological risk under RCP 4.5 are the most urbanized and industrialized districts, while those with the highest ecological risk under RCP 8.5 are of the highest rate in urbanization and the greatest decrease in planetary potential layer height. For both base years and 2030 under two RCPs, the ecological risk on developed land is the highest, while that on the forest is the lowest. Our study can provide useful information for environmental policy risk assessment.

Effects of particulate matter (PM2.5) on life history traits, oxidative stress, and defensome system in the marine copepod Tigriopus japonicus

Particulate matter (PM_2.5) generated in large cities creates new problems in marine ecosystems and may adversely affect its inhabitants. However, the mechanisms underlying the same remain unclear; hence, we investigated the effects of PM_2.5 on life history traits (e.g., mortality, development, and fecundity), cellular reactive oxygen species (ROS) levels, antioxidant enzyme (e.g., glutathione peroxidase [GPx], superoxide dismutase [SOD], and catalase [CAT]) activities, and the transcript levels of detoxification-related genes (cytochrome P450s [CYPs]) and antioxidant (glutathione S-transferases [GSTs]) in the copepod Tigriopus japonicus. Among the life history traits, developmental time was the only trait to significantly deviate (P < 0.05) in response to PM_2.5 (compared to that in the controls). Significant changes in ROS levels and antioxidant enzymatic activities (P < 0.05) in response to PM_2.5, suggested that PM_2.5 can induce oxidative stress, leading to adverse effects on the T. japonicus life history. In addition, PM_2.5 induced a differential regulation of various CYP and GST genes, particularly CYP307E1, GST-kappa, and GST-sigma were significantly upregulated (P < 0.05), suggesting that these genes likely play crucial roles in detoxification mechanisms and could be useful as reliable biomarkers for PM_2.5 toxicity. Overall, the results of this study provide new insights into the potential toxicity of PM_2.5.

Detrimental impact of fine dust on zebrafish: Investigating a protective agent against ocular-damage using in vitro and in vivo models

Pollution caused by fine dust is becoming a global problem in the aquatic environment. Many studies have investigated the hazards that fine dust may pose to terrestrial organisms; however, information on the effects on aquatic environments remain limited. In this study, the physicochemical characteristics of the fine dust associated with the captured powder or liquid state were compared using scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). Raw fine dust (RFD), in the captured powder state, was suspended in water (SFD), and the elemental composition, morphology, and size distribution of both were analyzed. Zebrafish were used as a model to study the effects of SFD-exposure on aquatic organisms. A fatal malformation was observed in the integuments of zebrafish exposed to SFD, specifically in the exterior and interior eye tissues. Furthermore, the exposure of SFD to Tg (flk; EGFP) zebrafish remarkably increased ocular vessel diameter expansion along with blood flow velocity. Regarding vessel diameter expansion, EA.hy926 cells exposed to SFD were adversely affected, with a significant increase in cell migration and capillary-like structure formation, which are angiogenic markers. The SFD-induced angiogenesis in vitro and in vivo was dramatically restored to normal via α/β-adenosine isolated from the anti-angiogenic brown algae Ishige okamurae extract. Taken together, the current study presents solid evidence of the altered physicochemical characteristics of SFD compared to RFD, and the detrimental impact of SFD in an aquatic in vivo zebrafish model. In addition, the protective effect of α/β-adenosine, a marine natural product, on SFD-induced angiogenesis suggests that it can be used as an agent to reduce the adverse effects of SFD on aquatic animals.

Assessment of the effects of seasonality on the ecotoxicity induced by the particulate matter using the animal model Caenorhabditis elegans

The present work aimed to establish potential changes in the ecotoxicological effects on C. elegans induced by the exposure of coarse (PM₁₀) and fine (PM_2.5) particulate matter collected during dry and rainy periods. We also analyzed the probable influence on the change of a city's activities as the mega-events result in air quality. The element levels evaluation was performed on PM, on the solutions of exposure, and C. elegans after exposure. Biochemical essays were performed to evaluate damage to C. elegans. The results showed that infrastructure works increased the levels of pollutants, generating increases in the concentrations of PM_2.5 and PM₁₀. The biochemical results suggested effects mediated by different mechanisms, where PM_2.5 induced an increase in antioxidant capacity with activation of the defense system and lipoperoxidation. Results suggest that PM₁₀ reduces the antioxidant capacity and activates the glutathione S-transferase activity enzymatic action, but also induces lipoperoxidation in all groups of animals exposed to samples collected during the dry period of 2016. Individuals exposed to PM_2.5 in 2017 wet and dry periods and PM₁₀ in 2016 and 2017 dry periods shown a decrease in size compared to controls, while for fertility data, there was a decrease only in individuals exposed to PM_2.5 in the periods that the highest levels of PM concentration. We conclude that despite the positive issues linked to the hosting of mega-events, their infrastructure requirements can compromise air quality and bring damage related to lipoperoxidation and physiological changes in the life cycle of biological systems, such as what happened to C. elegans exposed to tested extracts. Also, rainy events reduced the presence of these pollutants, washing the atmosphere.

Trophic Transfer and Toxicity of (Mixtures of) Ag and TiO2 Nanoparticles in the Lettuce-Terrestrial Snail Food Chain

The increasing application of biosolids and agrochemicals containing silver nanoparticles (AgNPs) and titanium dioxide nanoparticles (TiO2NPs) results in their inevitable accumulation in soil, with unknown implications along terrestrial food chains. Here, the trophic transfer of single NPs and a mixture of AgNPs and TiO2NPs from lettuce to snails and their associated impacts on snails were investigated. Both AgNPs and TiO2NPs were transferred from lettuce to snails with trophic transfer factors (defined as the ratio of the Ag/Ti concentration in snail tissues to the Ag/Ti concentration in lettuce leaves) of 0.2-1.1 for Ag and 3.8-47 for Ti. Moreover, the majority of Ag captured by snails in the AgNP-containing treatments was excreted via feces, whereas more than 70% of Ti was distributed in the digestive gland of snails in the TiO2NP-containing treatments. Additionally, AgNP-containing treatments significantly inhibited the activity of snails, while TiO2NP-containing treatments significantly reduced feces excretion of snails. Furthermore, the concurrent application of AgNPs and TiO2NPs did not affect the biomagnification and distribution patterns of Ag and Ti in snails, whereas their co-existence exhibited more severe inhibition of the growth and activity of snails than in the case of applying AgNPs or TiO2NPs alone. This highlights the possibility of nanoparticle transfer to organisms of higher trophic levels via food chains and the associated risks to ecosystem health.

A Risk and Decision Analysis Framework to Evaluate Future PM2.5 Risk: A Case Study in Los Angeles-Long Beach Metro Area

This study examines the L.A.-Long Beach Metro area concerning the future risk of the PM_2.5 concentration increase. Population expansion, economic growth, and temperature increase are incorporated to estimate the probability of the magnitude of PM_2.5 emission increase. Three possible sectors for the reduction of PM_2.5 emissions are considered: ocean-going vessels, refineries, and electricity-generating units. The decision of how best to allocate emissions-reduction efforts among these three sectors is analyzed using a quantitative and qualitative decision-analysis framework. For quantitative analysis, Expected Monetary Value (EMV) and Expected Utility (EU) methods are used to select the optimal sector to invest in. Based on the EMV calculation, the refineries sector is 3.5 times and 6.4 times more worthy of investment compared to the electricity-generating units and the ocean-going vessels sector, respectively. For the qualitative analysis, three criteria (investment efficiency, implementation difficulty, time to become effective) are considered in the decision-making process and sensitivity analysis is conducted to inform the ocean-going vessel sector is the optimal alternative for all possible scenarios. The refineries sector is more preferred than the electricity-generating units sector when the implementation difficulty's weight is smaller than 50%. This study provides a valuable risk and decision analysis framework for analyzing the air pollution problem associated with the future PM_2.5 concentration increase caused by three risk factors: population growth, economic growth, and climate change.

Long-term wet precipitation of PM2.5 disturbed the gut microbiome and inhibited the growth of marine medaka Oryzias melastigma

Wet precipitation, as an important process of geochemical cycling and the most effective way of cleaning fine atmospheric particles (PM_2.5), can introduce the toxic substances in the atmosphere into the water environment. The adverse effect of wet precipitation of PM_2.5 on marine fish is still unclear. In this study, PM_2.5 samples were collected from six locations along coastal areas of the south China sea for 30 days and used to simulate the impacts of multiday discontinuity wet precipitation of PM_2.5 on marine medaka (Oryzias melastigma) in the case of 30 days discontinuity heavy rain (rainfall ≥ 7.6 mm/h and persist 1 h each day). Results showed that wet precipitation of PM_2.5 significantly inhibited the body weight gain of fish. In accordance, the size and number of lipid droplets in liver of the exposed groups were lower than those in normal control (NC) group. The expressions of genes involving in lipid degradation including lipoprotein lipase gene (LPL) and carnitine palmitoyltransferase gene (CPT) were up-regulated after exposure. The composition, diversity and function of gut microbiome were affected by wet precipitation of PM_2.5. PM_2.5 from industrial areas that have higher concentrations of metal profiles show more obvious impacts than PM_2.5 from agricultural leisure areas that possessed lower concentrations. All together, the results indicated that wet precipitation of PM_2.5 can decrease the diversity of gut microbiome, affect the lipid metabolism, and finally suppress the growth of marine medaka. It confirmed the potential ecological risks of long-term rainfall in air pollution areas to the aquatic organisms.

Leveraging the effector independent nature of motor imagery when it is paired with physical practice

While considered analogous to physical practice, the nature of imagery-based skill acquisition—specifically whether or not both effector independent and dependent encoding occurs through motor imagery—is not well understood. Here, motor imagery-based training was applied prior to or after physical practice-based training to probe the nature of imagery-based skill acquisition. Three groups of participants (N = 38) engaged in 10 days of training of a dart throwing task: 5 days of motor imagery prior to physical practice (MIP-PP), motor imagery following physical practice (PP-MIP), or physical practice only (PP-PP). Performance-related outcomes were assessed throughout. Brain activity was measured at three time points using fMRI (pre/mid/post-training; MIP-PP and PP-MIP groups). In contrast with physical practice, motor imagery led to changes in global versus specific aspects of the movement. Following 10 days of training, performance was greater when motor imagery preceded physical practice, although remained inferior to performance resulting from physical practice alone. Greater activation of regions that support effector dependent encoding was observed mid-, but not post-training for the PP-MIP group. Findings indicate that changes driven by motor imagery reflect effector independent encoding, providing new information regarding how motor imagery may be leveraged for skill acquisition.

Saharan dust intrusions in the Iberian Peninsula: Predominant synoptic conditions

The Iberian Peninsula (IP) is recurrently affected by dust transport from the Sahara Desert and from the semi-arid Sahel regions. African dust is one of the most important sources of particulate matter in the southern Mediterranean. Therefore, it is vital to understand the underlying processes that lead to episodes of air pollution associated to the occurrence of dust intrusions. This work proposes to make an extended characterization of the preferential circulation weather patterns associated to the onset of dust events affecting the IP between 2006 and 2016. Saharan dust intrusions were analysed and an automatic objective classification procedure was used to classify circulation weather patterns associated to dust events. The spatial distribution of intrusion episodes is not homogeneous throughout the IP, occurring less frequently at northern and northwestern locations than at central and southern sites. Moreover, days with Saharan dust intrusions were more frequent in summer months, and more probable to occur under regimes with a southerly component. Finally, two extreme events with high concentration of particulate matter were analysed relatively to their life-cycle and particle trajectories. The distinct extreme episodes can be associated to different synoptic situations. However, and despite different large-scale configurations, a south or south-easterly component over the region is responsible for the establishment of a dust transport from the Saharan region towards Iberia, and thus leading to the intrusion onset. These results were supported by the calculation of back-trajectories which allowed to source apportioning the particles' origin, through a clear trajectory of air parcels originating from northern Africa in both events. The proposed framework can be useful to the prediction of dust and air pollution events based on the forecast of circulation weather patterns, as the results show that these events across the IP are mainly induced by specific patterns.

Evidence for Fossil Fuel PM1 Accumulation in Marine Biota

When fine particulates such as those with a diameter of approximately 1 μm (particulate matter, PM₁) are released from fossil fuel combustion into the air, they warm the atmosphere and contribute to millions of premature deaths in humans each year. Considerable quantities of PM₁ eventually enter the oceans as suspended particulates, yet subsequent removal mechanisms are poorly understood. In fact, the presence of PM₁ in marine biota has never been reported. Since sea anemones are opportunistic suspension feeders, they are anticipated to incorporate and accumulate PM₁ in their bodies. By histological examination, PM₁ was detected in 21 of the 22 sea anemones collected from Taiwan and Southeast China, with a depth of intertidal zone to 1000 m. PM₁, if present, was always detected in endodermal layers and had the same dominant color (i.e., black, brown, or green) in different species from the same site. The bioaccumulation factor of PM₁ in sea anemones was approximately 5-7 orders of magnitude. Based on radioisotope ¹⁴C results, the contribution of fossil fuel source PM₁ was 8-24%. Regardless of PM₁'s color, S and Fe were commonly detected by scanning electron microscopy and energy-dispersive spectrometry (SEM-EDS), suggesting anthropogenic sources. Furthermore, a maternal transfer of materials was suggested based on the existence of PM₁ in sea anemone eggs and in brooding and released juveniles. The significance of PM₁ accumulation by biota in aquatic ecosystems and the potential risk to living organisms via food webs warrant further investigation.

The Impact of Water-Soluble Inorganic Ions in Particulate Matter (PM2.5) on Litter Decomposition in Chinese Subtropical Forests

Although numerous studies have demonstrated the toxic effects of fine particulates less than 2.5 µm (PM2.5) on the health of humans, little information is available on the ecotoxicity of PM2.5. Water-soluble inorganic ions (WSII, including Na+, NH4+, K+, Mg2+, Ca2+, Cl−, NO3−, and SO42−) can compose more than 60% of PM2.5. To better understand the possible impacts of WSII-PM2.5 on leaf litter decomposition, we conducted an experiment in which two leaf litters from oak (Quercus variabilis) and pine (Pinus massoniana) dominant forests in subtropical China were incubated in microcosms containing their respective forest soils and treated with WSII-PM2.5. Our results showed that, after six-months of decomposition, the WSII-PM2.5 treatments inhibited leaf litter decomposition rates, carbon and nitrogen loss, microbial biomass, and enzyme activities in the two forests. In addition, higher WSII-PM2.5 concentration led to stronger negative effects. Comparative analysis showed that the negative effects of WSII-PM2.5 on oak forest were greater than on pine forest, relating to the higher susceptibility to changes of soil microenvironment in oak forests. WSII-PM2.5 may influence decomposition through soil acidification and salinization, which could also cause a sub-lethal depression in soil isopod activity. However, in the first month of decomposition, mass loss of the oak and pine leaf litters under the low concentration WSII-PM2.5 were 21.63% and 35.64% higher than that under the control, respectively. This suggests that transitory low concentrations of WSII-PM2.5 have a promoting effect on decomposition. Long-term PM2.5 exposure, therefore, may have profound ecosystem consequences by altering the balance of ecosystem carbon flux, nutrient cycling, and humus formation in the future.

Behavioural toxicity studies of Cyclope neritea and Nassarius mutabilis exposed to polycyclic aromatic hydrocarbons

The objective of the work was to study behavioural change of Cyclope neritea (sea snail) and Nassarius mutabilis (land snail) upon exposure to different levels of PAHs. Snail's behaviour was translated and expressed in Behavioural State Score (BSS) where the score ranged from "0" to "5" points refers to the ascending level of locomotion of a snail. A significant difference was found in snail's behaviour in 25.0 mg/L than in 0.5 mg/L with p value smaller than 0.01. BSS scores appear most frequent on the treatment and control group were 5 (61.5-64.5%) and 2 (41.0-45.0%), respectively. Intersex behaviour was found in all species (i.e. the same sex was grouped together) regardless of PAH concentrations. This is the first reported to study the behavioural change of snail sampled in Hong Kong area when exposed to PAHs. Further studies should be carried on the impact of snail's behaviour exposure on each congener in the family of PAHs.

Spatiotemporal Distribution of PM2.5 and O3 and Their Interaction During the Summer and Winter Seasons in Beijing, China

This study analyzed the spatiotemporal variations in PM2.5 and O3, and explored their interaction in the summer and winter seasons in Beijing. To this aim, hourly PM2.5 and O3 data for 35 air quality monitoring sites were analyzed during the summer and winter of 2016. Results suggested that the highest PM2.5 concentration and the lowest O3 concentration were observed at traffic monitoring sites during the two seasons. A statistically significant (p < 0.05) different diurnal variation of PM2.5 was observed between the summer and winter seasons, with higher concentrations during daytime summer and nighttime winter. Diurnal variations of O3 concentrations during the two seasons showed a single peak, occurring at 16:00 and 15:00 in summer and winter, respectively. PM2.5 presented a spatial pattern with higher concentrations in southern Beijing than in northern areas, particularly evident during wintertime. On the contrary, O3 concentrations presented a decreasing spatial trend from the north to the south, particularly evident during summer. In addition, we found that PM2.5 concentrations were positively correlated (p < 0.01, r = 0.57) with O3 concentrations in summer, but negatively correlated (p < 0.01, r = −0.72) with O3 concentrations in winter.

miRNA-218 regulates the proliferation and apoptosis of cervical cancer cells via targeting Gli3

Cervical cancer (CC) is one of the most malignant tumors that affect women. Recent studies have reported that microRNAs (miRs) serve important roles in CC. The aim of the present study was to investigate the role of miR-218 in CC and to verify its underlying mechanism. The results of reverse transcription-quantitative polymerase chain reaction (RT-qPCR) revealed that miR-218 was dramatically downregulated in CC tissues and cell lines. Furthermore, the expression of Gli3 and Ki67 was measured using RT-qPCR and the results revealed that levels of these proteins were negatively correlated with miR-218 in CC tissues. The protein expression levels were determined by western blotting. Then SiHa cell line was used to investigate the mechanism of CC. Following cell transfection, cell apoptosis and cycle analyses were performed using the flow cytometry. The results revealed that miR-218 overexpression significantly inhibited cell proliferation, apoptosis and cell cycle. Additionally, luciferase reporter assay revealed that Gli3 may be a novel and direct target of miR-218 in CC. Taken together, the results of the present study suggest that miR-218 overexpression or Gli3 knockdown may have potential as therapeutic strategies for the treatment of CC.

Transfers of embodied PM2.5 emissions from and to the North China region based on a multiregional input-output model

Atmospheric PM_2.5 pollution has become a global issue, and is increasingly being associated with social unrest. As a resource reliant local economy and heavy industry cluster, the North China region has become China's greatest emitter, and the source of much pollution spillover to outside regions. To address this issue, the current study investigates the transfers of embodied PM_2.5 emissions to and from the North China region (which is taken to include Hebei, Henan, Shandong, and Shanxi, and is referred to here as HHSS). The study uses a top-down pollutant emission inventory and environmentally extended multi-regional input-output (EE-MRIO) model. The results indicate that the HHSS area exported a total of 660 Gg of embodied PM_2.5 to other domestic provinces, mainly producing outflows to China's central coastal area (Jiangsu, Zhejiang, and Shanghai) and the Beijing-Tianjin region. HHSS also imported 224 Gg of embodied PM_2.5 from other domestic regions, primarily from Inner Mongolia and the northeast. Furthermore, the transfer of embodied emissions often occurred between geographically adjacent areas to save costs; Beijing and Tianjin mainly transferred embodied pollution to Hebei and Shanxi, whilst Jiangsu, Shanghai, and Zhejiang tended to import embodied air pollutants from Shandong and Henan. At the sectoral level, the melting and pressing of metals, the production of non-metallic products, and electric and heat power production were the three dominant economic sectors for PM_2.5 emissions, together accounting for 81% of total discharges. Capital formation played a key role in outflows (75%) in all sectors. Moreover, the virtual pollutant emissions exported to foreign countries also significantly affected HHSS' discharges significantly, making up 340 Gg. Allocating responsibility for some proportion of HHSS' emissions to the Beijing-Tianjin area and the central coastal provinces may be an effective approach for mitigating releases in HHSS.