Carbon dioxide (CO₂) and methane (CH₄) are the two major greenhouse gases (GHGs) in the atmosphere that contribute to global warming. Vehicle emissions on expressways cannot be neglected in the megacity Shanghai because oil accounts for 41% of the total primary energy consumption, and the expressway network carries 60% of the total traffic volume. The spatial distributions of CO₂ and CH₄ concentrations were monitored in situ on the expressways and in road tunnels using a mobile vehicle. The average CO₂ and CH₄ concentrations were 472.88 ± 34.48 ppm and 2033 ± 54 ppb on the expressways and 1308.92 ± 767.48 ppm and 2182 ± 112 ppb in the road tunnels in Shanghai, respectively. The highest CO₂ and CH₄ concentrations appeared on the Yan’an Elevated Road and the North-South Elevated Road, respectively, while their lowest values both occurred on the Huaxia Elevated Road passing through the suburban area. The hotspots of CO₂ and CH₄ were not consistent, suggesting that they have different sources. Tunnels had a “push-pull effect” on GHGs, and the traffic-congested Yan’an East Road Tunnel showed a dramatically increasing trend of GHG concentration from the entrance to the exit. This traffic-congested tunnel could accumulate a very high concentration of GHGs as well as other pollutants, which could introduce unhealthy conditions for both drivers and passengers. Significant correlations between CO₂ and CH₄ mostly appeared on the expressways and in the tunnels in Shanghai, suggesting the influences of vehicle exhaust. ΔCH₄/ΔCO₂ (the slope of the linear regression between CH₄ and CO₂) and the CH₄/CO₂ ratio could be used as indicators of vehicle exhaust sources because it increases from sources (e.g., road tunnels) to the observatories in the urban area.

Triclosan (TCS) is a chlorophenol which is highly bacteriostatic and used in a wide array of consumer products. TCS is now one of the most commonly detected organic pollutants in the sewage sludges. The sludge utilization for fertilizers on agricultural land would pose the risk of causing adverse effects on plant growth and yield by TCS. However, the toxicity of TCS toward plants is comparatively less understood. In this study, we assessed the effects of TCS on tobacco plants which were grown in MS medium or soils containing various concentrations of TCS. Our results indicated that TCS at the concentration of 2 mg/L could strongly inhibit the tobacco seed germination. TCS could suppress tobacco plant growth in soil with different concentrations (10, 20, and 50 mg/kg) of TCS through the downregulation of chlorophyll contents, restricting photosynthesis and increasing generation of reactive oxygen species (ROS). Salicylic acid (SA) plays important roles in the stress response of plants. The role of exogenous SA application in protecting tobacco plants from TCS stress was also investigated in this study. SA application could significantly increase net photosynthesis, enhance antioxidant enzyme activity, and thereby enhancing tobacco plant tolerance to TCS. Moreover, the activation of MPK3 and MPK6 induced by TCS was downregulated in plants with the treatment of SA. It was thus referred that mitogen-activated protein kinases (MAPKs) might play a key role in the signal transduction of TCS stress, and this process might be regulated by SA signaling. Overall, our results demonstrated that TCS had negative impacts on tobacco plants and SA played a protective role on tobacco plants against TCS stress.

Global climate change and national policies play an important role in regional ecosystem services, both of which should be fully considered when exploring their effective use and management. Bayesian belief network (BBN) is often used in complicated system modelling. Using a BBN to construct a network framework of ecosystem services under climate and policy scenarios for exploring the total suitability distribution of ecosystem services is of great significance. In this study, we develop BBN for the total suitability of water yield and carbon sequestration based on hydro-biogeochemical process. And then we predict the probabilities of the total suitability in 2050 through the BBN under multi-scenario simulations accounting for climate change, birth control and carbon tax policies. Finally, total suitability priority regions are mapped, which are synergy development, water yield suitability, carbon sequestration suitability and non-suitability, respectively. Our results indicate forest, cropland, urban area, and grassland have the largest areas under the representative concentration pathway (RCP) 2.6, RCP 4.5, RCP 6.0 and RCP 8.5, respectively. The abolition of the one-child policy has led to a significant expansion of urban areas, and the implementation of the carbon tax policy has greatly increased forest areas. Additionally, temperature, Normalized Vegetation Index (NDVI), precipitation and land use are the key driving factors that influence suitability. The suitable priority regions of different alternatives help policy makers consider ecological protection priorities while addressing management options.

Caddisfly larvae occur in streams and rivers, and many caddisfly species build protective cases using material from their habitat such as sand grains. At the same time, microplastics (MPs) are regularly deposited in aquatic sediments and are incorporated into caddisfly (Lepidostoma basale) cases in the field. However, it is unknown what the effects of MP incorporation into cases might be on the health of the caddisfly larvae. Hence, we offered two commonly used MPs (polyvinyl chloride (PVC) and polyethylene terephthalate (PET)) to L. basale larvae during a laboratory experiment. Both plastic types have a high density and co-occur with L. basale larvae in benthic habitats. In our experiment, L. basale actively used sand, PET and PVC MPs for building tube-like portable or emergency cases. The latter is a temporary shelter under which the larva can hide for immediate protection. Furthermore, case stability decreased with increasing PVC and PET particle content in the cases, suggesting that MPs may threaten caddisflies by destabilising cases. When case stability is reduced, the protective function of the cases is limited and the larvae may be more prone to predation. Additionally, larvae may be washed away by the current as plastic is lighter than sand. Both effects could limit the caddisfly’s survival, which could have far-reaching consequences as caddisfly larvae are important primary consumers in aquatic ecosystems. Graphical abstract

Recent studies have demonstrated that making the sorts of oxygen reactive, such as nitric oxide, can cause oxidative lipid damage, protein damage, and damage to the DNA of cells. Sperm DNA damage effect on the reduction of sperm mobility and damage of acrosome membrane lead to the inability of sperm to fertilize the oocyte. Increasing expression of endothelial nitric oxide synthase (eNOS) gene is seen in various diseases such as cardiovascular and infertility diseases. This study aimed to assess the association between eNOS gene single nucleotide polymorphism/SNP (rs2070744, T786C) and risk of male infertility and the quality of sperm parameters in an Iranian population. In this case-control study, 100 infertile men were enrolled as a patient group. Control groups consisted of 100 fertile men. T786C genotypes were determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results showed that T786C SNP, contained frequent genotype TC (p = 0.000; OR = 0.000; 95% CI = 0.000–0.015), TC + CC genotypes (p = 0.000; OR = 0.000; 95% CI = 0.000–0.015), and C allele (p = 0.000; OR = 0.00; 95% CI = 0.000–0.007), revealed a significant with male infertility. Based on the findings of this study suggested that although T786C SNP could not be applied as an appropriate genetic risk factor for male infertility, it probably may be considered a protective marker for other researchers. However, more comprehensive studies in different populations are required to confirm our data.

Zn is an essential trace metal in living beings. However, excessive concentrations can cause toxic effects even in the aquatic biota. Zn is widely used in different industrial sectors, which has increased its presence in aquatic environments. To assess the acute toxicity of Zn, bioassays were performed with the fish Gambusia sexradiata for a 96-h exposure using ZnCl₂ (0 and 15 salinity) and ZnO nanomaterials (0 salinity). The mean lethal concentrations (LC₅₀–96 h) for ZnCl₂ were 25.36 (19.64–32.76) and 177.91 (129.39–244.63) mg Zn L⁻¹ to 0 and 15 salinity, respectively. The increased concentration of ZnCl₂ showed a dose-response relationship; similarly, the increase in salinity significantly reduces the toxicity of Zn. Characterisation of ZnO nanomaterials was carried out by FTIR, DRX, SEM, DLS and zeta potential. The FTIR spectra showed the characteristic band of Zn-O vibration at 364 cm⁻¹, while DRX presents the hexagonal wurtzite structure with an average crystallite size of 40 nm. SEM micrographs reveal rod-like shapes with lengths and diameters of 40–350 nm and 90 nm, respectively. Agglomerates of 423 nm in water suspension were obtained by DLS and zeta potential of + 14.4 mV. Under these conditions, no mortality was observed due to the rapid flocculation/precipitation of ZnO nanomaterials, which involved brief interaction periods of Zn in the water column with the fish. Gambusia sexradiata is affected by increased Zn concentrations in hard water conditions, and salinity changes modified Zn toxicity, placing it as a suitable model for toxicity tests for this type of particles.

This study explores the contamination potential of groundwater due to the use of sodium chloride (NaCl) in the wintertime. The research was conducted in two Iranian cities, Malayer and Hamedan, where groundwater is the major source of water for drinking and irrigating purposes. However, the amount of deicing salt used in the former is about 10 times less than that used in the latter. The assessment of geochemical dataset from 2004 to 2018 revealed no significant trend in the groundwater characteristics of Malayer where the water quality indices were in the range of WHO and USEPA permissible limits. In contrast, the indices had a continually increasing trend (~ 2.3% annually) in Hamedan’s supply wells over the same period and particularly near the urban areas that showed higher levels (> 5 times on average) than those observed in Malayer. This could mainly be ascribed to the influx of halite. Based on the USSL diagram, the water samples retrieved from the latter system were mostly classified as C3-S1 (decreasing the soil fertility) and even as C4-S2 (harmful for agriculture activities). Chloride contamination rates also reached 250 mg/L, which could negatively affect the water potability and threaten the aquatics microorganisms. In this region, a rather similar distribution of NaCl and arsenic was observed, implying mobilization of toxic trace metals with the increased salt encroachment into the aquifer. Based on such findings, it is suggested that in snow-influenced cities (e.g., Hamedan), new approaches for winter maintenance be considered to prevent the gradual deterioration of water resources.

In forested watersheds, density, land cover, and its vertical structure are crucial factors for flood management, ecosystem monitoring, and biomass inventory. Nowadays, producing land cover maps with high accuracy has become a reality with the application of remote sensing techniques, but in some situations, it is not so easy to distinguish between the overstory and understory vegetation with only spectral information. The main goal of this study was to analyze the accuracy enhancement in overstory and understory land cover mapping at the watershed scale when using the data fusion of seasonal and annual time series of Sentinel-2 images complemented with low-density LiDAR and soil and vegetation indices. The study area was composed by two neighboring watersheds in Badajoz province (Spain). The accuracy of land cover classifications was trained in two ways: first, for each season and several soil-vegetation indices; and second, for the annual series and soil-vegetation indices. Next, LiDAR data were included in both analyses by means of a Boolean metric concerning the height. The obtained results showed that the overall accuracy was better with the annual evaluation when only spectral information was used for the classification. Additionally, if LiDAR data were included in the classification (data fusion), the overall accuracies were highly improved, especially in summer and autumn seasons. This improvement can be a significant issue in the analysis of vegetation structure and its spatial distribution as it is decisive for watershed ecosystem management.

Tremendous energy consumption appears as rapid economic development, leading to large amount of CO₂ emissions. Although plentiful studies have been made into the driving factors of CO₂ emissions, the existing literatures that take the spatial differences and temporal changes into consideration are few. Therefore, this study first analyzes the variations of total CO₂ emissions’ spatial distribution from 2008 to 2017 and present the changes of driving factors, finding significant spatial autocorrelation in CO₂ emissions at the province level, and that urbanization rate, per capita GDP and per capita CO₂ emissions increased significantly, but energy consumption structure and trade openness decreased. We then compared the effects of different factors affecting CO₂ emissions, using classic linear regression model, panel data model, and the geographically weighted regression (GWR) model, and the three models roughly agree on the effects of factors. The GWR model considering spatial heterogeneity provides more detailed results. Population, urbanization rate, per capita carbon emissions, energy consumption structure, and trade openness all have positive effects, while per capita GDP has a two-way impact on CO₂ emissions. The influence of urbanization rate and energy consumption structure in the central and western regions increased even faster than in eastern regions, and the impacts of trade openness in lower and higher opening areas are more significant. The population and per capita CO₂ emission have declining influences, among which the influence of population in coastal areas declined more slowly, while the rate of decline of per capita CO₂ emission was positively correlated with the local total CO₂ emissions. The Lorenz curve and the Gini coefficient reveal the inequality distribution of CO₂ emissions in various regions, with the highest CO₂ emissions growth in the medium-economic-level areas, where the key area of carbon mitigation is. Finally, per capita GDP reveals that China as a whole has the trend of inverted N-shape Kuznets curve, and the underdeveloped regions are in the rising stage between the two inflection points, while developed regions are at the end of the rising stage and about to reach the second inflection point.

The giant freshwater prawn, Macrobrachium rosenbergii, is an important species for Bangladesh’s national economy, aquatic biodiversity, and employment opportunities; furthermore, human health risk associated to consumption of this species has become a crucial issue. Eight trace metals (Pb, Cr, Ni, Cd, Fe, Cu, Zn, and Mn) in different body parts of M. rosenbergii (U/10 as large and U/12 and U/15 as medium size), and water collected from farm and wild sources along with the human health risks were assessed in this study. Except Cd, all trace metals exceeded the maximum permissible limits proposed by different authorities. Elevated levels of Pb, Cr, Fe, Cu, Zn, and Mn were found in the wild-caught prawn, whereas Ni and Cd were higher in farmed prawn. A higher trace metal contamination was recorded from the cephalothorax part than the abdomen of both sized prawns. However, trace metal concentrations between two sizes of prawns were not statistically significant (p > 0.05). The estimated daily intakes (EDI) values were higher than the recommended and/or tolerable daily intake for Pb and Cr. Moreover, the target hazard quotient (THQ) values were > 1 for Pb, Cd, Cu, and Zn, elucidating non-carcinogenic risks to the consumers. In addition, the target cancer risk (TR) values of Pb and Ni were high and exceeded the acceptable guideline of 10⁻⁶, explicating the possibility of carcinogenic risks. Therefore, the study concludes that the consumption of the studied prawn species contaminated with elevated levels of toxic metals is associated with higher degree of potential health risks.