Dissolved organic matter (DOM) has been recognized as a serious water quality problem in natural water bodies receiving pollution loads from point and nonpoint sources. The present study investigates the spatiotemporal variability of DOM composition in the Kushiro River and its tributaries (Eastern Hokkaido, Japan) impacted by the Kushiro wetland. Water samples were collected in the wet and dry seasons from several locations of the river and analyzed for DOM characteristics by UV–visible and excitation–emission matrix fluorescence spectroscopy techniques and by developing water quality index. Rather than the spatial effect, significant seasonal impacts on DOM pollution in the Kushiro River were observed. Overall concentrations of DOM decreased during the dry season. The increase of specific ultraviolet absorbance in the dry season indicated an increasing trend of humification, aromaticity and molecular weight of DOM. Five fluorescent peaks, including peaks A, C, M, B, and T were predicted by EEM spectra. Peaks A and C were found to be the most dominating peaks in both the seasons and indicated enrichment of humic-like matters in river water. The intensities of poly-aromatic humic substances as well as DOM components of microbial origin increase in the wet season and proteins like autochthonous DOM increase during the dry season. The study recognized the contribution of freshly produced DOM component by the decomposition of wetland plants in wet season and effect of snowfall in the dry season. Analysis of three fluorescence indices revealed that the river water primarily contains terrestrially dominated DOM. A significant impact of the adjacent WWTPs and wetland to the river water DOM were also observed. The water quality index of river water DOM showed low to medium levels of DOM pollution in the Kushiro River.

The present study aims to explore the co-movement between urbanization and environmental sustainability for the period 1950 to 2014 using the wavelet coherence technique within the global framework. The wavelet coherence technique allows us to investigate both the long-run and short-term causal relationships between urbanization and environmental sustainability within the global framework. The findings reveal that (i) wavelet correlation from the global perspectives indicates a significant wavelet relationship between urbanization and environmental sustainability for medium- and long-term horizons; however, the correlations are not significant for the short-term horizons; (ii) significant vulnerabilities in urbanization and environmental sustainability are observed at different periods and different frequency levels; (iii) urbanization has reliable power for explaining environmental sustainability at different periods between 1970 and 2000. Based on our study, we suggest that global urban planners and policymakers should support modern environment-friendly technologies and renewable energies to control global CO₂ emissions and pollutions created by industrialization; policy action to fight climate change is as well recommended as evidence supports to compact city theory.

Concerns about the pollution of farmlands by microplastics and the associated toxicology have increased in recent times; however, studies on this topic are scarce. In this study, two kinds of PVC microplastics with different particle sizes (PVC-a with particle sizes from 100 nm to 18 μm, and PVC-b with particle sizes from 18 to 150 μm) and different content levels (0.5%, 1%, and 2%) were used to analyze the effects of PVC microplastics on the physiological characteristics of the lettuce root system and leaves. The results showed that PVC-a and PVC-b had no significant effect on the lettuce root activity. However, 0.5%a and 1%a significantly increased the total length, surface area, volume, and diameter of roots. In terms of leaves, PVC-a and PVC-b had no significant effect on the malondialdehyde content, but 1%a significantly increased the superoxide dismutase activity. Carotenoid synthesis was promoted by PVC-a but inhibited by PVC-b. Furthermore, 1%a could reduce the ability of light energy absorption, dissipation, capture, and electron transfer. The gray correlation analysis indicated that PVC-a correlated to a considerable degree with the indices related to photosynthesis, while PVC-b was significantly correlated with the indices related to root morphology. This study provides insights into the ecotoxicological effect of microplastics on farmland crops and associated ecological risk assessment.

Agricultural activity, especially the increasing use of pesticides, is considered one of the main reasons for the decline of amphibian populations. Mancozeb (MCZ) is one of the most used fungicides worldwide, despite its ancient use and toxicity demonstrated in different taxa. However, there is limited information about the effects of MCZ in amphibians, which are keystones of riparian ecosystems. For species conservation purposes, it is essential to identify the most sensitive developmental period(s) of a given species to a xenobiotic. We evaluated the toxicity of a commercial fungicide of mancozeb, (80% active ingredient) on the early development of the common South American toad Rhinella arenarum (Anura, Bufonidae). Embryos from early blastula (S.4) and larvae from complete operculum (S.25) stages were exposed to a wide range of MCZ concentrations during acute, subchronic and chronic exposure (up to 504 h) periods. The toxicity profiles for lethal and sublethal effects were performed. At all exposure times, MCZ was more toxic to embryos, for instance, NOEC 504 h were 0.01 and 0.05 mg MCZ/L for embryos and larvae, respectively. Thus, embryo sensitivity was 5-fold higher than larvae. A Teratogenic Index of 14 indicated the significant teratogenic potential of this fungicide. Among sublethal effects, embryos exhibited a wide range of abnormalities with high incidence. The ecological risk assessment demonstrated that the estimated Risk Quotient value for Rhinella arenarum embryos at chronic exposure was higher than the Level of Concern value, which warns about the potential risk of MCZ for this native species.

Naphthalene (NAP) is found as a pollutant in water, soil, and air, and adsorption is the most prominent removal process of this compound, among the methods studied. A study concerning the types of adsorbents and the parameters with the greatest influence on the adsorption process is interesting to direct future works on new adsorbents. The use of multivariate data analysis tools becomes an appealing way to compile data obtained from bibliographic reviews and to establish a behavior in NAP adsorption. This work aims to evaluate the parameters with greater influence on NAP adsorption process regarding adsorption capacity (qeₑₓₚ) with the principal component analysis (PCA), and to group common NAP adsorbents by chemical characteristics through hierarchical cluster analysis (HCA). The variables qeₑₓₚ, S, [NAP]₀, T, CT, and [Ads] were used to perform PCA with correlation matrix. For the HCA, the variables S, [NAP]₀, T, CT, and [Ads] with average linkage method (UPGMA) and Euclidean distance were used. Through PCA, it is possible to infer that S and [NAP]₀ are the factors with greater influence in qeₑₓₚ of NAP, while T, CT, and [Ads] have little correlation. PCA also shows that activated charcoal is the adsorbent with higher qeₑₓₚ. HCA grouped the adsorbents into four groups by their chemical classes, except group A. Both PCA and HCA methods show themselves as potential tools to evaluate a data set of NAP adsorption processes.

This study investigates the relationship between climate change, the area under cultivation, fertilizer consumption, and cotton production in Pakistan from 1980 to 2018. The existence and nature of the short-term and long-term relationships are explored by using an autoregressive distributed lag (ARDL) model bounds testing approach. The estimated result of the ARDL bounds testing approach has shown the presence of cointegration between dependent and explanatory variables. The long-term estimates have revealed that the increasing average temperature has a positive insignificant effect, which implies that rising temperature is not increasing cotton yield in Pakistan. The findings of the area under cultivation and fertilizer consumption have revealed significant positive effects in both the long run and short run. This study urges Pakistan to reduce the pace of climate changes and increase water conservation by planting forests and constructing dams across major rivers along with the adoption of environmentally friendly production techniques and inputs.

Human civilization has reached an unprecedented height, but the industrialization of economic development also brings global warming, ozone depletion, acid rain, fresh water resources crisis, energy shortage, and environmental problems. In autumn and winter, haze becomes the usual state in the modern society, and PM2.5 has been becoming an important form of air pollution. The research found that PM2.5 brings great influence to the human body or daily life. To some extent, the PM2.5 also affects the propagation of electromagnetic waves near the ground, reducing the transmission performance of electromagnetic wave. Based on Mie scattering theory, this paper qualitatively analyzed the scattering effects of PM2.5 particles on every frequency band of electromagnetic wave in daily use. Then the paper takes the satellite navigation signals as a research example, selecting university of Wyoming Davis stations in Antarctica sounding data by measuring the tropospheric atmospheric meteorological parameters (including the atmosphere pressure, geopotential height of different layers, dew point temperature, relative humidity and specific humidity, wind direction, wind speed, and temperature). The paper inversed the refractive index distribution of the troposphere based on AlexNet model and described the error quantitatively. The simulation results show that the estimated error is less than 5.1455%, proving the high accuracy of the AlexNet model. To test the influence of PM2.5, the paper takes Jiuquan, a city with serious pollution, as an example. Comparison between the inversion results and IGS products shows that high concentration of PM2.5 pollution has little influence on the inversion of refractive index profile.

The production of Nile tilapia (Oreochromis niloticus) in Brazil exhibits the highest growth rate in the world and represents approximately 45% of the total fish production. The objective of the present study was to assess the risk for human health due the consumption of tilapia farmed in net cages in eight aquaculture parks in Brazil. The concentrations of pesticides (40 compounds), metals (Mn, Ni, Zn, Cd, Pb, and Sn), arsenic, and cyanotoxins (microcystins) were evaluated in 16 fish from each park. Among analyzed pesticides, pyraclostrobin (0.18–0.32 mg/kg) and fenthion (0.0026–0.0037 mg/kg) exhibited values above the limit of quantification in the tilapia from Aracoiaba, Castanhão, and Ilha Solteira. The highest concentrations of As (0.44 μg/g) in fish tissues were found in Juara, Mn (0.21 μg/g) in Castanhão, and Zi (11.5 μg/g) were found in Três Marias. Furnas and Linhares exhibited the lowest metal concentrations. The estimated daily intake of muscle by the average Brazilian with 70 kg body weight is below the reference dose for all studied metals in all parks. Total free microcystins showed an accumulation pattern (muscle < gill < liver). The highest concentration in muscle was found in Castanhão (1043 μg/kg) samples. The results showed that fish exhibited metal, As, and pesticide tolerable daily intake (TDI) below the limit and pose low risk for human consumption. Otherwise, TDI for microcystins in fish of all studied parks was above the maximum level recommended by the World Health Organization, indicating that there exists a toxicity risk of fish consumption.

The objective of the study is to examine the dynamic linkages between population growth, price level, poverty headcount ratio, and carbon emissions under investigation of different plausible hypothesis, including “population-induced poverty trap,” “welfare-reducing effects,” “environmental Kuznets curve,” and “pollution haven” hypotheses in the cross-sectional setting of 98 developed and developing countries for the period of 2011. The study used cross-sectional regression and switching regression regime for empirical analysis. The result shows a positive relationship between changes in price level and carbon emissions that verify “welfare-reducing effects,” while there is a negative relationship between population growth and poverty at varying poverty threshold to support the “Gary Becker human capital theory.” Further, there is a positive relationship between poverty rates and carbon emissions across countries. The results verified the “pollution haven” hypothesis in account of increase in pollution through financial liberalization policies. A U-shaped relationship is found between economic growth and carbon emissions in a given time period. The study concludes that globalized world should have to be careful when devising environmental sustainability policies, as it is important to provide social safety nets to the lower income strata group; hence, it would be helpful to achieve global green development agenda.

We evaluated the influence of the oil-related environmental contaminant benzene (0, 10, 100, or 1000 ng/mL) alone and in combination with apigenin, daidzein, or rutin (10 μg/mL each) on viability; proliferation (accumulation of proliferating cell nuclear antigen); apoptosis (accumulation of Bax); and release of progesterone (P), testosterone (T), and estradiol (E) in cultured porcine ovarian granulosa cells. Cell viability; proliferation; apoptosis; and release of P, T, and E have been analyzed by the trypan blue test, quantitative immunocytochemistry, and ELISA, respectively. Benzene did not affect apoptosis, but reduced ovarian cell viability and P and E release, and promoted proliferation and T output. Apigenin did not affect cell viability, but stimulated proliferation and T and E release, and inhibited apoptosis and P secretion. It prevented and reversed the action of benzene on proliferation and P and T release, and induced the inhibitory action of benzene on apoptosis. Daidzein promoted cell viability, proliferation, P release, but not apoptosis and T or E release. Daidzein induced the stimulatory effect of benzene on T, without modifying other effects. Rutin administered alone reduced cell viability and apoptosis, and promoted cell proliferation. Furthermore, rutin prevented and reversed the effect of benzene on proliferation and P and E release. These observations suggest the direct action of benzene and plant polyphenols on basic ovarian cell functions, and the ability of apigenin and rutin, but not of daidzein, to prevent benzene effects on the ovary.