Urbanization is an important direction for China’s future social development and an important focus of its carbon emission reduction path. China’s current administrative management is a vertical nested structure, and the characteristics of high-scale regions have a non-negligible impact on low-scale areas. Taking the county scale of the basic unit of economic and social development as the research scale, according to the panel data of the Yangtze River Delta from 2008 to 2016, a two-level hierarchical linear model (HLM) for carbon emission intensity is constructed, especially considering the characteristics of high-scale regions (i.e., low-carbon pilot cities) at the second level, and is combined with the mediating effect test method to analyze the impact path of urban development on carbon emissions intensity. The results show that (1) there is a spatial nesting relationship between regions of different scales, and the city scale can explain 85.21% of the carbon emissions intensity, which is much higher than the county scale. (2) There is an N-shaped curve relationship between urban development and carbon emissions intensity. After considering the high-scale factor (low-carbon pilot cities) at the city scale (the second level of the HLM), if a high-scale city is a low-carbon pilot city, then improvement in the level of urbanization in the county can promote a reduction in carbon intensity. (3) The impact path of urban development ⇄ per capita gross domestic product (the proportion of secondary industry, patent application volume) → carbon emissions intensity and urban development → the proportion of tertiary industry → carbon emissions intensity is significant. However, the path of the proportion of tertiary industry → urban development → carbon emissions intensity is not significant.

The bacterial community of an anaerobic granular sludge associated with uranium depletion was investigated following its exposure to uranium under different initial pH conditions (pH 4.5, 5.5, and 6.5). The highest uranium removal efficiency (98.1%) was obtained for the sample with an initial pH of 6.5, which also supported the highest bacterial community richness and diversity. Venn diagrams visualized the decrease in the number of genera present in both the inoculum and the uranium-exposed biomass as the initial pH decreased from 6.5 to 4.5. Compared with the inoculum, a significant increase in the abundances of the phyla Chloroflexi and Proteobacteria was observed following uranium exposure. At initial pH conditions of 6.5 to 4.5, the proportions of the taxa Anaerolineaceae, Chryseobacterium, Acinetobacter, Pseudomonas, and Sulfurovum increased significantly, likely contributing to the observed uranium removal. Uranium exposure induced a greater level of dynamic diversification of bacterial abundances than did the initial pH difference.

The original publication of this paper contains a mistake. The correct image of figure 3 is shown in this paper.

Water fluoridation is considered a cost-effective and practical method for controlling and preventing dental caries in the general population. The objective of this study was to evaluate the dental health status and risk indicators for dental caries in adult Brazilian Indians without exposition to dental caries–preventive effects of water fluoridation. Decayed (DT), missing (MT), and filled (FT) permanent teeth (DMFT), as well as plaque index, unstimulated salivary flow rate, salivary buffering capacity, and fasting blood glucose were examined in 225 adult Indians. Smoking habits and sociodemographic data were evaluated using a structured questionnaire. Drinking water samples from 10 Indian villages were analyzed for the natural fluoride concentration. The mean DMFT was 10.33 ± 6.91 (DT, 4.19 ± 3.99; MT, 4.99 ± 5.64; FT, 1.14 ± 1.75). DMFT index ≥ 9 was associated with age ≥ 35 years (p = 0.000), lower education (p = 0.03), and plaque index > 40% (p = 0.003). DT was associated only with plaque index (p = 0.03). MT was associated with age (p < 0.001) and plaque index (p = 0.01). FT was negatively associated with age (p = 0.02) and income (p = 0.02). Fluoride concentration varied from 0.01 to 0.07 mg/L and was not associated with dental health status (p ≥ 0.29). In conclusion, poorer dental health status was associated with older age, higher plaque index, and lower education and income levels. The fluoride level in the drinking water of Kiriri villages was lower than the level recommended for preventing dental caries. Water fluoridation may be recommended for this population.

Leather tanneries which produce significant amounts of solid waste, effluents, and emissions are a major contributor to industrial waste. A cleaner production program was launched by the government of Pakistan to implement the cleaner production measures for tanneries of Sialkot from 1999 to 2005. The main objective of this study is to identify the impact of a cleaner production program, along with other determinants of a cleaner production in the leather industry. The study analyses firm-level primary data collected from leather tanneries in Sialkot. The primary data were collected from tanneries in Sialkot. The econometric analysis is conducted using the Poisson regression analysis. Overall results show that there is no significant impact of cleaner production in 2015, while the panel data results indicate that the effect of cleaner production support by CPC on cleaner production practices diminished once the support came to an end. The other main factor is firm size, which indicates the financial position of the firm; international and regulator pressures are major determinants of the adoption of cleaner production measures. The analysis also indicates that there is higher probability of large firms adopting a cleaner production in comparison with small ones. Export orientation of firms is another important determinant of cleaner production. The enforcement of the environment compliance laws also has positive effect. The compliance with cleaner production measures is quite low, at 6.4 out of 19 cleaner production practice measures. There is a need to adopt measures that are environmentally friendly and are favorable towards both labor health and product quality, which are important for the sustainable growth of the tanning industry.

In this modern era, the importance of information and communication technology (ICT) cannot be ignored for sustainable human development. However, Pakistan has experienced a considerable gap between ICT economic growth and human development. In this regard, this study has modeled the relationship between ICT, economic growth, and the human development index (HDI) considering urbanization, foreign direct investment (FDI), and trade for the period from 1990 to 2014. An autoregressive distributed lag (ARDL) and vector error correction model (VECM) approaches are used to analyze the data. The empirical results reveal that ICT promote human development index. Along with, economic growth has a positive and significant impact on human development. Besides, urbanization, trade, and FDI discourage human development in Pakistan. Finally, bidirectional causality is detected between the aforementioned variables. Recommendations to policymakers regarding the productive role of FDI and trade are provided.

Grafting polyacrylamide (PAM) chains onto microparticles may combine the advantages of the flocculation property of the former and the fast sedimentation of the later to realize better flocculation performance. In this work, inexpensive microcrystalline cellulose (MCC) microparticles, and monomer of acrylamide (AM) were mixed, and then irradiated under microwave. The obtained material was characterized by Fourier transform infrared spectroscopy and X-ray diffraction, and the results demonstrated successful modification of MCC with AM on the particle surface. The modification procedure has been carefully investigated to obtain an optimum preparation condition. Kaolin suspension was selected as a model to evaluate the flocculation properties of the obtained AM-MCC. Our results indicate that the AM-MCC with the highest grafting ratio of 95.5% exhibits the best flocculation performance, which is even better than that of PAM, and the turbidity can be decreased to 1.4% of the naked kaolin suspension within 2.5 min. Therefore, this work provides a low cost strategy to prepare biodegradable AM-MCC, which may have promising potential application in the water treatment and other fields.

Arbuscular mycorrhizal (AM) fungi were of importance in mitigating soil erosion, which was highly influenced by biotic and abiotic factors, such as host plant growth and soil nutrient. To investigate the impact of nitrogen (N) fertilization on seasonal variance in AM colonization and soil erosion, we conducted a field experiment with rice cultivation under four N fertilizer levels (0 kg N ha⁻¹, 270 kg N ha⁻¹, 300 kg N ha⁻¹, and 375 kg N ha⁻¹ plus organic fertilizers) in the Taihu Lake region, China. We investigated AM colonization before rice transplantation, during rice growth, and after rice harvest. We also assessed soil splash erosion of intact soil cores sampled at tillering and after rice harvest. We found that AM colonization (indicated by percentage of root length colonization) varied from 15 to 73%, which was attributed to rice growth, N fertilization, and their interaction. Soil loss due to splash erosion was cut down by organic N fertilizer at tillering, while higher inorganic N fertilization significantly increased soil loss after rice harvest. Additionally, we found significantly negative relationships of AM colonization to soil loss but positive relationships to soil aggregate stability. We highlighted the potential role of AM fungi in decreasing soil erosion and suggested that high N fertilization should be considered carefully when seeking after high yields.

Numerous studies have investigated the impacts of ambient fine particulate matter (PM₂.₅) on human health. In this study, we examined the association of daily PM₂.₅ concentrations with the number of deaths for the cerebrovascular disease on the same day, using the generalized additive model (GAM) controlling for temporal trend and meteorological variables. We used the data between 2012 and 2014 from Shanghai, China, where the adverse health effects of PM₂.₅ have been of particular concern. Three different approaches (principal component analysis, shrinkage smoothers, and the least absolute shrinkage and selection operator regularization) were used in GAM to handle multicollinear meteorological variables. Our results indicate that the average daily concentration of PM₂.₅ in Shanghai was high, 55 μg/m³, with an average daily death for cerebrovascular disease (CVD) of 62. There was 1.7% raised cerebrovascular disease deaths per 10 μg/m³ increase in PM₂.₅ concentration in the unadjusted model. However, PM₂.₅ concentration was no longer associated with CVD deaths after controlling for meteorological variables. The results were consistent in the three modelling techniques that we used. As a large number of people are exposed to air pollution, further investigation with longer time period including individual-level information is needed to examine the association.

The application of biosorption operation has gained attention in the removal and retrieval of toxic metal ions from water bodies. Wastewater from industrial activity generally presents great complexity due to the coadsorption of cations to the inactive biomass binding sites. In this work, the competitive biosorption of Cu(II) and Ag(I) ions was studied in batch systems. A kinetic study applying a non-acidified and acidified waste of Sargassum filipendula in equimolar and non-equimolar metal samples was carried out and the acidified biosorbent was selected due to higher removal rates and selectivity of silver ions. The assays were performed with 2 g L⁻¹ of biosorbent concentration at 25 °C for 12 h and pH was controlled at around 5.0. Copper presented higher affinity for the biosorbent and a fast biosorption kinetic profile, while silver equilibrium times exhibited dependence on the copper concentration. External diffusion is the rate-limiting step in Cu(II) ion removal and it might also limit the kinetic rates of Ag(I) ions with intraparticle diffusion, depending on the initial concentration of metal cations. The ion-exchange mechanism is evidenced and complexation and electrostatic attraction mechanisms might be suggested, explained by simultaneous chemisorption and physisorption processes during the operation. Calcium and sodium were released in considerable amounts by the ion-exchange mechanism. Characterization analyses confirmed the role of several functional groups in the competitive biosorption accompanied by a homogenous covering of both metal ions on the surface of the particles. Particle porosity analyses revealed that the material is macroporous and an appreciable amount of macropores are filled with metal cations after biosorption.