The objective of this study was to estimate the concentrations of indoor air pollutants in unregulated public transport means in Korea and to determine the factors affecting the air quality as well as to assess the harmful effects of indoor air pollutants on the health of passengers. The correlation between particulate matter (PM₁₀) and number of passengers on intra-city buses, express buses, town shuttle buses, or rural buses was insignificant whether it was during rush hours or non-rush hours. In regard to PM₁₀ on express buses, there was no case where the standard limit was exceeded during the winter and summer seasons. In winter, however, the average concentration of PM10 increased by the travel distance. In regard to CO₂, there was a statistically significant correlation (p < 0.05) between CO₂ concentrations and the number of passengers, owing to human respiration. Unlike the case of PM₁₀, there was a difference between rush hours and non-rush hours. Regarding volatile organic compounds (VOCs) and aldehydes, the values were high among recently manufactured vehicles regardless of bus types. The standard limit was exceeded during the summer season, which seemed to be related to the temperature and humidity in both indoor and outdoor. The results of this study indicate that the excess mortality resulting from PM₁₀ was as high as the safety margin during both non-rush hours and rush hours among all unregulated public transportation means. The excess cancer risk and non-cancer risk of VOCs and aldehydes were as high as the safety margin during both non-rush hours and rush hours.

This study analyzes Kazakhstan’s influencing factors of energy-related carbon emissions in different stages, and the study period (1992–2014) was divided into four stages by using the logarithmic mean Divisia index (LMDI) method. In the low efficiency and high output stage, Kazakhstan had the most energy-related carbon emissions. The total energy-related carbon emissions might be positive or negative in the high efficiency and high output stage and the low efficiency and low output stage, and this was mainly determined by the energy intensity effect or the economic output effect. Different influencing factors had different effects in the different stages from 1992 to 2014. The economic output effect was the first contributor for promoting energy-related carbon emissions, and the energy intensity factor was the first contributor for suppressing energy-related carbon emissions from 1992 to 2014. Finally, policy recommendations in terms of the main influencing factors are put forward, including the low-carbon economic development mode transformation, technological innovation, and renewable energy development.

The objective of this study was to determine how the short-term exposure to a supraphysiological concentration of waterborne 17β-estradiol (E₂) influences on melatonin (Mel) and thyroxine (T₄) concentrations in plasma and E₂ and 11-ketotestosterone (11-KT) concentrations in plasma and gonads in both sexes of round goby (Neogobius melanostomus) during the pre-spawning, spawning, late spawning and non-spawning phases. The experimental protocol was based on short-term, repeated exposures of fish to a supraphysiological dose of waterborne E₂. Mel level was unchanged on exposure to E₂ during the investigated phases, and its role in determining a time frame for spawning in both sexes of round goby seems to be stable in those conditions. T₄ and sex steroids (E₂ and 11-KT) were sensitive to the exposure of E₂, and those changes influence gonads by accelerating oocyte development, ovulation and regression and inhibiting spermatogenesis in this species. The results demonstrate that the physiological responses of fish in all investigated phases were altered over a short window of exposure, indicating that short-term exposure to a supraphysiological dose of E₂ may impact fish in the wild. Furthermore, round goby can be recommended as a very suitable model for studying endocrine disruptors, which is sensitive to even short exposure to E₂.

The developing world is facing pivotal challenges in recent times. Among these, global warming has ominous repercussions on every segment of society, thus tracing its underlying causes is imperative. This research attempts to investigate the impact of urbanization and energy consumption on carbon dioxide emissions (CO2) for a panel of 8 Asian countries (Bangladesh, China, India, Indonesia, Malaysia, Nepal, Pakistan, and Sri Lanka) over the period 1982 to 2017. The analyses are executed using panel co-integration and Granger causality techniques. The main findings of panel co-integration reveal a long-run relationship between urbanization, energy consumption, and CO₂ emissions. Furthermore, the results indicate a positive and significant impact of urbanization and energy consumption on CO₂ emissions, indicating that urban development and high energy consumptions are barriers to improve environmental quality in the long run. The results also highlight bi-directional causality between energy consumption and urbanization, while unidirectional causality exists between energy consumption and CO₂ emissions. Based on the obtained results, this study offers useful policy implications for plummeting carbon emissions.

This study examines the relationship between foreign direct investment inflows and economic growth in a carbon function, by incorporating the role of urbanization, and coal consumption as additional variables to avoid omitted variable bias. The different order of integration from the unit root test suggested the adoption of a dynamic autoregressive distributed lag bounds testing procedure. The results confirmed the existence of a long-run equilibrium relationship between the outlined series within the period under investigation, with a high speed of convergence. The ARDL equilibrium relationship shows that coal consumption is the largest emitter of carbon dioxide emissions in both short- (0.77%) and long-run (0.86%). Economic growth was found to escalate CO₂ emission by approximately 0.27% (in the short-run) and 0.19% (in the long-run). The Granger causality test indicates a non-causal effect between FDI inflow and economic expansion in South Africa, which implies that FDI is not a driver of economic advancement. The empirical study shows a bidirectional causal effect between urbanization and foreign direct investment. This suggests that urban development stimulates foreign direct investment in South Africa. The findings reveal a one-way link from GDP to coal consumption, suggesting economic prosperity promotes coal consumption. The study underscores that economic development and the attraction of more economic investments is in part dependent on the conservative policy, development of urban centers through infrastructural improvement, and establishing industrial zones.

Sudden water pollution is a global environmental issue. On a large spatial scale, any pollution source may cause water pollution incidents. Dividing a large watershed into several units and giving each unit a different level would be favorable for managing sudden water pollution incidents. To scientifically divide an area into units and determine their risk grade of sudden water pollution, data of pollution sources were collected, and an area was divided into risk assessment units of sudden water pollution. The risk grade assessment was conducted following the analytic hierarchy process (AHP) and fuzzy comprehensive evaluation method. The technology combined with the AHP and fuzzy comprehensive evaluation (F-AHP) can generate the hydrology, pollution source, natural geography, and socioeconomic characteristics of each unit and provide a risk grade evaluation. A risk grade assessment was conducted using the Yongding River as a case study. The results show that the areas with high sudden water pollution risk were mainly distributed in Shanxi Datong and Hebei Zhangjiakou. Sufficient control of pollution sources in production processes and the establishment of necessary measures to strengthen inspections should reduce the risk of sudden water pollution.

Cardiovascular disease has always been the most serious public health problem in China. Although many studies have found that the risk of death caused by cardiovascular disease is related to air pollutants, the existing results are still inconsistent. The aim of this study was to investigate the effects of air pollutants on the risk of daily cardiovascular deaths in Hefei, China. Daily data on cardiovascular deaths, daily air pollutants, and meteorological factors from 2007 to 2016 were collected in this study. A time-series study design using a distributed lag nonlinear model was employed to evaluate the association between air pollutants and cardiovascular deaths. First, a single air pollutant model was established based on the minimum value of Akaike information criterion (AIC), and the single day lag effects and multi-day lag effects were discussed separately. Then, two-pollutant models were fitted. Subgroup analyses were conducted by gender (male and female), age (< 65 age and ≥ 65 age), and disease type (ischemic heart disease and cerebral vascular disease). There were 34,500 cases of cardiovascular deaths during the period 2007–2016, and the average concentrations of air pollutants (PM₁₀, SO₂, NO₂, PM₂.₅, CO, O₃) were 106.11, 20.34, 30.49, 72.59, 958.7, and 67.88 μg/m³, respectively. An increase of interquartile range (IQR) in PM₁₀, SO₂, NO₂, PM₂.₅, CO, and O₃ were associated with an increase of 4.34% (95%CI 1.54~7.23%) at lag 0–6, 5.79% (95%CI 2.43~9.27%) at lag 0–5, 4.47% (95%CI 1.64~7.37%) at lag 0–5, 3.14% (95%CI 0.03~6.36%) at lag 0–4, 3.11% (95%CI 0.21~6.10%) at lag 0–3, and 8.17% (95%CI 1.89~14.84%) at lag 0–5 in cardiovascular deaths, respectively. Females, older group (≥ 65 years) and deaths from cerebral vascular disease were more vulnerable to air pollution than males, younger individuals (< 65 years) and deaths from ischemic heart disease. Our results suggest that air pollution increased the risk of cardiovascular deaths in Hefei. These findings can provide evidence for effective air quality interventions in Hefei.

Evaluating the performance of water companies is of great importance for both water utilities and water regulators. This paper explores comparative levels of technical efficiencies and technology gap ratios with the metafrontier concept by estimating an input distance function using stochastic frontier techniques. The metafrontier framework is employed in the water services of water and sewerage companies (WaSCs) and water-only companies (WoCs) in England and Wales. The results show that the English and Welsh water industry is an efficient industry, with WaSCs more efficient than WoCs. On average, a water company can increase its technical efficiency by operating in more densely populated areas and by investing in technology to reduce bursts in water mains. We also link the efficiency results with the regulatory cycle to assess the impact of regulation on the efficiency levels of water companies.

Soil pollution with petroleum-based fuels is a serious issue causing environmental problems. Recently, the use of plasma technologies for soil remediation has shown an interest and great potential. The remediation process can be performed in a fast timeframe without adding supplementary chemical reagents or without additional pre-treatment of the polluted soil. As a result, the use of plasma enables to obtain highly effective degradation of pollutants. Thus, in the present experimental research, diesel fuel removal from contaminated soil by utilizing thermal water vapor arc plasma was investigated. It was found that increased concentration of diesel fuel in the soil raised carbon and hydrogen concentrations in the soil. Moreover, soil surface morphology was modified by causing the formation of bigger agglomerates. It was also determined that after the plasma treatment process, soil grains became akin in size and structure to clean soil grains. A complete desorption of carbon, which came from diesel fuel to the soil, and a slight decomposition of organic carbon present in the soil were observed during the soil remediation process. Thermogravimetric analysis showed that regardless of the diesel fuel concentration in the soil, four stages of mass loss were observed: moisture loss, vaporization, and combustion of diesel fuel as well as reduction of volatiles and char in the soil. Producer gas analysis indicated that during soil remediation diesel fuel was mainly converted to synthesis gas, i.e., a mixture of H₂, CO, and CO₂. Moreover, the decomposition of diesel fuel and the formation of synthesis gas depended on the amount of pollutant in the soil. According to the obtained results, thermal water vapor arc plasma was able to completely remove diesel fuel from polluted soil in the form of synthesis gas with no significant influence on soil’s properties.

The effect of external resistance on substrate removal and electricity generation was explored in microbial fuel cells (MFCs) simultaneously treating sulfide and nitrate. The MFCs were operated under three different conditions keeping open-circuit MFC as control. In batch mode, all the MFCs showed good capacity of simultaneously removing sulfide and nitrate regardless of external resistance. The voltage profile could be divided into rapid descent zone, bulge zone, and stability zone, which represents typical polarization behavior. Taking open circuit as control, low external resistance promoted the production of sulfate and nitrogen gas, while a strong link between product production and external resistance was evident based on Pearson correlation analyses. In addition, low external resistance improved the amount of transferred electrons, while the peak electronic quantity was noticed when the external resistance was equivalent to internal resistance. Moreover, the mechanism of substrate removal and electricity generation was hypothesized for the MFCs simultaneously treating sulfide and nitrate which explained the results well.