The synergistic effects of trace elements selenium (Se) and cadmium (Cd) are well known. But the reasons for the trending accumulation behavior in both trace elements are under debate in the scientific community. The present investigation was conducted to evaluate the impact of heat units on the accumulation behavior in two environments. Se and Cd were applied in three groups (T₀; 0:0, T₁; 0.4:1, T₂; 1:2) mg kg⁻¹. As the time of planting and heat units consumed by the crop to attain its physiological maturity appears to be different. The sunlight may contribute as an important manipulating factor for the accumulation of heavy metals in the plant. The results of the present study indicated that the behavior in the accumulation pattern of both elements appears to be distinct in the same material. The increased fertilizer treatment in soil bulk linearly increased the metal contents in rice grain. The studies between different plant parts disclosed panicle as the primary reservoir for Se and Cd accumulation. The plant sown earlier accumulates more Se than Cd while the plants uptake more Cd when sown 1 month later. The plant completes the critical developmental phases (tillering, heading, and flowering) within 20–30 days interval depending on the variety. But the late-sown plants complete these transitional phases within 9–10 days interval ultimately result in less utilization of heat units. These quick transitional changes may lead to the uptake of an ample amount of Cd contents in rice grain even at a low level of Cd stress (1 and 2 mg kg⁻¹), making rice unsafe for edible purposes. The proper time of planting could be effective in timely acclimatization of Se and Cd sequestration and translocation in rice various components. Graphical Abstract

Since NH₃ is a significant precursor to ammonium in PM₂.₅ and contributes significantly to atmospheric nitrogen deposition but largely remains unregulated in China, the insight into the source of NH₃ emissions by the isotopic investigation is important in controlling NH₃ emissions. In this study, atmospheric concentrations of NH₃ and water-soluble ion composition in PM₂.₅ as well as nitrogen isotope ratios in NH₄⁺ (δ¹⁵N-NH₄⁺) in Xiamen, China, were measured. Results showed that average NH₃ concentration for the five sites in Xiamen was 7.9 μg m⁻³ with distinct higher values in the warm season and lower values in the cold season, and PM₂.₅ concentration for the two sites (urban and suburban) was 59.2 μg m⁻³ with lowest values in summer. In the PM₂.₅, NH₄⁺ concentrations were much lower than NH₃ and showed a stronger positive correlation with NO₃⁻ than that with SO₄²⁻ suggesting the formation of NH₄NO₃ and equilibrium between NH₃ and NH₄⁺. Although the concentrations of NH₃ at the urban site were significantly higher than those at the suburban site, no significant spatial difference in NH₄⁺ and δ¹⁵N-NH₄⁺ was obtained. The distinct heavier δ¹⁵N-NH₄⁺ values in summer than in other seasons correlated well with the equilibrium isotopic effects between NH₃ and NH₄⁺ which depend on temperature. The initial δ¹⁵N-NH₃ values were in the range of waste treatment (− 25.42‰) and fossil fuel combustion (− 2.5‰) after accounting for the isotope fractionation. The stable isotope mixing model showed that fossil fuel–related NH₃ emissions (fossil fuel combustion and NH₃ slip) contributed more than 70% to aerosol NH₄⁺. This finding suggested that the reduction of NH₃ emissions from urban transportation and coal combustion should be a priority in the abatement of PM₂.₅ pollution in Xiamen.

Dependence of rural population on traditional fuel sources namely biomass has increased because of easy accessibility and affordability. The use of biomass fuels results in many environmental and health-related hazards. Rural households have little awareness about the ill effects of using biomass energy sources. This study investigated the patterns of rural household energy use and identified the role of information on the effects of biomasses on human health, in addition to other factors influencing households’ choices of energy sources. For this purpose, primary data from 196 households were collected from four districts of the Punjab province in Pakistan. Results showed that use of clean energy sources was limited to basic appliances and 90% of the respondents depended on biomass fuels. Estimates of the multivariate probit model showed that awareness about adverse impacts of biomass fuels as energy sources were significantly related with the choice of energy sources. Further, household head’s education level, household income, landholding, children under the age of 5 years and higher number of adult females were significantly related with the cleaner energy source choices. Distance to market increased the probability of the use of biomass energy sources. The study concluded that awareness campaigns regarding the benefits of using clean energy sources should be launched through print and electronic media while targeting rural women.

The aim of this paper is to systematically review the scientific literature on the possible relation of chronic mercury exposure and blood pressure among children and adolescents. We searched for observational studies in 6 electronic databases and grey literature for English, French or Spanish language studies published up to 30ᵗʰ November 2017. We performed a quality assessment of primary studies. We identified 8 articles involving 5 cohorts, 1 cross-sectional study and 1 case-control study. The participants had mean ages of between 3 and 17 years. Mercury was analysed in different matrices and periods of exposure. Four articles evaluated prenatal exposure, 2 evaluated both prenatal and postnatal exposures and 2 postnatal exposure. Blood pressure was measured according to different protocols. The association between mercury and blood pressure was adjusted by different covariates in each study. Four articles found a positive significant association between chronic mercury exposure and blood pressure in children or adolescents. Among these 4 articles, three of them evaluated prenatal exposure. There are still few studies assessing chronic mercury exposure and blood pressure in children and adolescents with inconsistency in results. Designs are very heterogeneous, which hampers their comparability. Evidence of this association is scarce and further research is needed.

This study provides a comprehensive assessment of firms’ operation and environmental protection polices in Nigeria and Ghana, where there has been a rising industrial growth amidst low regulatory and institutional frameworks. We analyze the extents to which firms’ adoption of environmental protection policies affect their performances. We use firm-level data of 842 firms (447 for Nigeria and 395 for Ghana) distributed across different regions of both countries for our descriptive and econometric estimations. We find, among other things, that firms’ adoption of internal policies on environmental protection is dismally low in both Nigeria (32%) and Ghana (17%), with policies focused on reducing solid (38%, Nigeria; and 35%, Ghana), gaseous (22%, Nigeria; and 44%, Ghana), and liquid (24%, Nigeria; and 14%, Ghana) pollution. Training appears to be an important intervention that can help improve firms’ adoption of such policies. We also found that firms’ adoption and implementation of environmental protection policies significantly improve their performance.

Indoor air pollution is an important risk factor for the generation of lung diseases in developing countries. The indigenous population is particularly susceptible to be exposed to the mixture of pollutants from the biomass burning, among them, polycyclic aromatic hydrocarbons (PAHs). The objective of this study was to assess respiratory health and exposure to PAHs in indigenous populations of the Huasteca Potosina in Mexico. The urinary metabolite 1-hydroxypyrene (1-OHP) was evaluated by HPLC with fluorescence detector, the forced expiratory volume in one second (FEV₁) and the FEV₁/FVC ratio (forced vital capacity) by spirometry in the Teenek indigenous adult population of the communities from Tocoy (TOC), Xolol (XOL), and Tanjajnec (TAN). A total of 134 subjects participated in the study: 64 from TOC, 30 from XOL, and 40 from TAN; in all the communities, high percentages of overweight and obesity were presented (from 50 to 73%). The average hours of firewood usage per year were 281.06, 284.6, and 206.6 in TOC, XOL, and TAN, respectively. The average of the three communities of the % FEV₁ post-bronchodilator was 86.1%. There were identified from 4.5 to 6.6% and from 12.5 to 15.5% of spirometric obstructive and restrictive patterns respectively, in all communities. The highest exposure levels reported as median were found in TOC (1.15 μmol/mol of creatinine) followed by TAN (0.94 μmol/mol of creatinine) and XOL (0.65 μmol/mol of creatinine). Considering the magnitude of the indigenous population exposed to pollutants from the biomass burning and the possible effects on respiratory health, it is important to design strategies that mitigate exposure and evaluate the effectiveness through biological monitoring and effects.

The aim of this work is to convert agroforestry residue to a novel adsorbent (M-1CTA-SDS-BT) used for adsorptive benzene sequestration from aqueous solution. In this study, the anionic surfactant-coated-cationized banana trunk was synthesized and characterized for batch adsorption of benzene from aqueous solution. The surface morphology, surface chemistry, surface area, and pore properties of the synthesized adsorbents were examined. It was proven that surface cationization successfully increased the benzene adsorption capacity of sodium dodecyl sulfate-coated adsorbents. The Langmuir isotherm model satisfactorily described the equilibrium adsorption data. The maximum benzene adsorption capacity (qₘₐₓ) of 468.19 μmol/g was attained. The kinetic data followed the pseudo-second-order kinetic model in which the rate-limiting step was proven to be the film diffusion. The batch-adsorbent regeneration results indicated that the M-1CTA-SDS-BT could withstand at least five adsorption/desorption cycles without drastic adsorption capacity reduction. The findings demonstrated the adsorptive potential of agroforestry-based adsorbent as a natural and cheap material for benzene removal from contaminated water.

This paper first visits the clean energy consumption for 21 OECD countries and 14 Emerging market countries through a panel unit root test with both sharp and smooth breaks covering the period from 1965 to 2016. The time-varying fitted intercepts of the estimation could better fit the path of clean energy consumption for selected countries. The empirical results suggest that not only sharp breaks should be considered, but also smooth breaks. The economic implications are insightful for the convergence of clean energy consumption for 22 of 35 countries. For USA, Canada, Austria, Germany, Greece, Ireland, UK, Australia, New Zealand, South Korea, Hungary, China, Philippines, and Thailand, the clean energy consumption is divergence. Policy encouragement policy would permanently affect not only clean energy consumption path, but also aggregate economic sectors related to consume clean energy.

In this paper, we discussed some major issues that hinder giant panda protection, such as diverse and mixed threats, habitat fragmentation, as well as the survey method to be improved, and some new protection actions appeared, such as the pilot program for the giant panda national park system and the administration of the giant panda national park was established. These information could provide important information for giant panda protection.

Turbulence-induced flocculation of cohesive fine-grained sediment plays an important role in the transport characteristics of pollutants and nutrients absorbed on the surface of sediment in estuarine and coastal waters via the complex processes of sediment transport, deposition, resuspension and consolidation. In this study, the concept of Shannon entropy based on probability is applied to modelling turbulence-induced flocculation of cohesive sediment in water. Using the hypothesis regarding the cumulative distribution function, the function of floc size with flocculation time is derived by assuming a characteristic floc size as a random variable and maximizing the Shannon entropy, subject to certain constraints. The Shannon entropy-based model is capable of modelling the variation in floc size as the flocculation time progresses from zero to infinity. The model is tested against some existing experimental data from the literature and against a few deterministic mathematical models. The model yields good agreement with the observed data and yields better prediction accuracy than the other models. The parameter that has been incorporated into the model exhibits an empirical power-law relationship with the flow shear rate. An empirical model formulation is proposed, and it exhibits high prediction accuracy when applied to existing experimental data.