Most of the countries of South America depend heavily on mining and agriculture, which develops through the destruction of the forest. The expansion of the agricultural frontier is more visible in countries with proximity to the Amazon. Otherwise, the increase in urban primacy and real income per capita has led to an increase in the use of non-renewable energy in recent decades. The interest in quantifying greenhouse gas emissions has increased, oriented towards the search for mechanisms that mitigate the irreversible effects of climate change. In this context, the objective of this research is to examine the causal link among non-renewable energy consumption and real GDP per capita in greenhouse gas emissions in ten countries of South America during 1971–2014. In addition, we group the countries according to their productive structure and we incorporate the structural changes of each country in the econometric estimations, allowing to significantly improve the understanding of the sources of greenhouse gases. We use cointegration and causality techniques for time series data, and we found that there is a relationship of short- and long-term equilibrium between the three variables in all countries. The causality test indicates that in Bolivia, Peru, and Uruguay, there is causality from the consumption of non-renewable energy to greenhouse gas emissions. Likewise, in Venezuela and the agricultural countries, GDP causes greenhouse gas emissions. An implication of the public policy derived from this research is that most of the countries of South America can promote a change in the energy matrix to contribute to the mitigation of greenhouse gas emissions without limiting economic growth.

Krossfjord-Kongsfjord system situated on the west coast of Svalbard archipelago is an ideal location to investigate the impacts of climate change on the environment. As a consequence of global warming, metal concentrations in the Arctic region are increasing due to permafrost melting and changes in biological processes. Therefore, the fjord sediments were studied for identification of provenance, mobility, bioavailability, and potential toxicity of metals in the fjord environment. Finer sediments and organic matter were found to be higher away from the glacier outlets, while coarser sediments were found to be higher near the glacier head. Illite, kaolinite, and chlorite constituted the clay mineral assemblage which had slightly influenced the metal distributions. The variations in metal abundance were attributed largely to the glacial activity along with the influence of Atlantic water mass in western Spitsbergen. Fjord system received sediment from the weathering of rocks indicating an input of terrigenous material. Comparison of metals in bulk sediment with Arctic sediment quality guidelines (ASQGs) showed that Zn and Cu were enriched in the sediment. However, to avoid the overestimation of the risk associated, fractionation of the metals was carried out which revealed higher Mn and Co in labile phases that pose a considerable risk to the biota.

In the present study, PANI-TiO₂ nanocomposites have been used in suspended and immobilized form for photocatalytic degradation of Acid Yellow 17 (AY-17) dye under visible light. PANI-TiO₂ nanocomposites were immobilized in polystyrene cubes to form PANI-TiO₂ @ polystyrene cubes. The nanocomposites were found to be visible light active both in suspended and immobilized form. PANI-TiO₂ nanocomposite with 13% TiO₂ loading was found to be the optimum in terms of maximum degradation of AY-17. The efficiency of floating bed photoreactor (FBR) operated in liquid recycle mode using PANI-TiO₂ @ polystyrene cubes was studied. In this reactor, around 89% degradation of 1 L of AY-17 with an initial concentration of 10 mg/L could be achieved with 2.83 g/L per pass of immobilized catalyst. The FBR operated with PANI-TiO₂ @ polystyrene cubes has exhibited good performance as a photocatalytic reactor and may be recommended over other conventional photo reactors for treatment of wastewater contaminated with synthetic dyes. The kinetics of degradation of AY-17 by photocatalysis under visible light with suspended PANI-TiO₂ and PANI-TiO₂ @ polystyrene cubes followed first-order kinetics. The values of apparent kinetic parameter for degradation by immobilized photocatalysts are lower than the corresponding kinetic parameter for suspended photocatalysts. It confirms the existence of diffusional limitations in photocatalysis by PANI-TiO₂ @polystyrene cubes.

The effects of climate change and anthropogenic activities on the concentration of heavy metal in maize were quantitatively characterized in this study to help us better understand the complex interactions among the groundwater, vadose, plant, and atmosphere layers in the critical zone. We hypothesized that climate change and groundwater resource exploitation firstly affected the shallow groundwater level, and then the groundwater table fluctuation (GTF) impacted the concentration of heavy metal in maize through the critical zone (CZ) structure and parameters. To test our hypothesis, we collected 960 soil and 288 maize samples from the Luan River catchment in the North China Plain. The Groundwater Modeling System software was used to describe the effects of precipitation and groundwater resource exploitation on the groundwater table, and then, the structural equation method was employed to characterize the quantitative effects of GTF, precipitation, and air temperature on the concentration of heavy metal in maize. The results indicate that the influence coefficients of the effects of climate change and anthropogenic activities on the concentrations of Fe, Mn, Cr As, Pb, and Sr were 0.1595, 0.088, 0.0042, − 0.0092, 0.2219, and 0.0493 in the north plain, respectively, and 0.0256, 0.0151, 0.0816, − 0.2264, 0.1125, and − 0.0106 in the south plain of the study region, respectively. Since the human health risks of metals were mainly attributed to Fe, Mn, and Cr in the Luan River catchment, increasing the groundwater resource exploitation volume is an effective way to decrease the Fe, Mn, and Cr contents in maize by decreasing the shallow groundwater table.

Atmospheric PM₂.₅-bound polycyclic aromatic hydrocarbons (PAHs) were analyzed over urban and rural sites during January to December 2018. Total annual average concentration of PM₂.₅ was 74.41 ± 24.96 μg/m³ over urban and 52.03 ± 13.11 μg/m³ over rural site during study time. The annual average concentration of PM₂.₅ over urban and rural atmospheres were found approximately twice in urban and found also higher over rural site, with respect to National Ambient Air Quality (NAAQ) standard of 40 μg/m³ for PM₂.₅ concentration. The annual concentration of PAHs was 750.80 ± 19.49 ng/m³ over urban, and, over rural, it was 559.59 ± 17.56 ng/m³. The seasonal variation of concentration of PAHs was in order of winter > post-monsoon > summer > monsoon. The most predominant PAHs were IcP (17.21%), B(ghi) P(15.22%), BkF (11.60%), DBahA (11.34%) and BbF (10.91%) to the total PAH concentration over urban site; over rural site, most predominant PAHs were IcP (16.02%), B(ghi)P, (15.63%), BkF (11.46%), DBahA (11.12%) and BbF (8.99%) of total PAHs. DBahA concentration was contributed approximately 46% carcinogenicity over both urban and rural sites, and BaP contributes 33.56% carcinogenicity over urban site and 34.62% carcinogenicity over rural site of total PAH samples. The Excess Life Time Cancer Risk (ELCR) values over urban were found at acceptable limit 10⁻⁶–10⁻⁴ given by the United States Environmental Protection Agency. Over rural site, the ELCR value was found near about acceptable limit. Diagnostic ratio analysis demonstrated that major sources of PAHs were pyrogenic sources and vehicular emission over study. Air parcel through trajectories over study site also contributed in PAH concentration.

Slim tobacco products shall appear by their look less harmful. In 2013, the European Union ministers discussed to ban them. However, only a ban on small package sizes was realized. To add more data for exposure risk assessment of slim tobacco products, the particulate matter (PM) amount in second-hand smoke (SHS) of super-slim size cigarettes compared with a king size brand was investigated. PM amount of four super-slim size cigarette types of the brand Couture was analysed in comparison with the king-size reference cigarette. Therefore, SHS was produced in an enclosed space with a volume of 2.88 m³ by an automatic environmental tobacco smoke emitter. PM size fractions PM₁₀, PM₂.₅ and PM₁ were measured in real time using a laser aerosol spectrometer. SHS of Couture Gold contained about 36% and Couture Purple about 28% more PM than the reference cigarette. In contrast, Couture Green emitted about 37% and Couture Silver about 53% less PM than the reference cigarette. Depending on the brand, the PM₂.₅ mean concentrations increased up to 1538 μg/m³. This exceeds the 24-h mean concentration of at most 25 μg/m³ according to the WHO Air quality guidelines about 62-fold. Smoking in enclosed rooms leads to a massive increase of PM. The PM pollution by slim-size tobacco products are substantial and sometimes higher than by king size tobacco products. Therefore, SHS exposure from slim-size tobacco products is not less harmful to health. Decision makers should take this aspect in consideration.

In situ chemical oxidations are known to remediate PAH contaminations in groundwater and soils. In this study, batch-scale oxidations aim to compare the PAC (polycyclic aromatic compound) degradation of three oxidation processes traditionally applied for soil treatment: permanganate, heat-activated persulfate (60 °C) and Fenton-like activated by magnetite, to results obtained with ferrates (Feⱽᴵ). Widely studied for water treatments, ferrates are efficient on a wide range of pollutants with the advantage of producing nontoxic ferric sludge after reaction. However, fewer works focus on their action on soil, especially on semi-industrial grade ferrates (compatible with field application). Oxidations were carried out on sand spiked with dense non-aqueous phase liquid (DNAPL) sampled in the groundwater of a former coking plant. Conventional 16 US-EPA PAHs and polar PACs were monitored, especially potential oxygenated by-products that can be more harmful than parent-PAHs. After seven reaction days, only the Fenton-like showed limited degradation. Highest efficiencies were obtained for heat-activated persulfate with no O-PAC ketones formed. Permanganate gave important degradation, but ketones were generated in large amount. The tested ferrates not only gave slightly lower yields due to their auto-decomposition but also induced O-PAC ketone production, suggesting a reactional pathway dominated by oxidoreductive electron transfer, rather than a radical one.

This article presents a bibliometric study of 200 European publications released between 2001 and 2016, about the contamination of mushrooms by selected elements. The analysis includes figures on the type of analyte, its concentration, the species of fungi, and its country of origin. In the literature review, 492 species of mushrooms (wild-growing and cultured) found in 26 European countries and their concentration of 74 associated elements were analysed. The papers, which dealt mainly with the heavy metal (Cd, Cu, Fe, Pb, and Zn) concentrations of mushrooms, primarily came from Turkey, Poland, Spain, and the Czech Republic. More than 50% of the publications provided data about edible mushrooms. The results of the bibliometric analysis showed that over the 16 years, European research on fungal contamination by selected analytes has not lessened in popularity and is ongoing. Many of the studies underlined the need to assess the risk to human health arising from the consumption of contaminated mushrooms taken from various habitats. These results were the effect of, among other things, the strong interest in studies carried out on edible species, in which concentrations of mainly heavy metals that are dangerous to health and are marked were indicated (Cd, Pb, and Hg).

Plastic and hydrocarbon pollution in aquatic ecosystems is a worldwide reality and serious concern today. Plastic debris presents a threat to ecosystems and organisms. Hydrocarbons are also considered priority pollutants. The hydrophobicity of the polymer in combination with the high surface area causes plastics to act as a vector for organic contaminants such as hydrocarbons. The first aim of this work was to evaluate the presence of plastic and hydrocarbon pollution in water from two reefs and two rivers and to identify plastic in six sediment beaches in Veracruz State, Mexico. In addition, the second aim was to analyse the ability of a bacterial consortium to biodegrade hydrocarbons in an airlift bioreactor and to identify degrading bacterial strains of polyethylene terephthalate (PET). Microplastics (100 nm–5 mm) were found in four water samples. Fragments of plastic collected from the reefs ranged in size from 0.716 to 32 μm and in rivers from 0.833 to 784 μm. On the sediment beaches, macroplastics of sizes 2–10 cm were detected. A number of hydrocarbons were also detected in the water samples of both reefs and one river, including n-octane, n-nonane, phenanthrene, n-eicosane, n-dotriacontane, n-hexatriacontane, n-triacontane, and n-tetratriacontane. As a biotechnological alternative for remediation of hydrocarbons and plastics, we attempted to produce a collection of native microorganisms able to degrade them. This work shows results from the bioprospection of a bacterial consortium (Xanthomonas, Acinetobacter bouvetii, Shewanella, and Aquamicrobium lusatiense) for hydrocarbon biodegradation in an airlift bioreactor. The tested consortium was able to successfully degrade the maximum diesel concentration (20 g L⁻¹) tested for 10 days. Also, the first visual evidence of PET degradation by an isolated forest-native bacterial strain showed that Bacillus muralis is the most efficient degrader.

Considering the reduction of fossil fuel resources and the increase of environmental pollutions, everyone is aware of the importance of saving on consumption of energies generated from fossil fuels. Global statistics demonstrates that 30–40% of the energy across different countries worldwide is used in residential buildings. Therefore, one way of efficiency and optimization of energy consumption is to construct buildings that consume the least energy for heating and cooling. Aiming for the analysis of the total amount of annual energy required for heating and cooling, this research was conducted in a combined novel method (simulation and descriptive-analytic) on four samples of a two-story building, simulated in Design Builder Software in the four main directions of north, east, south, and west by using the weather data of warm climate, seeking the optimum orientation and ranking of the said buildings based on CO₂ emissions. The research results show that among the four sample buildings, the east-facing building ranked first with the minimum CO₂ emissions and the west-facing building won second place in the window to wall ratio (WWR) of 40%. Also, the building in a hot climate was considered, since it produced CO₂ annually 12,633 kg. No significant change is observed in the amount of CO₂ emissions in southeast, south, and southwest orientations, although smaller WWR (30% and 20%) is recommended for these three orientations.