The supply of potassium (K) is a strategy to increase the tolerance of plants exposed to Cd toxicity. The aim of this study was to verify the influence of K on the growth and potential of Tanzania guinea grass (Panicum maximum Jacq. cv. Tanzania (syn. Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L. Jacobs)) for Cd phytoextraction as well as to evaluate nutritional attributes of this grass under conditions of Cd stress. The experiment was conducted in a randomized complete block design, using a 3 × 4 factorial arrangement, with three replications. Three rates of K (0.4, 6.0, and 11.6 mmol L⁻¹) were combined with four rates of Cd (0.0, 0.5, 1.0, and 1.5 mmol L⁻¹) in nutrient solution. Two plant growth periods were evaluated. The increase in K supply to plants exposed to Cd rates of up to 1.0 mmol L⁻¹ caused increase in morphogenic and production attributes, as well as reduction in tiller mortality rate, in the second growth period. K concentrations (in both harvests) increased, while calcium and magnesium concentrations in the second harvest decreased with increasing Cd rates. The high availability of Cd (1.5 mmol L⁻¹) in the nutrient solution caused decrease in relative chlorophyll index (RCI) in both harvests. The high supply of K to plants exposed to Cd resulted in high shoot dry mass production, reducing Cd concentration in the photosynthetic tissues (which means great tolerance of the plant) and increasing the accumulation of this metal in the shoots that can be harvested. Therefore, K increases the Cd phytoextraction capacity of Tanzania guinea grass.

A combination of local (i.e. firefighting training facilities) and remote sources (i.e. long-range transport) is assumed to be responsible for the occurrence of per- and polyfluoroalkyl substances (PFASs) in Svalbard (Norwegian Arctic). However, no systematic elucidation of local PFASs sources has been conducted yet. Therefore, a survey was performed aiming at identifying local PFAS pollution sources on the island of Spitsbergen (Svalbard, Norway). Soil, freshwater (lake, draining rivers), seawater, meltwater run-off, surface snow and coastal sediment samples were collected from Longyearbyen (Norwegian mining town), Ny-Ålesund (research facility) and the Lake Linnévatnet area (background site) during several campaigns (2014–2016) and analysed for 14 individual target PFASs. For background site (Linnévatnet area, sampling during April to June 2015), ΣPFAS levels ranged from 0.4 to 4 ng/L in surface lake water (n = 20). PFAS in meltwater from the contributing glaciers showed similar concentrations (~ 4 ng/L, n = 2). The short-chain perfluorobutanoate (PFBA) was predominant in lake water (60–80% of the ΣPFASs), meltwater (20–30%) and run-off water (40%). Long-range transport is assumed to be the major PFAS source. In Longyearbyen, five water samples (i.e. 2 seawater, 3 run-off) were collected near the local firefighting training site (FFTS) in November 2014 and June 2015, respectively. The highest PFAS levels were found in FFTS meltwater run-off (118 ng/L). Perfluorooctane sulfonic acid (PFOS) was the most abundant compound in the FFTS meltwater run-off (53–58% PFASs). At the research station Ny-Ålesund, seawater (n = 6), soil (n = 9) and freshwater (n = 10) were collected in June 2016. Low ΣPFAS concentrations were determined for seawater (5–6 ng/L), whereas high ΣPFAS concentrations were found in run-off water (113–119 ng/L) and soil (211–800 ng/g dry weight (dw)) collected close to the local FFTS. In addition, high ΣPFAS levels (127 ng/L) were also found in freshwater from lake Solvatnet close to former sewage treatment facility. Overall, at both FFTS-affected sites (soil, water), PFOS was the most abundant compound (60–69% of ΣPFASs). FFTS and landfill locations were identified as major PFAS sources for Svalbard settlements.

Alpha-cypermethrin (α-cypermethrin), an important chiral pyrethroid insecticide, is frequently detected in human samples. Because of the possible human health risks caused by α-cypermethrin, we studied dynamics, residues, and metabolism of α-cypermethrin in five common vegetables (tomato, cucumber, rape, cabbage, and pepper) on enantiomeric levels after foliar spray. α-Cypermethrin was qualified by a HP-5 column and its enantiomers could be separated by gas chromatograph (GC) using a BGB-172 chiral column. The results of degradation showed that α-cypermethrin dissipated rapidly in vegetables with half-lives being only 2.85–8.88 days. Stereoselective degradation was observed on pepper and cucumber while the two metabolites (cis-DCCA and 3-PBA) of α-cypermethrin were not detected during its dissipation in all plants. This is the first evidence of enantioselective degradation of α-cypermethrin in the five common vegetables and the results should be considered in future environmental risk and food safety evaluations.

In this investigation, performance and emission characteristics for enhancing LPG, hydrogen, and hydroxy with E20 were evaluated for the understanding of which fuel combination performs better in a gasoline engine. In the upper sequence, hydroxy-hydrogen-LPG could perform best in terms of brake thermal efficiency (BTE) and brake-specific fuel consumption (BSFC). The induction of gaseous fuel improves CO, CO₂, and HC emission but increases the NOx emission. More concisely, the enhancement of hydroxy with E20 shows the best engine performance for highest BTE while lowest BSFC as well as lowest exhaust emissions (CO, HC, except NOx).

During coal mining activities, a lot of coal gangue is produced, which usually contains high mercury (Hg) concentrations as well as the acid mine drainage (AMD) generator of pyrite. In the present study, the total mercury (THg) and methylmercury (MeHg) in gangue, water, sediment, paddy soil, and rice samples, collected from abandoned coal mining areas, were analyzed. Results showed that the THg concentrations ranged from 0.37 to 35 mg/kg (11 ± 8.4 mg/kg) and 0.15 to 19 mg/kg (2.0 ± 3.9 mg/kg) in gangue and sediments, respectively. For paddy soils, the THg concentrations and MeHg varied from 0.16 to 0.91 mg/kg and 0.71 to 11 ng/g, respectively. Rice samples exhibited wide concentration ranges of THg (3.0–22 ng/g) and MeHg (0.71–8.9 ng/g). Sequential extraction of Hg revealed that the nitric acid-extractable state Hg (F4) was the dominant Hg species in gangue and sediment, while humic acids state Hg (F3) was the dominant form in paddy soil. Compared with gangue, higher percentages of F3 and the residual state Hg (F5) in both sediment and soil samples implied the transformation of F4 to F3 and F5 during transportation. Soil n-HAs (the difference between the total organic carbon and humic acids) were positively correlated with both THg and MeHg in soil and rice, indicating that n-HAs enhance Hg bioavailability under acidic conditions. Further studies should be conducted to reveal the factors influencing the transformation of different Hg fractions, providing ideas on decreasing the bioavailability of Hg in coal mining areas.

Beijing and its surrounding areas implemented a series of stringent measures to ensure good air quality during the Asia-Pacific Economic Cooperation (APEC) summit. These measures included restrictions on traffic, constructions, and industrial activities. The diurnal variations of carbonyls, 24-h PM₂.₅, and its chemical species were investigated before, during, after APEC, and the 2015 summer. The average concentrations of carbonyls, formaldehyde, acetaldehyde, and acetone were decreased by 65.2%, 78.6%, 41.5%, and 55.6% during APEC, respectively. The concentrations of propene equivalent, the ozone formation potential, and the contribution to OH· removal by carbonyls during APEC were approximately 27–33% of those during the preceding interval. The temporal variation of carbonyls during APEC was similar to that of other air pollutants, except for O₃; however, the diurnal variation of carbonyls was consistent with that of O₃, with the highest values at noon and the lowest ones at night during APEC. Large variations in C1/C2 (0.95–9.41) and C2/C3 (5.70–15.71) were observed during the sampling period. The correlations analysis, diagnostical ratios, and diurnal variations of carbonyls indicated that primary sources were not an important source and secondary formation was the dominant source of atmospheric carbonyls during the entire period. The control measures not only reduced primary carbonyl emissions but also dramatically reduced secondary carbonyl precursors, such as NOₓ and volatile organic compounds (VOCs), resulting in the low level of carbonyls during APEC. In addition, the potential health effects of carbonyls were evaluated and the cancer risk from formaldehyde and acetaldehyde was significantly higher before APEC than during the other intervals.

Black-odor rivers have become a prominent environmental problem, especially for developing countries. A laboratory experiment was conducted to determine the optimum operating parameters of artificial aquatic plants (AAP) to provide a theoretical and scientific basis for their application in black-odor rivers. The purification mechanism of operating parameters for AAP was also explored at the micro-organic and genetic levels by high-throughput sequencing. Chemical oxygen demand (COD) and ammonia nitrogen (NH₄⁺-N) were measured in systems with different AAP lengths and pH. After 24 days, the best removal efficiencies of APP for COD and NH₄⁺-N were 90.07 and 82.40% for 100 cm and 90.70 and 91.90% for pH values of 8.0–9.0, respectively. High-throughput sequencing analysis revealed that the relative abundance of Flavobacterium in the AAP was 7.80% at 50 cm, while the proportion increased to 29.30% at 100 cm. The abundance of microorganisms improved continuously with increased length, and the ratio of Acinetobacter increased obviously at pH 8.0–9.0 relative to pH 6.0–7.0. Furthermore, the AAP were used in Qihe Artificial Wetland in Shandong Province, China. The results revealed that the average removal efficiencies of AAP for COD and NH₄⁺-N were 27.75 and 14.34%, respectively, in the artificial wetland. Therefore, AAP was beneficial to the growth of bacteria and could be used in the treatment of black-odor rivers.

Biofuel is a renewable energy source for transportation. Given the toxicity associated with particulate polycyclic aromatic hydrocarbons (PAHs) is not fully understood, investigating the difference of adverse health risks posed between vapor and particulate PAH emissions from biodiesel-fueled engine combustion was the objective of this study. Three different fuel types, including typical diesel, emulsified diesel with a water fraction from 10 to 19% (v/v), and emulsified biodiesel with water (10%) and biofuel fractions from 10 to 40% (v/v), were studied. The fugacity model and risk assessment were conducted to predict the health risks when different fuels were used. In the results, the addition of water and biofuel elevated and reduced the total PAH emissions in the exhausts, respectively. After the emission, chrysene and benzo(a)anthracene were two dominant carcinogenic species in the environment. The excess cancer risk of the PAH emission significantly decreased (e.g., up to two orders of magnitude) while the emulsified biodiesel was applied, with limiting the formation of benzo(a)pyrene being the explanation. The PAH emissions with molecular weights ranging from 166 to 255 g/mol were significantly different between the vapor and particulate phases during the emulsified biodiesel combustion (p < 0.01). From the viewpoint of cancer risk, the contribution posed by the particulate PAHs was significantly greater than those by the vapor PAHs (e.g., from 54% (benzo(a)pyrene) to 76% (benzo(b)fluoranthene)). Benzo(a)pyrene and chrysene represent the species with the highest and lowest risks, respectively. The multi-ringed PAHs with four or five rings were more indicative of potential cancer risk posed by the PAHs associated with particulate matters during combustion of the emulsified biodiesel.

Ambient air pollution is nowadays one of the most crucial contributors to deteriorating health status worldwide. The components of air pollution include PM₂.₅ and PM₁₀, NO₂, SO₂, CO, O₃, and organic compounds. They are attributed to several health outcomes, for instance, cardiovascular diseases (CVD), respiratory diseases, birth outcomes, neurologic diseases, and psychiatric diseases. The objective of this study is to evaluate the association between different ambient air pollutants and the above-mentioned health outcomes. In this systematic review, a total of 76 articles was ultimately selected from 2653 articles, through multiple screening steps by the aid of a set of exclusion criteria as non-English articles, indoor air pollution assessment, work-related, occupational and home-attributed pollution, animal studies, tobacco smoking effects, letters to editors, commentaries, animal experiments, reviews, case reports and case series, out of 19,862 published articles through a systematic search in PubMed, Web of Science, and Scopus. Then, the associations between air pollution and different health outcomes were measured as relative risks and odds ratios. The association between air pollutants, PM₂.₅ and PM₁₀, NO₂, SO₂, CO, O₃, and VOC with major organ systems health was investigated through the gathered studies. Relative risks and/or odds ratios attributed to each air pollutant/outcome were ultimately reported. In this study, a thorough and comprehensive discussion of all aspects of the contribution of ambient air pollutants in health outcomes was proposed. To our knowledge up to now, there is no such comprehensive outlook on this issue. Growing concerns in concert with air pollution-induced health risks impose a great danger on the life of billions of people worldwide. Should we propose ideas and schemes to reduce ambient air pollutant, there will be dramatic reductions in the prevalence and occurrence of health-threatening conditions.

Geochemical records from peatlands are important tools for the interpretation of environmental signals preserved in the peat and the understanding anthropogenic impacts on remote mountain regions. In this paper, six ²¹⁰Pb-dated peat cores located at 500–1900 m above sea level (asl) in the Changbai Mountains were used to reconstruct the pollution history over the past 150 years in northeastern (NE) China. The cores physicochemical parameters and 10 key chemical elements were analyzed by inductively coupled plasma atomic emission spectroscopy (ICP-AES). Results from loss on ignition (LOI), total organic carbon (TOC), and lithogenic element (Ti, Fe, and Mn) analysis show that the peatlands (Ch, Yc1 and Jb) over 900 m asl are ombrotrophic and the lower altitude peatlands (Dng, Jc, and Ha) are minerotrophic. There is a decreasing trend of trace element distribution with the altitude, mainly due to the local source input. The content of the magnetic particles and trace elements (Cu, Ni, Pb and Zn) as well as their accumulation rates document 150 years of pollution history in the Changbai Mountain region. There is a significant elevated pattern of the geochemical records after the New China, which might mark the start date of Anthropocene since the 1950s in this region. The peatlands at the lower altitude (i.e., Dng and Ha) record the earliest fingerprints of metal contamination due to the starting period of massive reclaiming and immigrating in the Changbai Mountain region. The major increase of trace elements since the 1980s probably suggests a significant deterioration of the local environment due to the fast industrial and urbanization development after the Reform and Opening up in China.