Energy crops are an important renewable source for energy production in future. To ensure high yields of crops, N fertilization is a common practice. However, knowledge on environmental impacts of bioenergy plantations, particularly in systems involving trees, and the effects of N fertilization is scarce. We studied the emission of volatile organic compounds (VOC), which negatively affect the environment by contributing to tropospheric ozone and aerosols formation, from Miscanthus and willow plantations. Particularly, we aimed at quantifying the effect of N fertilization on VOC emission. For this purpose, we determined plant traits, photosynthetic gas exchange and VOC emission rates of the two systems as affected by N fertilization (0 and 80 kg ha−1 yr−1). Additionally, we used a modelling approach to simulate (i) the annual VOC emission rates as well as (ii) the OH. reactivity resulting from individual VOC emitted. Total VOC emissions from Salix was 1.5- and 2.5-fold higher compared to Miscanthus in non-fertilized and fertilized plantations, respectively. Isoprene was the dominating VOC in Salix (80–130 μg g−1 DW h−1), whereas it was negligible in Miscanthus. We identified twenty-eight VOC compounds, which were released by Miscanthus with the green leaf volatile hexanal as well as dimethyl benzene, dihydrofuranone, phenol, and decanal as the dominant volatiles. The pattern of VOC released from this species clearly differed to the pattern emitted by Salix. OH. reactivity from VOC released by Salix was ca. 8-times higher than that of Miscanthus. N fertilization enhanced stand level VOC emissions, mainly by promoting the leaf area index and only marginally by enhancing the basal emission capacity of leaves. Considering the higher productivity of fertilized Miscanthus compared to Salix together with the considerably lower OH. reactivity per weight unit of biomass produced, qualified the C4-perennial grass Miscanthus as a superior source of future bioenergy production.

Rapid industrialization in China in recent decades has resulted in soil contamination in some areas, raising the concern about food safety. Consumption of rice represents a major exposure route for the toxic elements cadmium (Cd) and arsenic (As). We collected 160 polished rice from local markets in 20 provinces in China and determined total Cd and As concentrations and As speciation. Total Cd concentration ranged from below the detection limit to 0.77 mg kg−1, with 10% of the samples exceeding the Chinese limit (0.2 mg kg−1). Rice Cd concentration showed a distinct geographical pattern, increasing from low levels in the north to high levels in the south of China. Median daily Cd intake from rice varied from 0.01 μg kg−1 body weight in the north to 0.61 μg kg−1 body weight in the south of China, representing between 1% and 73% of the tolerable daily intake (TDI) recommended by FAO/WHO. The highest median Cd intake from rice was in Hunan province with 2 times TDI. Total As concentration ranged from 0.011 to 0.186 mg kg−1, with inorganic As (iAs) and dimethylarsinic acid (DMAs) on average accounting for 69% and 31%, respectively. All samples were below the Chinese limit for iAs in rice (0.2 mg kg−1). There was no clear geographical pattern in rice total As concentration, but rice produced in northeastern China contained higher percentages of DMAs and lower percentages of iAs. This study highlights a high risk of Cd exposure from rice consumption for the population of southern China and suggested strategies for reducing Cd accumulation in rice crop.

Plastic pollution in the environment is currently receiving worldwide attention. Improper dumping of disused or abandoned plastic wastes leads to contamination of the environment. In particular, the disposal of municipal wastewater effluent, sewage sludge landfill, and plastic mulch from agricultural activities is a serious issue and of major concern regarding soil pollution. Compared to plastic pollution in the marine and freshwater ecosystems, that in the soil ecosystem has been relatively neglected. In this study, we discussed plastic pollution in the soil environment and investigated research on the effects of plastic wastes, especially microplastics, on the soil ecosystem. We found that earthworms have been predominantly used as the test species in investigating the effects of soil plastic pollution on organisms. Therefore, further research investigating the effects of plastic on other species models (invertebrates, plants, microorganisms, and insects) are required to understand the effects of plastic pollution on the overall soil ecosystem. In addition, we suggest other perspectives for future studies on plastic pollution and soil ecotoxicity of plastics wastes, providing a direction for such research.

Spatial and seasonal variations in nitrate contamination are a globally concern. While numerous studies have used δ¹⁵N-NO₃ and δ¹⁸O-NO₃ to elucidate the dominant sources of nitrate in groundwater, this approach has significant limitations due to the overlap of nitrate isotopic ranges and the occurrence of nitrate isotopic fractionation. This study quantitatively assessed the spatial and seasonal variations in the proportional contributions of nitrate sources from different land uses in the Tarom watershed in North-West Iran. To achieve this aim, orthogonal projection of the hydrochemical and isotopic dataset of the principal component analysis (PCA) as well as correlation coefficient matrix (Corr-PCA) were evaluated to reduce the dimensionality of the inter-correlated dataset. Next, a nitrate isotopic biplot accompanied with a Bayesian isotope mixing model (SIAR) were applied to specify the spatial and seasonal trends in the proportional contribution of three dominant sources of nitrate (fertilizers, animal manure and residential waste) in the watershed. Finally, in order to provide a sensitive framework for nitrate source appointment and overcome the associated limitations of dual nitrate isotope application, the integration of boron isotope (δ¹¹B) and strontium isotopic ratio (⁸⁷Sr/⁸⁶Sr) was introduced. The results revealed that the mean contribution of residential sewage increased (17%–27.5%), while the mean contribution of fertilizers decreased (28.3%–19%), from late spring to early autumn. Also, fertilizer was the highest contributor (42.1% ± 3.2) during late spring, especially in regions with more than 75% agricultural land. Meanwhile, the mean contribution of sewage was highest in early autumn (32.1% ± 2.8) in the areas with more than 20% residential land. These results were confirmed by coupled application of δ¹¹B and ⁸⁷Sr/⁸⁶Sr. This study provides a useful insight for environmental managers to verify groundwater pollution contributors and to better apply remedial solutions.

Stormwater samples were collected from six different land use sites with three time-intervals during a precipitation event on August 12, 2016, from a community of Beijing, China. A total of 46 species volatile organic compounds (VOCs) were detected in these stormwater samples, including methyl tertiary-butyl ether (MTBE), aromatic hydrocarbons, halogenated aromatics, Halogenated alkanes, and alkenes. The total VOC concentrations varied in the six sites following order: highway junction > city road > gas station > park > campus > residential area, except for MTBE, which was much higher at gas station compared to other land use sites. ANOVA results indicated both land use and precipitation time intervals could significantly affect the VOC concentrations even in the small area. The Beijing atmospheric VOC concentrations were too low to explain the high concentrations in stormwater, suggesting that land surfaces may be the main sources of VOC other than the ambient atmosphere. MTBE and other VOCs correlation analysis indicated that MTBE mostly came from gasoline emissions, spills or vehicle exhausts, whereas the BTEX (benzene, toluene, ethylbenzene, Xylenes) and the halogenated aromatics were transferred from chemical plants through land surfaces accumulating and the wind blowing atmospheric VOCs. Xylenes/ethylbenzene (X/E) ratios variations indicated that stormwater incorporated larger amount of fresh emitted air during the precipitation event than prior to it. Information of these stormwater VOCs in this study could be used in the community pollution reduction strategies.

The wide usage of hexachlorocyclohexanes (HCHs) as pesticides has caused soil pollution and adverse health effects through direct contact or bioaccumulation in the food chain. This study quantified major HCH isomers in farmland topsoils across China, and evaluated their correlations with microbial community structure, function, and abiotic variables (e.g., moisture, pH, and temperature). Recalcitrant β-HCH was more abundant than α-, γ-, and δ-HCHs, and α-HCH enantiomeric fractions (EF) were larger than 0.5, indicating preferential degradation of (−)-α-HCH. Sphingomonas was not only a predominant population (especially in samples collected in the south), but also a promising biomarker indicating total- and β-HCH residuals, and EF values of α-HCH. Soil moisture and temperature were among the most influential factors that structured the diversity and function of soil microbial communities. The results suggested that increasing soil moisture (in the range of 5–45%) would benefit the growth of HCH-degrading populations and the enrichment of HCH-degradation related pathways. Revealing the site-specific relationships between topsoil physical, chemical, and microbial properties will benefit the in situ bioremediation of farmlands with relatively low HCH residuals across the world.

Environmental pollution, local climatic conditions and their association with the prevalence and exacerbation of asthma are topics of intense current medical investigation.Air pollution in the area of Vladivostock was estimated both by the index of emission volumes of "air gaseous components" (nitrogen oxide and nitrogen dioxide, formaldehyde, hydrogen sulfide, carbon monoxide) in urban atmosphere and by mass spectrometric analysis of precipitates in snow samples. A total of 172 local asthma patients (101 controlled-asthma patients–CAP and 71 non-controlled asthma patients – nCAP) were evaluated with the use of spirometry and body plethysmography. Airway obstruction reversibility was evaluated with the use of an inhaled bronchodilator. Using discriminant analysis the association of environmental parameters with clinical indices of asthma patients is explored and thresholds of impact are established.CAP presented high sensitivity to large-size suspended air particles and to several of the studied climatic parameters. Discriminant analysis showed high values of Wilks’ lambda index (α = 0.69–0.81), which implies limited influence of environmental factors on the respiratory parameters of CAP. nCAP were more sensitive and susceptible to the majority of the environmental factors studied, including air suspended toxic metals particles (Cr, Zn and Ni). Air suspended particles showed higher tendency for pathogenicity in nCAP population than in the CAP, with a wider range of particle sizes being involved. Dust fractions ranging from 0 to 1 μm and from 50 to 100 μm were additionally implicated compared to CAP group. Considerably lowest thresholds levels of impact are calculated for nCAP.

The combined pollution of radionuclides and heavy metals has been given rise to widespread concern during uranium mining. The influence of As(V) on U(VI) immobilization by Mucor circinelloides (M. circinelloides) was investigated using batch experiments. The activity of antioxidative enzymes and concentrations of thiol compounds and organic acid in M. circinelloides increased to respond to different U(VI) and As(V) stress. The morphological structure of M. circinelloides changed obviously under U(VI) and As(V) stress by SEM and TEM analysis. The results of XANES and EXAFS analysis showed that U(VI) was mainly reduced to nano-uraninite (nano-UO2, 30.1%) in U400, while only 9.7% of nano-UO2 was observed in the presence of As(V) in U400-As400 due to the formation of uranyl arsenate precipitate (Trögerite, 48.6%). These observations will provide the fundamental data for fungal remediation of uranium and heavy metals in uranium-contaminated soils.

Simultaneous aggregation and retention of nanoparticles can occur during their transport in porous media. In this work, the concurrent aggregation and transport of GO in saturated porous media were investigated under the conditions of different combinations of temperature, cation type (valence), and electrolyte concentration. Increasing temperature (6–24 °C) at a relatively high electrolyte concentration (i.e., 50 mM for Na⁺, 1 mM for Ca²⁺, 1.75 mM for Mg²⁺, and 0.03 and 0.05 mM for Al³⁺) resulted in enhanced GO retention in the porous media. For instance, when the temperature increased from 6 to 24 °C, GO recovery rate decreased from 31.08% to 6.53% for 0.03 mM Al³⁺ and from 27.11% to 0 for 0.05 mM Al³⁺. At the same temperature, increasing cation valence and electrolyte concentration also promoted GO retention. Although GO aggregation occurred in the electrolytes during the transport, the deposition mechanisms of GO retention in the media depended on cation type (valence). For 50 mM Na⁺, surface deposition via secondary minima was the dominant GO retention mechanism. For multivalent cation electrolytes, GO aggregation was rapid and thus other mechanisms such as physical straining and sedimentation also played important roles in controlling GO retention in the media. After passing through the columns, the GO particles in the effluents showed better stability with lower initial aggregation rates. This was probably because less stable GO particles with lower surface charge densities in the porewater were filtered by the porous media, resulting in more stable GO particle with higher surface charge densities in the effluents. An advection–dispersion-reaction model was applied to simulate GO breakthrough curves and the simulations matched all the experimental data well.

Studies differentiating the cardiorespiratory morbidity effects of PM₂.₅, PM₁₀, and PM₂.₅∼₁₀ (i.e. coarse PM or PMc) are still limited and inconsistent.To estimate the acute, cumulative, and harvesting effects of exposure to the three size-specific PM on cardiorespiratory morbidity, and their concentration-response relations.A total of 6,727,439 emergency department (ED) visits were collected from 16 public teaching hospitals in Guangzhou, from January 1st 2012 to December 31st 2015, among which over 2.1 million were asthma, COPD, pneumonia, respiratory tract infection (RTI), hypertension, stroke, and coronary heart disease (CHD). Distributed lag non-linear models (DLNM) was used to estimate the associations between the three size-specific PM and ED visits for the cardiovascular diseases. Long-term trends, seasonality, influenza epidemics, meteorological factors, and other gas pollutants, including SO2, NO₂, and O₃, were adjusted. We stratified the analyses by gender and age.Elevated PM₂.₅ and PM₁₀ were significantly associated with increased ED visits for pneumonia, RTI, and CHD at both lag₀ and lag₀₋₃. A 10 μg/m³ increment of PMc (at lag₀₋₁₄) was estimated to increase ED visits for pneumonia by 6.32% (95% CI, 4.19, 8.49) and for RTI by 4.72% (95% CI, 3.81, 5.63), respectively. PMc showed stronger cumulative effects on asthma in children than elderly. We observed significant harvesting effects (i.e. morbidity displacements) of the three size-specific PM on respiratory but very little on cardiovascular ED visits. The concentration-response curves suggested non-linear relations between exposures to the three different sizes of PM and respiratory morbidity.Overall, the three size-specific PM demonstrated distinct acute and cumulative effects on the cardiorespiratory diseases. PM₂.₅ and PMc would have significant effects on pneumonia and RTI. Strategies should be considered to further reduce levels of ambient PM₂.₅ and PMc.