The effects of elevated ozone on C (carbon), N (nitrogen) and P (phosphorus) ecological stoichiometry and nutrient resorption in different organs including leaves, stems and roots were investigated in poplar clones 546 (P. deltoides cv. ‘55/56’ × P. deltoides cv. ‘Imperial’) and 107 (P. euramericana cv. ‘74/76’) with a different sensitivity to ozone. Plants were exposed to two ozone treatments, NF (non-filtered ambient air) and NF60 (NF with targeted ozone addition of 60 ppb), for 96 days in open top chambers (OTCs). Significant ozone effects on most variables of C, N and P ecological stoichiometry were found except for the C concentration and the N/P in different organs. Elevated ozone increased both N and P concentrations of individual organs while for C/N and C/P ratios a reduction was observed. On these variables, ozone had a greater effect for clone 546 than for clone 107. N concentrations of different leaf positions ranked in the order upper > middle > lower, showing that N was transferred from the lower senescent leaves to the upper ones. This was also indicative of N resorption processes, which increased under elevated ozone. N resorption of clone 546 was 4 times larger than that of clone 107 under ambient air (NF). However, elevated ozone (NF60) had no significant effect on P resorption for both poplar clones, suggesting that their growth was only limited by N, while available P in the soil was enough to sustain growth. Understanding ecological stoichiometric responses under ozone stress is crucial to predict future effects on ecological processes and biogeochemical cycles.

Knowledge of environmental risk factors for stroke and their role are limited. We performed a case-cohort study to evaluate the association between serum persistent organic pollutants (POPs) level and stroke risk.526 subcohort members and 111 stroke incidence cases were identified from the Korean Cancer Prevention Study-II. Serum levels of POPs were measured using gas chromatography/high-resolution mass spectrometry. The hazard ratios (HRs) for stroke (ischemic, hemorrhagic, and all stroke types) were estimated using the weighted Cox regression model. Age, sex, body mass index, smoking status, physical activity, family history of cardiovascular disease, and hypertension were adjusted in the weighted Cox regression model.After adjusting for potential confounding factors, increased risk for stroke was observed among participants with serum concentration of p,p'-DDE in the highest tertile compared to those in the lowest tertile (HR = 4.10, 95% CI: 1.58, 10.59). A similar association was estimated for PCB118 (HR = 2.33, 95% CI: 1.04, 5.22), PCB156 (HR = 3.42, 95% CI: 1.42, 8.23), and PCB138 (HR = 3.80, 95% CI: 1.48, 9.76). For TEQ, stroke was three times as likely to occur among subjects with TEQ in the highest tertile compared to those in the lowest tertile (HR = 3.12, 95% CI: 1.27, 7.65). PCBs were positively associated with ischemic stroke, but not with hemorrhagic stroke.Elevated serum POPs levels were associated with an increased risk of stroke, especially ischemic stroke.

Static environmental exposure assessment models based on material flow analysis (MFA) have previously been used to estimate flows of engineered nanomaterials (ENMs) to the environment. However, such models do not account for changes in the system behavior over time. Dynamic MFA used in this study includes the time-dependent development of the modelling system by considering accumulation of ENMs in stocks and the environment, and the dynamic release of ENMs from nano-products. In addition, this study also included regional variations in population, waste management systems, and environmental compartments, which subsequently influence the environmental release and concentrations of ENMs. We have estimated the flows and release concentrations of nano-SiO₂, nano-iron oxides, nano-CeO₂, nano-Al₂O₃, and quantum dots in the EU and six geographical sub-regions in Europe (Central Europe, Northern Europe, Southern Europe, Eastern Europe, South-eastern Europe, and Switzerland). The model predicts that a large amount of ENMs are accumulated in stocks (not considering further transformation). For example, in the EU 2040 Mt of nano-SiO₂ are stored in the in-use stock, 80,400 tonnes have been accumulated in sediments and 65,600 tonnes in natural and urban soil from 1990 to 2014. The magnitude of flows in waste management processes in different regions varies because of differences in waste handling. For example, concentrations in landfilled waste are lowest in South-eastern Europe due to dilution by the high amount of landfilled waste in the region. The flows predicted in this work can serve as improved input data for mechanistic environmental fate models and risk assessment studies compared to previous estimates using static models.

A heterotrophic arsenite [As(III)]-oxidizing bacterium Agrobacterium tumefaciens GW4 isolated from As(III)-rich groundwater sediment showed high As(III) resistance and could oxidize As(III) to As(V). The As(III) oxidation could generate energy and enhance growth, and AioR was the regulator for As(III) oxidase. To determine the related metabolic pathways mediated by As(III) oxidation and whether AioR regulated other cellular responses to As(III), isobaric tags for relative and absolute quantitation (iTRAQ) was performed in four treatments, GW4 (+AsIII)/GW4 (-AsIII), GW4-ΔaioR (+AsIII)/GW4-ΔaioR (-AsIII), GW4-ΔaioR (-AsIII)/GW4 (-AsIII) and GW4-ΔaioR (+AsIII)/GW4 (+AsIII). A total of 41, 71, 82 and 168 differentially expressed proteins were identified, respectively. Using electrophoretic mobility shift assay (EMSA) and qRT-PCR, 12 genes/operons were found to interact with AioR. These results indicate that As(III) oxidation alters several cellular processes related to arsenite, such as As resistance (ars operon), phosphate (Pi) metabolism (pst/pho system), TCA cycle, cell wall/membrane, amino acid metabolism and motility/chemotaxis. In the wild type with As(III), TCA cycle flow is perturbed, and As(III) oxidation and fermentation are the main energy resources. However, when strain GW4-ΔaioR lost the ability of As(III) oxidation, the TCA cycle is the main way to generate energy. A regulatory cellular network controlled by AioR is constructed and shows that AioR is the main regulator for As(III) oxidation, besides, several other functions related to As(III) are regulated by AioR in parallel.

SO₂ and NOX pollution have significantly reduced the air quality in China in past decades. Haze and acid rain have negatively affected the health of animals, plants, and human beings. Documented studies have shown that air pollution is influenced by multiple socioeconomic driving forces. However, the relative contributions of these driving forces are not well understood. In this study, using the structural equation model (SEM), we quantified the contributing effects of various forces driving air pollution in 2015 in prefecture-level cities of China. Our results showed that there has been significant control of SO₂ pollution in the past 20 years. The annual average SO₂ concentration has dropped from 83 μg/m³ in 1996 to 21 μg/m³ in 2015, while the annual average NOX concentration has increased from 47 μg/m³ in 1996 to 58 μg/m³ in 2015. We evaluated data on the annual average concentrations of SO₂, which in some cities may mask the differences of SO₂ concentrations between different months. Hence, SO₂ pollution should continue to be controlled in accordance with existing policies and regulations. However, we suggest that NOX should become the new focus of air pollution prevention and treatment. The SEM results showed that industrial scale, city size, and residents’ activities have a significant impact on NOX pollution. Among these, industrial scale had the highest contribution. The findings from our study can provide a theoretical basis for the formulation of NOX pollution control policy in China.

Fine sediment transport in rivers is exacerbated during flood events. These particles may convey various contaminants (i.e. metals, pathogens, industrial chemicals, etc.), and significantly impact water quality. The exceptional June 2016 flood of the Seine River (catchment area: 65 000 km2, France), potentially mobilized and deposited contaminated materials throughout the Paris region. Flood sediment deposits (n = 29) were collected along the Seine River and its main tributaries upstream (Yonne, Loing and Marne Rivers) and downstream of Paris (Oise and Eure Rivers). Fallout radionuclides (137Cs, 7Be) were measured to characterize the sources of the material transiting the river, while trace elements (e.g. Cr, Ni, Zn, Cu, As, Cd, Sb, Pb, Tl, Ag) and stable lead isotopes (206Pb/207Pb) were analyzed to quantify the contamination of sediment transported during the flood. In upper sections of the Seine River, sediment mainly originated from the remobilization of particles with a well-balanced contribution of surface and subsurface sources. In the upstream tributaries, sediment almost exclusively originated from the remobilization of subsurface particles. In Paris and downstream of Paris, recently eroded particles and surface sources dominated, suggesting particles were mainly supplied by urban runoff and the erosion of agricultural soils. The highest metal concentrations and Enrichment Factors (EF) were found in the sediment collected in the Loing, Orge and Yvette upstream tributaries. Although these inputs were diluted in the Seine River, an increase in elemental concentrations was observed, progressing downstream through Paris. However, EFs in sediment collected along the Seine River were lower or in the same range of values sampled over the last several decades, reflecting the progressive decontamination of the urbanized Seine River basin.

An in-depth understanding of the impacts of surface roughness on road-deposited sediment (RDS) build-up and wash-off is essential for the estimation of surface runoff loads and design of RDS control measures. In this study, RDS build-up and wash-off dynamic processes were investigated on paired asphalt and concrete road surfaces with 35 days of continuous sampling during different natural rainfall events. Our results showed that RDS build-up loads and grain size composition were affected by surface roughness, while the impact of surface roughness on the length of the dynamic equilibrium period was not notable. Selective wash-off of RDS with different effects according to grain size are more likely to occur on asphalt road surfaces during rainfall-runoff, but the RDS wash-off percentage is not affected by surface roughness during snowmelt-runoff. Both total apparent depression depth and micro-depression structures influence RDS build-up and wash-off dynamics. These results imply that surface roughness has combined effects on RDS build-up and wash-off dynamics during the generation and control of urban diffuse pollution.

Nitrous oxide (N₂O) is a major greenhouse gas, with elevated emission being reported from subtropical forests that receive high nitrogen (N) deposition. After 10 years of monthly addition of ammonium nitrate (NH₄NO₃) or sodium nitrate (NaNO₃) to a Mason pine forest at Tieshanping, near Chongqing city in Southwest China, the simulated N deposition was stopped in October 2014. The results of soil N₂O emissions monitoring in different seasons during the nitrogen application period showed that nitrogen addition significantly increased soil N₂O emission. In general, the N₂O emission fluxes were positively correlated to nitrate (NO₃⁻) concentrations in soil solution, supporting the important role of denitrification in N₂O production, which was also modified by environmental factors such as soil temperature and moisture. After stopping the application of nitrogen, the soil N₂O emissions from the treatment plots were no longer significantly higher than those from the reference plots, implying that a decrease in nitrogen deposition in the future would cause a decrease in N₂O emission. Although the major forms of N deposition, NH₄⁺ and NO₃⁻, had not shown significantly different effects on soil N₂O emission, the reduction in NH₄⁺ deposition may decrease the NO₃⁻ concentrations in soil solution faster than the reduction in NO₃⁻ deposition, and thus be more effective in reducing N₂O emission from N-saturated forest soil in the future.

Several studies have been carried out to examine nitrous oxide (N₂O) emissions from agricultural soils in the past. However, the emissions of N₂O particularly during amelioration of acidic soils have been rarely studied. We carried out the present study using a rice-rapeseed rotation soil (pH 5.44) that was amended with dolomite (0, 1 and 2 g kg⁻¹ soil) under 60% water filled pore space (WFPS) and flooding. N₂O emissions and several soil properties (pH, NH₄⁺N, NO₃⁻-N, and nosZ gene transcripts) were measured throughout the study. The increase in soil pH with dolomite application triggered soil N transformation and transcripts of nosZ gene controlling N₂O emissions under both water regimes (60% WFPS and flooding). The 60% WFPS produced higher soil N₂O emissions than that of flooding, and dolomite largely reduced N₂O emissions at higher pH under both water regimes through enhanced transcription of nosZ gene. The results suggest that ameliorating soil acidity with dolomite can substantially mitigate N₂O emissions through promoting nosZ gene transcription.

Recent decade has witnessed accelerating expansion of chemical industry and increasing conflicts between the local citizens, governmental authorities and project developers, especially in some coastal and port cities in China. Development and transformation of chemical industrial parks has been adopted as a national initiative recently. However, there is a paucity of research examining public perspectives on chemical industrial parks and their risks. Aiming to understand public perception, attitude, and response and the factors underlying the support/acceptance of chemical industry park, this paper investigated 418 residents neighboring to two chemical industrial parks, Dalian in Bohai Rim through face-to-face questionnaire survey. The results showed the knowledge of the respondents on the chemical industrial parks development was very limited. The respondents had complex perceptions on the environmental impacts, risks control, social-economic benefits, and problem awareness. The current levels of information disclosure and public participation were very low. The central governmental official (44.3%) was the most trustworthy group by the respondents. Only 5.5% and 23.2% of the respondents supported the construction of a new CIP nearby and far away their homes, whilst 13% thought new CIP project as acceptable. The spearman correlation analysis results showed a strong NIMBY effect (Not In My Backyard). Factor analysis results demonstrated five latent factors: knowledge, benefit, information, trust, and participation. Multiple linear regression analysis indicated how socio-demographic differences and five latent factors might impact on the support/acceptance of the chemical industrial parks. Education level, trust, information, and participation were significant predictors of public support/acceptance level. This study contributes to our limited knowledge and understanding of public sentiments to the chemical industry parks in China.