Exploring the HONO source during the COVID-19 pandemic in a megacity in China.

HONO is a critical precursor of •OH, but its sources are controversial due to its complex formation mechanism. This study conducted comprehensive observations in Zhengzhou from April 26 to May 11, 2022. Low NOx concentrations were observed during the Covid epidemic period (EP) (10.4 ± 3.0 ppb), compared to the pre-epidemic period (PEP) (12.5 ± 3.8 ppb). The mean HONO concentration during EP (0.53 ± 0.34 ppb) was 0.09 ppb lower than that during PEP (0.62 ± 0.53 ppb). The decrease in HONO concentration during EP came mainly at night due to the reduction in the direct emission (Pemi) (0.03 ppb/hr), the homogeneous reaction between •OH and NO (POH+NO) (0.02 ppb/hr), and the heterogeneous conversion of NO2 on the ground (0.01 ppb/hr). Notably, there was no significant change in daytime HONO concentration. The daytime HONO budget indicated that the primary HONO sources during PEP were the nitrate photolysis (Pnitrate), followed by the POH+NO, Pemi, the photo-enhanced reaction of NO2 on the ground (Pground+hv) and aerosol surface (Paerosol+hv). The primary HONO sources were Pnitrate, POH+NO, Pemi, and Paerosol+hv during EP, respectively. The missing source has a high correlation with solar radiation, there might be other photo-related HONO sources or the contributions of photosensitized reactions were underestimated. In the extremely underestimated cases, HONO production rates from the Pnitrate, Pground+hv, and Paerosol+hv increased by 0.17, 0.10, and 0.10 ppb/hr during PEP, 0.23, 0.13, and 0.16 ppb/hr during EP, and Pnitrate was still the primary source during both PEP and EP.

Low-temperature Reduction of NOx by NH3 with Unity Conversion on Nanofilament MnO2/Activated Semi-Coke Catalyst.

Selective catalytic reduction of nitrogen oxides with NH3 at low temperatures remains a key goal for industrial applications. However, effective catalysts operating at 90 oC are rarely reported, limiting SCR scenarios to high-temperature conditions. Herein, we report a unique MnO2 nanofilament catalyst grown on activated semi-coke synthesized via a one-step in situ hydrothermal approach, which exhibits a stable and marked 100% conversion rate of NO to N2 with 100% selectivity at 90 oC, superior to the other prepared structures (nanowires, nanorods, and nanotubes). Temperature-programmed desorption shows a large number of acid sites on MnO2(NFs)/ASC, benefiting the formation of NH4+ ions. Meanwhile, diffuse reflectance infrared Fourier transform spectroscopy reveals the activation of NO with O2 to form bidentate nitrate/bridging nitrate NO2 intermediates via bidentate nitrate species, triggering the Fast SCR with NH3 at low temperatures. Such an effective, easy-to-prepare, and low-cost catalyst paves a new pathway for low-temperature SCR for a wide range of application scenarios.

Decoupling the influence of NOx in flue gas on the application of nano-amorphous selenium for mercury removal.

Nitrogen oxides are inevitable hazardous components in coal-fired flue gas. This study designed a series of experiments and combined theoretical calculations to systematically investigate the effect of NOx on the removal of element mercury (Hg0) by nano-amorphous selenium (nano-a-Se). It was found that the impact of NOx on the removal of Hg0 by nano-a-Se primarily involves two mechanisms: competitive adsorption between NOx and Hg0, and the induced reduction effect of NOx on chemisorbed mercury (HgSe). NO inhibits the removal of Hg0 by nano-a-Se, and competitive adsorption is identified as the main influencing factor. Whereas the inhibitory effect of NO2 on the adsorption of Hg0 by nano a-Se can be counteracted due to its oxidizing effect on Hg0. Therefore, although NO2 presents stronger competitiveness than NO in the competitive adsorption with Hg0, it still shows a promoting effect on Hg0 removal, with 50 ppm NO2 restoring 5.7 % of the Hg0 removal efficiency. Additionally, the mechanism of NOx-induced reduction of HgSe was investigated in detail. NO2 is more capable of inducing the reduction of Hg(II) from HgSe to Hg0. This study presents new insights into the underlying influence mechanism, which could provide valuable references for the application of other selenium-based adsorbents.

Optimization of municipal solid waste incineration for low-NOx emissions through numerical simulation.

With urbanization, municipal solid waste (MSW) generation is increasing. Traditional landfill methods face land shortages and environmental pollution. Waste incineration, which reduces waste and recovers resources, has become a key management method. However, nitrogen oxides (NOx) produced during incineration severely impact the environment, requiring improved control technologies. This study optimized three denitrification technologies-air staging, flue gas recirculation (FGR), and selective non-catalytic reduction (SNCR)-using numerical simulations. The research provides support for improving waste incinerator efficiency and stability while reducing NOx emissions, aiding the sustainable development of waste incineration technology. By optimizing the primary and secondary air distribution ratios, the initial NOx generation was reduced by 8.39%. When 20% of the recirculated flue gas was introduced as secondary air, NOx generation was reduced by 23.54%, and boiler efficiency increased to 83.78%. The study examined the impact of different sludge mixing ratios on the temperature and NOx emissions within the context of municipal solid waste (MSW) incineration. Initially, the study aimed to address the environmental concerns of NOx emissions during the incineration process by exploring how the introduction of sludge at various mixing ratios would affect combustion parameters. The results showed that a sludge mixing ratio between 3 and 13% optimized the combustion process with 7% being the most effective in balancing temperature control and NOx emissions. Specifically, the best value of the sludge mixing ratio refers to achieving an optimal reduction in NOx emissions while maintaining stable incinerator operation. The chemical compositions of the sludge included key elements such as carbon (C), hydrogen (H), nitrogen (N), sulfur (S), and oxygen (O), with approximate proportions of C: 31.2%, H: 4.7%, N: 2.5%, S: 0.6%, and O: 31.8%.

Nitrogen isotope characteristics and importance of NOx from biomass burning in China.

Biomass burning is a primary source of atmospheric nitrogen oxide (NOx), however, the lack of isotopic fingerprints from biomass burning limits their use in tracing atmospheric nitrate (NO3-) and NOx. A total of 25 biomass fuels from 10 provinces and regions in China were collected, and the δ15N values of biomass fuels (δ15N-biomass) and δ15N-NOx values of biomass burning (δ15N-NOx values of BB, open burning, and rural cooking stove burning) were determined. The δ15N-NOx values of open burning and rural cooking stove burning ranged from -0.8 ‰ to 11.6 ‰ and 0.8 ‰ to 9.5 ‰, respectively, indicating a significant linear relation with δ15N-biomass. Based on the measured δ15N-NOx values of BB and biomass burning emission inventory data, the δ15N-NOx values of BB in different provinces and regions of China were calculated using the δ15N-NOx model, with a mean value of 5.0 ± 1.8 ‰. The spatial variations in the estimated δ15N-NOx values of BB in China were mainly controlled by the differences in the δ15N-NOx values and the proportions of NOx emissions from various straw burning activities in provinces and regions of China. Furthermore, by using the combined local emissions of biomass burning with regional transportations of NOx based on air-mass backward trajectories, we established an improved δ15N-NOx model and obtained more accurate δ15N-NOx values of BB in regions (2.3 ‰ to 8.4 ‰). By utilising the reported δ15N-NOx values of precipitation and particulate matter from 21 cities in China and the more accurate δ15N-NOx values of BB, the NOx contributions from four sources (mobile sources, coal combustion, biomass burning, and microbial N cycle) at the national scale were estimated using a Bayesian model. The significant contributions of biomass burning (20.9 % to 44.3 %) to NOx emissions were revealed, which is vital for controlling NOx emissions in China.

Beyond lung cancer: air pollution and bladder, breast and prostate cancer incidence.

BACKGROUND: The carcinogenicity of air pollution and its impact on the risk of lung cancer is well known; however, there are still knowledge gaps and mixed results for other sites of cancer. METHODS: The current study aimed to evaluate the associations between ambient air pollution [fine particulate matter (PM2.5) and nitrogen oxides (NOx)] and cancer incidence. Exposure assessment was based on historical addresses of >900 000 participants. Cancer incidence included primary cancer cases diagnosed from 2007 to 2015 (n = 30 979). Cox regression was used to evaluate the associations between ambient air pollution and cancer incidence [hazard ratio (HR), 95% CI]. RESULTS: In the single-pollutant models, an increase of one interquartile range (IQR) (2.11 µg/m3) of PM2.5 was associated with an increased risk of all cancer sites (HR = 1.51, 95% CI: 1.47-1.54), lung cancer (HR = 1.73, 95% CI: 1.60-1.87), bladder cancer (HR = 1.50, 95% CI: 1.37-1.65), breast cancer (HR = 1.50, 95% CI: 1.42-1.58) and prostate cancer (HR = 1.41, 95% CI: 1.31-1.52). In the single-pollutant and the co-pollutant models, the estimates for PM2.5 were stronger compared with NOx for all the investigated cancer sites. CONCLUSIONS: Our findings confirm the carcinogenicity of ambient air pollution on lung cancer and provide additional evidence for bladder, breast and prostate cancers. Further studies are needed to confirm our observation regarding prostate cancer. However, the need for more research should not be a barrier to implementing policies to limit the population's exposure to air pollution.

Effect of nitrogen oxides and sulfur oxides to triphenyl phosphate degradation and cytotoxicity on surface of different transition metal salts.

Nitrogen oxides and sulfur oxides, as the dominant toxic gases in the atmosphere, can induce severe human health problems under the composite pollutant conditions. Currently the effect of nitrogen or sulfur oxides in atmospheric environment to the degradation and cytotoxicity of triphenyl phosphate (TPhP) on atmospheric particle surfaces still remain poorly understood. Hence, laboratory simulation methods were used in this study to investigate the effect and related mechanism. First, particle samples were prepared with the TPhP coated on MnSO4, CuSO4, FeSO4 and Fe2(SO4)3 surface. The results showed that, when nitrogen or sulfur oxides were present, more significant TPhP degradation on all samples can be observed under both light and dark conditions. The results proved nitrogen oxides and sulfur oxides were the vital influence factors to the degradation of TPhP, which mainly promoted the OH generation in the polluted atmosphere. The mechanism study indicated that diphenyl hydrogen phosphate (DPhP) and OH-DPhP were two main stable degradation products. These degradation products originated from the phenoxy bond cleavage and hydroxylation of TPhP caused by hydroxyl radicals. In addition, no TPhP related organosulfates (OSs) or organic nitrates (ON) formation were observed. Regarding the cytotoxicity, all the particles can induce more significant cellular injury and apoptosis of A549 cells, which may be relevant to the adsorbed nitrogen oxides or sulfur oxides on particles surfaces. The superfluous reactive oxygen species (ROS) generation was the possible reason of cytotoxicity. This research can supply a comprehensive understanding of the promoting effect of nitrogen and sulfur oxides to TPhP degradation and the composite cytotoxicity of atmospheric particles.

[Personal nitrogen oxides exposure levels and related influencing factors in adults over 35 years old in Tianjin and Shanghai].

OBJECTIVE: To investigate personal exposures to nitrogen oxides (NOX) and nitrogen di-oxide (NO2) and the influence of baseline personal characteristics, living environment and daily activity patterns of the participants on the exposures among adults over 35 in Tianjin and Shanghai. METHODS: In this panel study, 91 healthy nonsmoking adults aged over 35 from Tianjin and Shanghai participated in our study. The study was conducted in summer and winter. The participants were followed for three times with an interval of at least two weeks. Only participants in Shanghai were followed once in winter because of the COVID-19 pandemic. Twenty-seven participants completed follow-up visits in both seasons. We measured their 24 h personal exposures to NOX and NO2and collected their baseline and time-activity information through questionnaire/diary. The linear mixed model was used to analyze the associations between potential influencing factors and personal NOX and NO2 exposure levels. RESULTS: There were 349 follow-up visits with valid 24 h personal NO2 and NOX exposure measurements in the two cities. The ave-rage 24 h personal exposures to NO2 and NOX (volume fraction) in Tianjin participants were 18.0×10-9 and 26.2×10-9 in summer, and 31.0×10-9 and 54.9×10-9 in winter, respectively; and the average 24 h personal exposures to NO2 and NOX in Shanghai participants were 38.7×10-9 and 100.0×10-9 in summer, and 45.5×10-9 and 139.2×10-9 in winter, respectively. The results of univariate regression analysis showed that their personal NOX exposure levels were significantly associated with city, season, gender, average daily cooking times, and ambient NO2 concentrations measured at fixed-site monitoring stations. In addition to the above factors, the personal NOX exposure levels were also significantly associated with educational level and the personal NO2 exposure levels were also significantly associated with passive smoking, average daily home time, cooking energy type, residential distance from main traffic road, and use of kitchen ventilators. Multivariate regression analysis showed that the personal exposure levels of NO2 and NOX were significantly lower in Tianjin than that in Shanghai, were significantly lower in summer than that in winter, and were significantly and positively associated with ambient NO2 concentrations measured at fixed-site monitoring stations. In addition, personal NOX exposure levels were significantly lower in females than in males, and personal NO2 exposure levels were significantly positively associated with average daily cooking times and significantly inversely associated with average daily home time. For every interquartile range (IQR) increase (12.7×10-9) in ambient NO2, the personal NO2 exposure levels increased by 27.5% (95%CI: 17.0%-38.9%), and personal NOX exposure levels increased by 16.1% (95%CI: 7.1%-25.8%). CONCLUSION: Season, city and ambient NO2 concentrations are significant influencing factors of personal exposure levels of NO2and NOX. At the same time, the personal exposures levels of NO2are also affected by lifestyle factors. Our study provides scientific evidence for making precise air pollution control decisions and reducing the exposure levels of NOX in the population.

Atom Pairing Enhances Sulfur Resistance in Low-Temperature SCR via Upshifting the Lowest Unoccupied States of Cerium.

Environmentally benign cerium-based catalysts are promising alternatives to toxic vanadium-based catalysts for controlling NOx emissions via selective catalytic reduction (SCR), but conventional cerium-based catalysts unavoidably suffer from SO2 poisoning in low-temperature SCR. We develop a strongly sulfur-resistant Ce1+1/TiO2 catalyst by spatially confining Ce atom pairs to different anchoring sites of anatase TiO2(001) surfaces. Experimental results combined with theoretical calculations demonstrate that strong electronic interactions between the paired Ce atoms upshift the lowest unoccupied states to an energy level higher than the highest occupied molecular orbital (HOMO) of SO2 so as to be catalytically inert in SO2 oxidation but slightly lower than HOMO of NH3 so that Ce1+1/TiO2 has desired ability toward NH3 activation required for SCR. Hence, Ce1+1/TiO2 shows higher SCR activity and excellent stability in the presence of SO2 at low temperatures with respect to supported single Ce atoms. This work provides a general strategy to develop sulfur-resistant catalysts by tuning the electronic states of active sites for low-temperature SCR, which has implications for practical applications with energy-saving requirements.

Quantifying NOx point sources with Landsat and Sentinel-2 satellite observations of NO2 plumes.

We show that the Landsat and Sentinel-2 satellites can detect NO2 plumes from large point sources at 10 to 60 m pixel resolution in their blue and ultrablue bands. We use the resulting NO2 plume imagery to quantify nitrogen oxides (NOx) emission rates for several power plants in Saudi Arabia and the United States, including a 13-y analysis of 132 Landsat plumes from Riyadh power plant 9 from 2009 through 2021. NO2 in the plumes initially increases with distance from the source, likely reflecting recovery from ozone titration. The fine pixel resolutions of Landsat and Sentinel-2 enable separation of individual point sources and stacks, including in urban background, and the long records enable examination of multidecadal emission trends. Our inferred NOx emission rates are consistent with previous estimates to within a precision of about 30%. Sources down to ~500 kg h-1 can be detected over bright, quasi-homogeneous surfaces. The 2009 to 2021 data for Riyadh power plant 9 show a strong summer peak in emissions, consistent with increased power demand for air conditioning, and a marginal slow decrease following the introduction of Saudi Arabia's Ambient Air Standard 2012.

Modeling the Oxygen Isotope Anomaly (Δ17O) of Reactive Nitrogen in the Community Multiscale Air Quality Model: Insights into Nitrogen Oxide Chemistry in the Northeastern United States.

Atmospheric nitrate, including nitric acid (HNO3), particulate nitrate (pNO3), and organic nitrate (RONO2), is a key atmosphere component with implications for air quality, nutrient deposition, and climate. However, accurately representing atmospheric nitrate concentrations within atmospheric chemistry models is a persistent challenge. A contributing factor to this challenge is the intricate chemical transformations involving HNO3 formation, which can be difficult for models to replicate. Here, we present a novel model framework that utilizes the oxygen stable isotope anomaly (Δ17O) to quantitatively depict ozone (O3) involvement in precursor nitrogen oxides N O x = N O + N O 2 photochemical cycling and HNO3 formation. This framework has been integrated into the US EPA Community Multiscale Air Quality (CMAQ) modeling system to facilitate a comprehensive assessment of NO x oxidation and HNO3 formation. In application across the northeastern US, the model Δ17O compares well with recently conducted diurnal Δ17O(NO2) and spatiotemporal Δ17O(HNO3) observations, with a root mean square error between model and observations of 2.6 ‰ for Δ17O(HNO3). The model indicates the major formation pathways of annual HNO3 production within the northeastern US are NO+OH (46 %), N2O5 hydrolysis (34 %), and organic nitrate hydrolysis (12 %). This model can evaluate NO x chemistry in CMAQ in future air quality and deposition studies involving reactive nitrogen.

Europium insertion into MgAl hydrotalcite-like compound to promote the photocatalytic oxidation of nitrogen oxides.

Easy synthesis of efficient, non-toxic photocatalysts is a target to expand their potential applications. In this research, the role of Eu3+ doping in the non-toxic, affordable, and easily prepared MgAl hydrotalcite-like compounds (HTlcs) was explored in order to prepare visible light semiconductors. Eu doped MgAl-HTlcs (MA-xEu) samples were prepared using a simple coprecipitation method (water, room temperature and atmospheric pressure) and europium was successfully incorporated into MgAl HTlc frameworks at various concentrations, with x (Eu3+/M3+ percentage) ranging from 2 to 15. Due to the higher ionic radius and lower polarizability of Eu3+ cation, its presence in the metal hydroxide layer induces slight structural distortions, which eventually affect the growth of the particles. The specific surface area also increases with the Eu content. Moreover, the presence of Eu3+ 4f energy levels in the electronic structure enables the absorption of visible light in the doped MA-xEu samples and contributes to efficient electron-hole separation. The microstructural and electronic changes induced by the insertion of Eu enable the preparation of visible light MgAl-based HTlcs photocatalysts for air purification purposes. Specifically, the optimal HTlc photocatalyst showed improved NOx removal efficiency, ∼ 51% (UV-Vis) and 39% (visible light irradiation, 420 nm), with excellent selectivity (> 96 %), stability (> 7 h), and enhanced release of •O2- radicals. Such results demonstrate a simple way to design photocatalytic HTlcs suitable for air purification technologies.

Alder expansion stimulates nitrogen oxide (NOx) emissions from southern Eurasian permafrost peatlands.

Nitrogen oxides (NOx) play an important role for atmospheric chemistry and radiative forcing. However, NOx emissions from the vast northern circumpolar permafrost regions have not been studied in situ due to limitations of measurement techniques. Our goals were to validate the offline analytical technique, and based on this, to widely quantify in situ NOx emissions from peatlands in the southern Eurasian permafrost region. To this end, we conducted a comparison of online and offline flux measurements in 2018 and 2019 using the synthetic air flushing, steady-state opaque chamber method. With differences in annual average and cumulative fluxes less than 0.1 µg N m-2 h-1 and 0.01 kg N ha-1 year-1, the online and offline fluxes were in good agreement, demonstrating the feasibility of conducting offline measurements in remote regions without power supply. The flux measurements over 2 years showed obvious NOx emissions of 0.05-0.14 and 0.13-0.30 kg N ha-1 year-1 in the hollow and hummock microtopography of permafrost peatlands, respectively. The rapid expansion of alder (Alnus sibirica) in the peatlands induced by permafrost degradation significantly increased soil mineral N contents and NOx emissions depending on the age of alder (0.64-1.74 and 1.44-2.20 kg N ha-1 year-1 from the alder forests with tree ages of 1-10 years and 11-20 years, respectively). Alder expansion also intensively altered the thermal state of permafrost including the sharp increases of soil temperatures during the non-growing season from October to April and active layer thickness. This study provides the first in situ evidences of NOx emissions from the northern circumpolar permafrost regions and uncovers the well-documented expansion of alders can substantially stimulate NOx emissions and thus, significantly affect air quality, radiative forcing, and ecosystem productivity in the pristine regions.

Microbubble-encapsulated Cobalt Nitrato Complexes for Ultrasound-triggerable Nitric Oxide Delivery.

Cobalt complexes exhibit versatile reactivity with nitric oxide (NO), enabling their utilization in applications ranging from homogeneous catalysis to NO-based modulation of biological processes. However, the coordination geometry around the cobalt center is complex, the therapeutic window of NO is narrow, and controlled NO delivery is difficult. To better understand the complexation of cobalt with NO, we prepared four cobalt nitrato complexes and present a structure-property relationship for ultrasound-triggerable NO release. We hypothesized that modulation of the coordination geometry by ligand-modification would improve responsiveness to mechanical stimuli, like ultrasound. To enable eventual therapeutic testing, we here first demonstrate the in vitro tolerability of [Co(ethylenediamine)2(NO)(NO3)](NO3) in A431 epidermoid carcinoma cells and J774A.1 murine macrophages, and we subsequently show successful encapsulation of the complex in poly(butyl cyanoacrylate) microbubbles. These hybrid Co-NO-containing microbubbles may in the future aid in ultrasound imaging-guided treatment of NO-responsive vascular pathologies.

Quantifying instantaneous nitrogen oxides emissions from power plants based on space observations.

Thermal power plants are significant contributors to nitrogen oxides (NOx), impacting global atmospheric conditions and human health. Satellite observations, known for their continuity and global coverage, have become an effective means of quantifying power plant emissions. Previous studies, often accumulating long temporal data into integrated plumes, resulted in substantial errors in annual emissions at the individual power plant level due to neglecting variations in emissions and diffusion conditions. This study presents, for the first time, the quantification of instantaneous NOx emissions based on single overpass observations from the Tropospheric Monitoring Instrument (TROPOMI) aboard the Sentinel-5 Precursor satellite. By addressing the temporal variability of power plant emissions, it effectively reduces annual estimation errors. Comparative analysis between the Exponentially-Modified Gaussian (EMG) and Gaussian Plume Model (GPM) simulations demonstrates the capability of EMG to provide instantaneous emission estimates based on actual plumes, exhibiting closer proximity to actual monitoring values than GPM. Applying the EMG method, we quantify the instantaneous emission rates of six power plants in the United States. Comparing annual emission estimations at individual power plants with traditional integrated plume results, our method demonstrates a 63.7 % improvement in annual emission estimations. This study offers more detailed data on power plant emissions, providing a new avenue for better understanding the emission behavior of thermal power plants.

Long-term ambient air pollution and coronary atherosclerosis: Results from the Swedish SCAPIS study.

BACKGROUND AND AIMS: Despite firm evidence for an association between long-term ambient air pollution exposure and cardiovascular morbidity and mortality, results from epidemiological studies on the association between air pollution exposure and atherosclerosis have not been consistent. We investigated associations between long-term low-level air pollution exposure and coronary atherosclerosis. METHODS: We performed a cross-sectional analysis in the large Swedish CArdioPulmonary bioImaging Study (SCAPIS, n = 30 154), a random general population sample. Concentrations of total and locally emitted particulate matter <2.5 µm (PM2.5), <10 µm (PM10), and nitrogen oxides (NOx) at the residential address were modelled using high-resolution dispersion models. We estimated associations between air pollution exposures and segment involvement score (SIS), coronary artery calcification score (CACS), number of non-calcified plaques (NCP), and number of significant stenoses, using ordinal regression models extensively adjusted for potential confounders. RESULTS: Median 10-year average PM2.5 exposure was 6.2 µg/m3 (range 3.5-13.4 µg/m3). 51 % of participants were women and 51 % were never-smokers. None of the assessed pollutants were associated with a higher SIS or CACS. Exposure to PM2.5 was associated with NCP (adjusted OR 1.34, 95 % CI 1.13, 1.58, per 2.05 µg/m3). Associations with significant stenoses were inconsistent. CONCLUSIONS: In this large, middle-aged general population sample with low exposure levels, air pollution was not associated with measures of total burden of coronary atherosclerosis. However, PM2.5 appeared to be associated with a higher prevalence of non-calcified plaques. The results suggest that increased risk of early-stage atherosclerosis or rupture, but not increased total atherosclerotic burden, may be a pathway for long-term air pollution effects on cardiovascular disease.

Causal relationship between air pollution and chronic obstructive pulmonary disease in European and East Asian populations: a Mendelian randomization study.

Epidemiologic studies have suggested a possible association between air pollution and chronic obstructive pulmonary disease (COPD), but it is controversial and difficult to draw causal inferences. Five methods were adopted to evaluate the causal relationship between air pollution and COPD in European and East Asian populations by using MR Analysis. A statistically significant causal relationship between PM2.5 and COPD was observed in the European population (OR: 2.34; 95% CI: 1.06-5.05; p = 0.033). Statistical significance remained after adjustment for confounding factors (adjusted OR: 2.28; 95% CI: 1.01-5.20; p = 0.048). In East Asian populations, PM2.5 absorbance, a proxy for black carbon, was statistically associated with COPD (OR: 1.41; 95% CI: 1.09-1.81; p = 0.007). We did not adjust for confounders in East Asian populations, as the association was independent of known confounders (e.g. smoking, respiratory tract infections, etc.). In conclusion, increased concentrations of PM2.5 and PM2.5 absorbance were associated with an increased risk of COPD.

Characterization of the H2/NOx reaction process over the La0.9Ce0.1Co0.9Pd0.1O3-BaO/Al2O3 catalyst.

An excellent textual properties and performance La0.9Ce0.1Co0.9Pd0.1O3-BaO/Al2O3 catalyst was synthesized. The reaction mechanism of H2/NOx over the La0.9Ce0.1Co0.9Pd0.1O3-BaO/Al2O3 catalyst was investigated by temperature programmed reduction/ desorption/ surface reaction (TPR/D/SR) technologies and in-situ diffuse reflectance Fourier transform (DRIFT) technology. The results show that cerium or palladium species are inserted into the cells of LaCoO3, as well as they synergetic promote the redox properties of the La0.9Ce0.1Co0.9Pd0.1O3-BaO/Al2O3 catalyst. Surface activated nitrates exist over the La0.9Ce0.1Co0.9Pd0.1O3-BaO/Al2O3 catalyst, with thermal stable increasing in the order: absorbed N2O4 < monodentate nitrates < chelating bidentate nitrates < nitrates unidentate < free ionic nitrates < bulk free ionic nitrates. H2 preferentially reacted with absorbed N2O4 and monodentate nitrates at low temperatures, due to their high activity. The concentration of generated NH3 from the redox reaction of H2/NOx achieves the maximum value between 350 and 450 °C over the La0.9Ce0.1Co0.9Pd0.1O3-BaO/Al2O3 catalyst. Compared with the NOx adsorption process at 50 °C, monodentate nitrates and absorbed N2O4 disappeared due to their low thermal stability, chelating bidentate nitrates become stronger, as well as free ionic nitrates converted to bulk free ionic nitrates with higher thermal stability at 350 °C. When H2 is exposed to NOx species adsorbed on La0.9Ce0.1Co0.9Pd0.1O3-BaO/Al2O3, chelating bidentate nitrates and bulk free ionic nitrates are consumed gradually, indicating that although the bulk free ionic nitrates own high stability, it also could be consumed by involving in the H2/NOx reaction at 350 °C. The quantitative H2/NO reaction experiments confirmed the results of H2-TPSR and NSR. It is beneficial to the formation of NH3 when the H2/NO ratio is more than 2.5. Comparing traditional Pt-BaO/Al2O3 catalyst, the La0.9Ce0.1Co0.9Pd0.1O3-BaO/Al2O3 catalyst exhibit an excellent performance, including considerable NH3 production property, lower N2O selectivity, and the precious metal saving.

Co-adsorption performance of iodine and NOX in iodine exhaust gas by NH2-MIL-125.

Ti-based MOFs exhibit ultra-high stability in radioactive waste gases containing nitrogen oxides (NOX) and are effective in capturing radioactive iodine. In this study, NH2-MIL-125 was synthesized via a one-pot solvothermal method and its adsorption performance for iodine was investigated using batch adsorption experiments, the stability of materials was tested by simulating post-processing conditions. The results indicated that NH2-MIL-125 had a maximum iodine adsorption capacity of 1.61 g/g at 75 â„ƒ and reached adsorption equilibrium within 60 min, and the adsorption capacity of methyl iodine reached 776.9 mg/g. The material also exhibited excellent stability and iodine adsorption performance in the presence of NOX. After soaking in NO2 for 24 h, its structure remained stable and the adsorption capacity for iodine remained at 231.5 mg/g. The excellent co-adsorption performance of NH2-MIL-125 on iodine and NOX was attributed to the synergistic effects of Ti-OH groups and amino functional groups. These findings provide a reference for the capture of radioactive iodine and also demonstrate the potential of NH2-MIL-125 for iodine capture during spent fuel reprocessing.

Regulatory Insights for On-Board Monitoring of Vehicular NOx Emission Compliance.

Nitrogen oxide (NOx) emissions from heavy-duty diesel vehicles (HDDVs) have adverse effects on human health and the environment. On-board monitoring (OBM), which can continuously collect vehicle performance and NOx emissions throughout the operation lifespan, is recognized as the core technology for future vehicle in-use compliance, but its large-scale application has not been reported. Here, we utilized OBM data from 22,520 HDDVs in China to evaluate their real-world NOx emissions. Our findings showed that China VI HDDVs had a 73% NOx emission reduction compared with China V vehicles, but a considerable proportion still faced a significant risk of higher NOx emissions than the corresponding limits. The unsatisfactory efficiency of the emission treatment system under disadvantageous driving conditions (e.g., low speed or ambient temperature) resulted in the incompliance of NOx emissions, especially for utility vehicles (sanitation/garbage trucks). Furthermore, the observed intertrip and seasonal variability of NOx emissions demonstrated the need for a long-term continuous monitoring protocol instead of instantaneous evaluation for the OBM. With both functions of emission monitoring and malfunction diagnostics, OBM has the potential to accurately verify the in-use compliance status of large-scale HDDVs and discern the responsibility of high-emitting activities from manufacturers, vehicle operators, and driving conditions.