Increase In NO2 Concentration Research Articles

Association Between Air Pollution and Case-Specific Mortality in North-Eastern Part of Poland. Case-Crossover Study with 4,500,000 Person-Years of Follow-Up (PL-PARTICLES Study)

Background: Recent studies have reported associations between air pollution and daily mortality. The majority of them are conducted in highly polluted areas. Therefore, we aimed to assess the short-term impact of air pollution on cardiovascular (CVD)-, coronary artery-related (CAD)-, and cerebrovascular-related (CbVD) mortality in moderately polluted cities. Methods: The analysis with a time-stratified case-crossover design was performed. Findings: The interquartile range (IQR) increase in PM2.5 (OR 1×036, 95%CI 1×016–1×056, P<0×0001) and PM10 concentration (OR 1×034, 95%CI 1×015–1×053, P<0×0001) was associated with increased CVD mortality on lag 0 and this effect persisted on following days. The effects of PMs were more expressed in association with CAD-related mortality (OR for PM2.5 =1×045, 95%CI 1×012–1×080, P=0×01), (OR for PM10 =1×044, 95%CI 1×010–1×078, P=0×01). Additionally, IQR increase in NO2 concentration was associated with increased CAD-related mortality at lag 0-1 (OR=1×055, 95%CI .1×004–1×108, P=0×03). This effect is no longer observed when using the multi-pollutant model. The highest OR for PMs was noted in Suwalki compared to Bialystok and Łomza. In a comparison of seasons, we noted higher CVD mortality OR in the cold season for PM10 in Suwalki (P=0×047) and Bialystok (P=0×001). However, the impact of PM10 (P=0×03) on CAD-related mortality was higher in the warm season. Interpretation: The impact of PMs on CVD mortality is also observed in moderately polluted areas. This adverse health effect was more apparent in CAD mortality. Differences in effect size and seasonality may depend on the source of air pollution. Funding: None to declare. Declaration of Interest: None to declare. Ethical Approval: This study was approved by the ethics committee of the Medical University of Bialystok (R-1-002/18/2019) and was registered at ClinicalTrials.gov (NCT04541498).

Impacts of Transportation Emissions on the Risk of Mortality: Findings from the Literature and Policy Implications

Introduction: Externalities from transportation, and in particular exposure to vehicle emissions have been considered a possible cause of several negative health outcomes including mortality. However, the existing findings are too inconsistent to drive a well-founded exposure-response function to be fully exploited to curb the negative impacts of transportation systems on public health. In this study, we investigate the association between exposure to air pollution and mortality. We then evaluate how using different air quality methods may result in detecting different health outcomes. Methods: We conduct an analysis of reviewing a representative sample of main published studies that specifically focused on the association between vehicle air pollution and mortality. Results: Our study finds that vehicle air pollution may increase the risk of mortality through a slightly high association. Most importantly, the risk of overall mortality increases by 5% per 10 µg/m3 increase in NO2 concentration, 2% per unit of traffic intensity on the road, and 7% per unit of distance closer to the road. Conclusion: The findings imply the role of exposure to vehicle emissions in increasing the risk of mortality. The method used to detect the health outcomes can alter the health finding from positive to null or vice versa and even extensively affect the analysis outcomes. The results suggest the need for establishing indicators to benchmark the performance of air quality methods and emphasize the necessity to integrate public health measures into the urban and transportation planning process.

Nitrogen dioxide increases the risk of mortality in idiopathic pulmonary fibrosis.

Ambient air pollution is associated with the prognosis of idiopathic pulmonary fibrosis (IPF) patients. We aimed to identify the impacts of individual exposure to particulate matter with a 50% cut-off aerodynamic diameter of 10 μm (PM10) and nitrogen dioxide (NO2) on IPF patients' mortality.1114 patients (mean age 65.7 years; male 80.5%) diagnosed with IPF between 1995 and 2016 were included in this study. Individual-level long-term concentrations of PM10 and NO2 at residential addresses of patients were estimated using a national-scale exposure prediction model. The effect of PM10 and NO2 on mortality was estimated using a Cox proportional hazards model adjusted for individual- and area-level covariates.The median follow-up period was 3.8 years and 69.5% of the patients died or underwent lung transplantation. When adjusted for individual- and area-level covariates, a 10 ppb increase in NO2 concentration was associated with a 17% increase in mortality (hazard ratio (HR) 1.172, 95% CI 1.030-1.344; p=0.016). When IPF patients were stratified by age (≥65 versus <65 years) or by sex, NO2 was a significant prognostic factor for mortality in the elderly (HR 1.331, 95% CI 1.010-1.598; p=0.010). When stratified by age and sex jointly, NO2 showed the stronger association with mortality in elderly males (HR 1.305, 95% CI 1.072-1.598; p=0.008) than in other groups. PM10 was not associated with IPF mortality in all patients and in subgroups stratified by age or sex.Our findings suggest that increased exposure to NO2 can increase the risk of mortality in patients with IPF, specifically in elderly males.

How have surface NO2 concentrations changed as a result of the UK’s COVID-19 travel restrictions?

Restrictions as a result of the COVID-19 pandemic have led to fewer vehicles on UK roads. Since fuel combustion is responsible for a large fraction of UK emissions it is expected that surface NO2 concentrations would reduce as a result. However, over parts of the UK, surface NO2 concentrations have increased following the implementation of travel restrictions. NO2 measurements from 142 Automatic Urban and Rural Network sites are combined with meteorological data from the Met Office high-resolution weather prediction model to build site specific models. These models predict NO2 concentrations given no change in emissions. It is found that both meteorological and emission changes contribute to the observed changes in NO2 concentrations. Given no change in emissions, changes in meteorology between pre- and post-lockdown periods would have led to a mean increase in NO2 concentrations of +6%. Conversely, changes in emissions would have led to a mean reduction in NO2 concentrations of -18%, resulting in the observed total change in NO2 concentrations of −12%. However at some sites the reduction in emissions is smaller than the increase in NO2 concentrations due to meteorology. The largest increases associated with changes in the meteorology are seen at rural sites (+20%) where NO2 measurements are representative of large areas and thus dominated by the regional advection of secondary NO2 from Europe. Conversely, the largest decreases associated with reduced emissions are found at urban traffic and urban background sites (−27% and −14% respectively) where NO2 concentrations are representative of local areas and thus dominated by local reduction in emissions from vehicles. As lockdown measures are relaxed, NO2 concentrations are likely to return to pre-COVID levels, but these results demonstrate that changes in our behaviour can result in positive impacts on air quality and illustrate the effectiveness of travel-reducing strategies in urban areas.

Validity of air pollution annoyance to assess long-term exposure to air pollution in Belgium

Abstract Background In environmental epidemiology, air pollution exposure is often estimated at the population level. To avoid the risk of exposure misclassification, one possibility is to interpolate air pollution measures at the residence through Geographical Information Systems. However, this might imply cumbersome administrative procedures. Data on air pollution annoyance from surveys can be an alternative to assess individual exposure to air pollution. This study investigates the association between air pollution annoyance and individual air pollution exposure. Methods Analyses were carried out based on a linkage of data from the Belgian Health Interview Survey (HIS 2008 and 2013; &amp;gt;15 years; n = 9347) and annual means of air pollution concentration at the residence. Self-reported air pollution annoyance was assessed through a five-point Likert scale. Statistical analyses included Spearman correlation coefficient, analysis of variance and multivariable ordinal logistic regressions (OLR). Results A significant exposure-response relationship was observed between long-term air pollution exposure and self-reported air pollution annoyance. However, Spearman coefficients were low (0.18-0.24), meaning a high heterogeneity of annoyance levels for a given exposure. In multivariable OLR, the odds of being annoyed by air pollution was 2.10 (95% CI: 1.86-2.67) times higher for each Interquartile range (IQR) increase in NO2 concentration (PM2.5: 1.77 [95% CI: 1.53-2.07], PM10: 1.61 [95% CI: 1.33-1.67], black carbon: 1.45 [95% CI: 1.27-1.67]). Air pollution annoyance depended largely on individual factors especially health status. Conclusions Air pollution exposure has a significant influence on self-reported air pollution annoyance. However, many other factors were found to influence annoyance, independently of the exposure. We found a limited validity of self-reported air pollution annoyance to assess individual long-term exposure to air pollution. Key messages Significant exposure-response relationship between individual long-term air pollution exposure and self-reported air pollution annoyance. Limited validity of self-reported air pollution annoyance for assessing individual long term exposure to air pollution.

Nitrogen dioxide and asthma emergency department visits in California, USA during cold season (November to February) of 2005 to 2015: A time-stratified case-crossover analysis

Nitrogen dioxide (NO2) is responsible for aggravating respiratory diseases, particularly asthma. The aim of this study is to investigate the association between NO2 exposure and asthma emergency department (ED) visits during the cold season (November–February) in five populated locations (Sacramento, San Francisco, Fresno, Los Angeles, and San Diego) of California from 2005 to 2015 (1320 Days). Conditional logistic regression models were used to obtain the odds ratio (OR) and 95% confidence interval (CI) associated with a 5 ppb increase in NO2 concentration for the 19,735 ED visits identified. An increase in NO2 exposure increased the odds of having asthma ED visits for the studied population. The potential effect modification by sex (female and male), race (White, Black, Hispanic, and Asian), and age (2–5, 6–18, 19–40, 41–64, and ≥65) was explored. A 5 ppb increase in the concentration of NO2 during lag 0–30 was associated with a 56% increase in the odds of having an asthma ED visit (OR = 1.560, CI: 1.428–1.703). Sex was not found to be a modifier. Asthma ED visits among all the races/ethnicities (except Asians) were associated with NO2 exposure. Whites had the highest OR 75% (OR = 1.750, CI: 1.417–2.160) at lag 0–30 in response to NO2 exposure. The association between NO2 exposure and asthma ED visits was positive among all age groups except for 19 to 40 years old; the OR was higher among 2 to 18 year old (at lag 0–30: age group 2–5 (OR = 1.699, CI: 1.399–2.062), and age group 6–18 (OR = 1.568, CI 1.348–1.825)). For stratification by location, San Diego and Fresno were found to have the highest OR, compared to the other studied locations.

Exposure to air pollution-a trigger for myocardial infarction? A nine-year study in Bialystok-the capital of the Green Lungs of Poland (BIA-ACS registry).

This study aimed to assess the effect of air pollution and weather conditions on the frequency of hospital admissions due to acute coronary syndrome (ACS) in the population of Bialystok, known as the capital of the Green Lungs of Poland. The study analyzed the medical records of 2,645 patients living within the borders of Bialystok who were treated for ACS between 2009 and 2017 and the data on air pollutants-nitrogen dioxide (NO2), sulfur dioxide (SO2), and particulate matter with a diameter of 2.5μm or less (PM2.5) and 10μm or less (PM10)-and the basic meteorological factors (temperature, humidity, and atmospheric pressure). A time-stratified case-crossover study design was applied to assess the effects of particulate matter, the concentration of gases, and weather conditions on ACS. The number of patients admitted for ST-segment elevation myocardial infarction, non-ST-segment elevation myocardial infarction (NSTEMI), and unstable angina (UA) was 791, 999, and 855, respectively. The daily concentration norm for PM2.5 recommended by the World Health Organization (WHO) was exceeded in 692 days (i.e., 24.58% of the observation period). The significant increase in the number of ACS hospitalizations was associated with an interquartile-range increase in NO2 concentration, with an odds ratio of 1.08 (95% confidence interval (CI): 1.02-1.15, P=0.01), 1.09 (95% CI: 1.01-1.18, P=0.03), and 1.11 (95% CI: 1.00-1.22, P=0.048) for patients with ACS, NSTEMI, and UA, respectively. The study showed that the effects of air pollution and weather conditions on the number of ACS hospitalizations are also observed in cities with moderately polluted or good air quality. NO2 was identified as the main air pollutant affecting the incidence of ACS.

Indium-Doped ZnO Porous Cages Derived from ZIF-8 for Ppb-Level NO2 Detection

Introduction Nowadays, environment, health and safety problems caused by NO2 are attracting more and more attention. Extensive efforts have been made to investigate and develop various novel detectors including resistance-type sensors, mixed potential sensors and optical sensors to satisfy the increasing demand of NO2 detection. Among these different kinds of detectors, resistance-type gas sensors, primarily based on metal oxide semiconductors, have received wide attention due to their high sensitivity, fast response, and low cost. As one of typical metal oxide semiconductors, ZnO has been widely investigated for detecting NO2 gas [1]. However, NO2 detection at the ppb level is rarely achieved for ZnO-based sensors. Recent studies have shown that gas-sensing properties of ZnO are highly related with the microstructure and can be further enhanced via selective doping [2]. Among different doping elements, indium (In) has attracted great attention. The advantages of In-doping are the followings: In2O3 is an important material for NO2sensing; In3+ (80 pm) can partly substitute Zn2+ (74 pm) due to their similar ionic radii, generating more free electrons. In this work, pure and In-doped ZnO porous cages were synthesized by a ZIF-8-based template method and their gas-sensing performance was systematically studied. Method In-doped ZnO porous cages were prepared via a one-pot synthesis route. Briefly, 4.05 g of Zinc nitrate hexahydrate was dissolved into 200 mL methanol. Appropriate amounts of Indium(III) acetylacetonate and 200 mL of a methanol solution containing 3.34 g 2-methylimidazole were added under stirring. The resulting solutions were stirred for 20 min and aged for 18 h at room temperature. After precipitation, obtained ZIF-8 derivativeswere washed with methanol via centrifugation. The precipitates were further dried at 60 °C for 24 h and calcined at 400 °C for 3 h to obtain pristine or In-doped ZnO powders. The obtained samples are hereafter denoted as In/ZnO-X, where X represents the nominal In/Zn atomic ratio (multiplied by 100) used during the synthesis, e.g., In/ZnO-0 for un-doped ZnO, In/ZnO-2 for In/Zn of 2.0 at.%, In/ZnO-10 for In/Zn of 10.0 at.%. Results and Conclusions Typical SEM images of the samples are presented in Fig. 1. For pristine ZnO, well-separated nanocages were observed (Fig. 1a). As can be seen from Fig1b-c, the size of the nanocages appeared larger with the increase of In doping content. Fig. 2a shows the electrical resistance for the fabricated gas sensors measured in air. Typical semiconductor behavior was observed, i.e., resistance decreased as temperature rose. Furthermore, the resistance remarkably decreased with increase of Indium content. Fig. 2b presents the temperature dependence of the gas response to 10 ppm NO2 for all the obtained sensors. For the un-doped sample (In/Zn-0), the response first increased with temperature, reached a maximum at 300 °C, and then decreased. The increasing addition content of In to ZnO resulted in significant increase of response to NO2. For In/ZnO-10, the response was 339 at 300 °C, 22 times higher than that of In/ZnO-0. Fig. 2c depicts sensor response as a function of NO2 concentration for In-doped ZnO sensors at 300 °C. It can be clearly seen that the gas response increased with increase of NO2 concentration for all the sensors, and at each concentration the response for In/ZnO-10 was much higher than those of the other sensors. Furthermore, the gas response varied almost linearly with the NO2 concentration until the measured concentration exceeded 1 ppm. This linear dependence is favorable for calibration and determination of the gas concentration in practical applications. Fig. 2d depicts the dynamic response and recovery curves for the In/ZnO-10 sensor in the concentration range of 10-100 ppb, which were measured by alternately exposing the sensor to ambient air and air/NO2 mixture at the optimal operating temperature of 300 °C. The response to 10 ppb NO2 was 3.7, which identified the excellent performance of In/ZnO for ppb-level NO2 detection. Unlike the greatly increased NO2response, the response to the main interfering gas, H2S, only slightly increased with In doping, indicating marked increase of the NO2 selectivity.

THE SPATIOTEMPORAL VARIATION OF HEAVY NO2 POLLUTION CENTER (HPC): A CASE STUDY IN THREE CHINESE URBAN AGGLOMERATIONS

Abstract. Air pollution episode, which are periods with excessive air pollutants, can cause a sharp increase in mortality and morbidity. Nitrogen oxides have an adverse impact on human health and the environment. Previous studies mainly focus on the time period, the frequency, and the duration of heavy NO2 pollution, while ignored its spatial extent which is pivotal in providing early warning and prediction. In this study, we investigated the spatiotemporal variation of the heavy NO2 pollution extent (i.e., heavy pollution center), analyzed its association with meteorological condition and further predicted its distribution in the future. A case study in Jing-Jin-Ji (JJJ), Yangtze River Delta (YRD) and Pearl River Delta (PRD) urban agglomerations showed that the HPC exhibited evident seasonal (winter &gt; summer) and inter-city (mega and medium cities &gt; small cities) differences. In concretion analysis, the HPC areas were negatively correlated with temperature and precipitation, suggesting that dry and cold meteorological conditions were responsible for the severe NO2 pollution events. Trend analysis showed that the small and medium cities may serve as the HPC in the future. During the 2005–2016, the medium and small cities in JJJ experience a more rapid increase in NO2 concentration in comparison to mega cities. Meanwhile, in YRD and PRD, a more rapid decrease was witnessed in the mega cities. The results of this study would provide support for early warning and prediction of heavy air pollutants and offer scientific insights for air pollution episode management.

Nitric oxide scavenging of hydroxyl radicals in a nanosecond pulsed plasma discharge gas–liquid reactor

A continuous gas–liquid film flow reactor with a nanosecond power supply was utilized to produce , , and NO2 from Ar/NO mixtures (gas phase) and deionized water (liquid phase). High concentrations of added NO were used as an ·OH scavenger and to provide insight into the reaction pathways. Chemical analysis of the products exiting the reactor was performed by quenching the liquid samples to eliminate the post-plasma reactions. The gas phase products were analyzed using FTIR and the liquid phase samples were analyzed using ion chromatography and UV–vis spectrophotometer. The concentrations of , and NO2 increased with increasing inlet concentrations of NO while the concentration of H2O2 decreased moderately. The plasma gas temperature was approximately 565 K and was unaffected by the NO feed concentration, while the electron density varied from 4.83 × 1016 cm−3 to 1.16 × 1017 cm−3 for inlet NO concentrations of 0 ppm to 20 000 ppm, respectively. The increase in NO2 concentration in the gas phase suggests that ·OH provides a source of atomic oxygen (O). The results also suggest that ·OH plays an important role in the formation of HNO2 and HNO3 by directly reacting with NO and NO2, respectively. The highest production rate of ·OH was 6.5 × 10−6 moles s−1 at 20 000 ppm inlet NO. The energy yield of ·OH was 5.7 × 10−7 moles J−1 at 20 000 ppm inlet NO and is in agreement with our previous work and other literature reports.

Influence of Humidity on NO2-Sensing and Selectivity of Spray-CVD Grown ZnO Thin Film above 400 °C

Thin films are being used more and more in gas sensing applications, relying on their high surface area to volume ratio. In this study, ZnO thin film was produced through a thermal aerosol spraying and chemical vapor deposition (spray-CVD) process at 500 °C using zinc acetate as a precursor. The phase identification and the morphologies of the film were investigated by XRD and SEM, respectively. Gas-sensing properties of the ZnO thin film were evaluated toward NO2, CO, and NO at a moderate temperature range (400–500 °C) in dry and humid air (relative humidity = 2.5, 5, 7.5, and 10% RH). The obtained results show good sensor signal for both NO2 (ΔR/R0 = 94%) and CO (92%) and poor sensor signal to NO (52%) at an optimum temperature of 450 °C in dry air. The response and recovery times decrease with the increase of NO2 concentration. In the presence of humidity (10% of RH), the sensor is more than twice as sensitive to NO2 (70%) as CO (29%), and accordingly, exhibits good selectivity toward NO2. As the amount of humidity increases from 2.5 to 10% RH, the selectivity ratio of ZnO thin film to NO2 against CO increases from 1 to 2.4. It was also observed that the response and the recovery rates decrease with the increase of relative humidity. The significant enhancement of the selectivity of ZnO thin film toward NO2 in the presence of humidity was attributed to the strong affinity of OH species with NO2.

Air pollution and respiratory hospital admissions in Shiraz, Iran, 2009 to 2015

Air pollution has been identified as one of the most challenging health issues in urban areas worldwide.The aim of this study was to investigate the association between short-term exposure to ambient air pollution and respiratory disease over a long-term period in Shiraz, one of the largest cities in Iran. Methods: hospital admissions due to respiratory diseases (asthma, pneumonia, chronic obstructive pulmonary disease (COPD) and pleural effusion) in residents of Shiraz between March 21, 2009 and March 20, 2015 were included. Demographics for each patient and meta data to include principal meteorological variables (temperature and relative humidity) and five ambient pollutants (CO, O3, SO2, NO2, and PM10) were also included. Statistical analysis was performed by Poisson regression in single-pollutant generalized linear model with principal component analysis (GLPCA) to analyze the relationship between pollutants and hospital admissions at the 0–9 cumulative lag day period. Pearson correlation test was used to determine the relationship between different pollutants, temperature and humidity. ResultsIt was found that the highest increase in asthma admission was related to PM10 (relative risk (RR) = 1.31, 95% CI = 1.17, 1.47). For COPD, the rate of hospital visits significantly increased with the increase in NO2 concentration (RR = 1.17, 95% CI = 1.09.1.27). In the children's hospital, O3 (RR = 1.25, 95% CI = 1.06, 1.47) and SO2 (RR = 1.17, 95% CI = 1.07, 1.28) affected the asthma admissions and all contaminants (highest RR observed was for NO2 (RR = 1.28 95% CI = 1.18, 1.40) affected pneumonia admissions on cumulative lag days of 0–9. Conclusions: These data confirm an association between ambient air pollutants and hospital admissions due to respiratory disease.

Comparison of regulated emission factors of Euro 6 LDV in Nordic temperatures and cold start conditions: Diesel- and gasoline direct-injection

Local air pollution in Norwegian wintertime is characterized by an increase in NO2 concentrations, due to poor dispersion and increased vehicle emissions. The focus of this study is therefore the characterisation of exhaust vehicle emissions in cold ambient temperatures. Euro 6 Gasoline Direct Injection (GDI) cars and diesel cars were tested in the laboratory in cold temperatures, including with cold start of the engine. Results show high emissions of CO2, PM and NOx. For the first time, we report also elevated NOx values for GDI vehicles. Further measurements are required to investigate whether these results are the beginning of a new trend of high NOx emissions from GDIs, or if these results represent singular events, but it may indicate that further NOx traps or catalysts are required for these vehicles. Understanding the relationship of cold ambient temperatures and vehicle emissions is also particularly important for air quality dispersion modelling, which do not currently account for emission temperature dependence.

The synergetic control of NO2 and O3 concentrations in a manufacturing city of southern China

This study explored effective methods to control NO2 and O3 concentrations in a manufacturing city, Foshan, in the Pearl River Delta (PRD) region. A “double high” pollution episode (i.e., both NO2 and O3 concentrations exceeding the ambient air quality standards of China) was selected as a typical case to identify a collaborative control method for NO2 and O3 by using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) and the Empirical Kinetic Modeling Approach (EKMA). Considering the nonlinear relationship between O3 and its precursors; we scaled down the volatile organic carbons (VOC) and NOx emission inventories to investigate O3 responses. The results showed that Foshan is VOC-sensitive and that the VOC-NOx reduction ratio more than 1:1 not only helped to steadily reduce O3 concentrations but also to avoid an increase in NO2 concentrations. On-road and Non-road mobile sources and ports were found to be the dominant sources of NO2, while O3 was mostly affected by organic solvents in Foshan. Controls on ports and the organic solvents are key to achieving a synergetic control of NO2 and O3 pollution in Foshan. About 2.5% and 2.0% reduction in NO2 and O3 concentrations, respectively, were found to require only a 3.6% reduction in NOx emissions from ports and a 10.6% reduction in VOC emission from organic solvents. In addition to the “double high” episode, this control scheme has been extended to verify the effects of NO2 and O3 pollution controls under various synoptic weather conditions.

Nitrogen dioxide air pollution and preterm birth in Shanghai, China

BackgroundNitrogen dioxide (NO2) is a typical indicator of traffic-related air pollution, and few studies with exposure assessment of high resolution have been conducted to explore its association with preterm birth in China. ObjectivesTo investigate the association between NO2 exposure based on a land use regression (LUR) model and preterm birth in Shanghai, China. MethodsA retrospective cohort study was performed among 25,493 singleton pregnancies in a major maternity hospital in Shanghai, China, from 2014 to 2015. A temporally adjusted LUR model was used to predict the prenatal exposure to NO2 based on residence address of each gravida. Logistic regression was performed to evaluate the associations of ambient NO2 exposure with preterm birth during six exposure periods, including the entire pregnancy, the first trimester, the second trimester, the third trimester, the last month, and the last week before delivery. Sensitivity analysis with a matched case-control design was conducted to test the robustness of the association between NO2 exposure and preterm birth. ResultsThe average NO2 concentrations during the entire pregnancy was 48.23 µg/m3 among all participants. A 10 µg/m3 increase in NO2 concentrations was associated with preterm birth, with an adjusted odds ratio of 1.03 (95% confidence interval [CI]: 0.96,1.10) for exposures during the entire pregnancy, 1.00 (95%CI: 0.95,1.06) in the first trimester, 1.01 (95%CI: 0.96,1.07) in the second trimester, 1.07 (95%CI: 1.02,1.13) in the third trimester, 1.10 (95%CI: 1.04,1.15) and 1.05 (95%CI: 1.00,1.09) in the month and week before delivery, respectively. The results of the matched case–control analysis were generally consistent with those of main analyses. ConclusionNO2 may increase the risk of preterm birth, especially for exposures during the third trimester, the month and the week before delivery in Shanghai, China.

Exposure to NO2 and children hospitalization due to respiratory diseases in Ribeirão Preto, SP, Brazil.

The effects of exposure to air pollutants on human health are mainly reflected in respiratory diseases in children and elderly ones. An ecological time series study was carried out in Ribeirão Preto/SP data to examine the role of exposure to air pollutants and hospital admissions due to respiratory diseases in children under 10 years old. The study period was between January, 2011 and December, 2013. Particulate Matter (PM10), Nitrogen dioxide (NO2), and ozone (O3), temperature and air relative humidity, were analyzed to estimate the association with hospital admissions using a generalized linear model of Poisson's regression with lags of zero up to seven days after exposure to pollutants, adjusted by the day of the week, seasonality and effective temperature. The significance level adopted was p < 0.05. NO2, when analyzed in single pollutant model shown to be significant at lag 2 and 3 and when analyzed in the multi-pollutant model it shown to be significant at lags 2 up to 5, and lag 7 with relative risk between 1.05 and 1.09 per 10 μg/m3 increase in NO2 concentration, with an excess of 150 hospital admission and substantial increase in costs to Public Health System. The data enable the local health managers can take action to minimize these effects.

Prediction of mortality resulted from NO2 concentration in Tehran by Air Q+ software and artificial neural network

In this study, for the first time, the combination of Air Q+ software and wavelet neural network was used to predict the mortality rate caused by the increase in NO2 concentration in Tehran. In the combination of these two softwares, the wavelet neural network software was used to predict daily NO2 concentration based on 12 effective parameters, and then the annual concentration of NO2 was calculated using the daily concentration of wavelet neural network output. Then, annual concentration of NO2 was used as the input of Air Q+ software. The mortality rate was calculated by Air Q+ software. In this research, the most appropriate predictive algorithm for neural network was studied and layer recurrent algorithm was the most appropriate algorithm. Then, capability of this network was enhanced to predict future NO2 concentration by wavelet transformation, and wavelet neural network was designed. Also, NO2 concentration is predicted for future 47 months by using of the time series of the previous data and the wavelet neural network. Analyzing the sensitivity of mortality resulted from NO2 concentration was done by using of wavelet neural network and Air Q+ software, and it was concluded that the increase or decrease in the parameters affecting NO2 concentration will affect the mortality rate. This research has identified petrol consumption as the most influential parameter. The conclusion is that by lowering the 10% of petrol consumption, the mortality based on NO2 concentration in ambient air will decrease about 50%.

Hollow ZSM-5 encapsulated Pt nanoparticles for selective catalytic reduction of NO by hydrogen

Pt nanoparticles were successfully encapsulated in hollow ZSM-5 single crystals by tetrapropylammonium hydroxide (TPAOH) hydrothermal treatment with an “dissolution-recrystallization” process. The prepared Pt/hollow ZSM-5 (Pt/h-ZSM-5re) sample exhibited the best activity and a maximum NO conversion of 84% can be achieved at 90 °C with N2 selectivity of 92% (GHSV = 50,000 h−1). Meanwhile, Pt/h-ZSM-5re catalyst exhibited excellent SO2, H2O resistance and durability, which was related to the stabilization of Pt active sites by hollow structure during H2-SCR. It was found that the increase of NO2 concentration in the feed gas mixture led to an activity decline. In addition, the H2-SCR reaction routes over Pt/hollow ZSM-5 catalyst at different temperature were investigated.

Air pollution as a risk factor for increasing hospitalizations of preschool wheeze in Hong Kong

Background: Wheeze has been reported to affect one-third of preschoolchildren. While different wheeze patterns have been shown to predict future asthma risk, limited data are available on the risk factors for preschool wheeze in Asia. Methods: Preschool children admitted to hospitals through emergency departments for wheeze, from 2004 to 2015 in Hong Kong, were retrospectively identified. Potential risk factors for admissions over the same period were retrieved (i.e., air pollutants, preterm delivery, and maternal age). Results: A total of 46,258 patients meeting the inclusion criteria were identified during the 12-year period. The preschool wheeze admission rate increased by 34% over the past 12 years, with an average year-on-year rise of 4.2%. Environmental nitrogen dioxide (NO2) concentration was significantly associated with an increase in admission for preschool wheeze (r = 0.63, P = 0.028). Univariate regression analysis was performed on potential risk factors. Annual average NO2concentration (P = 0.007) and maternal age more than 40 years (P = 0.012) were significant risk factors. For multivariable regression analysis, annual average NO2concentration (β = 0.18, 95% confidence interval = 0.06–0.30) was the only independent factor associated with preschool wheeze admission. Conclusions: The increase of NO2concentration is a significant risk factor for the increase in hospitalizations for preschool wheeze in Hong Kong.

Systematic Review and Meta-Analysis of the Association between Ambient Nitrogen Dioxide and Respiratory Disease in China.

Objective: This study aimed to assess the quantitative effects of short-term exposure of ambient nitrogen dioxide (NO2) on respiratory disease (RD) mortality and RD hospital admission in China through systematic review and meta-analysis. Methods: A total of 29 publications were finally selected from searches in PubMed, Web of Science, CNKI and Wanfang databases. Generic inverse variance method was used to pool effect estimates. Pooled estimates were used to represent the increased risk of RD mortality and RD hospital admission per 10 μg/m3 increase in NO2 concentration. Results: Positive correlations were found between short-term NO2 exposure and RD in China. RD mortality and RD hospital admission respectively increased by 1.4% (95% CI: 1.1%, 1.7%) and 1.0% (95% CI: 0.5%, 1.5%) per 10 μg/m3 increase in NO2 concentration. Differences were observed across geographic regions of China. The risk of RD mortality due to NO2 was higher in the southern region (1.7%) than in the north (0.7%). Conclusions: Evidence was found that short-term exposure to NO2 was associated with an increased risk of RD mortality and RD hospital admission in China and these risks were more pronounced in the southern regions of the country, due in part to a larger proportion of elderly persons with increased susceptibility to NO2 in the population compared with the north.