Nitrogen Dioxide Concentrations Research Articles

Classification and concentration estimation of CO and NO2 mixtures under humidity using neural network-assisted pattern recognition analysis

This study addresses the concerns regarding the cross-sensitivity of metal oxide sensors by building an array of sensors and subsequently utilizing machine earning techniques to analyze the data from the sensor arrays. Sensors were built using In2O3, Au-ZnO, Au-SnO2, and Pt-SnO2 and they were operated simultaneously in the presence of 25 different concentrations of nitrogen dioxide (NO2), carbon monoxide (CO), and their mixtures. To investigate the effects of humidity, experiments were conducted to detect 13 distinct CO and NO2 gas combinations in atmospheres with 40% and 90% relative humidity. Principal component analysis was performed for the normalized resistance variation collected for a particular gas atmosphere over a certain period, and the results were used to train deep neural network-based models. The dynamic curves produced by the sensor array were treated as pixelated images and a convolutional neural network was adopted for classification. An accuracy of 100% was achieved using both models during cross-validation and testing. The results indicate that this novel approach can eliminate the time-consuming feature extraction process.

Cleaner air for vulnerable people – Finding better locations for essential building premises

Long-term exposure to ambient air pollution even at relatively low concentrations is associated with adverse health effects especially for children, the elderly and people with pre-existing chronic disease. Due to a variety of urban planning decisions, essential building premises attended by these vulnerable groups may be sited in locations exposed to higher levels of air pollution. Using high spatial resolution air pollution concentrations estimated by satellite-based Land Use Regression (LUR) models in Australia, we mapped and approximated the annual average concentrations of particulate matter (PM2.5) and nitrogen dioxide (NO2) at schools, child care centres, aged care facilities and hospitals across Sydney. We found that 137 (3.1 %) and 287 (6.4 %) of the total number of essential buildings assessed were exposed to annual average PM2.5 and NO2 concentrations, respectively, where: the air pollutant concentrations were greater than the median concentration of other locations in the surrounding Local Government Area (LGA), and; air pollutant levels were greater than the 90th percentile concentrations for Sydney, and; air pollution at the essential building location was at least 1 µg/m3 for PM2.5 or 2 ppb for NO2 greater than the 25th percentile concentration of other locations in the LGA. Based on these criteria, we found that many essential building premises in Sydney were in high air pollution locations and there were other meaningfully lower air pollution locations within the surrounding area. Air quality is becoming an increasingly important issue for local jurisdictions to consider as more essential amenities are required to serve denser populations in busier places exposed to more air pollution. Our study showed that high resolution maps can be used as a health-based planning tool to encourage the siting of buildings at locations better protective of health.

Densification versus urban sprawl. Modeling the impact of two urban growth scenarios on air quality

This study analyzes the impact of urban form on air pollution for two urban growth scenarios in 2040 for Quito, Ecuador: Urban sprawl (low-density outward expansion) and densification (the population increase occurs within the 2017 city boundaries). We estimate concentrations of carbon monoxide (CO), nitrogen oxides (NOx), nitrogen dioxide (NO2), ozone (O3), and particulate matter with an aerodynamic diameter equal to or less than 2.5 μm (PM2.5). Two downscaled global emission pathways (ECLIPSE) that present a lower/upper range are applied: 1) Current legislation emissions, CLE, and 2) Maximum technically feasible reductions, MTFR. The population is expected to increase by 50%, from 3 million in 2017 to 4.5 million in 2040. The sprawl scenario considerably increases the urban area by 52%. However, these new areas hold only 9% of the population. Both pathways present considerably lower emissions for 2040 than in 2017. Emissions for all sectors, except transportation, are the same for both scenarios. Transport emissions for the densification scenario are 32% lower than for urban sprawl.Due to reduced emissions, the 2040 scenarios result in lower CO, NOx, and PM2.5 concentrations for both pathways compared to 2017. This drop is more marked for the MTFR pathway compared to CLE. Contrary to our expectations, the two scenarios result in similar annual concentrations at the metropolitan level. Even when emission variations are considerable, differences between the scenarios are relatively small, particularly for CO, O3, and PM2.5, due to high regional contributions. However, the spatial distribution of concentrations within urban areas differs significantly; thus, the sprawl scenario results in a larger surface with higher CO, NOx, NO2, and PM2.5 levels and the opposite for O3. Still, due to the population distribution, the densification scenario exposes more residents to higher CO, O3, and PM2.5 values, and the sprawl scenario exposes more inhabitants to higher concentrations of NO2 and NOx.We find an improvement in air quality for both scenarios in 2040 compared to 2017. The annual average NO2 concentrations exceed local regulations in a small urban area only for the CLE pathway. In contrast, for PM2.5, the area and population exposed to levels that exceed the local regulation are higher than that for NO2 and more significant for the densification than the sprawl scenario and for the CLE than the MTFR pathway.

Impacts of industrial production and air quality by remote sensing on nitrogen dioxide concentration and related effects: An econometric approach

The high concentration of nitrogen dioxide (NO2) is to blame for West Java's poor Air Quality Index (AQI). So, this study aims to determine the influence of industrial activity as reflected by the value of its imports and exports, wind speed, and ozone (O3) on the high concentration of tropospheric NO2. The method used is the econometric Vector Error Correction Model (VECM) approach to capture the existence of a short-term and long-term relationship between tropospheric NO2 and its predictor variables. The data used in this study is in the form of monthly time series data for the 2018–2022 period sourced from satellite images (Sentinel-5P and ECMWF Climate Reanalysis) and publications of the Central Bureau of Statistics (BPS-Statistics Indonesia). The results explained that, in the short-term, tropospheric NO2 and O3 influence each other as they would in a photochemical reaction. In the long-term, exports from the industrial sector and wind speed have a significant effect on the concentration of tropospheric NO2. The short-term effect occurs directly in the first month after the shock, while the long-term effect occurs in the second month after the shock. Wind gusts originating from industrial areas cause air conditions to be even more alarming because tropospheric NO2 pollutants spread throughout the region in West Java. Based on the coefficient correlation result, the high number of pneumonia cases is one of the impacts caused by air pollution.

Quantifying anomalies of air pollutants in 9 U.S. cities during 2020 due to COVID-19 lockdowns and wildfires based on decadal trends

The COVID-19 pandemic led many state and local governments in the United States to enact lockdowns to control the spread of the virus. These actions led to lower on-road emissions as a significant portion of the workforce began working from home. Here, we examine the concentrations of primary pollutants, nitrogen dioxide (NO2) and carbon monoxide (CO), a secondary pollutant, ozone (O3), and one that is both a primary and secondary pollutant, particulate matter (PM2.5), from 9 U.S. cities in 2020 using data reported to the U.S. Environmental Protection Agency to determine how they changed during the pandemic. We used a multiple linear regression model fitted to historical data to account for meteorology and found concentrations of NO2, O3, and CO generally decreased in the 9 cities in late March and early April, consistent with previous literature and a fuel-based emissions inventory. We further found the decadal trends of the 4 pollutants were decreased in the summer months for most of the cities studied. An analysis of weekend decreases in NO2 was consistent with previous studies; however, the weekend increases in O3 were typically dominated by reduced NOx titration. We further detect anomalous increases in NO2, CO, O3, and PM2.5 in western U.S. cities in the late summer, which we attribute to wildfire emissions. Finally, we examined diel profiles to determine when changes due to COVID-19 lockdowns and late-summer wildfires were most apparent during the day.

Studies on the variation in concentrations of respirable suspended particulate matter (PM10), NO2 and SO2 in and around Nagpur

The objective of this study is to assess the long-term variation in concentrations of Respirable suspended particulate matter (PM10), sulphur dioxide (SO2) and nitrogen dioxide (NO2) in the ambient air of Nagpur (India) during 2011-2018. The pollution data during the above period at three locations, viz., residential (Station-I), industrial (Station-II), and commercial location (Station-III) has been analyzed. The highest daily average concentration of PM10 at residential, industrial, and commercial locations was found 154 microgm/m3, 199 microgm/m3, and 153 microgm/m3, whereas, the average annual concentration at these locations was found 101.87 microgm/m3, 115.37 microgm/m3 and 98.75 microgm/m3, respectively during the above period. The highest daily average concentration of SO2 was found at 18 microgm/m3, 22 microgm/m3 and 19 microgm/m3 and the average annual concentration was 13.25 microgm/m3, 13.5 microgm/m3, 13 microgm/m3 at respective locations. And the highest daily average concentration of NO2 was found 77 microgm/m3, 60 microgm/m3, 60 microgm/m3 and the annual average concentration was 44.125 microgm/m3, 41.825 microgm/m3 and 40.25 microgm/m3 at the respective locations. The exceedance factors for PM10 varied from 'moderate to high' at the residential and commercial locations and from 'high to moderate' at the industrial location. Planetary boundary layer height (PBLH) and ventilation coefficient (VC) were also estimated over the region for 2011-2018. The maximum PBLH and VC observed during the study period was in the summer season, and the minimum was in the post-monsoon season. Annual and Seasonal Air quality index analysis shows that the level of pollution was in the range of SATIFACTORY to MODERATE. A study of seasonal analysis of PM10, SO2 and NO2 showed that the higher concentrations were found in winter relative to summer with the least concentration occurring during the monsoon season. A regression analysis was performed to check PM10's interdependence with other contaminants. A positive association was found between PM10 and SO2 for all seasons. A negative association was found between PM10 and NO2 in summer for all the stations and winter at Station-I and Station-III. Similarly, the correlation between PM10 and meteorological parameters such as wind speed and temperature was found to be negative whereas it was positive for relative humidity.

Does residential exposure to air pollutants influence mortality and cardiovascular morbidity of older people from primary care?

BackgroundDiseases affecting the cardiovascular system are the most common cause of death worldwide. In addition to classical risk factors of atherosclerosis, long-term exposure to particulate matter with particles of size up to 10 µm (PM10) in the atmosphere has become an increasing focus of scientific attention in recent decades. This study analyses the associations of residential-associated air pollutants exposure with all-cause mortality and cardiovascular morbidity of older patients in a primary care setting.MethodsThe “German Epidemiological Trial on Ankle Brachial Index” (getABI) is a prospective cohort study that started in 2001 and included 6,880 primary care patients with a follow-up of 7 years. The PM10 and nitrogen dioxide (NO2) concentrations in the atmosphere are interpolated values from the study "Mapping of background air pollution at a fine spatial scale across the European Union". The primary outcome in this analysis is death of any cause, a secondary outcome is onset of PAD. Cox proportional hazards regression was used in a two-step modelling, the first step with basic adjustment only for age, sex, and one or more air pollutants, the second with additional risk factors.ResultsA total of 6,819 getABI patients were included in this analysis. 1,243 of them died during the study period. The hazard ratio (HR) (1.218, 95%-confidence-interval (CI) 0.949–1.562) for the risk of death from any cause was elevated by 22% per 10 µg/m3 increase of PM10 in the fully adjusted model, although not statistically significant. Increased PM10 exposure in combination with the presence of PAD had a significantly increased risk (HR = 1.560, 95%-CI: 1.059-2.298) for this endpoint in the basic adjustment, but not in the fully adjusted model. 736 patients developed peripheral artery disease (PAD) during the course of the study. There was no association of air pollutants and the onset of PAD.ConclusionsOur analysis renders some hints for the impact of air pollutants (PM10, NO2, and proximity to major road) on mortality. Interaction of PAD with PM10 was found. There was no association of air pollutants and the onset of PAD.Trial registrationGerman Clinical Trials Register: DRKS00029733 (19/09/2022).

Unveiling Air Pollution in Crimean Mountain Rivers: Analysis of Sentinel-5 Satellite Images Using Google Earth Engine (GEE)

This article presents an assessment of atmospheric pollutant concentrations based on state-of-the-art geoinformation research methods that utilize Sentinel-5 satellite imagery, the cloud computing platform Google Earth Engine (GEE), and ArcGIS 10.8 software. The spatial distributions of some pollutants (nitrogen dioxide, sulfur dioxide, formaldehyde, carbon monoxide, methane) in the atmosphere are analyzed on the example of the basins of the Zapadnyy Bulganak, Alma, Kacha, Belbek, and Chernaya rivers on the north-western slope of the Crimean Mountains. The concentrations of the average annual and average monthly values of pollutants for each catchment area are compared. The GEE (Google Earth Engine) platform is used for extracting annual and monthly average rasters of pollutant substances, while ArcGIS is utilized for enhanced data visualization and in-depth analytical processing. Background concentrations of pollutants within protected natural areas are calculated. By comparing the spatial and temporal distribution of pollutant values with the background concentrations within these protected areas, a complex index of atmospheric pollution is constructed. The spatial and temporal variability of nitrogen dioxide (NO2) concentrations has been thoroughly examined. Based on the regression analysis (R > 0.85), the field of values of the total amount of emissions (which are analyzed for only six points in the study area and in the surrounding areas) was restored on the basis of the spatial and temporal heterogeneity of the field of distribution of nitrogen dioxide values (NO2). Since air pollution can have negative consequences, both for human health and for the ecosystem as a whole, this study is of great importance for assessing the ecological situation within the river basins of the north-western slope of the Crimean Mountains. This work also contributes to a general understanding of the problem of gas emissions, whose study is becoming increasingly relevant. The aim of this research is to assess the potential application of Sentinel-5 satellite imagery for air quality assessment and pollution analysis within the river basins of the north-western slopes of the Crimean Mountains. The significance of this study lies in the innovative use of Sentinel-5 satellite imagery to investigate air pollution in extensive regions where a regular network of observation points is lacking.

Smoke toxicity to the biota and the biological activity of soils when modeling fires

The paper presents the results of our study on the effect of one type of pyrogenic factor (smoke) after burning coniferous wood chips on several bioindicators (soil enzymes, microorganisms, mesofauna, plants of agricultural crops). Exposition to smoke for 60 minutes was found to significantly affect the enzymatic activity of common chernozem. Fumigation caused a decrease in such enzymes as catalase, peroxidase, polyphenol oxidase and invertase. The enzymes of the oxidoreductase class were the most sensitive to smoke. High toxicity of gaseous combustion products to the soil flora and fauna was revealed. The acute toxicity of smoke to the bioindicators was determined as a result of fumigation. High mortality of test objects (Eisenia fetida, Nauphoeta cinerea) was recorded in our experiments. Soil microorganisms (Azotobacter chroococcum and Penicillium chrysogenum) proved to be informative after 30–120 minutes of fumigation. Resistance of plant sprouts (Raphanus sativus, Triticum aestivum, and Pisum sativum) to combustion gaseous products was revealed. An experiment to analyze the chemical composition of gases in smoke was performed. Such hazardous compounds as sulphur dioxide (SO2), nitrogen oxide and dioxide (NO, NO2), carbon monoxide (CO), acetaldehyde (C2H4O), formaldehyde (CH2O), phenol (C6H6O) hydroxybenzene and others were found to be contained therein. Our analysis revealed that the concentrations of carbon monoxide were 714 times higher than its maximum permissible concentration (MPC), which acetaldehyde was 24,100 times higher. The nitrogen oxide and nitrogen dioxide concentrations were 100 and 300 times higher, respectively.

Measurement of nitrogen oxide (NOx) emissions in fuel-combustion equipment and analysis of their impact on city air condition

The object of the research is to ensure environmental safety and maximum efficiency of fuel burning equipment. Energy facilities (thermal power plant, boiler houses) are among the biggest air polluters in the city. Nitrogen oxides (NO, NO2, NOx) occupy a significant place among the toxic gases contained in the flue gases of fuel-burning equipment. These substances have a negative impact on the ecological state of the city and are regulated by the Order of the Ministry of Natural Resources of Ukraine dated 27.06.2006 No. 309 on the approval of standards for maximum permissible emissions of pollutants from stationary sources. The principles of measurement unity are considered, including the presentation of measurement results in standard units (ppm, mg/m3). Conversion from volume concentration (ppm) to mass (mg/m3) is given. Measurements of the concentration of nitrogen oxides were carried out. In the course of research, instrumental measuring tools were used, which made it possible to obtain the values of nitrogen dioxide concentrations in gas boiler flue emissions. In particular, the average maximum concentrations of the main pollutants exceed 62.58 mg/m3. Analyzing the concentration of flue gases allows to determine the concentration of pollutants and to adjust the optimal operation of the equipment as much as possible, achieving a reduction in emissions and compliance with the approved emission standards. Obtained data on background concentrations of nitrogen dioxide in the city of Kyiv, amounting to 1.33 MPC. Using the data of instrumental measurements with the method of calculating concentrations of harmful substances in the atmospheric air and background concentrations, a map of emission dispersion was created. Fields of surface concentrations were plotted on the scattering map, which makes it possible to compare the obtained values with the hygienic standards of atmospheric air. By combining instrumental measurement methods and calculation methods, the volume of emissions was determined and the impact on atmospheric air pollution of the city was assessed.

The Aggravation of Summertime Nocturnal Ozone Pollution in China and Its Potential Impact on the Trend of Nitrate Aerosols

AbstractTropospheric ozone (O3) concentration continued to increase over past years, thereby becoming a growing environmental concern in China. Most studies have focused on the analysis of daily maximum 8‐hr O3 concentration, while there is still a dearth of investigations of nocturnal O3. Here, by analyzing the data of 1,313 sites from the China National Environmental Monitoring Center, we show a remarkable increase in the nocturnal O3 concentration during summertime of 2015–2019 in most regions of China, revealing an aggravation of nocturnal O3 pollution. Combining with a GeoDetector model and statistical analysis, we clarify that the aggravation of nocturnal O3 pollution is mainly caused by reduction in both ambient nitrogen dioxide (NO2) concentration and wet scavenging in recent years. We further reveal that the increasing O3 may have enhanced the nocturnal particulate nitrate () formation through N2O5 heterogeneous hydrolysis, and thereby driving the variation and long‐term trend of nocturnal .

Impacts of COVID-19 Lockdown on Air Quality in Shenzhen in Spring 2022

The short-term reduction of air pollutant emissions is an important emergency control measure for avoiding air pollution exceedances in Chinese cities. However, the impacts of short-term emission reductions on the air qualities in southern Chinese cities in spring has not been fully explored. We analyzed the changes in air quality in Shenzhen, Guangdong before, during, and after a city-wide lockdown associated with COVID-19 control during March 14 to 20, 2022. Stable weather conditions prevailed before and during the lockdown, such that local air pollution was strongly affected by local emissions. In-situ measurements and WRF-GC simulations over the Pearl River Delta (PRD) both showed that, due to reductions in traffic emissions during the lockdown, the concentrations of nitrogen dioxide (NO2), respirable particulate matter (PM10), and fine particulate matters (PM2.5) in Shenzhen decreased by (-26±9.5)%, (-28±6.4)%, and (-20±8.2)%, respectively. However, surface ozone (O3) concentration did not change significantly[(-1.0±6.5)%]. TROPOMI satellite observations of formaldehyde and nitrogen dioxide column concentrations indicated that the ozone photochemistry in the PRD in spring 2022 was mainly controlled by the volatile organic compound (VOCs) concentrations and was not sensitive to the reduction in nitrogen oxide (NOx) concentrations. Reduction in NOx may even have increased O3, because the titration of O3 by NOx was weakened. Due to the small spatial-temporal extent of emission reductions, the air quality effects caused by this short-term urban-scale lockdown were weaker than the air quality effects across China during the widespread COVID-19 lockdown in 2020. Future air quality management in South China cities should consider the impacts of NOx emission reduction on ozone and focus on the co-reduction scenarios of NOx and VOCs.

Critical analysis of the determining factors of environmental hazard and measures to reduce it in the system «boiler house – heat consumers – environment»

Purpose. Analysis of the determining factors of the ecological danger of urban boiler houses according to the volume of pollutant emissions and their dispersion in the city atmosphere, as well as a critical review of the existing means of saving heat and fuel resources, aimed at reducing the specified emissions and increasing the level of environmental safety of urban areas. The methods. A critical analysis of the characteristics of urban boiler houses and their environmental hazards was carried out based on the volume of emissions of pollutants into the atmosphere, which were determined according to the normative calculation method, and the analysis of existing approaches to the conservation of heat and fuel resources was carried out taking into account the technologies of building insulation. Findings. Іt is shown that, due to the large number of municipal boilers, they are the only source of urban pollution scattered throughout the city, which reduces the environmental safety of the city in proportion to rising emissions and consumption of boilers, valuable fuel resources. The originality. For the first time it was proved that the contribution of boilers to the total background concentration of pollutants in the urban atmosphere, in particular, the content of nitrogen dioxide in the number of other oxides, is about 20%, which allows to classify all municipal boilers as a significant air pollution with industrial enterprises and motor transport. Practical implementation. It is shown that the insulation of buildings, as a type of technology for the reconstruction of their facades, reaches 87% of all major repairs of buildings, and in the reconstruction of multi-storey residential buildings in cities with large obsolete (about 50… 100 years of operation) housing should be considered promising "Wet facades".

Assessment of variations in air quality in cities of Ecuador in relation to the lockdown due to the COVID-19 pandemic

This study analyzes the effect of lockdown due to COVID-19 on the spatiotemporal variability of ozone (O3), sulfur dioxide (SO2), and nitrogen dioxide (NO2) concentrations in different provinces of continental Ecuador using satellite information from Sentinel – 5P. The statistical analysis includes data from 2018 to March 2021 and was performed based on three periods defined a priori: before, during, and after lockdown due to COVID-19, focusing on the provinces with the highest concentrations of the studied gases (hotspots). The results showed a significant decrease in NO2 concentrations during the COVID-19 lockdown period in all the study areas: the Metropolitan District of Quito (DMQ) and the provinces of Guayas and Santo Domingo de los Tsáchilas. In the period after lockdown, NO2 concentrations increased by over 20% when compared to the pre-lockdown period, which may be attributable to a shift towards private transportation due to health concerns. On the other hand, SO2 concentrations during the lockdown period showed irregular, non-significant variations; however, increases were observed in the provinces of Chimborazo, Guayas, Santa Elena, and Morona Santiago, which could be partly attributed to the eruptive activity of the Sangay volcano during 2019–2020. Conversely, O3 concentrations increased by 2–3% in the study areas; this anomalous behavior could be attributed to decreased levels of NOx, which react with ozone, reducing its concentration. Finally, satellite data validation using the corresponding data from monitoring stations in the DMQ showed correlation values of 0.9 for O3 data and 0.7 for NO2 data, while no significant correlation was found for SO2.

Semiconducting MOFs on ultraviolet laser-induced graphene with a hierarchical pore architecture for NO2 monitoring

Due to rapid urbanization worldwide, monitoring the concentration of nitrogen dioxide (NO2), which causes cardiovascular and respiratory diseases, has attracted considerable attention. Developing real-time sensors to detect parts-per-billion (ppb)-level NO2 remains challenging due to limited sensitivity, response, and recovery characteristics. Herein, we report a hybrid structure of Cu3HHTP2, 2D semiconducting metal-organic frameworks (MOFs), and laser-induced graphene (LIG) for high-performance NO2 sensing. The unique hierarchical pore architecture of LIG@Cu3HHTP2 promotes mass transport of gas molecules and takes full advantage of the large surface area and porosity of MOFs, enabling highly rapid and sensitive responses to NO2. Consequently, LIG@Cu3HHTP2 shows one of the fastest responses and lowest limit of detection at room temperature compared with state-of-the-art NO2 sensors. Additionally, by employing LIG as a growth platform, flexibility and patterning strategies are achieved, which are the main challenges for MOF-based electronic devices. These results provide key insight into applying MOFtronics as high-performance healthcare devices.

Source apportionment of nitrogen pressures at a Chalk-fed groundwater-dependent wetland

Abstract In Groundwater-Dependent Terrestrial Ecosystems (GWDTEs), atmospheric nitrogen (N) inputs have often been studied in isolation from terrestrial groundwater and surface water inputs. We describe for the first time the development and application of a combined atmospheric and terrestrial N source apportionment methodology, able to identify contributing catchment and N loadings to GWDTEs. We combined all N inputs using a site-specific conceptual model supported by 12 months’ monitoring for a Chalk-fed GWDTE at Newbald Becksies, East Yorkshire. We discuss implications for effective catchment management, wetland protection and development of a source apportionment methodology. Potential sources of nitrate include: atmospheric deposition, mineralization, leaching from agricultural soils, manure heaps, septic tanks, sewer and mains water leakage. Atmospheric deposition was calculated from measurements of ammonia and nitrogen dioxide concentrations together with rainfall inputs of ammonium and nitrate. Quantification of agricultural sources used the FarmScoper modelling tool to estimate nitrate leaching in the groundwater catchment. Comparison between modelled nitrate concentrations in leachate (15–17 mg N l −1 ) and observed groundwater nitrate concentrations (12.3–19.8 mg N l −1 ) are good. The majority of nitrate is leached from arable land. FarmScoper allows mitigation scenarios to be tested, supporting measures to reduce nitrate within a groundwater catchment.

Bootstrap inference for skew-normal unbalanced heteroscedastic one-way classification random effects model

In this paper, the one-sided hypothesis testing and interval estimation problems for the fixed effect and variance component functions are considered in the skew-normal unbalanced heteroscedastic one-way classification random effects model. Firstly, the Bootstrap approach is used to establish test statistic for fixed effect. Secondly, the test statistics and confidence intervals for variance component functions are constructed by Bootstrap approach and generalized approach, and their theoretical properties are discussed. The Monte Carlo simulation results indicate that the Bootstrap approach performs better than the generalized approach in most cases. Finally, the above approaches are illustrated with two real examples of the annual average concentrations of fine particulate matter and nitrogen dioxide.

Short-term effects of tropospheric ozone and other environmental factors on emergency admissions due to pregnancy complications: A time-series analysis in the Madrid Region

Air pollution has been linked to adverse neonatal outcomes, mainly in the case of prolonged exposures. This study focuses on the short-term effects on maternal health.We conducted a retrospective ecological time-series study in the Madrid Region covering the period 2013–2018. The independent variables were mean daily concentrations of tropospheric ozone (O3), particulate matter (PM10/PM2.5) and nitrogen dioxide (NO2), as well as noise levels. The dependent variables were daily emergency hospital admissions due to complications in pregnancy, childbirth and the puerperium. Poisson generalised linear regression models were fitted to quantify the relative and attributable risks, controlling for trend, seasonality, the autoregressive nature of the series, and a number of meteorological factors.There were 318 069 emergency hospital admissions due to obstetric complications across the 2191 days of study. Of this total: 13 164 (95%CI: 9930–16 398) admissions were attributable to exposure to O3, the only pollutant to show a statistically significant (p < 0.05) association with admissions due to hypertensive disorders; and 10 575 (95%CI: 3573–17 566) admissions were attributable to daytime noise levels, while admissions due to hyperemesis gravidarum and vomiting were related to exposure to night noise. Other pollutants which also displayed statistically significant associations were: NO2 concentrations, with admissions due to vomiting and preterm labour; PM10 concentrations, with premature rupture of membranes: and PM2.5 concentrations, with total complications.Exposure to a range of air pollutants, and ozone in particular, is associated with a higher number of emergency hospital admissions due to gestational complications. Hence, surveillance of environmental effects on maternal health should be intensified, and plans and strategies to minimise these should be drawn up.

A rapid assessment of stubble burning and air pollutants from satellite observations.

For the last several years, the air quality of India's capital Delhi and surrounding region (NCR) has been degrading to a very poor and severe category during the autumn season. In addition to the various sources of air pollutants within the NCR region, the stubble burning in Punjab and Haryana states contributes to the poor air quality in this region. The current study employs the Moderate Resolution Imaging Spectroradiometer (MODIS) active fire products and TROPOspheric Monitoring Instrument (TROPOMI) products on carbon monoxide (CO) and nitrogen dioxide (NO2) concentrations for spatio-temporal assessment of stubble burning and associated emissions. The analysis performed in the Google Earth Engine (GEE) platform indicated a nearly threefold rise in crop residue burning in November than in October, with 92.58% and 7.42% reported from Punjab and the Haryana states in November, respectively. The study highlights the availability of near-real-time remote sensing observations and the utility of the GEE platform for rapid assessment of stubble burning and emissions thereof, having the potential for developing mitigation strategies.

25 Using Advanced in Vitro Approaches to Elucidate the Differential Toxicity of Nitrogen Dioxide and Particulate Matter in Ambient Air Pollution

Abstract Ambient nitrogen dioxide (NO2) and particulate matter (PM) concentrations are often found to be proportional, such that inhalation of one pollutant is expected to be accompanied by the inhalation of the other. Epidemiological evidence consistently demonstrates the health burdens associated with the inhalation of NO2 and PM, though has difficulty deciphering the inhalation hazard of either pollutant individually. Airway models can be exposed to NO2 and PM separately or as a co-exposure in vitro, allowing mechanisms of toxicity to be elucidated. Herein, NCI-H441 cells were exposed to either 780 ng/cm2 Printex 90 carbon black (CB) (a surrogate model of PM) using a VitroCell Cloud12, 5 ppm NO2 (within a modified Coy hypoxic cabinet) or a combination of NO2+CB over 24 hours. Cytotoxicity was not altered by NO2 or CB (trypan blue exclusion assay), however CB, and to a lesser extent CB+NO2 exposure resulted in a non-significant increase in membrane permeability (p&amp;gt;0.05). qPCR revealed no alterations in expression of superoxide dismutase 1 (SOD1) for any exposure condition. Both CB and NO2 exposures resulted in significantly increased IL6 and IL8 release (ELISA) (p&amp;lt;0.05), although co-exposure of the two pollutants did not augment the detected IL6 or IL8 levels. These data indicate NO2 and CB produce an inflammatory response in this model, though little evidence suggests that NO2 and CB act in an additive or synergistic manner via this pathway. Additional work remains ongoing to establish the mechanisms of toxicity utilising an anatomically relevant triple cell co-culture of the alveolar epithelial barrier.