Gaseous Air Pollutants Research Articles

Effect of pollution with a number of gases on patients with type 2 diabetes in gas stations

Diabetes is a metabolic disease characterized by elevated blood sugar levels for long periods. This disease is widely spread among the world's population, as it is currently observed that its incidence is increasing, and this is mainly due to a sedentary lifestyle and an excessive calorie diet. An increase in glucose uptake and a decrease in insulin resistance are One of the main factors that improve glycemic control is against diabetes. In order to know the role of gaseous air pollutants and their impact on type 2 diabetes, this study came as it included 90 people from Diyala Governorate / central Iraq (males only), their ages ranged between (24-60) years and they were distributed among 25 individuals with type 2 diabetes. 2 working in gas stations and 40 people working in gas stations also at risk of pollution and 25 people in a control group and for the period from January 2, 2021 to March 5, 2021 for the winter season, and for the period from July 15, 2021 to August 22 2021 for the summer, as the study was conducted in the winter and summer seasons.

Impacts of long-term ambient particulate matter and gaseous pollutants on circulating biomarkers of inflammation in male and female health professionals

BackgroundSystemic inflammation may serve as a biological mechanism linking air pollution to poor health but supporting evidence from studies of long-term pollutant exposure and inflammatory cytokines is inconsistent. ObjectiveWe studied associations between multiple particulate matter (PM) and gaseous air pollutants and pro- and anti-inflammatory cytokines within two nationwide cohorts of men and women. MethodsData were obtained from 16,151 women in the Nurses' Health Study and 7,930 men in the Health Professionals' Follow-up Study with at least one measure of circulating adiponectin, C-Reactive Protein (CRP), Interleukin-6 (IL-6) or soluble tumor necrosis-factor receptor-2 (sTNFR-2). Exposure to PM with aerodynamic diameter ≤2.5, 2.5–10, and ≤10 μm (PM2.5, PM2.5-10, PM10) and nitrogen dioxide (NO2) was estimated using spatio-temporal models and were linked to participants’ addresses at the time of blood draw. Averages of the 1-, 3-, and 12-months prior to blood draw were examined. Associations between each biomarker and pollutant were estimated from linear regression models adjusted for individual and contextual covariates. ResultsIn adjusted models, we observed a 2.72% (95% CI: 0.43%, 5.95%), 3.11% (−0.12%, 6.45%), and 3.67% (0.19%, 7.26%) increase in CRP associated with a 10 μg/m3 increase in 1-, 3-, and 12- month averaged NO2 in women. Among men, there was a statistically significant 5.96% (95% CI: 0.07%, 12.20%), 6.99% (95% CI: 0.29%, 14.15%), and 8.33% (95% CI: 0.35%, 16.94%) increase in CRP associated with a 10 μg/m3 increase in 1-, 3-, and 12-month averaged PM2.5-10, respectively. Increasing PM2.5-10 was associated with increasing IL-6 and sTNFR-2 among men over shorter exposure durations. There were no associations with exposures to PM2.5 or PM10, or with adiponectin. Findings were robust to sensitivity analyses restricting to disease-free controls and non-movers. ConclusionsAcross multiple long-term pollutant exposures and inflammatory markers, associations were generally weak. Focusing on specific pollutant-inflammatory mechanisms may clarify pathways.

Mass transfer behaviour and energy utilization efficiency of gas sparged rotating cylinder reactor and possible applications

This work aims to investigate the mass transfer behaviour of a gas sparged rotating cylinder electrochemical reactor suitable for conducting diffusion-controlled liquid-solid and gas-liquid-solid reactions. Variables studied were: cylinder rotation speed, N2 superficial velocity and the effect of sodium lauryl sulphate surface-active agent concentration. Gas sparging enhanced the rate of mass transfer by a factor ranging from 1.1 to 2.67. Addition of sodium lauryl sulphate reduced the rate of mass transfer by an amount ranging from 2.7 to 27%. The effect of specific power consumption (∈) on the mass transfer coefficient of un-sparged rotating cylinder was found to agree fairly with the well-known Calderbank – Moo-Young equation. The performance of the gas sparged rotating cylinder was expressed in terms of the criterion kA∈. The value of kA∈ was found to increase with decreasing gas superficial velocity and cylinder rotation speed. Possible applications of the present study for designing electrochemical reactors suitable for conducting diffusion limited reactions such as production of H2O2, flue gas desulphurization and air pollution control were highlighted. The possible use of the present reactor as a catalytic reactor for conducting diffusion controlled biochemical reactions catalyzed by immobilized enzyme or cell was noted.

Efficient Photothermal Elimination of Formaldehyde under Visible Light at Room Temperature by a MnOx-Modified Multi-Porous Carbon Sphere.

Volatile organic compounds (VOCs) exert a serious impact on the environment and human health. The development of new technologies for the elimination of VOCs, especially those from non-industrial emission sources, such as indoor air pollution and other low-concentration VOCs exhaust gases, is essential for improving environmental quality and human health. In this study, a monolithic photothermocatalyst was prepared by stabilizing manganese oxide on multi-porous carbon spheres to facilitate the elimination of formaldehyde (HCHO). This catalyst exhibited excellent photothermal synergistic performance. Therefore, by harvesting only visible light, the catalyst could spontaneously heat up its surface to achieve a thermal catalytic oxidation state suitable for eliminating HCHO. We found that the surface temperature of the catalyst could reach to up 93.8 °C under visible light, achieving an 87.5% HCHO removal efficiency when the initial concentration of HCHO was 160 ppm. The microporous structure on the surface of the carbon spheres not only increased the specific surface area and loading capacity of manganese oxide but also increased their photothermal efficiency, allowing them to reach a temperature high enough for MnOx to overcome the activation energy required for HCHO oxidation. The relevant catalyst characteristics were analyzed using XRD, measurement of BET surface area, scanning electron microscopy, HR-TEM, XPS, and DRS. Results obtained from a cyclic performance test indicated high stability and potential application of the MnOx-modified multi-porous carbon sphere.

Preparing the Public Opinion in the Community to Accept Distributed Energy Systems and Renewable Energy

Global energy consumption has reached unprecedented levels over the last century due to population growth and economic growth. There have been significant changes in the global energy economy to reduce greenhouse gas emissions and air pollutants. Due to this trend, many countries around the world are promoting electric technologies as fuel-saving alternatives. The Israeli energy industry integrates renewable sources into its supply system and streamlines consumption. Nevertheless, Israelis know too little about smart meters, energy storage systems, and other modern power grid technology, which enables a decentralized approach to energy management referred to as distributed energy systems (DES). Using distributed energy systems to generate energy on-site and manage loads can reduce costs, improve reliability, and secure revenue. An effective public education program can help prepare public opinion and reduce barriers to smart use and energy efficiency in the home. By educating schoolchildren, we will present a way to prepare the public in the community to accept distributed energy systems and renewable energy. In challenging times, it is vital to make great efforts and to remember that change begins with education and that the best way to achieve intelligent usage and energy efficiency is to start with our children.

Establishment of Repeated In Vitro Exposure System for Evaluating Pulmonary Toxicity of Representative Criteria Air Pollutants Using Advanced Bronchial Mucosa Models.

There is mounting evidence that shows the association between chronic exposure to air pollutants (particulate matter and gaseous) and onset of various respiratory impairments. However, the corresponding toxicological mechanisms of mixed exposure are poorly understood. Therefore, in this study, we aimed to establish a repeated exposure setting for evaluating the pulmonary toxicological effects of diesel exhaust particles (DEP), nitrogen dioxide (NO2), and sulfur dioxide (SO2) as representative criterial air pollutants. Single, combined (DEP with NO2 and SO2), and repeated exposures were performed using physiologically relevant human bronchial mucosa models developed at the air–liquid interface (bro-ALI). The bro-ALI models were generated using human primary bronchial epithelial cells (3–4 donors; 2 replicates per donor). The exposure regime included the following: 1. DEP (12.5 µg/cm2; 3 min/day, 3 days); 2. low gaseous (NO2: 0.1 ppm + SO2: 0.2 ppm); (30 min/day, 3 days); 3. high gaseous (NO2: 0.2 ppm + SO2: 0.4 ppm) (30 min/day, 3 days); and 4. single combined (DEP + low gaseous for 1 day). The markers for pro-inflammatory (IL8, IL6, NFKB, TNF), oxidative stress (HMOX1, GSTA1, SOD3,) and tissue injury/repair (MMP9, TIMP1) responses were assessed at transcriptional and/ or secreted protein levels following exposure. The corresponding sham-exposed samples under identical conditions served as the control. A non-parametric statistical analysis was performed and p < 0.05 was considered as significant. Repeated exposure to DEP and single combined (DEP + low gaseous) exposure showed significant alteration in the pro-inflammatory, oxidative stress and tissue injury responses compared to repeated exposures to gaseous air pollutants. The study demonstrates that it is feasible to predict the long-term effects of air pollutants using the above explained exposure system.

Short-term exposure to gaseous air pollutants and daily hospitalizations for acute upper and lower respiratory infections among children from 25 cities in China

To examine the short-term association between gaseous air pollutants (CO, NO2, SO2, and O3) and all-cause respiratory disease, acute upper respiratory infections (AURIs) as well as acute lower respiratory infections (ALRIs) among children, we conducted the study from 25 major cities in China. Hospitalization records of children aged 0–18 years due to all-cause respiratory diseases (889,926), AURIs (97,858), and ALRIs (642,154) from 2016 to 2019 were extracted. Concentrations of CO, NO2, SO2, and O3 were averaged across monitoring stations. Generalized additive models were used to estimate the associations between gaseous air pollutants and daily hospitalizations for all-cause respiratory disease, AURIs, and ALRIs. The meta-analysis was used to combine the city-specific estimates. A 10 mg/m3 increase in CO at lag01, and a 10 μg/m3 increase in NO2, SO2, and O3 at lag01 were associated with 1.65% (95%CI, 0.41–2.91), 0.54% (95%CI, 0.30–0.79), 0.60% (95%CI, 0.22–0.99), and 0.23% (95%CI, 0.06–0.39) increase of hospitalizations due to all-cause respiratory disease, respectively. For the disease subtype, O3 only had adverse effects on AURIs, CO and SO2 mainly on ALRIs, and NO2 on both AURIs and ALRIs. Children aged 4–6years were more vulnerable to the effects of CO and NO2, but those aged <1year were more susceptible to SO2 and O3. Besides, the O3 effect was stronger in the warm season than in the cold season. The study indicated that short-term exposure to CO, NO2, SO2, and O3 was associated with increased hospitalization for pediatric respiratory disease, and the association may vary by position of the respiratory tract, age, and season.

Real-time detection of vehicle-originated condensable particulate matter through thermodenuder integrated aerosol measurement method at tailpipes

Condensable particulate matter (CPM) corresponds to primary particulate matter ≤2.5 μm (PM2.5) obtained through the condensation of gaseous air pollutants caused by temperature drops in the atmosphere. The internal combustion of vehicle engines can produce CPM because of the condensable compounds in the exhaust gas. Conventional CPM measurement methods have been developed for coal-fired power plants with stable emissions through sampling and off-site analyses. They are therefore unsuitable for detecting the rapidly changing vehicle-originated CPM. In addition, the current system for evaluating PM2.5 from vehicles, based on the particle measurement program (PMP) protocol, provides only the emission factors of total PM2.5 (and not CPM separately) at a fixed temperature (∼25 °C) and dilution ratio (∼ × 35). This study reports, for the first time, the development of a real-time detection method for vehicle-originated CPM through a thermodenuder (TD) integrated with real-time aerosol instruments. This method was designed to reduce the loss of CPM due to condensation and diffusion while sampling the exhaust gas. It permits the investigation of the effects of dilution gas temperature (5–45 °C) and dilution ratio (up to × 30) on the formation of CPM. During the feasibility test of this method using a diesel vehicle (Euro-4), the real-time total particle number concentrations (PNs) matched well with those obtained by a PMP protocol-based evaluation system. Moreover, this method detected PNs concentrations ten times higher than the detection limit (4 × 106 particles/cm3) of the PMP-based system. The emission factors of the total PM2.5 with a bulk density (1 g/cm3) measured by this method also showed consistency with the results of the PMP protocol. The mass emission factor of CPM determined by deploying the TD was ∼14.57 mg/km (∼63% contribution to the total PM2.5).

Association between gaseous air pollutants and idiopathic nephrotic syndrome in children: a 12-year population-based cohort study

BackgroundTo date, there is insufficient knowledge about the association of air pollution and childhood nephrotic syndrome in the real world. This study aimed to evaluate the effects of the three common gaseous air pollutants, including sulfur dioxide, total hydrocarbon, and methane, on the risk of idiopathic nephrotic syndrome (INS) in children.MethodsWe collected data from the Taiwan National Health Insurance Research Database and Taiwan Air Quality-Monitoring Database. Children younger than 18 years old, identified from January 1, 2000, were followed up until the first diagnosis of INS was established or until December 31, 2012. We measured the incidence rates and hazard ratios for INS stratified based on the quartiles (Q1–Q4) of air pollutant concentration. Multivariate Cox proportional hazards models were also applied by adjusting age, sex, monthly income, and urbanization.ResultsCompared with participants exposed to Q1 concentrations, the adjusted hazard ratios (aHRs) for INS increased progressively along the four quartiles of sulfur dioxide, total hydrocarbon, and methane, from 1 (Q1) to 1.78 (Q4), 1 (Q1) to 3.49 (Q4), 1 (Q1) to 7.83 (Q4), respectively.ConclusionsOur study revealed that children with exposure to higher concentrations of sulfur dioxide, total hydrocarbon, and methane was associated with an increased risk of INS.

An emission inventory update for Tehran: The difference between air pollution and greenhouse gas source contributions

Many highly populated cities are still struggling to reach clean air targets, while the zero greenhouse gas emission objectives may accelerate the path toward healthy air for all. Still, there is a fine line between intensive electrification's impact on greenhouse gas emissions and criteria air contaminants depending on the source of the electricity. In this study, the previous version of the emission inventory for Tehran was evaluated and re-calculated in a detailed bottom-up approach to provide the most updated data on the contribution of stationary sources derived by power plants vs. mobile sources. The objectives were to update the emission inventory for improved policymaking, study the impact of changes in emissions in 4 years, provide a detailed methodology for cities highly impacted by transportation emissions, and exercise a simple yet effective modelling task for emission inventory evaluation. The study included all possible sources in the mobile sector with eight categories of fleet composition, industries, power plants, house heating, and point sources related to transportation such as terminals and gas stations. It also included exhaust, non-exhaust, and evaporative emissions for mobile sources. An intensive data collection campaign was launched to collect activity data. The traffic information was obtained from a travel-demand model and validated by traffic counting. The license plate registration database provided detailed fleet composition based on vehicle technology, fuel, age, and state of maintenance.The emission inventory calculated annual emissions of 478 kt for CO, 103 kt for NOx, 91 kt for VOCs, and 19 kt for SOx. TSP was estimated at 10.4 kt. NOx emissions were significantly increased from 87 to 102.6 ktonnes per year (17% increase) and were confirmed by an increase in the annual mean concentration of NO2 from 39.4 to 53.4 ppb (35% increase) between 2013 and 2017. A notable observation was the impact of house heating on CO2,eq emissions. More than 30% of CO2,eq emissions were from house heating (natural gas, predominantly methane) in a city where total air contaminant emissions are highly driven by the transportation sector. The result clearly shows the differences between zero-emission target paths for the two objectives of greenhouse gas emissions and air quality. An integrated approach is needed to develop policies that will lead o zero-emission GHG targets while keeping the air clean.

Spatial and temporal variation of air pollutant emissions from forest fires in China

Warm and dry climate conditions favor the occurrence of forest fires. Forest burning leads to the discharge of large amounts of particles and trace gases that play an important role in air quality degradation and have impact on human health. To date, most studies on China's forest fire emissions have concentrated in certain regions, also with a relatively coarse temporal resolution. In this study, we used the INteractive Fire and Emission algoRithm for Natural envirOnments (INFERNO), as well as high-resolution land cover data to compile a forest fire emission inventory for China in 2020. The variations of forest combustion emissions were then analyzed at the provincial and seasonal level. The results show that forest fires were concentrated in southern China and northeastern China, which are in agreement with MODIS observations. Total CO2, CO, CH4, NOx, SO2, PM2.5, OC, and BC emissions were estimated to be 3.06 × 104, 1.87 × 103, 96.92, 34.95, 13.84, 208, 116.03, and 9.95 Gg, respectively. Provinces with higher emissions were found in Yunnan, Guangdong, Hunan, and Sichuan. Peak emission from forest fire occurred in spring and winter, mainly from January to April, during which contributed 70% of the total forest fire contaminants emissions. The algorithm used in this study can be easily coupled in the meteorological model and air quality model to estimate the occurrence of fire and calculate pollutant emission online. This study updated emissions information that may support future research and policy development on greenhouse gas reduction and air pollution control.

Characterizing Real-World Particle-Bound Polycyclic Aromatic Hydrocarbon Emissions from Diesel-Fueled Construction Machines

This study employed an onboard emission measurement system to measure the real-world emission factors of particulate matter (PM), particle-bound polycyclic aromatic hydrocarbons (PAHs), and gaseous air pollutants for different types of diesel-fueled non-road construction machines operated inside confined spaces within a brick manufacturing factory located in Taiwan. To the best knowledge of the authors, this is the first study that reports real-world PM, PAH, and gaseous pollutant emission factors for non-road engines in Taiwan. The mean real-world fuel-specific emission factors of PM, carbon monoxide, total hydrocarbons, and nitric oxide were 0.712–1.17, 8.27–17.9, 3.04–5.77, and 38.1–96.8 g/kg-fuel, respectively, for the test machines. Likewise, mean ΣPAHs emission factors ranged from 157 to 230 μg/kg-fuel for three types of test machines. Further, the average emission of particle-bound PAH per unit PM emission ranged from 213 to 384 μg-PAH/g-PM. Among the analyzed PAHs, the medium-molecular weight (3- and 4-ring) compounds contributed to the largest share of particle-bound PAH emissions. However, in terms of Benzo[a]pyrene equivalent (BaPeq) toxicity, the high-molecular weight (5- and 6-ring) PAHs were more important, as they had the highest BaPeq toxic emission factors. This study provides detailed composition and emission factors of particle-bound PAHs in non-road diesel construction machine emissions, which may be useful as a chemical fingerprint for source apportionment studies.

Urban Air Pollution and Emergency Department Visits for Neoplasms and Outcomes of Blood Forming and Metabolic Systems.

This study focused on investigating possible associations between exposure to urban air pollution and the number of emergency department (ED) visits for various health outcomes. The outcomes were grouped into four chapters of the International Classification of Diseases Tenth Revision (ICD-10) system (i.e., Chapter II-IV: “Neoplasms”, “Diseases of the blood”, “Endocrine, nutritional and metabolic diseases”, and XVIII: “Symptoms, signs and abnormal clinical and laboratory findings“). The data were collected for the city of Toronto, Canada, (2004–2015, 4292 days). Four gaseous air pollutants (carbon monoxide (CO), nitrogen dioxide (NO2), ground level ozone (O3), and sulfur dioxide (SO2)) and fine particulate matter (PM2.5), and two calculated air quality health indexes (AQHI) based on Toronto were used. The statistical models were constructed by applying the conditional Poisson regression. The exposure was assessed over a maximum of 15 days (time lags 0–14 days). An analysis was performed with the following strata: sex, age, and seasons. Relative risks (RR) and their 95% confidence intervals (95%CI) were estimated for an increase in concentration by a one interquartile range (IQR). For the AQHI (composed of NO2, O3, and PM2.5), IQR = 1, the estimations for lag 1 and all patients, are RR = 1.023 (95%CI: 1.008, 1.038), 1.026 (1.012, 1.040), 1.013 (1.003, 1.024), and 1.007 (1.003, 1.010) for Chapters II–IV and XVIII, respectively. The results show that in the four large, analyzed health groups, the impact of air quality mainly occurs over a short period (from current day to a maximum of 3 days after exposure).

Metro systems and urban development: Impacts and implications

Many cities in the world have developed metro systems. Metro systems affect urban development in many ways, such as enhancing labour force mobility, increasing urban productivity and promoting urban underground space (UUS) utilisation to accommodate urban functions. This paper explores the relationship between metro systems and urban development, with particular focus on the comprehensive impacts of metro development on the economic, environmental and social development of cities. The contribution of metro systems to urban development has been confirmed by numerous studies in many cities in the world. The positive capitalisation of metro systems is reflected in property values in areas surrounding metro systems, although the impacts may vary spatially, temporally and geographically. In addition, metro systems impact on the natural and built environments by reducing air pollution and greenhouse gas emissions, encouraging new development and urban renewal, sharping urban development and land use, facilitating commercial growth and residential development, promoting the utilisation of UUS, and increasing mixed land use and urban density. However, there are mixed effects, both positive and negative, of metro systems on equality of transit opportunity, accessibility and connectivity, public health, travel behaviour, personal identity, travel experience and safety. This study sheds light on the impacts of metro systems on urban development, and provides important information for urban and transport planners and policy-makers wishing to develop metro systems to support sustainable urban development.

Gaseous air pollutants and DNA methylation in a methylome-wide association study of an ethnically and environmentally diverse population of U.S. adults

Epigenetic mechanisms may underlie air pollution-health outcome associations. We estimated gaseous air pollutant-DNA methylation (DNAm) associations using twelve subpopulations within Women's Health Initiative (WHI) and Atherosclerosis Risk in Communities (ARIC) cohorts (n = 8397; mean age 61.3 years; 83% female; 46% African-American, 46% European-American, 8% Hispanic/Latino). We used geocoded participant address-specific mean ambient carbon monoxide (CO), nitrogen oxides (NO2; NOx), ozone (O3), and sulfur dioxide (SO2) concentrations estimated over the 2-, 7-, 28-, and 365-day periods before collection of blood samples used to generate Illumina 450 k array leukocyte DNAm measurements. We estimated methylome-wide, subpopulation- and race/ethnicity-stratified pollutant-DNAm associations in multi-level, linear mixed-effects models adjusted for sociodemographic, behavioral, meteorological, and technical covariates. We combined stratum-specific estimates in inverse variance-weighted meta-analyses and characterized significant associations (false discovery rate; FDR<0.05) at Cytosine-phosphate-Guanine (CpG) sites without among-strata heterogeneity (PCochran's Q > 0.05). We attempted replication in the Cooperative Health Research in Region of Augsburg (KORA) study and Normative Aging Study (NAS). We observed a −0.3 (95% CI: −0.4, −0.2) unit decrease in percent DNAm per interquartile range (IQR, 7.3 ppb) increase in 28-day mean NO2 concentration at cg01885635 (chromosome 3; regulatory region 290 bp upstream from ZNF621; FDR = 0.03). At intragenic sites cg21849932 (chromosome 20; LIME1; intron 3) and cg05353869 (chromosome 11; KLHL35; exon 2), we observed a −0.3 (95% CI: −0.4, −0.2) unit decrease (FDR = 0.04) and a 1.2 (95% CI: 0.7, 1.7) unit increase (FDR = 0.04), respectively, in percent DNAm per IQR (17.6 ppb) increase in 7-day mean ozone concentration. Results were not fully replicated in KORA and NAS. We identified three CpG sites potentially susceptible to gaseous air pollution-induced DNAm changes near genes relevant for cardiovascular and lung disease. Further harmonized investigations with a range of gaseous pollutants and averaging durations are needed to determine the effect of gaseous air pollutants on DNA methylation and ultimately gene expression.

A Comparison of Functional Fillers—Greenhouse Gas Emissions and Air Pollutants from Lignin-Based Filler, Carbon Black and Silica

The transformation from a fossil-based economy to a sustainable and circular bioeconomy is urgently needed to achieve the climate targets of the Paris Agreement, reduce air pollution and ensure a long-term competitive economy. Due to its carbonaceous and aromatic basic components, lignin has the potential for material valorization within bioeconomy. So far, lignin produced in the pulp and paper industry has mainly been used internally to generate thermal process energy, as it is difficult to extract it from biomass in a pure and unaltered form. The valorization of lignin to improve the economics of pulp mills is a current aim of the industry. Hydrothermal treatment (HTT) of a partial flow from the lignin stream to produce a functional filler for use in polymer blends is one valorization option. The environmental assessment of the lignin-based HTT filler, conducted using life cycle assessment (LCA), shows that substitution of the conventional fillers carbon black and silica could be associated with significant reductions in greenhouse gas emissions and air pollutants. Depending on the allocation methodology and the reference filler considered, approx. 5 kg CO2 eq./kg filler, 80–93% SO2 emissions, 27–79% PM emissions, and 88–98% PAH emissions can be saved.

Use of SEM/EDX methods for the analysis of ambient particulate matter adhering to the skin surface.

The skin is exposed to numerous particulate and gaseous air pollutants. The ones that need particular attention are the particles that adhere to the skin surface, which can later cause direct skin damage. This study aimed to characterize air pollution (AP) particles adhered to the human skin by using scanning electron microscopy (SEM) combined with X-ray dispersive energy spectrometry (EDX). Tape stripping was performed from six healthy volunteers exposed to urban AP to collect stratum corneum samples from the cheeks and forehead. The samples were analysed using SEM equipped with EDX system with a silicon drift detector at an accelerating voltage of 20 keV. After the preliminary examination, the particles were located and counted using 1000× magnification. Each particle was analysed, increasing magnification up to 5000× for precise dimension measurement and elemental composition analysis. At least 100 fields or a surface of approximately 1 mm2 were examined. Particles adhered to the skin were identified in all samples, with a particle load ranging from 729 to 4525. The average area and perimeter of all particles identified were 302 ± 260 μm2 and 51 ± 23 μm subsequently, while the equivalent circular diameter was, on average, 14 ± 6 μm. The particles were classified into ten groups based on morphology and elemental composition. Chlorides were the most numerous particle group (21.9%), followed by carbonaceous organic particles (20.3%), silicates (18%), carbonates (16.4%), metal-rich particles (14%), and a minor number of bioaerosols, quartz-like, and fly ash particles. The SEM-EDX analysis provides evidence of the contamination of exposed skin to various airborne PM of natural or anthropogenic origin. This method may provide new insights into the link between exposure to AP and AP-induced skin damage.

Elder people can be more susceptible to the association between short-term ambient air pollution and sleep disorder outpatient visits: a time-series study.

Sleep disorders attract increasing concerns. However, the evidence of the association between ambient air pollution and sleep disorders is limited. Therefore, our aim was to determine the association between short-term air pollution exposure and outpatient visits for sleep disorders in Xi'an, the largest city in Northwest China. Baseline outpatient data of daily sleep disorders between 2011 and 2013 were collected. Quasi-Poisson distribution was applied by adjusting the day of the week and weather conditions. A total of 49,282 sleep disorder outpatient visits were recorded. The most significant association between air pollutants and outpatient visits was observed on concurrent day: per 10μg/m3 increase of NO2, SO2, and PM10 at lag 0 corresponded to increased outpatient sleep disorder visits at 0.22% (95% CI: 0.03%, 0.42%), 1.53% (95% CI: 0.53, 2.53%), and 2.57% (95% CI: 1.33%, 3.82%), respectively. As for gender-specific analysis, there was no statistically significant difference between males and females. The result of season-specific analysis showed no statistically significant difference between warm seasons and cool seasons, either. As for age-specific analysis, obvious associations were observed in 20-40 age group (NO2) and > 40 age group (PM10 and SO2), while no evident association was found for the young age group (< 20years old). Conclusively, short-term exposure to air pollutants, especially gaseous air pollutants, might increase the risk of sleep disorders, and such association appears to be more obvious in elder people. We provide novel data that there may be age differences in the relationship between short-term air pollution exposure and sleep disorders.

Concentrations of indoor gaseous air pollutants and risk factors associated with childhood asthma in Benin City, Nigeria.

Pollutants from various indoor sources account for indoor air pollution mostly in developing countries and pose health risks to children. This study assessed the levels of indoor gaseous pollutants and environmental risk factors associated with asthma in children. A cross-sectional household survey was conducted among 304 children between the ages of 1 and 17years. Indoor pollution at home was investigated using a modified international survey on asthma and allergies in childhood (ISAAC) questionnaire. Concentrations of indoor gaseous pollutants (CO, SO2 and NO2) were measured in two hundred and twenty-five randomly selected households using a MultiRae lite gas meter. The data obtained were analysed using SPSS for windows version 21.0. The risk factors for childhood asthma were obtained as odds ratios (ORs) using multivariate logistic regression. Mean concentrations of indoor gaseous pollutants ranged between 2.34-3.14 and 2.21-2.61mg/m3 (CO), 0.02-0.05 and < 0.002-0.03mg/m3 (NO2) and < 0.002-0.03 and < 0.002-0.02mg/m3 (SO2) in the wet and dry seasons. The mean values of pollutants were within the WHO permissible limits. The morbidity rates of clinical asthma, physician-diagnosed asthma and recurrent wheeze in the past 12months among the respondents were 5.6%, 2.6% and 11.8% respectively. There was no association between asthma prevalence and air pollutant exposures except with CO (R = 0.130). However, the number of occupants, family history of asthma, current smoking, use of kerosene and proximity of residence to the highway with significant (p < 0.05) odds ratios (12.4, 3.51, 2.51, 7.20 and 3.46) were independent contributors to current asthma in children. The study showed that exposure to household risk factors contributed to increased asthma among children in the study locations.

Study of the Potential Effects of Gate-Hold Strategies on Arrival and Departure Operations at Charlotte Douglas International Airport

We employed discrete-event simulation with embedded multivariate statistical models for time and situation-dependent parameters to study the potential impact of regulating the release of planes from their terminal gates in peak periods to reduce congestion on ramps and taxiways at Charlotte Douglas International Airport, a major U.S. hub for of the world’s largest airline, American Airlines. Gate-holding strategies are one of several operational strategies to reduce aviation’s carbon footprint. They have been shown to reduce fuel consumption, air pollution, and greenhouse gas emissions, but past studies have concentrated on taxi times and fuel consumption of outbound aircraft without considering the potential disruptions on inbound traffic, which may be blocked from reaching their intended gates. We verified that reductions in outbound taxi times could be achieved without delaying the times when planes lifted off for departure but, depending on the gate-hold rules employed and the intensity of flight operations, more delays and gate changes occurred for arriving aircraft. Our models allow intensive examination of the tradeoffs involved in improving system performance with various strategies.