LitSearch-NOx (2024)

Project ID

4767

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NAAQS

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April 12, 2023, 4:32 a.m.

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Journal Article

Abstract  Background Air-pollution levels have been trending downward progressively over the past several decades in southern California, as a result of the implementation of air quality-control policies. We assessed whether long-term reductions in pollution were associated with improvements in respiratory health among children. Methods As part of the Children's Health Study, we measured lung function annually in 2120 children from three separate cohorts corresponding to three separate calendar periods: 1994-1998, 1997-2001, and 2007-2011. Mean ages of the children within each cohort were 11 years at the beginning of the period and 15 years at the end. Linear-regression models were used to examine the relationship between declining pollution levels over time and lung-function development from 11 to 15 years of age, measured as the increases in forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) during that period (referred to as 4-year growth in FEV1 and FVC). Results Over the 13 years spanned by the three cohorts, improvements in 4-year growth of both FEV1 and FVC were associated with declining levels of nitrogen dioxide (P<0.001 for FEV1 and FVC) and of particulate matter with an aerodynamic diameter of less than 2.5 μm (P= 0.008 for FEV1 and P<0.001 for FVC) and less than 10 μm (P<0.001 for FEV1 and FVC). These associations persisted after adjustment for several potential confounders. Significant improvements in lung-function development were observed in both boys and girls and in children with asthma and children without asthma. The proportions of children with clinically low FEV1 (defined as <80% of the predicted value) at 15 years of age declined significantly, from 7.9% to 6.3% to 3.6% across the three periods, as the air quality improved (P=0.001). Conclusions We found that long-term improvements in air quality were associated with statistically and clinically significant positive effects on lung-function growth in children. (Funded by the Health Effects Institute and others.).

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Journal Article

Abstract  We evaluated the use of ion-exclusion chromatographic systems for analyzing the behavior of inorganic ions (e. g., bicarbonate, sulfate, chloride, nitrate, phosphate, dissolved silicate, sodium, ammonium, potassium, magnesium, and calcium ions) in a suburban river located in Jakarta, Indonesia. Carbonate, phosphate, and silicate ion concentrations were determined using ion-exclusion chromatography (IEC) on a weakly acidic cation-exchange resin column (WCX) in the H+-form with water eluent. Other ions were identified by ion-exclusion/cation-exchange chromatography (IEC/CEC) on a WCX column with tartaric acid eluent. The use of IEC systems for water quality monitoring was advantageous for the following reasons: (1) the concentrations of analyte ions, except NO3- and silicate ions, increased from upstream to downstream; and (2) the speciation of inorganic nitrogen ions could be analyzed by single injection into the IEC/CEC. The IEC approach provided beneficial information for the construction of sewage treatment facilities in our study area. Results showed that (1) the analyte concentrations for samples obtained in the downstream area were higher than those in the upstream area owing to contamination by domestic sewage; (2) the concentrations of NO3- and NH4+ correlated with the concentration of dissolved oxygen; and (3) bicarbonate concentrations increased downstream, likely due to respiration of bacteria and dissolution of concrete under low-oxygen conditions.

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Journal Article

Abstract  The aim of this study was to evaluate the relative performance of three nitrification inhibitors (NIs) viz. calcium carbide (CaC2), and plant derivatives of Pongamia glabra Vent. (karanj) and Melia azedarach (dharek) in regulating N transformations, inhibiting nitrification and improving N recovery in soil-plant systems. In the first experiment under laboratory incubation, soil was amended with N fertilizer diammonium phosphate [(NH4)(2)HPO4] at a rate of 200 mg N kg(-1), N + CaC2, N + karanjin, and N + M. azedarach and incubated at 22 A degrees C for 56 days period. Changes in total mineral N (TMN), NH4 (+)-N and NO3 (-)-N were examined during the study. A second experiment was conducted in a glasshouse using pots to evaluate the response of wheat to these amendments. Results indicated that more than 92 % of the NH4 (+) initially present had disappeared from the mineral N pool by the end of incubation. Application of NIs i.e., CaC2, karanjin, and M. azedarach resulted in a significant reduction in the extent of NH4 (+) disappearance by 49, 32, and 13 %, respectively. Accumulation of NO3 (-)-N was much higher in N amended soil 57 % compared to 11 % in N + CaC2, 13 % in N + karanjin, and 18 % in N + M. azedarach. Application of NIs significantly increased growth, yield, and N uptake of wheat. The apparent N recovery in N-treated plants was 20 % that was significantly increased to 38, 34, and 37 % with N + CaC2, N + karanjin, and N + M. azedarach, respectively. Among the three NIs tested, CaC2 and karanjin proved highly effective in inhibiting nitrification and retaining NH4 (+)-N in the mineral pool for a longer period.

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Journal Article

Abstract  The absorption-oxidation of nitrogen oxide (NO) induced by aqueous solutions of sodium persulfate (Na2S2O8) in the presence of SO2 has been studied in a bubble column reactor operated in semibatch mode. The effects of Na2S2O8 concentration (0.01-0.20 M), temperature (23-70 degrees C), 1550 ppm gas-phase SO2, and solution pH on NO removal (1000 ppm gas-phase concentration) were investigated. The presence of SO2 dramatically improved NO gas absorption and oxidation while it was itself completely removed. The NO fractional conversions in the presence of SO2 ranged from 77% to 83%, with the greatest effect occurring at lower temperatures (23 and 30 degrees C). While persulfate concentration of 0.1 M appeared optimal for aqueous NO removal, both in the absence and presence of SO2, significant improvements in NO removal were observed for persulfate concentrations of >0.05 M but antagonistic effects were observed with concentrations of <0.05 M in the presence of SO2, compared to without SO2. The pH range of 6.5-8.5 appears to be ideal for NO removal in the presence of SO2. The individual and simultaneous chemistry of NOx and SO2 removal by persulfate is discussed. The results demonstrate the feasibility of removing NOx and SOx simultaneously by aqueous scrubbing.

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Journal Article

Abstract  P. Adoniadis, N. Vordos, D. V. Bandekas, A. Ioannou. Improvement of Power Factor. Technoeconomical Application in a Case Study at the Industrial Area of Kavala // Electronics and Electrical Engineering. - Kaunas: Technologija, 2012. - No. 2(118). - P. 38-42. The reduction of energy supplies, the increase of the problems of environmental pollution and generally the negative effects of electrical energy production, necessitate the energy saving. The optimization of the power factor saves energy in industrial applications. This paper aims to study the cos phi using compensation capacitors, the benefits of replacement them, the method of optimization using these capacitors, in order to succeed the best technoeconomical solution and a cause study in Industry Campus of Kavala. Ill. 6, bibl. 4, tabl. 4 (in English; abstracts in English and Lithuanian).

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Journal Article

Abstract  Large eddy simulation (LES) method is employed to investigate the effect of the hydrogen content of fuel on the H-2/CH4 flame structure under the moderate or intense low-oxygen dilution (MILD) condition. The turbulence-chemistry interaction of the numerically unresolved scales is modelled using the PaSR method, where the full mechanism of GRI-2.11 represents the chemical reactions. The influence of hydrogen concentration on the flame structure is studied using the profiles of temperature, CH2O and OH mass fractions and the diffusion profiles of un-burnt fuel through the flame front. Furthermore, more details are investigated by contours of OH, HCO and CH2O radicals in an area near the nozzle exit zone. Results show that increasing the hydrogen content of fuel reinforces the MILD combustion zone and increases the peak value of the flame temperature and OH mass fraction. This increment also increases the flame thickness and reduces the OH oscillations and diffusion of the un-bumt fuel through the flame front. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

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Journal Article

Abstract  A Particle-Into-Liquid Sampler - Total Organic Carbon (PILS-TOC) and fraction collector system was flown aboard a Twin Otter aircraft sampling prescribed burning emissions in South Carolina in November 2011 to obtain smoke marker measurements. The fraction collector provided 2 min time-integrated offline samples for carbohydrate (i.e., smoke markers levoglucosan, mannosan, and galactosan) analysis by high-performance anion-exchange chromatography with pulsed amperometric detection. Each fire location appeared to have a unique Delta levoglucosan/Delta water-soluble organic carbon (WSOC) ratio (RF01/RF02/RF03/RF05 = 0.163 +/- 0.007 mu g C mu g(-1) C, RF08 = 0.115 +/- 0.011 mu g C mu g(-1) C, RF09A = 0.072 +/- 0.028 mu g C mu g(-1) C, and RF09B = 0.042 +/- 0.008 mu g C mu g(-1) C, where RF means research flight). These ratios were comparable to those obtained from controlled laboratory burns and suggested that the emissions sampled during RF01/F02/RF03/RF05 were dominated by the burning of grasses, RF08 by leaves, RF09A by needles, and RF09B by marsh grasses. These findings were further supported by the Delta galactosan/Delta levoglucosan ratios (RF01/RF02/RF03/RF05 = 0.067 +/- 0.004 mu g mu g(-1), RF08 = 0.085 +/- 0.009 mu g mu g(-1), and RF09A = 0.101 +/- 0.029 mu g mu g(-1)) obtained as well as by the ground-based fuel and filter sample analyses during RF01/RF02/RF03/RF05. Differences between Delta potassium/Delta levoglucosan ratios obtained for these prescribed fires vs. laboratory-scale measurements suggest that some laboratory burns may not accurately represent potassium emissions from prescribed burns. The Delta levoglucosan/Delta WSOC ratio had no clear dependence on smoke age or fire dynamics suggesting that this ratio is more dependent on the type of fuel being burned. Levoglucosan was stable over a timescale of at least 1.5 h and could be useful to help estimate the air quality impacts of biomass burning.

Journal Article

Abstract  BACKGROUND: Epidemiological studies have demonstrated associations between noise exposure and cardiovascular events. However, there have been few studies of possible underlying mechanisms.

OBJECTIVES: We examined the association between individual daytime noise exposure and heart rate variability (HRV).

METHODS: In a prospective panel study in Augsburg, Germany (March 2007-December 2008), 110 individuals participated in 326 electrocardiogram recordings with a mean duration of 6 hr. Five-minute averages of heart rate (HR) and HRV parameters were determined. Individual noise exposure was measured as A-weighted equivalent continuous sound pressure levels (L-eq). Effects were estimated using additive mixed models adjusted for long-and short-term time trends and physical activity. Due to nonlinear exposure-response functions, we performed piecewise linear analyses with a cut-off point at 65 dB(A).

RESULTS: Concurrent increases of 5dB(A) in L-eq < 65dB(A) were associated with increases in HR (percent change of mean value: 1.48%; 95% CI: 1.37, 1.60%) and the ratio of low-frequency (LF) to high-frequency (HF) power (4.89%; 95% CI: 3.48, 6.32%), and with decreases in LF (-3.77%; 95% CI: -5.49, -2.02%) and HF (-8.56%; 95% CI: -10.31, -6.78%) power. Standard deviation of normal-to-normal intervals (SDNN) was positively associated with concurrent noise < 65dB(A) (5.74%; 95% CI: 5.13, 6.36) but negatively associated with noise lagged by 5-15 min (-0.53% to -0.69%). Associations with cardiac function were less pronounced for noise >= 65dB(A), with some in opposite directions from associations with noise < 65dB(A). Concurrent associations were modified by sex and age.

CONCLUSIONS: Individual daytime noise exposure was associated with immediate changes in HRV, suggesting a possible mechanism linking noise to cardiovascular risk. Noise at lower levels may have health consequences beyond those resulting from "fight-or-flight" responses to high levels of noise.

Journal Article

Abstract  BACKGROUND: Few recent studies examined acute effects on health of individual chemical species in the particulate matter (PM) mixture, and most of them have been conducted in North America. Studies in Southern Europe are scarce. The aim of this study is to examine the relationship between particulate matter constituents and daily hospital admissions and mortality in five cities in Southern Europe.

METHODS: The study included five cities in Southern Europe, three cities in Spain: Barcelona (2003-2010), Madrid (2007-2008) and Huelva (2003-2010); and two cities in Italy: Rome (2005-2007) and Bologna (2011-2013). A case-crossover design was used to link cardiovascular and respiratory hospital admissions and total, cardiovascular and respiratory mortality with a pre-defined list of 16 PM10 and PM2.5 constituents. Lags 0 to 2 were examined. City-specific results were combined by random-effects meta-analysis.

RESULTS: Most of the elements studied, namely EC, SO4(2-), SiO2, Ca, Fe, Zn, Cu, Ti, Mn, V and Ni, showed increased percent changes in cardiovascular and/or respiratory hospitalizations, mainly at lags 0 and 1. The percent increase by one interquartile range (IQR) change ranged from 0.69% to 3.29%. After adjustment for total PM levels, only associations for Mn, Zn and Ni remained significant. For mortality, although positive associations were identified (Fe and Ti for total mortality; EC and Mg for cardiovascular mortality; and NO3(-) for respiratory mortality) the patterns were less clear.

CONCLUSIONS: The associations found in this study reflect that several PM constituents, originating from different sources, may drive previously reported results between PM and hospital admissions in the Mediterranean area.

Journal Article

Abstract  Relatively little is known about long term effects of wood smoke on population health. A wood combustion marker - levoglucosan - was measured using a standardized sampling and measurement method in four European study areas (Oslo, The Netherlands, Munich/Augsburg, Catalonia) to assess within and between study area spatial variation. Levoglucosan was analyzed in addition to: PM2.5, PM2.5 absorbance, PM10, polycyclic aromatic hydrocarbons (PAH), nitrogen oxides (NOx), elemental and organic carbon (EC/OC), hopanes, steranes and elemental composition. Measurements were conducted at street, urban and regional background sites. Three two-week samples were taken per site and the annual average concentrations of pollutants were calculated using continuous measurements at one background reference site. Land use regression (LUR) models were developed to explain the spatial variation of levoglucosan. Much larger within than between study area contrast in levoglucosan concentration was found. Spatial variation patterns differed from other measured pollutants: PM2.5, NOx and EC. Levoglucosan had the highest spatial correlation with ΣPAH (r=0.65) and the lowest with traffic markers - NOx, Σhopanes/steranes (r=-0.22). Levoglucosan concentrations in the cold (heating) period were between 3 and 20 times higher compared to the warm period. The contribution of wood-smoke calculated based on levoglucosan measurements and previous European emission data to OC and PM2.5 mass was 13 to 28% and 3 to 9% respectively in the full year. Larger contributions were calculated for the cold period. The median model R(2) of the LUR models was 60%. The LUR models included population and natural land related variables. In conclusion, substantial spatial variability was found in levoglucosan concentrations within study areas. Wood smoke contributed substantially to especially wintertime PM2.5 OC and mass. The low to moderate correlation with PM2.5 mass and traffic markers offers the potential to assess health effects of wood smoke separate from traffic-related air pollution.

Journal Article

Abstract  Traffic is considered one of the major polluting sectors and as a consequence a significant cause for the measured exceedances of ambient air quality limit values mainly in urban areas. The Greater Athens Area (located in Attica), the most populated area in Greece, faces severe air pollution problems due to the combination of high road traffic emissions, complex topography and local meteorological conditions. Even though several efforts were made to construct traffic emission inventories for Greece and Attica, still there is not a spatially and temporally resolved one, based on data from relevant authorities and organisations. The present work aims to estimate road emissions in Greece and Attica based on the top down approach. The programme COPERT 4 was used to calculate the annual total emissions from the road transport sector for the period 2006-2010 and an emission inventory for Greece and Attica was developed with high spatial (6×6km(2) for Greece and 2×2km(2) for Attica) and temporal (1-hour) resolutions. The results revealed that about 40% of national CO2, CO, VOC and NMVOC values and 30% of NOx and particles are emitted in Attica. The fuel consumption and the subsequent reduction of annual mileage driven in combination with the import of new engine anti-pollution technologies affected CO2, CO, VOC and NMVOC emissions. The major part of CO (56.53%) and CO2 (66.15%) emissions was due to passenger cars (2010), while heavy duty vehicles (HDVs) were connected with NOx, PM2.5 and PM10 emissions with 51.27%, 43.97% and 38.13% respectively (2010). The fleet composition, the penetration of diesel fuelled cars, the increase of urban average speed and the fleet renewal are among the most effective parameters towards the emission reduction strategies.

Journal Article

Abstract  BACKGROUND: Elevated pediatric asthma morbidity has been observed in rural US communities, but the role of the ambient environment in exacerbating rural asthma is poorly understood.

OBJECTIVES: To investigate associations between particulate matter less than 2.5μm in diameter (PM2.5) and pediatric asthma exacerbations in an agricultural community of Washington State.

METHODS: School-aged children with asthma (n=58) were followed for up to 25 months with repeated measures of respiratory health. Asthma symptoms and quick-relief medication use were assessed biweekly through phone administered surveys (n=2023 interviews). In addition, subjects used home peak flow meters on a daily basis to measure forced expiratory volume in one second (FEV1) (n=7830 measurements). Regional PM2.5 was measured at a single air monitor located centrally in the study region. To assess relationships between PM2.5 and these outcomes we used linear regression with generalized estimating equations, adjusting for meteorological and temporal confounders. Effect modification by atopy was explored as well.

RESULTS: An interquartile increase (IQR) in weekly PM2.5 of 6.7μg/m(3) was associated with an increase in reported asthma symptoms Specific symptoms including wheezing, limitation of activities, and nighttime waking displayed the strongest associations. FEV1 as a percent of predicted decreased by 0.9% (95%CI: -1.8, 0.0) for an IQR increase in PM2.5 one day prior, and by 1.4% (95%CI: -2.7, -0.2) when restricted to children with atopic asthma.

CONCLUSIONS: This study provides evidence that PM2.5 in an agricultural setting contributes to elevated asthma morbidity. Further work on identifying and mitigating sources of PM2.5 in the area is warranted.

Journal Article

Abstract  The aim of the study was to evaluate the risk of DNA damage in lymphocytes of pregnant women with respect to hormonal and nutritional status and to air pollution in Lesser Poland. The study was performed on 39 healthy pregnant women. The oxidative DNA damage, alkali-labile sites and uracil in DNA of lymphocytes were measured by using the comet assay. The concentration of 17beta-estradiol, progesterone, DHEA, cholesterol, vitamin B12 and folates were determined. Dietary data were assembled from food diaries. Voivodeship Inspectorate for Environmental Protection in Krakow using automatic pollution monitoring system provided the air pollution information, such as concentrations of PM10, PM2.5, NO, NO2, SO2, CO and O3. Many statistical correlations between DNA damage and air pollutants concentration were found however their biological meaning is still to be explained. It should be taken under consideration, that the protective effect of air pollutants is a result of hormesis, as the measured amounts of air pollutants during the study did not exceed the admissible levels. There was found no diet-and air pollution interaction.

Journal Article

Abstract  The relationship between external exposure and internal doses of polycyclic aromatic hydrocarbons (PAHs) has not been established for people living in industrial areas. This study was carried out to estimate the relationship between particle-phase PAH exposure and urinary 1-hydroxypyrene (1-OHP) levels among the adults living near a large petrochemical complex in Mailiao, Taiwan. We measured urinary 1-OHP in 781 residents above 35 years old and PM2.5 PAHs within a 20-km radius downwind from the petrochemical complex. Urinary 1-OHP was analyzed by high performance liquid chromatography, while 16 ambient particle-phase PAHs were measured by gas chromatography mass spectrometry. External exposures to individual PAHs at each study subject's address were estimated by kriging interpolation from air sampling results and regressed against the subjects' urinary 1-OHP levels, adjusting for confounding factors. The study population's urinary 1-OHP levels ranged from 0.001 to 3.005μmol/mol-creatinine with significantly higher levels for females, grilled food consumers, and residents living close to roads. All 16 particle-phase PAHs were present in the study area with total PAH concentrations ranging from 0.111 to 1.982ng/m(3). The spatial distribution of 4- and 5-ring PAHs identified high-concentration hotspots close to the complex in Mailiao. The multiple regression models showed that the adults' urinary 1-OHP levels were significantly correlated with 5 out of the 16 PAHs, including benzo[a]anthracene, benzo[k]fluoranthene, fluoranthene, pyrene, and dibenzo[a,h]anthracene; a 0.01ng/m(3) increase in the concentration of these 5 PAHs at the study subjects' addresses was associated with a 20% elevation in urinary 1-OHP levels (μg/g-creatinine). Emissions from a petrochemical complex can elevate particle-phase PAH concentrations in surrounding areas and increase the urinary 1-OHP levels of adults living nearby.

Journal Article

Abstract  The Société de pneumologie de langue française defines acute exacerbation of chronic obstructive pulmonary disease (AE COPD) as an increase in daily respiratory symptoms, basically duration ≥ 48h or need for treatment adjustment. Etiology of EA COPD are mainly infectious, viral (rhinovirus, influenzae or parainfluenzae virus, coronavirus, adenovirus and respiratory syncytial virus) or bacterial (Haemophilus influenzae, Streptococcus pneumoniae, or Moraxella catarrhalis). Pollutant exposure can also lead to AE COPD, such as NO2, SO2, ozone or particulates (PM10 and PM2.5). In 30% the etiology remains unknown. Differential diagnoses of AE COPD include infectious pneumonia, pneumothorax, acute heart failure and pulmonary embolism. Presences of signs of severity impose hospitalization: signs of respiratory distress, shock, acute confusion but also fragile patients, insufficient home support or absence of response to initial treatment. AE COPD treatments consist on increase in bronchodilators, chest physiotherapy, and antibiotics if sputum is frankly purulent. Systemic corticosteroids should not be systematic. Recommended dose is 0.5 mg/kg on short course (5-7 days). During hospitalization, oxygen supplementation and thromboprophylaxis could be prescribed. The main interest in non-invasive ventilation is persistent hypercapnia despite optimal medical management. During ambulatory management or hospitalization, clinical assessment at 48-72 h is mandatory.

Journal Article

Abstract  In order to find relationship between exposure to traffic and traffic-related air pollutants, pulmonary function tests and a detailed questionnaire were conducted among 3997 selected inhabitants of Warsaw (Poland) and 988 residents of rural areas. Advanced statistical analyses (including GRM models, correspondence analysis and parametrical tests) have been completed. Statistically significant differences between average percentages of predicted values of pulmonary function parameters were found. Among urban area inhabitants the values of FEV1, MEF50 and FEV1/FVC were statistically significant (p<0.05) lower compared with the residents of rural areas (in the non-smoking group this differences were strong (p<0.001)). General linear regression models indicated that residence in the vicinity of urban busy roads fosters a decrease of spirometric parameters. Physical activity however has a positive effect on pulmonary function (exemplified by FEV1) and allows to reduce part of the negative health effects of traffic-related emissions. The results of the presented study demonstrate that long-term residence under the influence of heavy traffic and high concentrations of traffic-related air pollutants reduces respiratory function parameters, which may result in increased bronchial hyperresponsiveness.

Journal Article

Abstract  For more than a century, clinicians have attempted to subdivide asthma into different phenotypes based on triggers that cause asthma attacks, the course of the disease, or the prognosis. The first phenotypes that were described included allergic asthma, intrinsic or nonallergic asthma, infectious asthma, and aspirin-exacerbated asthma. These phenotypes are being reviewed elsewhere in this issue of the journal. The present article focuses on developing and emerging clinical asthma phenotypes. First, asthma phenotypes that are associated with environmental exposures (occupational agents, cigarette smoke, air pollution, cold dry air); second, asthma phenotypes that are associated with specific symptoms or clinical characteristics (cough, obesity, adult onset of disease); and third, asthma phenotypes that are based on biomarkers. This latter approach is the most promising because it attempts to identify asthma phenotypes with different underlying mechanisms so that therapies can be better targeted toward disease-specific features and disease outcomes can be improved.

Journal Article

Abstract  Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease and a growing health concern, especially in children, because of its high prevalence and associated low quality of life. Genetic predisposition, environmental triggers, or interactions between them contribute to the pathophysiology of AD. Therefore, it is very important to identify and control risk factors from the environment in susceptible subjects for successful treatment and prevention. Both indoor and outdoor air pollution, which are of increasing concern with urbanization, are well-known environmental risk factors for asthma, whereas there is relatively little evidence in AD. This review highlights epidemiologic and experimental data on the role of air pollution in patients with AD. Recent evidence suggests that a variety of air pollutants, such as environmental tobacco smoke, volatile organic compounds, formaldehyde, toluene, nitrogen dioxide, and particulate matter, act as risk factors for the development or aggravation of AD. These air pollutants probably induce oxidative stress in the skin, leading to skin barrier dysfunction or immune dysregulation. However, these results are still controversial because of the low number of studies, limitations in study design, inaccurate assessment of exposure and absorption, and many other issues. Further research about the adverse effects of air pollution on AD will help to expand our understanding and to establish a better strategy for the prevention and management of AD.

Journal Article

Abstract  Metropolitan greenhouse gas and air emissions inventories can better account for the variability in vehicle movement, fleet composition, and infrastructure that exists within and between regions, to develop more accurate information for environmental goals. With emerging access to high quality data, new methods are needed for informing transportation emissions assessment practitioners of the relevant vehicle and infrastructure characteristics that should be prioritized in modeling to improve the accuracy of inventories. The sensitivity of light and heavy-duty vehicle greenhouse gas (GHG) and conventional air pollutant (CAP) emissions to speed, weight, age, and roadway gradient are examined with second-by-second velocity profiles on freeway and arterial roads under free-flow and congestion scenarios. For GHG and CAP upper and lower bounds of each factor show the potential variability which could exist in emissions assessments across U.S. cities. When comparing the effects of changes in these characteristics across U.S. cities against average characteristics of the U.S. fleet and infrastructure, significant variability in emissions is found to exist. GHGs from light-duty vehicles could vary by -2%-11% and CAP by -47%-228% when compared to the baseline. For heavy-duty vehicles the variability is -21%-55% and -32%-174%, respectively. The results show that cities should more aggressively pursue the integration of emerging big data into regional transportation emissions modeling, and the integration of these data is likely to impact GHG and CAP inventories and how aggressively policies should be implemented to meet reductions. A web-tool is developed to aide cities in improving emissions uncertainty.

Journal Article

Abstract  Excessive occurrence of microalgae on needles of gymnosperms was reported for the first time in the 1980s from the Scandinavian countries. Since then, it has been repeatedly encountered on needles from various European forest habitats. The abundance of these biofilms has been related to the climatic conditions, such as temperature and precipitation, as well as to the air pollution by nitrogen and sulfur oxides. Urban areas typically have relatively homogenous climates and profound variation in levels of air pollution. Therefore, variation in the occurrence of biofilms in localities within an urban area may be related to local anthropogenic air pollution. We investigated the abundance of biofilms occurring on needles of the common yew (Taxus baccata) in the city of Prague, Czech Republic. The biofilms were composed of algae, fungi and particulate matter. The cover area of the biofilms was marginally explained by a positive influence of short-term maximum atmospheric levels of nitrogen dioxide (NO2). The amounts of the microalgae were also positively influenced by short-term maximum NO2 levels. In addition, high atmospheric levels of particulate matter (PM10) were related to low abundance of algae. The microbial biofilms growing on widely cultivated conifers, such as the common yew, form one of the few commonly occurring natural communities in highly urbanized central areas of temperate European cities. Consequently, we propose that microscopic analysis of biofilms may be used as a rapid and cheap method to collect ecological data. Such data may be used in biomonitoring schemes illustrating the effects of anthropogenic air pollution on natural microcommunities in urban areas.

Journal Article

Abstract  BACKGROUND: Atmospheric pollution is a major public health concern. It can affect placental function and restricts fetal growth. However, scientific knowledge remains too limited to make inferences regarding causal associations between maternal exposure to air pollution and adverse effects on pregnancy. This study evaluated the association between low birth weight (LBW) and maternal exposure during pregnancy to traffic related air pollutants (TRAP) in São Paulo, Brazil.

METHODS AND FINDINGS: Analysis included 5,772 cases of term-LBW (<2,500 g) and 5,814 controls matched by sex and month of birth selected from the birth registration system. Mothers' addresses were geocoded to estimate exposure according to 3 indicators: distance from home to heavy traffic roads, distance-weighted traffic density (DWTD) and levels of particulate matter ≤10 µg/m3 estimated through land use regression (LUR-PM10). Final models were evaluated using multiple logistic regression adjusting for birth, maternal and pregnancy characteristics. We found decreased odds in the risk of LBW associated with DWTD and LUR-PM10 in the highest quartiles of exposure with a significant linear trend of decrease in risk. The analysis with distance from heavy traffic roads was less consistent. It was also observed that mothers with higher education and neighborhood-level income were potentially more exposed to TRAP.

CONCLUSIONS: This study found an unexpected decreased risk of LBW associated with traffic related air pollution. Mothers with advantaged socioeconomic position (SEP) although residing in areas of higher vehicular traffic might not in fact be more expose to air pollution. It can also be that the protection against LBW arising from a better SEP is stronger than the effect of exposure to air pollution, and this exposure may not be sufficient to increase the risk of LBW for these mothers.

Journal Article

Abstract  PURPOSE OF REVIEW: To review the pharmacological considerations and rationale for treating small-airway disease in asthma via the inhaled and systemic route, and to also directly address the comparison between small vs. large aerosol particles in the management of asthmatic patients.

RECENT FINDINGS: Airway inflammation in patients with asthma is predominantly present within the small airways and this region is the main contributor to airflow limitation. Assessing small-airway dysfunction has advanced in the last decade, allowing us to compare this region in disease to health and also in response to treatment. Recent pharmaceutical developments have led to inhaler devices with smaller aerosols and systemic biologic treatments, enabling therapeutic drug delivery to the distal lung regions. The question therefore is does targeting the small airways directly translate into health benefits for asthmatic patients with respect to an improvement in their disease control and quality of life?

SUMMARY: Studies now show that treating the peripheral airways with smaller drug particle aerosols certainly achieve comparable efficacy (and some studies show superiority) compared with large particles, a reduction in the daily inhaled corticosteroid dose, and greater asthma control and quality of life in real-life studies. Hence, the small airways should not be neglected when choosing the optimal asthma therapy.

Journal Article

Abstract  Two important reasons for China's air pollution are the high emission factors (emission per unit of product) of pollution sources and the high emission intensity (emissions per unit of GDP) of the industrial structure. Therefore, a wide variety of policy measures, including both emission abatement technologies and economic adjustment, must be implemented. To support such measures, this study used the production- and consumption-based emissions accounting approaches to simulate the SO2, NOx, PM2.5, and VOC emissions flows among producers and consumers. This study analyzed the emissions and GDP performance of 36 production sectors. The results showed that the equipment, machinery, and devices manufacturing and construction sectors contributed more than 50% of air pollutant emissions, and most of their products were used for capital formation and export. The service sector had the lowest emission intensities, and its output was mainly consumed by households and the government. In China, the emission intensities of production activities triggered by capital formation and export were approximately twice that of the service sector triggered by final consumption expenditure. This study suggests that China should control air pollution using the following strategies: applying end-of-pipe abatement technologies and using cleaner fuels to further decrease the emission factors associated with rural cooking, electricity generation, and the transportation sector; continuing to limit highly emission-intensive but low value-added exports; developing a plan to reduce construction activities; and increasing the proportion of service GDP in the national economy.

Journal Article

Abstract  Current knowledge of daytime HONO sources remains incomplete. A large missing daytime HONO source has been found in many places around the world, including polluted regions in China. Conventional understanding and recent studies attributed this missing source mainly to ground surface processes or gas-phase chemistry, while assuming aerosols to be an insignificant media for HONO production. We analyze in situ observations of HONO and its precursors at an urban site in Beijing, China, and report an apparent dependence of the missing HONO source strength on aerosol surface area and solar ultraviolet radiation. Based on extensive correlation analysis and process-modeling, we propose that the rapid daytime HONO production in Beijing can be explained by enhanced hydrolytic disproportionation of NO2 on aqueous aerosol surfaces due to catalysis by dicarboxylic acid anions. The combination of high abundance of NO2, aromatic hydrocarbons, and aerosols over broad regions in China likely leads to elevated HONO levels, rapid OH production, and enhanced oxidizing capacity on a regional basis. Our findings call for attention to aerosols as a media for daytime heterogeneous HONO production in polluted regions like Beijing. This study also highlights the complex and uncertain heterogeneous chemistry in China, which merits future efforts of reconciling regional modeling and laboratory experiments, in order to understand and mitigate the regional particulate and O3 pollutions over China.

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