Air pollution and health in urban areas

Indoor air quality and sick building syndrome symptoms in administrative office at public university

Sick Building Syndrome (SBS) is an illness among workers linked to time spent in a building. This study aimed to investigate the Indoor Air Quality (IAQ) and symptoms of Sick Building Syndrome (SBS) among administrative office workers. The IAQ parameters consist of ventilation performance indicators, and physical and chemical parameters were measured using specified instruments for three days during weekdays. The SBS symptoms were assessed by a questionnaire adopted from the Industry Code of Practice of Indoor Air Quality (ICOP-IAQ) 2010 among 19 employees from the office in East Coast Malaysia. Relationship between past symptoms and present symptoms which are draught (past symptoms) with feeling heavy headed (present symptoms) (r = 0.559, p < 0.05), room temperature too high (past symptoms) was highly correlated with feeling heavy headed (present symptoms) (r = 0.598, p < 0.01) and cough (present symptoms) (r = 0.596, p < 0.01). Room temperature (past symptoms) has a positive medium relationship with cough (present symptoms) (r = 0.477, p < 0.05) and scaling itching scalp or ears (present symptoms) has a relationship between stuffy bad air (r = 0.475, p < 0.05) and dry air (r = 0.536, p < 0.05). There was a significant association between RH with drowsiness (χ2 = 7.090, p = 0.049) and dizziness (χ2 = 7.090, p = 0.049). The association was found between temperature and SBS symptoms between temperature with headache (χ2 = 7.574, p = 0.051), feeling heavy-headed (χ2 = 8.090, p = 0.046), and skin rash itchiness (χ2 = 7.451, p = 0.044). Air movement also showed a positive association with symptoms of feeling heavy-headed (x2 = 8.726, p = 0.021). PM10 has positive significance with SBSS which are feeling heavy-headed (χ2 = 7.980, p = 0.023), and eyer's irritation (χ2 = 7.419, p = 0.038). The conclusion of this study showed that there were positive significant between temperature and relative humidity toward SBSS.

Functionalized Multiwalled Carbon Nanotubes for Highly Stable Room Temperature and Humidity-Tolerant Triethylamine Sensing

Triethylamine (TEA) poses a significant threat to our health and is extremely difficult to detect at the parts-per-billion (ppb) level at room temperature. Carbon nanotubes (CNTs) are versatile materials used in chemiresistive vapor sensing. However, achieving high sensitivity and selectivity with a low detection limit remains a challenge for pristine CNTs, hindering their widespread commercial application. To address these issues, we propose functionalized multiwalled CNTs (MWCNTs) with carboxylic acid (COOH)-based sensing channels for ultrasensitive TEA detection under ambient conditions. Advanced structural analyses confirmed the necessary modification of MWCNTs after functionalization. The sensor exhibited excellent sensitivity to TEA in air, with a superior noise-free signal (10 ppb), an extremely low limit of detection (LOD ≈ 0.8 ppb), excellent repeatability, and long-term stability under ambient conditions. Moreover, the response values became more stable, demonstrating excellent humidity resistance (40-80% RH). Notably, the functionalized MWCNT sensor exhibited improved response and recovery kinetics (200 and 400 s) to 10 ppm of TEA compared to the pristine MWCNT sensor (400 and 1300 s), and the selectivity coefficient for TEA gas was improved by approximately three times against various interferants, including ammonia, formaldehyde, nitrogen dioxide, and carbon monoxide. The remarkable improvements in TEA detection were mainly associated with the large specific surface area, abundant active sites, adsorbed oxygen, and other defects. The sensing mechanism was thoroughly explained by using Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and gas chromatography-mass spectrometry (GC-MS). This study provides a new platform for CNT-based chemiresistive sensors with high selectivity, low detection limits, and enhanced precision with universal potential for applications in food safety and environmental monitoring.

Graphene-based chemiresistive gas sensors

Gas sensors allow the monitoring of the chemical environment of humans, which is often crucial for their wellbeing or even survival. Miniaturization, reversibility, and selectivity are some of the key challenges for serial use of chemical sensors. This tutorial review describes critical aspects when using nanomaterials as sensing substrates for the application in chemiresistive gas sensors. Graphene has been shown to be a promising candidate, as it allows gas sensors to be operated at room temperature, possibly saving large amounts of energy. In this review, an overview is given on the general mechanisms for gas-sensitive semiconducting materials and the implications of doping and functionalization on the sensing parameters of chemiresistive devices. It shows in detail how different challenges, like sensitivity, response time, reversibility and selectivity have been approached by material development and operation modes. In addition, perspectives from the area of data analysis and intelligent algorithms are presented, which can further enhance these sensors' usability in the field.

Physisorption-Mediated Charge Transfer in TiS2 Nanodiscs: A Room Temperature Sensor for Highly Sensitive and Reversible Carbon Dioxide Detection

Real-time and high-performance monitoring of trace carbon dioxide (CO2) has become a necessity due to its substantial impact on the global climate, human health, indoor occupancy, and crop productivity. Two-dimensional materials such as transition metal dichalcogenides (TMDs) have gained significant interest in gas sensing applications owing to their intrinsically high surface-to-volume ratio. However, the research has been limited to prominent TMDs such as WS2 and MoS2. Specifically, the chemiresistive sensing performance of titanium disulfide (TiS2) has rarely been investigated. We present an electric-field-assisted TiS2 nanodisc assembly for the fabrication of a low-cost, low-power CO2 gas sensor based on charge transfer between physisorbed CO2 analyte molecules and TiS2 nanodiscs operating at room temperature. The physiochemical properties of the synthesized TiS2 nanodiscs were investigated via scanning electron microscopy (SEM), electron diffraction spectroscopy (EDS), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy. The fabricated sensor demonstrated an ultra-high sensor response of 60%, a fast response time of 37 s toward 500 ppm CO2 gas, and the lowest detection limit of 5 ppm under ambient conditions. The low adsorption energies and vdW interaction between CO2 molecules and TiS2 resulted in easy desorption, allowing the sensor to self-recover without the need for external stimuli, which is hardly been witnessed in other 2D material analogues. Furthermore, the sensor has excellent reproducibility and stability for successive analyte exposures, as well as excellent selectivity for CO2 over other interfering gases. This reported sensor based on 2D TMDs is the first of its type to integrate such a broad range of sensor characteristics (such as high sensor response and sensitivity, rapid response and recovery times, a high signal-to-noise ratio, and excellent selectivity at room temperature) into a single, revolutionary device for CO2 detection.

The effect of air quality parameters on new COVID-19 cases between two different climatic and geographical regions in Turkey

Different health management strategies may need to be implemented in different regions to cope with diseases. The current work aims to evaluate the relationship between air quality parameters and the number of new COVID-19 cases in two different geographical locations, namely Western Anatolia and Western Black Sea in Turkey. Principal component analysis (PCA) and regression model were utilized to describe the effect of environmental parameters (air quality and meteorological parameters) on the number of new COVID-19 cases. A big difference in the mean values for all air quality parameters has appeared between the two areas. Two regression models were developed and showed a significant relationship between the number of new cases and the selected environmental parameters. The results showed that wind speed, SO₂, CO, NO_X, and O₃ are not influential variable and does not affect the number of new cases of COVID-19 in the Western Black Sea area, while only wind speed, SO₂, CO, NO_X, and O₃ are influential parameters on the number of new cases in Western Anatolia. Although the environmental parameters behave differently in each region, these results revealed that the relationship between the air quality parameters and the number of new cases is significant.

Gas sensors based on the oxide skin of liquid indium

Various non-stratified two-dimensional (2D) materials can be obtained from liquid metal surfaces that are not naturally accessible. Homogenous nucleation on atomically flat interfaces of liquid metals with air produces unprecedented high-quality oxide layers that can be transferred onto desired substrates. The atomically flat and large areas provide large surface-to-volume ratios ideal for sensing applications. Versatile crucial applications of the liquid metal-derived 2D oxides have been realized; however, their gas-sensing properties remain largely underexplored. The cubic In₂O₃ structure, which is nonlayered, can be formed as an ultrathin layer on the surface of liquid indium during the self-limiting Cabrera-Mott oxidation process in the air. The morphology, crystal structure, and band structure of the harvested 2D In₂O₃ nanosheets from liquid indium are characterized. Sensing capability toward several gases, both inorganic and organic, entailing NO₂, O₂, NH₃, H₂, H₂S, CO, and Methyl ethyl ketone (MEK) are explored. A high ohmic resistance change of 1974% at 10 ppm, fast response, and recovery times are observed for NO₂ at an optimum temperature of 200 °C. The sensing fundamentals are investigated for NO₂, and its performances and cross-selectivity to different gases are analyzed. The NO₂ sensing response from room temperature to 300 °C has been measured and discussed, and stability after 24 hours of continuous operation is presented. The results demonstrate liquid metal-derived 2D oxides as promising materials for gas sensing applications.

Physiological status of House Sparrows (Passer domesticus) along an ozone pollution gradient

Mexico City is one of the most polluted cities in the world, and one in which air contamination is considered a public health threat. Numerous studies have related high concentrations of particulate matter and ozone to several respiratory and cardiovascular diseases and a higher human mortality risk. However, almost all of those studies have focused on human health outcomes, and the effects of anthropogenic air pollution on wildlife species is still poorly understood. In this study, we investigated the impacts of air pollution in the Mexico City Metropolitan Area (MCMA) on house sparrows (Passer domesticus). We assessed two physiological responses commonly used as biomarkers: stress response (the corticosterone concentration in feathers), and constitutive innate immune response (the concentration of both natural antibodies and lytic complement proteins), which are non-invasive techniques. We found a negative relationship between the ozone concentration and the natural antibodies response (p = 0.003). However, no relationship was found between the ozone concentration and the stress response or the complement system activity (p > 0.05). These results suggest that ozone concentrations in air pollution within MCMA may constrain the natural antibody response in the immune system of house sparrows. Our study shows, for the first time, the potential impact of ozone pollution on a wild species in the MCMA presenting the Nabs activity and the house sparrow as suitable indicators to assess the effect of air contamination on the songbirds.

The Significance of Software Engineering to Forecast the Public Health Issues: A Case of Saudi Arabia

In the recent years, public health has become a core issue addressed by researchers. However, because of our limited knowledge, studies mainly focus on the causes of public health issues. On the contrary, this study provides forecasts of public health issues using software engineering techniques and determinants of public health. Our empirical findings show significant impacts of carbon emission and health expenditure on public health. The results confirm that support vector machine (SVM) outperforms the forecasting of public health when compared to multiple linear regression (MLR) and artificial neural network (ANN) technique. The findings are valuable to policymakers in forecasting public health issues and taking preemptive actions to address the relevant health concerns.

Oxidative Damage of Aliphatic Amino Acid Residues by the Environmental Pollutant NO3·: Impact of Water on the Reactivity

The rate of oxidative damage of aliphatic amino acids and dipeptides by the environmental pollutant nitrate radical (NO₃^·) in an aqueous acidic environment was studied by laser flash photolysis. The reactivity dropped by a factor of about four for amino acid residues with secondary amide bonds and by a factor of up to nearly 20 for amino acid residues with tertiary amide bonds, compared with that in acetonitrile. According to density functional theory studies, the lower reactivity is due to protonation of the amide moiety, whereas in neutral water, hydrogen bonding with the amide should have little impact on the absolute reaction rate compared with that in acetonitrile. This finding can be rationalized by the high reactivity and broad reaction pattern of NO₃^·. Although hydrogen bonding involving the amide group raises the energies associated with some electron transfer processes, alternative low-energy pathways remain available so that the overall reaction rate is barely affected. The undiminished high reactivity of NO₃^· toward aliphatic amino acid residues in a neutral aqueous environment highlights the health-damaging potential of exposure to the combined air pollutants nitrogen dioxide (NO₂^·) and ozone (O₃).

The Adverse Effects of Air Pollution on the Eye: A Review

Air pollution is inevitably the result of human civilization, industrialization, and globalization. It is composed of a mixture of gases and particles at harmful levels. Particulate matter (PM), nitrogen oxides (NOx), and carbon dioxides (CO₂) are mainly generated from vehicle emissions and fuel consumption and are the main materials causing outdoor air pollution. Exposure to polluted outdoor air has been proven to be harmful to human eyes. On the other hand, indoor air pollution from environmental tobacco smoking, heating, cooking, or poor indoor ventilation is also related to several eye diseases, including conjunctivitis, glaucoma, cataracts, and age-related macular degeneration (AMD). In the past 30 years, no updated review has provided an overview of the impact of air pollution on the eye. We reviewed reports on air pollution and eye diseases in the last three decades in the PubMed database, Medline databases, and Google Scholar and discussed the effect of various outdoor and indoor pollutants on human eyes.

Increasing co-occurrence of fine particulate matter and ground-level ozone extremes in the western United States

Wildfires and meteorological conditions influence the co-occurrence of multiple harmful air pollutants including fine particulate matter (PM_2.5) and ground-level ozone. We examine the spatiotemporal characteristics of PM_2.5/ozone co-occurrences and associated population exposure in the western United States (US). The frequency, spatial extent, and temporal persistence of extreme PM_2.5/ozone co-occurrences have increased significantly between 2001 and 2020, increasing annual population exposure to multiple harmful air pollutants by ~25 million person-days/year. Using a clustering methodology to characterize daily weather patterns, we identify significant increases in atmospheric ridging patterns conducive to widespread PM_2.5/ozone co-occurrences and population exposure. We further link the spatial extent of co-occurrence to the extent of extreme heat and wildfires. Our results suggest an increasing potential for co-occurring air pollution episodes in the western US with continued climate change.

9,10-Phenanthrenequinone provokes dysfunction of brain endothelial barrier through down-regulating expression of claudin-5

Chronic exposure to diesel exhaust particle (DEP) is considered to provoke dysfunction of the blood-brain barrier, but the detailed molecular mechanism remains unclear. In this study, we investigated the toxic effects of five DEP components against human vascular cells and found that, among them, 9,10-phenanthrenequinone (9,10-PQ), a major tricyclic quinone in DEP, most potently elicits the cellular toxicities. Additionally, treatment with 9,10-PQ at its cytolethal concentrations (more than 2 μM) facilitated the production of reactive oxygen species (ROS), caspase activation, and DNA fragmentation in human brain microvascular endothelial (HBME) cells, inferring that high concentrations of 9,10-PQ elicit the cell apoptosis through the ROS-dependent mechanism. Measurement of trans-endothelial electrical resistance and paracellular permeability showed that treatment with sublethal concentrations (less than 1 μM) of 9,10-PQ elevates permeability across HBME cell monolayer. Immunofluorescence observation and Western blotting analysis also revealed that the 9,10-PQ treatment remarkably down-regulated the intercellular localization and expression of claudin-5 (CLDN5), a tight junctional protein that plays a key role in function of the blood-brain barrier, and the down-regulation was markedly recovered by pretreatment with a proteasome inhibitor Z-Leu-Leu-Leu-CHO. This result may indicate that sublethal concentrations of 9,10-PQ facilitate the dysfunction of the endothelial cell barrier through lowering in the expression and proteasomal proteolysis of CLDN5. The treatment with 9,10-PQ promoted nitric oxide (NO) production presumably through the induction of inducible NO synthase. In addition, the 9,10-PQ-mediated down-regulation of CLDN5 was ameliorated and deteriorated by pretreating with a scavenger and donor, respectively, of NO. Similarly to the 9,10-PQ treatment, treatment with a donor of peroxynitrite, a highly reactive oxidant formed by the reaction of NO and superoxide anion, resulted in the marked reduction of CLDN5 expression and elevation of 26S proteasome-based proteolytic activities. Thus, it is suggested that the formation of NO and peroxynitrite participates in the mechanism of brain endothelial cell barrier dysfunction elicited by 9,10-PQ.

Association with Ambient Air Pollutants and School Absence Due to Sickness in Schoolchildren: A Case-Crossover Study in a Provincial Town of Japan

The effect of ambient air pollutants and Asian dust (AD) on absence from school due to sickness has not been well researched. By conducting a case-crossover study, this study investigated the influence of ambient air pollutants and desert sand dust particles from East Asia on absence from school due to sickness. From November 2016 to July 2018, the daily cases of absence due to sickness were recorded in five elementary schools in Matsue, Japan. During the study period, a total of 16,915 absence cases were recorded, which included 4865 fever cases and 2458 cough cases. The relative risk of overall absence in a 10-μg/m³ increment of PM_2.5 and a 0.1-km^-1 of desert sand dust particles from East Asia were found with 1.28 (95%CI: 1.15-1.42) and 2.15 (1.04-4.45) at lag0, respectively. The significant influence of PM_2.5 persisted at lag5 and that of desert sand dust particles at lag2. NO₂ had statistically significant effects at lag2, lag3, and lag4. However, there was no evidence of a positive association of O_x and SO₂ with absence from school. These results suggested that PM_2.5, NO₂, and AD increased the risk of absence due to sickness in schoolchildren.

Asthma: New Integrative Treatment Strategies for the Next Decades

Asthma is a chronic disease whose main anatomical-functional alterations are grouped into obstruction, nonspecific bronchial hyperreactivity, inflammation and airway remodeling. Currently, the Global Initiative of Asthma 2020 (GINA 2020) suggests classifying it into intermittent cases, slightly persistent, moderately persistent and severely persistent, thus determining the correct guidelines for its therapy. In general, the drugs used for its management are divided into two groups, those with a potential bronchodilator and the controlling agents of inflammation. However, asthmatic treatments continue to evolve, and notable advances have been made possible in biological therapy with monoclonal antibodies and in the relationship between this disease and oxidative stress. This opens a new path to dietary and herbal strategies and the use of antioxidants as a possible therapy that supports conventional pharmacological treatments and reduces their doses and/or adverse effects. This review compiles information from different published research on risk factors, pathophysiology, classification, diagnosis and the main treatments; likewise, it synthesizes the current evidence of herbal medicine for its control. Studies on integrative medicine (IM) therapies for asthmatic control are critically reviewed. An integrative approach to the prevention and management of asthma warrants consideration in clinical practice. The intention is to encourage health professionals and scientists to expand the horizons of basic and clinical research (preclinical, clinical and integrative medicine) on asthma control.

Pulmonary functions of commercial tricyclists (Keke Napep riders) in Enugu State, Nigeria

Background

Tricyclists are continuously exposed to vehicle emissions and other environmental pollutants, due to the nature of their job and vehicle design, which may be hazardous to health. However, there is paucity of data on the pulmonary functions of commercial tricyclists in Nigeria, which should have provided insight into any relevant health concerns in this population, hence this study.

Objectives

This study evaluated the pulmonary functions of tricyclists, in comparison with those of age-matched non-tricyclists.

Methods

Two hundred and ten (210) [150 commercial tricyclists; 60 non-tricyclists] males (aged 20–65 years) participated in this unmatched case-control study in Enugu, Enugu state, Nigeria. Their pulmonary functions [Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV1), Peak Expiratory Flow Rate (PEFR)] were assessed using a computerized spirometer. Independent T-test and Pearson Chi-square were used to analyze data at a significant level of P<0.05.

Results

Cough (46.0%) and dust allergies (40.7%) were the commonest reported respiratory symptoms among tricyclists. There were significant differences in the FVC (P<0.001), FEV1 (P<0.001) and PEFR (P<0.001) between the two groups, with tricyclists showing lower pulmonary function values. FEV1/FVC was <70% with increased FVC in 83.3% of the tricyclists, suggesting restrictive pulmonary abnormalities.

Conclusion

Decreased pulmonary function values of commercial tricyclists in this study is suggestive of their predisposition to occupation-related pulmonary disorders, particularly the restrictive patterns.

Relationship between atmospheric pollutants and risk of death caused by cardiovascular and respiratory diseases and malignant tumors in Shenyang, China, from 2013 to 2016: an ecological research

Background:

Air pollutants and their pathogenic effects differ among regions and seasons. We aimed to explore the relationship between fine particulate matter (PM_2.5), sulfur dioxide (SO₂), and ozone-8 hours (O₃-8h) concentrations in heating and non-heating seasons and the associated death risk due to cardiovascular diseases (CDs), respiratory diseases (RDs), and malignant tumors.

Methods:

Data were collected in Shenyang, China, from April 2013 to March 2016. We analyzed the correlation or lagged effect of atmospheric pollutant concentration, meteorological conditions, and death risk due to disorders of the circulatory system, respiratory system, and malignant tumor in heating and non-heating seasons. We also used multivariate models to analyze the association of air pollutants during holidays with the death risk due to the evaluated diseases while considering the presence or absence of meteorological factors.

Results:

An increase in the daily average SO₂ concentration by 10 μg/m³ increased the death risk by CDs, which reached a maximum of 2.0% (95% confidence interval [CI]: 1.3%–2.7%) on lagging day 4 during the non-heating season and 0.2% (95% CI: 0.1%–0.4%) on lagging day 3 during the heating season. The risk of death caused by RDs peaked on lagging day 1 by 0.8% (95% CI: 0.4%–1.2%) during the heating season. An increase in O₃-8h concentration by 10 μg/m³ increased the risk of RD-related death on lagging day 2 by 1.0% (95% CI: 0.4%–1.7%) during the non-heating season, which was significantly higher than the 0.1% (95% CI: 0–0.9%) increase during the heating season. Further, an increase in the daily average PM_2.5 concentration by 10 μg/m³ increased the risk of death caused by RDs by 0.3% and 0.8% during heating and non-heating seasons, respectively, which peaked on lagging day 0. However, air pollution was not significantly associated with the risk of death caused by malignant tumors.

Conclusion:

Short-term exposure to PM_2.5, SO₂, and O₃ during the non-heating season resulted in higher risks of CD-related death, followed by RD-related death.

Assessment of Reducing Pollutant Emissions in Selected Heating and Ventilation Systems in Single-Family Houses

The article presents the results of a study aiming to select the optimal source of heat for a newly designed single-family home. Commercial software was used to compare heating and ventilation systems involving a bituminous coal boiler, a condensing gas boiler, a biomass boiler, a heat pump with water and glycol as heat transfer media. The effectiveness of natural ventilation, mechanical ventilation with a ground-coupled heat exchanger, and solar heater panels for water heating were evaluated. The analysis was based on the annual demand for useful energy, final energy, and non-renewable primary energy in view of the pollution output of the evaluated heating systems. The analysis revealed that the heat pump with water and glycol was the optimal solution. However, the performance of the heat pump in real-life conditions was below its maximum theoretical efficiency. The biomass boiler contributed to the highest reduction in pollutant emissions (according to Intergovernmental Panel on Climate Change Change guidelines, carbon dioxide emissions have zero value), but it was characterized by the highest demand for final energy. Mechanical ventilation with heat recovery was required in all analyzed systems to achieve optimal results. The introduction of mechanical ventilation decreased the demand for final energy by 10% to around 40% relative to the corresponding heating systems with natural ventilation.

Ginseng alleviates microbial infections of the respiratory tract: a review

The detrimental impact of air pollution as a result of frequent exposure to fine particles posed a global public health risk mainly to the pulmonary disorders in pediatric and geriatric population. Here, we reviewed the current literature regarding the role of ginseng and/or its components as antimicrobials, especially against pathogens that cause respiratory infections in animal and in vitro models. Some of the possible mechanisms for ginseng-mediated viral inhibition suggested are improvements in systemic and mucosa-specific antibody responses, serum hemagglutinin inhibition, lymphocyte proliferation, cell survival rate, and viral clearance in the lungs. In addition, ginseng reduces the expression levels of proinflammatory cytokines (IFN-γ, TNF-α, IL-2, IL-4, IL-5, IL-6, IL-8) and chemokines produced by airway epithelial cells and macrophages, thus preventing weight loss. In case of bacterial infections, ginseng acts by alleviating inflammatory cytokine production, increasing survival rates, and activating phagocytes and natural killer cells. In addition, ginseng inhibits biofilm formation and induces the dispersion and dissolution of mature biofilms. Most clinical trials revealed that ginseng, at various dosages, is a safe and effective method of seasonal prophylaxis, relieving the symptoms and reducing the risk and duration of colds and flu. Taken together, these findings support the efficacy of ginseng as a therapeutic and prophylactic agent for respiratory infections.

Two-Dimensional, Few-Layer MnPS3 for Selective NO2 Gas Sensing under Ambient Conditions

In this study, two-dimensional few-layer MnPS₃ is introduced as a selective and reversible NO₂ gas sensor in dry nitrogen (N₂) under ambient conditions. The solvent exfoliation technique is utilized to exfoliate bulk MnPS₃ into a few layers, which are further assembled as thin films by the vacuum filtration method. The films are subsequently transferred onto a sensing device and used for NO₂ sensing. Exfoliated MnPS₃ shows excellent sensitivity toward NO₂ gas with a low detection limit of a few tens of ppb at 25 °C. A sensitivity of 9530% is obtained at 35 ppm concentration of NO₂ with the theoretical limit of detection calculated to be ∼9.5 ppb. The sensor is highly selective toward NO₂ gas (with respect to interferents NO, NH₃, H₂, CO, CO₂, C₂H₂, and O₂) and is fully reversible under ambient conditions. The time constant is determined to be in the range of 30-160 s for adsorption and desorption processes. Raman spectroscopy reveals that the mechanism of sensing is based on charge transfer interactions between the sensor and analyte. This study opens up ways to fabricate gas sensors using few-layer metal phosphochalcogenides (MPX₃).

Health Impact Assessment (HIA) of a fluvial environment recovery project in a medium-sized Spanish town

INTRODUCTION

The Interdepartamental Public Health Plan of Catalonia (2014) seeks to enforce Health in All Policies (HiAP) at the regional and local levels. Within this context, the City Council of Sant Andreu de la Barca (SAB), the Metropolitan Area of Barcelona (MAB), and the Public Health Agency of Catalonia started a Health Impact Assessment (HIA) of an urbanistic redesign of the Llobregat fluvial area in SAB, the results of which are presented in this paper.

METHODOLOGY

In 2018, after a HIA screening, a prospective nonquantitative HIA was conducted. Politicians, professionals, and citizens participated in identifying potential impacts. Impacts were prioritized and linked to health determinants, scientific evidence, and potentially affected social groups. Afterwards, recommendations were formulated in order to improve the health impacts of the project. Finally, indicators were selected to evaluate HIA implementation.

RESULTS

The HIA was successfully implemented with the participation of technicians and citizens of SAB. The health impacts identified were mainly related to environmental, public safety, lifestyle, socioeconomic, and political contexts. Ten recommendations were defined to minimize the potential negative health impacts of the project, with six of them directly included and only one dismissed due to incompatibility.

CONCLUSION

A HIA was successfully carried out in the medium-sized town of Catalonia, promoting Health in all Policies at a local level and improving health impacts of an urbanistic project.

Stability and Sensing Enhancement by Nanocubic CeO2 with {100} Polar Facets on Graphene for NO2 at Room Temperature

Metal oxides with a polar surface interact strongly with polar NO₂ molecules, thus facilitating sensitive detection of NO₂. In this work, the composites comprising graphene and cubic CeO₂ nanoparticles with the {100} polar surface are prepared by a hydrothermal technique, and they exhibit fast response, excellent selectivity, stable recovery, and sensitive detection with a low detection limitation of 1 ppm for NO₂ at room temperature. According to the first-principle calculations, the adsorption energy of NO₂ on the CeO₂{100} polar surface is the most negative corresponding to the strongest interactions between them. The formation energy of oxygen vacancies (O_v) on the {100} polar plane is also negative, and the abundant O_v facilitates the adsorption of NO₂. The internal electric field near the polar surface promotes the charge separation and accelerates the charge exchange between NO₂ and the composites. In addition, graphene promotes electron transfer at the interface and improves the stability of the CeO₂{100} polar surface. The composites of graphene and metal oxides with a polar surface are excellent for NO₂ detection, and the discovery reveals a new sensing strategy.

Trace Metal Content and Health Risk Assessment of PM10 in an Urban Environment of León, Mexico

Trace metal concentrations in PM10 were measured in an urban–industrial site in León, Mexico in three different seasons. PM10 were collected in quartz fiber filters of 47 mm diameter using low volume equipment operating with a controlled flow of 5 L min−1 over 24 h. Mass concentrations were gravimetrically determined and it was found that PM10 samples showed values in excess of the Mexican standard and the established values by WHO during cold dry and warm dry seasons. Morphology of selected particles was studied by SEM-EDS analysis, and the elemental composition was determined. Collected samples were analyzed by atomic absorption spectrometry in order to quantify ambient air concentrations of some trace metals (Cu, Co, Zn, Cd, Fe, Mg, and Mn). Median concentrations of trace metals showed the maximum value for iron (3.079 μgm−3) and the minimum value for Cd (0.050 μgm−3) over the entire period. From the meteorological analysis, it was found that sources located SW and ESE of the sampling site contributed to the levels of trace metals in PM10 in the studied site. The health risk assessment found that the population of León is at increased lifetime risk of experiencing cancer because of exposure to these concentrations of PM10 and their trace metal content.

Low-Dose Carbon Monoxide Inhibits Rhinovirus Replication in Human Alveolar and Airway Epithelial Cells

Carbon monoxide (CO) and nitric oxide (NO) exhibit physiological properties that include the activation of guanylate cyclase. NO inhibits replication of rhinovirus (RV), a major cause of the common cold and exacerbation of bronchial asthma and chronic obstructive pulmonary disease. However, the anti-rhinoviral effects of CO remain unclear. This study investigated whether the exogenous application of low-dose CO could inhibit RV replication in human alveolar and airway epithelial cells. A549 human lung carcinoma cells with alveolar epithelial features and primary cultures of human tracheal epithelial (HTE) cells were pretreated with CO (100 ppm) and infected with a major group RV, type 14 RV (RV14). CO exposure reduced RV14 titers in the supernatants and RV RNA levels in A549 and HTE cells. The treatment with a guanylate cyclase inhibitor, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, reversed the inhibitory effects of CO exposure on RV14 replication in A549 cells. Pretreatment of A549 cells with 8-Br-cGMP, a cell-permeable cGMP analog, caused the decrease in RV14 replication, while CO exposure increased cGMP production. CO exposure also increased the expression levels of interferon (IFN)-γ mRNA and protein. In contrast, pretreatment with CO did not increase DNA fragmentation and did not reduce the expression of intercellular adhesion molecule-1, the RV14 receptor, or the number of acidic endosomes, through which RV RNA enters the cytoplasm. These findings suggest that low-dose CO may decrease RV14 replication in alveolar and airway epithelial cells. IFN-γ production, which is induced by CO exposure via guanylate cyclase activation-mediated cGMP production, may be involved in RV14 replication inhibition.

Recent progress and perspectives of gas sensors based on vertically oriented ZnO nanomaterials

Vertically oriented zinc oxide (ZnO) nanomaterials, such as nanorods (NRs), nanowires (NWs), nanotubes (NTs), nanoneedles (NNs), and nanosheets (NSs), are highly ordered architectures that provide remarkable properties for sensors. Furthermore, these nanostructures have fascinating features, including high surface-area-to-volume ratios, high charge carrier concentrations, and many surface-active sites. These features make vertically oriented ZnO nanomaterials exciting candidates for gas sensor fabrication. The development of efficient methods for the production of vertically oriented nanomaterial electrode surfaces has resulted in improved stability, high reproducibility, and gas sensing performance. Moving beyond conventional fabrication processes that include binders and nanomaterial deposition steps has been crucial, as the materials from these processes suffer from poor stability, low reproducibility, and marginal sensing performance. In this feature article, we comprehensively describe vertically oriented ZnO nanomaterials for gas sensing applications. The uses of such nanomaterials for gas sensor fabrication are discussed in the context of ease of growth, stability on an electrode surface, growth reproducibility, and enhancements in device efficiency as a result of their unique and advantageous features. In addition, we summarize applications of gas sensors for a variety of toxic and volatile organic compound (VOC) gases, and we discuss future directions of the vertically oriented ZnO nanomaterials.

Pathway analysis of a genome-wide gene by air pollution interaction study in asthmatic children

OBJECTIVES

We aimed to investigate the role of genetics in the respiratory response of asthmatic children to air pollution, with a genome-wide level analysis of gene by nitrogen dioxide (NO2) and carbon monoxide (CO) interaction on lung function and to identify biological pathways involved.

METHODS

We used a two-step method for fast linear mixed model computations for genome-wide association studies, exploring whether variants modify the longitudinal relationship between 4-month average pollution and post-bronchodilator FEV1 in 522 Caucasian and 88 African-American asthmatic children. Top hits were confirmed with classic linear mixed-effect models. We used the improved gene set enrichment analysis for GWAS (i-GSEA4GWAS) to identify plausible pathways.

RESULTS

Two SNPs near the EPHA3 (rs13090972 and rs958144) and one in TXNDC8 (rs7041938) showed significant interactions with NO2 in Caucasians but we did not replicate this locus in African-Americans. SNP-CO interactions did not reach genome-wide significance. The i-GSEA4GWAS showed a pathway linked to the HO-1/CO system to be associated with CO-related FEV1 changes. For NO2-related FEV1 responses, we identified pathways involved in cellular adhesion, oxidative stress, inflammation, and metabolic responses.

CONCLUSION

The host lung function response to long-term exposure to pollution is linked to genes involved in cellular adhesion, oxidative stress, inflammatory, and metabolic pathways.

Is Long-term Ambient Air Pollutant Exposure a Risk Factor for Irritable Bowel Syndrome in Children? A 12-year Longitudinal Cohort Study

Background/Aims

Recent studies suggest that air pollution may play a role in gastrointestinal disorders. However, the effect of long-term exposure to air pollution on childhood irritable bowel syndrome (IBS) is unclear. Hence, we conducted a nationwide cohort study to investigate the association between long-term air pollution exposure and the incidence and risk of IBS in Taiwanese children during 2000-2012.

Methods

We collected data from the Taiwan National Health Insurance Research Database, linked to the Taiwan Air Quality-Monitoring Database according to the insurant living area and the air quality-monitoring station locations. Children < 18 years old, identified from January 1st, 2000, were followed-up until IBS diagnosis or December 31st, 2012. The daily average air pollutant concentrations were categorized into 4 quartile-based groups (Q1-Q4). We measured the incidence rate, hazard ratios (HRs), and 95% confidence intervals for IBS stratified by the quartiles of air pollutant concentration.

Results

A total of 3537 children (1.39%) were diagnosed with IBS within the cohort during the follow-up period. The incidence rate for IBS increased from 0.84 to 1.76, from 0.73 to 1.68, from 0.85 to 1.98, and from 0.52 to 3.22 per 1000 person-years, with increase in the carbon monoxide, nitrogen dioxide, non-methane hydrocarbon, and methane quartile (from Q1 to Q4) exposure concentration, respectively. The adjusted HR for IBS increased with elevated carbon monoxide, nitrogen dioxide, non-methane hydrocarbon, and methane exposure in Q4 to 1.98, 2.14, 2.19, and 5.87, respectively, compared with Q1.

Conclusion

Long-term ambient air pollutant exposure is an environmental risk factor for childhood IBS.

Air Pollution and Angioedema

OBJECTIVE

To identify environmental factors that may precipitate angioedema.

STUDY DESIGN

Case series with chart review.

SETTING

An urban tertiary care medical center.

SUBJECTS AND METHODS

After institutional review board approval was obtained, a chart review of all patients who presented to Temple University Hospital with angioedema from January 2012 to December 2014 was performed. Patient demographics and hospital course were gathered. Environmental data on the dates of presentation, including precipitation, humidity, and air pollution, were obtained from regional Environmental Protection Agency online data banks and used for statistical analysis.

RESULTS

In total, 408 patients, representing 450 episodes of angioedema, met the inclusion criteria for the study. Most patients were female (58%), African American (74%), and on an angiotensin-converting enzyme inhibitor (ACE-I) upon presentation (61%). Days with unhealthy levels of air pollution were associated with an increased likelihood of angioedema presentation (odds ratio [OR], 1.82; confidence interval [CI], 1.01-3.30; P = .046). Subgroup analysis revealed that elevated ground-level ozone was the primary air pollutant significantly associated with angioedema presentations (OR, 4.95; CI 1.92-12.76; P = .0009). Higher ground-level ozone was also associated with ACE-I angioedema presentations (P = .017) but not with non-ACE-I angioedema presentations (P = .86). Air quality was not predictive of angioedema severity or need for intubation.

CONCLUSION

Angioedema is a complex, multifactorial disease resulting in potentially life-threatening complications. This is the first study to demonstrate that higher levels of air pollution, specifically ground-level ozone, are associated with significantly increased rates of angioedema episodes, although not severity.

Exposure measurement error in air pollution studies: A framework for assessing shared, multiplicative measurement error in ensemble learning estimates of nitrogen oxides

BACKGROUND

Increasingly ensemble learning-based spatiotemporal models are being used to estimate residential air pollution exposures in epidemiological studies. While these machine learning models typically have improved performance, they suffer from exposure measurement error that is inherent in all models. Our objective is to develop a framework to formally assess shared, multiplicative measurement error (SMME) in our previously published three-stage, ensemble learning-based nitrogen oxides (NO_x) model to identify its spatial and temporal patterns and predictors.

METHODS

By treating the ensembles as an external dosimetry system, we quantified shared and unshared, multiplicative and additive (SUMA) measurement error components in our exposure model. We used generalized additive models (GAMs) with a smooth term for location to identify geographic locations with significantly elevated SMME and explain their spatial and temporal determinants.

RESULTS

We found evidence of significant shared and unshared multiplicative error (p < 0.0001) in our ensemble-learning based spatiotemporal NO_x model predictions. Unshared multiplicative error was 26 times larger than SMME. We observed significant geographic (p < 0.0001) and temporal variation in SMME with the majority (43%) of predictions with elevated SMME occurring in the earliest time-period (1992-2000). Densely populated urban prediction regions with complex air pollution sources generally exhibited highest odds of elevated SMME.

CONCLUSIONS

We developed a novel statistical framework to formally evaluate the magnitude and drivers of SMME in ensemble learning-based exposure models. Our framework can be used to inform building future improved exposure models.

The short-term effects of air pollutants on hospitalizations for respiratory disease in Hefei, China

Previous studies have shown that ambient air pollution is associated with respiratory morbidity. However, the effects of air pollutants on health have rarely been studied in China. Our study aimed to estimate the short-term effects of particulate air pollutants on hospitalizations for three types of respiratory disease: pneumonia, chronic obstructive pulmonary disease (COPD), and asthma. We collected data on daily admissions for patients with each disease from the New Rural Cooperative Medical System (NRCMS) in Hefei, China. Daily records of air pollutants and meteorological data from January 2014 to March 2016 were also obtained. Distributed lag nonlinear models were employed in the analysis to evaluate the association between daily air pollutants and admissions. The highest effect of each pollutant on COPD hospital admission was observed with PM_2.5 at lag 12 (RR = 1.068, 95% CI 1.017 to 1.121) and PM₁₀ at lag 10 (RR = 1.031, 95% CI 1.002 to 1.060), for an increase of 10 μg/m³ in concentrations of the pollutants. The short-term effects of PM₁₀ on asthma hospital admissions peaked at lag 12 (RR = 1.057, 95% CI 1.010 to 1.107). According to our stratified analysis, we found that the effects on COPD admission were more pronounced in the warm season than in the cold season, and the elderly (≥ 65 years) and females were more vulnerable to air pollution.

Air pollution and Parkinson's disease: A systematic review and meta-analysis up to 2018

BACKGROUND

Recent epidemiological findings investigate effects of exposure to air pollution on neurodegenerative disease. We performed a systematic review and meta-analysis to investigate the association between air pollution exposure and Parkinson's disease (PD).

METHODS

We performed an extensive literature search in PubMed and Google Scholar databases and further searched for unpublished results in conference abstracts until November 2018. We identified 102 unique studies referring to air pollution and PD, from which 15 were included in the meta-analyses. We applied random-effects models to combine risk estimates and investigated between studies heterogeneity. We assessed publication bias through plots and the Egger's test in cases of sufficient number of studies. We assessed associations accounting for multi-pollutant exposures and effect modification patterns by sex and smoking habits.

RESULTS

We identified 13 reports investigating associations of PD with long-term exposure to regulated air pollutants whilst two reported associations for short-term exposure to PM_2.5. The pooled relative risk (RR) for incidence of PD following an increase in long-term exposure for 10 μg/m³ in PM_2.5 was 1.06 (95% Confidence Interval (CI): 0.99, 1.14) and in NO₂ 1.01 (95%CI: 0.98, 1.03), while for 5 ppb increase in O₃ 1.01 (95% CI: 1.00, 1.02) and for 1 mg/m³ in CO 1.34 (95% CI: 0.85, 2.10); the pooled RR for a hospital admission due to PD after a 10 μg/m³ increase in PM_2.5 short-term exposure was 1.03 (95% CI: 1.01, 1.05). There was high heterogeneity between study-specific results for most of the analyses, attributed to different populations under study. Effects were robust to multi-pollutant adjustment while there were indications of higher particles' effects among non smokers.

CONCLUSIONS

We found weak evidence for an association between air pollution, mostly originating from traffic, and PD. Although meta-analysis increases power to detect small associations in rare outcomes, further research is needed to elaborate our suggestive associations. Such results are of public health significance since population aging in developed countries is expected to increase incidence of PD.

Associations of greenness, greyness and air pollution exposure with children's health: a cross-sectional study in Southern Italy

BACKGROUND

Due to the complex interplay among different urban-related exposures, a comprehensive approach is advisable to estimate the health effects. We simultaneously assessed the effect of "green", "grey" and air pollution exposure on respiratory/allergic conditions and general symptoms in schoolchildren.

METHODS

This study involved 219 schoolchildren (8-10 years) of the Municipality of Palermo, Italy. Data were collected through questionnaires self-administered by parents and children. Exposures to greenness and greyness at the home addresses were measured using the normalized difference vegetation index (NDVI), residential surrounding greyness (RSG) and the CORINE land-cover classes (CLC). RSG was defined as the percentage of buffer covered by either industrial, commercial and transport units, or dump and construction sites, or urban fabric related features. Two specific categories of CLC, namely "discontinuous urban fabric - DUF" - and "continuous urban fabric - CUF" - areas were found. Exposure to traffic-related nitrogen dioxide (NO₂) was assessed using a Land-Use Regression model. A symptom score ranging from 0 to 22 was built by summing affirmative answers to twenty-two questions on symptoms. To avoid multicollinearity, multiple Logistic and Poisson ridge regression models were applied to assess the relationships between environmental factors and self-reported symptoms.

RESULTS

A very low exposure to NDVI ≤0.15 (1st quartile) had a higher odds of nasal symptoms (OR = 1.47, 95% CI [1.07-2.03]). Children living in CUF areas had higher odds of ocular symptoms (OR = 1.49, 95% CI [1.10-2.03]) and general symptoms (OR = 1.18, 95% CI [1.00-1.48]) than children living in DUF areas. Children living in proximity (≤200 m) to High Traffic Roads (HTRs) had increased odds of ocular (OR = 1.68, 95% CI [1.31-2.17]) and nasal symptoms (OR = 1.49, 95% CI [1.12-1.98]). A very high exposure to NO₂ ≥ 60 μg/m³ (4th quartile) was associated with a higher odds of general symptoms (OR = 1.28, 95% CI [1.10-1.48]). No associations were found with RGS. A Poisson ridge regression model on the symptom score showed that children living in proximity to HTRs (≤200 m) had a higher symptoms score (RR = 1.09, 95% CI [1.02-1.17]) than children living > 200 m from HTRs. Children living in CUF areas had a higher symptoms score (RR = 1.11, 95% CI [1.03-1.19]) than children living in DUF areas.

CONCLUSIONS

Multiple exposures related to greenness, greyness (measured by CORINE) and air pollution within the urban environment are associated with respiratory/allergic and general symptoms in schoolchildren. No associations were found when considering the individual exposure to greyness measured using the RSG indicator.

Highly selective and reversible NO2 gas sensor using vertically aligned MoS2 flake networks

We demonstrate a highly selective and reversible NO₂ resistive gas sensor using vertically aligned MoS₂ (VA-MoS₂) flake networks. We synthesized horizontally and vertically aligned MoS₂ flakes on SiO₂/Si substrate using a kinetically controlled rapid growth CVD process. Uniformly interconnected MoS₂ flakes and their orientation were confirmed by scanning electron microscopy, x-ray diffraction, Raman spectroscopy and x-ray photoelectron spectroscopy. The VA-MoS₂ gas sensor showed two times higher response to NO₂ compared to horizontally aligned MoS₂ at room temperature. Moreover, the sensors exhibited a dramatically improved complete recovery upon NO₂ exposure at its low optimum operating temperatures (100 °C). In addition, the sensing performance of the sensors was investigated with exposure to various gases such as NH₃, CO₂, H₂, CH₄ and H₂S. It was observed that high response to gas directly correlates with the strong interaction of gas molecules on edge sites of the VA-MoS₂. The VA-MoS₂ gas sensor exhibited high response with good reversibility and selectivity towards NO₂ as a result of the high aspect ratio as well as high adsorption energy on exposed edge sites.

The neurotoxicity induced by PM2.5 might be strongly related to changes of the hippocampal tissue structure and neurotransmitter levels

Objective: The complex components of PM2.5 including metal elements transported through the blood brain barrier could induce nervous system damage. This study discusses the relationship between rats' learning and memory and changes in the hippocampal neuron histomorphology and neurotransmitter levels induced by PM2.5 exposure. Methods: Male rats were treated with different concentrations of PM2.5 by tracheal perfusion once per week for up to 12 weeks. After the rats were sacrificed, the main metal element contents (Al, Pb, Cu, Mn, As, Cr, Cd, and Ni) of the blood and whole hippocampus, levels of neurotransmitters released in the whole hippocampus and relative receptors, and changes in the hippocampal structure were detected. Results: The results showed that PM2.5 significantly reduced the cognitive learning abilities of rats. PM2.5 exposure increased the contents of hippocampal lead, manganese, and aluminum. The level of glutamic acid was increased in the hippocampal tissues of the 20 mg kg-1 group, in combination with the decreased N-methyl-d-aspartate glutamate receptor (NMDAR) and increased metabotropic glutamate receptor type1 (mGluR1) expression. Increased clearance, a mild disorder of arrangement, and mild edema could be observed in the rat hippocampal neurons treated with PM2.5. Conclusion: PM2.5-induced defects in learning and memory may be related to the morphological abnormalities of the hippocampus and the abnormal expression of neurotransmitters and their receptors.

Socioeconomic inequalities in health during the Great Recession: A scoping review of the research literature

Aims: The so-called ‘Great Recession’ in Europe triggered widespread concerns about population health, as reflected by an upsurge in empirical research on the health impacts of the economic crisis. A growing body of empirical studies has also been devoted to socioeconomic inequalities in health during the Great Recession. The aim of the current study is to summarise this health inequality literature by means of a scoping review. Methods: We have performed a scoping review of the research literature (English language) published in the years 2012–2017. Only empirical papers with (a) health status measured on the individual level, (b) information on socioeconomic position (i.e. employment status, educational level, income/wealth, and/or occupational class), and (c) data from European countries in both pre- and post-crisis years were considered relevant. In total, 49 empirical studies fulfilled these inclusion criteria. Results: The empirical findings in the 49 included studies predominantly show that socioeconomic inequalities in health either increased or remained stable from pre- to post-crisis years. Two-thirds (65%) of the studies found evidence of either increasing or partially increasing health inequalities. Thus, people in lower socioeconomic strata fared worse overall in terms of health during the Great Recession, compared to people with higher socioeconomic status. Conclusions: The Great Recession in Europe tends to be followed by increasing socioeconomic inequalities in health. Policymakers should take note of this finding. Widening socioeconomic inequalities in health is a major cause of concern, in particular if health deterioration among ‘vulnerable groups’ is caused by accelerating cumulative disadvantages.

Ultrasensitive and Fully Reversible NO2 Gas Sensing Based on p-Type MoTe2 under Ultraviolet Illumination

The unique properties of two-dimensional (2D) materials make them promising candidates for chemical and biological sensing applications. However, most 2D material sensors suffer from extremely long recovery time due to the slow molecular desorption at room temperature. Here, we report an ultrasensitive p-type molybdenum ditelluride (MoTe₂) gas sensor for NO₂ detection with greatly enhanced sensitivity and recovery rate under ultraviolet (UV) illumination. Specifically, the sensitivity of the sensor to NO₂ is dramatically enhanced by 1 order of magnitude under 254 nm UV illumination as compared to that in the dark condition, leading to a remarkable low detection limit of 252 ppt. More importantly, the p-type MoTe₂ sensor can achieve full recovery after each sensing cycle well within 160 s at room temperature. Finally, the p-type MoTe₂ sensor also exhibits excellent sensing performance to NO₂ in ambient air and negligible response to H₂O, indicating its great potential in practical applications, such as breath analysis and ambient NO₂ detection. Such impressive features originate from the activated interface interaction between the gas molecules and p-type MoTe₂ surface under UV illumination. This work provides a promising and easily applicable strategy to improve the performance of the gas sensors based on 2D materials.

Analysis of air quality in Dire Dawa, Ethiopia

Ambient air quality was monitored and analyzed to develop air quality index and its implications for livability and climate change in Dire Dawa, Ethiopia. Using survey research design, 16 georeferenced locations, representing different land uses, were randomly selected and assessed for sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbon dioxide (CO₂), carbon monoxide (CO),volatile organic compounds (VOCs), and meteorological parameters (temperature and relative humidity). The study found mean concentrations across all land uses for SO₂ of 0.37 ± 0.08 ppm, NO₂ of 0.13 ± 0.17 ppm, CO₂ of 465.65 ± 28.63 ppm, CO of 3.35 ± 2.04 ppm, and VOCs of 1850.67 ± 402 ppm. An air quality index indicated that ambient air quality for SO₂ was very poor, NO₂ ranged from moderate to very poor, whereas CO rating was moderate. Significant positive correlations existed between temperature and NO₂, CO₂, and CO and between humidity and VOCs. Significant relationships were also recorded between CO₂ and NO₂ and between CO and CO₂. Poor urban planning, inadequate pollution control measure, and weak capacity to monitor air quality have implications for energy usage, air quality, and local meteorological parameters, with subsequent feedback into global climate change. Implementation of programs to monitor and control emissions in order to reduce air pollution will provide health, economic, and environmental benefits to the city.

IMPLICATIONS

The need to develop and implement emission control programs to reduce air pollution in Dire Dawa City is urgent. This will provide enormous economic, health, and environmental benefits. It is expected that economic effects of air quality improvement will offset the expenditures for pollution control. Also, strategies that focus on air quality and climate change present a unique opportunity to engage different stakeholders in providing inclusive and sustainable development agenda for Dire Dawa.

Cytotoxicity of Air Pollutant 9,10-Phenanthrenequinone: Role of Reactive Oxygen Species and Redox Signaling

Atmospheric pollution has been a principal topic recently in the scientific and political community due to its role and impact on human and ecological health. 9,10-phenanthrenequinone (9,10-PQ) is a quinone molecule found in air pollution abundantly in the diesel exhaust particles (DEP). This compound has studied extensively and has been shown to develop cytotoxic effects both in vitro and in vivo. 9, 10-PQ has been proposed to play a critical role in the development of cytotoxicity via generation of reactive oxygen species (ROS) through redox cycling. This compound also reduces expression of glutathione (GSH), which is critical in Phase II detoxification reactions. Understanding the underlying cellular mechanisms involved in cytotoxicity can allow for the development of therapeutics designed to target specific molecules significantly involved in the 9,10-PQ-induced ROS toxicity. This review highlights the developments in the understanding of the cytotoxic effects of 9, 10-PQ with special emphasis on the possible mechanisms involved.

Air pollution and admissions due to ST elevation myocardial infarction-a time-series study from northwest of Iran

We investigated the association between the levels of air pollutants and the number of daily admissions due to ST segment elevation myocardial infarction (STEMI) in a metropolitan in the northwest of Iran. Daily concentrations of common air pollutants were obtained for the greater city of Tabriz for a period of 2 years. These reports included sulfur dioxide (SO2), nitrogen dioxide (NO2), nitric oxide (NO), nitrogen byproducts (NOx), carbon monoxide (CO), ozone (O3), and particulate matters < 10 μm (PM10). The census of admissions for STEMI was retrieved for the same period from hospital registries. The association of daily variations in air pollutant levels and the daily number of STEMI admissions were investigated in a time-series analysis. In the multi-pollutant model adjusting for long-term trend, seasonality, and temperature, a significant association was found for 1-h [NO2] and 24-h [CO]. A marginally significant association was observed for 24-h [NO2] and 8-h [CO]. The 24-h [CO] had the strongest association with the number of admissions with STEMI. Maximum 1-h concentrations of NO2 on the same day and on the prior day as well as 24-h concentrations of CO on the prior day were independently associated with increased number of STEMI admissions. However, daily concentrations of SO2, NO, O3, and PM10 were not associated with the frequency of hospital admissions for STEMI.

Associations of short-term exposure to ambient air pollutants with emergency ambulance calls for the exacerbation of essential arterial hypertension

We investigated the association between daily emergency ambulance calls (EAC) for elevated blood pressure that occurred during the time intervals of 8:00-13:59, 14:00-21:59, and 22:00-7:59, and exposure to CO, PM₁₀, and ozone. We used Poisson regression to explore the association between the risk of EAC and short-term variation of pollutants, adjusting for seasonality and weather variables. Before noon, the risk was associated with an interquartile range (IQR) (7.9 μg/m³) increase in PM₁₀ at lag 2-4 days below the median (RR = 1.08, p = 0.031) and with an IQR (0.146 mg/m³) increase in CO at lag 6-7 below the median (RR = 1.05, p = 0.028). During 14:00-21:59, the risk was associated with an IQR (18.8 μg/m³) increase in PM₁₀ on the previous day below the median (RR = 1.04, p = 0.031). At night, EAC were negatively affected by lower O₃ (lag 0-2) below the median (per IQR decrease RR = 1.10, p = 0.018) and a higher PM₁₀ at lag 0-1 above the median for the elderly (RR = 1.07, p = 0.030).

UV-Activated MoS2 Based Fast and Reversible NO2 Sensor at Room Temperature

Two-dimensional materials have gained considerable attention in chemical sensing owing to their naturally high surface-to-volume ratio. However, the poor response time and incomplete recovery at room temperature restrict their application in high-performance practical gas sensors. Herein, we demonstrate ultrafast detection and reversible MoS₂ gas sensor at room temperature. The sensor's performance is investigated to NO₂ at room temperature, under thermal and photo energy. Incomplete recovery and high response time of ∼249 s of sensor are observed at room temperature. Thermal energy is enough to complete recovery, but it is at the expense of sensitivity. Further, under photo excitation, MoS₂ exhibits an enhancement in sensitivity with ultrafast response time of ∼29 s and excellent recovery to NO₂ (100 ppm) at room temperature. This significant improvement in sensitivity (∼30%) and response time (∼88%) is attributed to the charge perturbation on the surface of the sensing layer in the context of NO₂/MoS₂ interaction under optical illumination. Moreover, the sensor shows reliable selectivity toward NO₂ against various other gases. These unprecedented results reveal the potential of 2D MoS₂ to develop a low power portable gas sensor.

Blood lead level is a positive predictor of uremic pruritus in patients undergoing hemodialysis

Although uremic pruritus (UP) is a common and annoying symptom for end-stage renal disease patients on hemodialysis (HD) and peritoneal dialysis, its pathogenesis is poorly understood. However, systemic inflammation is one of the possible pathogenesis of UP, and blood lead level (BLL) has been noted to be associated with inflammation and nutritional status in long-term HD patients. There might be an interaction or association, therefore, between BLL and UP through systemic inflammation. We analyzed cross-sectional data among 866 participants. All of the 866 patients in this study were stratified into groups with low-normal (<10 μg/dL), high-normal (10-20 μg/dL), and abnormal BLLs (>20 μg/dL). The associations between UP and BLL and the clinical data were analyzed. Multivariate logistic regression demonstrated that HD duration, non-anuria, log ferritin, serum low-density lipoprotein, log BLL, high-normal BLL, and high BLL were associated with UP. In conclusion, BLL was positively associated with UP.

Short-Term Associations between Air Pollution Concentrations and Respiratory Health-Comparing Primary Health Care Visits, Hospital Admissions, and Emergency Department Visits in a Multi-Municipality Study

Acute effects of air pollution on respiratory health have traditionally been investigated with data on inpatient admissions, emergency room visits, and mortality. In this study, we aim to describe the total acute effects of air pollution on health care use for respiratory symptoms (ICD10-J00-J99). This will be done by investigating primary health care (PHC) visits, inpatient admissions, and emergency room visits together in five municipalities in southern Sweden, using a case-crossover design. Between 2005 and 2010, there were 81,019 visits to primary health care, 38,217 emergency room visits, and 25,271 inpatient admissions for respiratory symptoms in the study area. There was a 1.85% increase (95% CI: 0.52 to 3.20) in the number of primary health care visits associated with a 10 µg/m³ increase in nitrogen dioxide (NO₂) levels in Malmö, but not in the other municipalities. Air pollution levels were generally not associated with emergency room visits or inpatient admissions, with one exception (in Helsingborg there was a 2.52% increase in emergency room visits for respiratory symptoms associated with a 10 µg/m³ increase in PM₁₀). In conclusion, the results give weak support for short-term effects of air pollution on health care use associated with respiratory health symptoms in the study area.

Resveratrol inhibits urban particulate matter-induced COX-2/PGE2 release in human fibroblast-like synoviocytes via the inhibition of activation of NADPH oxidase/ROS/NF-κB

Human fibroblast-like synoviocytes (FLSs) play a role in joint synovial inflammation in rheumatoid arthritis (RA). Some evidence indicates that particulate matter (PM) in air pollution could contribute to the progression of RA. However, more research is needed to clarify this relationship. Up-regulation of cyclooxygenase (COX)-2 and its metabolite prostaglandin E₂ (PGE₂) are implicated in various inflammatory diseases. Resveratrol, a polyphenol found mainly in grapes and red wine, has antioxidant and anti-inflammatory activities. In the present study, we demonstrated that resveratrol reduced PM-induced COX-2/PGE₂ expression in human FLSs, and attenuated PM-enhanced NADPH oxidase activity and ROS generation. In addition, PM induced Akt, ERK1/2, or p38 MAPK activation, which was inhibited by resveratrol. Finally, we demonstrated that PM enhanced NF-κB p65 phosphorylation and the NF-κB promoter activity, which were reduced by pretreatment with a ROS inhibitor or resveratrol. Thus, we concluded that resveratrol functions as a suppressor of PM-induced inflammatory signaling pathways by inhibiting COX-2/PGE₂ expression.