Carbon Monoxide Research Articles

Carbon monoxide (CO) and particulate matter (PM) emissions during the combustion of wood pellets in a small-scale combustion unit – Influence of aluminum-(silicate-)based fuel additivation

The additivation of solid biofuels has proven to be an effective method for reducing total particulate matter (TPM) and carbon monoxide (CO) emissions, as well as for reducing ash-related problems related to, e.g., fouling and slagging. During the combustion with additives, potassium (K) released from the solid biofuels is bound into temperature-stable compounds, thus preventing the formation of inorganic (i.e., K-based) TPM. Simultaneously by reducing K in the gas phase, the inhibition of gas-phase oxidation (e.g., CO oxidation) due to interference of K within the existing radical pool is hindered. Particularly kaolin, an aluminum-silicate-based additive has proven effective in reducing not only TPM but also CO emissions. The mitigation effects on CO emissions have previously been reported mostly in a subordinate role and explanations are given in the form of hypotheses. In this study, seven additives (i.e., kaolin, kaolinite, meta-kaolinite, aluminum hydroxide, muscovite, muscovite coated with titanium dioxide and kalsilite, each at 0.3 wt%a.r.) were investigated during wood pellet combustion in a small-scale furnace (7.8 kW). For both CO and TPM emissions, kaolin proved to be most effective (i.e., −52% CO, −49% TPM), followed by muscovite, kaolinite, TiO2 coated muscovite, aluminum hydroxide, and meta-kaolinite.

Indoor Air Quality and Sick Building Syndrome among Caretakers in Childcare Centers

Sick Building Syndrome (SBS) refers to the health-related symptoms of exposure to an unhealthy microenvironment, especially poor indoor air quality This study investigated the associations of indoor air quality including particulate matter (PM10 and PM2 5), Carbon Dioxide (CO2), Carbon Monoxide (CO), Total Volatile Organic Compounds (TVOCs), and childcare center environment with SBS symptoms among caretakers. SBS was assessed using a self-reported questionnaire The prevalence of SBS was 77 78% among caretakers PM10 negatively correlated with CO2 (r=0 -558; p<0 01) PM10 levels were associated with any reported symptoms of SBS (OR=7 38; 95%CI 1 98 - 27 53), and upper respiratory symptoms (OR= 12 00; 95%CI 1 46 – 98 08) PM2 5 showed no association with SBS Using air refresher was associated with upper respiratory symptoms (OR=5 10; 95%CI 1 46 – 13 59), lower respiratory symptoms (OR=3 64; ; 95%CI 1.22 - 10.82).

Home Air Quality Monitoring System

Abstract: The quality of indoor air is a critical determinant of health and well-being, particularly Given the considerable amount of time individuals invest indoors. Recognizing the pivotal role of air quality, this paper introduces a novel Home Air Quality Monitoring System (HAQMS) designed to provide real-time, accurate assessments of air quality within residential environments. The HAQMS integrates advanced sensors and IoT (Internet of Things) technologies to detect and quantify a wide range of air pollutants, including particulate matter (PM2.5 and PM10), volatile organic compounds (VOCs), carbon dioxide (CO2), carbon monoxide (CO), and ozone (O3).The system architecture is delineated into three primary components: the sensor array for pollutant detection, a data processing unit employing advanced algorithms for real-time data analysis, and a user interface for displaying air quality metrics and providing health recommendations. Utilizing machine learning techniques, the system not only reports currentair quality but also predicts future air quality levels based on historical data and trend analysis. This predictive feature is pivotal for proactive measures in maintaining indoor air quality.

Home Air Quality Monitoring System

Abstract: The quality of indoor air is a critical determinant of health and well-being, particularly Given the considerable amount of time individuals invest indoors. Recognizing the pivotal role of air quality, this paper introduces a novel Home Air Quality Monitoring System (HAQMS) designed to provide real-time, accurate assessments of air quality within residential environments. The HAQMS integrates advanced sensors and IoT (Internet of Things) technologies to detect and quantify a wide range of air pollutants, including particulate matter (PM2.5 and PM10), volatile organic compounds (VOCs), carbon dioxide (CO2), carbon monoxide (CO), and ozone (O3).The system architecture is delineated into three primary components: the sensor array for pollutant detection, a data processing unit employing advanced algorithms for real-time data analysis, and a user interface for displaying air quality metrics and providing health recommendations. Utilizing machine learning techniques, the system not only reports currentair quality but also predicts future air quality levels based on historical data and trend analysis. This predictive feature is pivotal for proactive measures in maintaining indoor air quality.

Serological Biomarkers in Individuals with Interstitial Lung Disease after SARS-CoV-2 Infection and Association with Post-COVID-19 Symptoms

Patients with interstitial lung disease (ILD) represent a vulnerable population against an acute SARS-CoV-2 infection. It has been observed that up to 80% of patients with ILD can develop post-COVID-19 symptomatology one year after. This secondary analysis aimed to, 1, compare serological biomarkers before and after surpassing a SARS-CoV-2 infection in individuals with interstitial lung disease (ILD) and, 2, to compare serological biomarkers between ILD patients who develop and those who do not develop post-COVID-19 symptoms. Seventy-six patients with ILD (40.4% women, age: 69, SD: 10.5 years) who survived a SARS-CoV-2 infection participated. High-resolution computerized tomography (CT) of the lungs, two pulmonary function tests (forced vital capacity (FVC) and diffusion value of carbon monoxide (DLCO)) and fourteen serological biomarkers were collected before and after SARS-CoV-2 infection. Participants were asked for the presence of post-COVID-19 symptomatology a mean of twelve (SD: eight) months after infection. Sixty patients (79%) showed post-COVID-19 symptoms (mean: 3.5, SD 1.1), with fatigue (68.4%), dyspnea (31.5%), and concentration loss (27.6%) being the most prevalent. Creatine phosphokinase (CPK) was the only biomarker showing differences in our study. In fact, CPK levels were higher after the acute SARS-CoV-2 infection (mean difference: 41.0, 95%CI 10.1 to 71.8, p = 0.03) when compared to before the infection. Thus, CPK levels were also higher in ILD patients with post-COVID-19 fatigue (mean difference: 69.7, 95%CI 12.7 to 126.7, p = 0.015) or with post-COVID-19 dyspnea (mean difference: 34.8, 95%CI 5.2 to 64.4, p = 0.025) than those patients without these post-COVID-19 symptoms. No significant changes in CT or functional pulmonary tests were observed after COVID-19 in patients with ILD. In conclusion, patients with ILD exhibited an increase in CPK levels after SARS-CoV-2 infection, albeit no changes in other serological biomarkers were identified. Similarly, the presence of post-COVID-19 fatigue or dyspnea was also associated with higher CPK levels in ILD patients. Studies investigating long COVID mechanisms in vulnerable populations such as ILD are needed.

Differential effects of balloon pulmonary angioplasty on chronic thromboembolic pulmonary disease

BackgroundDecreased diffusing capacity of the lungs for carbon monoxide (DLco) is associated with microvascular damage in chronic thromboembolic pulmonary hypertension (CTEPH). Balloon pulmonary angioplasty (BPA) is an effective treatment for...

ANALYSIS OF THE NUMBER OF DEATHS DUE TO POISONING BY THE MOST COMMON POISONOUS SUBSTANCES IN THE LVIV REGION IN 2018-2023

Drunkenness is an acute social and cultural problem in Ukraine. Alcoholic poisoning occupies a leading position among household poisonings. Alcohol is the cause of more than 60% of all fatal poisonings. Each year, more than 40,000 people in Ukraine die from alcohol poisoning. Carbon monoxide poisoning also occupies a leading position, the statistics are very sad, adults die, children die. Poisoning with narcotics and psychotropic substances is a very urgent medical and social problem, which is far from being solved today. Aim of the work. To analyse the mortality rate due to poisoning by the most common types of poisons by age and sex of the deceased in Lviv and the region for the period 2018-2023. Materials and methods. In the work, a statistical analysis of expert conclusions from the archive of the Lviv Regional Bureau of Forensic Medicine for the period 2018-2023 was conducted. Results. The article provides quantitative indicators of cases of fatal poisoning, their prevalence trends, identifies the most common poisonous substances, and analyses mortality rates by age and sex. Conclusions. There is a downward trend in the total number of deaths due to poisoning. In 2023, the number of poisoning deaths will be almost halved compared to 2018. The most common poison is ethyl alcohol, 60% of people from the total number of poisonings, the second place in terms of number of deaths was carbon monoxide poisoning 21.5%, the third place was poisoning by narcotic substances 5.1%. Mortality due to poisoning in men is more than 5 times higher than in women, and men in their 40s and 50s die most often.

Management and outcomes of interstitial lung disease associated with anti-synthetase syndrome: A systematic literature review.

Anti-synthetase syndrome (ASS) is a chronic autoimmune condition, with interstitial lung disease (ILD) being a key feature. This systematic literature review (SLR; CRD42023416414) aimed to summarise treatments and outcomes of ILD associated with ASS (ASS-ILD). Databases were searched for articles discussing ASS-ILD management and outcomes, published 1946-September 2023.Screening and data-extraction were performed by two reviewers. Meta-analysis, using a random effects model, and paired t-tests, were undertaken where appropriate to evaluate post-treatment-change in Pulmonary Function Tests (PFT). Ten articles were included, comprising 514 patients: 67.8% female, mean age 52.4years (SD4.6). Baseline high-resolution computed tomography was documented in 447 patients (86.9%); the most common pattern was non-specific interstitial pneumonia (n = 220; 49.2%). The most common myositis-associated autoantibody was anti-Jo1 (48%) with 27.8% having associated anti-Ro52 antibodies.Pooled estimates, after meta-analysis, for baseline Forced Vital Capacity (FVC) was 60.8% predicted (SE 2.1), and Diffusion Capacity of Lungs for Carbon Monoxide (DLco) was 49.8% (SE 3.5). After one-year, pooled improvement in FVC was 14.1% from baseline (SE 3.1) and in DLco was 15.1% (SE 2.8). Paired t-test demonstrated significant overall improvement in FVC (p = 0.007) and DLco (p = 0.002).Patients receiving RTX had 12.2% improvement in FVC and 2.9% increase in DLco at one-year; for patients receiving CYC, there was 17% improvement and 6.3% increase, respectively. 28 deaths were reported. Our SLR, the first to summarise management and outcomes of ASS-ILD, found no conclusive difference between effectiveness of treatments. More robust trials are required to reduce morbidity and mortality resulting from ASS-ILD.

Microwave pyrolysis of polypropylene, and high-density polyethylene, and catalytic gasification of waste coffee pods to hydrogen-rich gas

Plastic waste poses a critical environmental challenge for the world. The proliferation of waste plastic coffee pods exacerbates this issue. Traditional disposal methods such as incineration and landfills are environmentally unfriendly, necessitating the exploration of alternative management strategies. One promising avenue is the pyrolysis in-line reforming process, which converts plastic waste into hydrogen. However, traditional pyrolysis methods are costly due to inefficiencies and heat losses. To address this, for the first time, our study investigates the use of microwave to enhance the pyrolysis process. We explored microwave pyrolysis for polypropylene (PP), high-density polypropylene (HDPE), and waste coffee pods, with the latter primarily comprising polypropylene. Additionally, catalytic ex-situ pyrolysis of coffee pod pyrolysis over a nickel-based catalyst was investigated to convert the evolved gas into hydrogen. The single-stage microwave pyrolysis results revealed the highest gas yield at 500 °C for HDPE, and 41 % and 58 % (by mass) for waste coffee pods and polypropylene at 700 °C, respectively. Polypropylene exhibited the highest gaseous yield, suggesting its readiness for pyrolytic degradation. Waste coffee pods uniquely produced carbon dioxide and carbon monoxide gases because of the oxygen present in their structure. Catalytic reforming of evolved gas from waste coffee pods using a 5 % nickel loaded activated carbon catalyst, yielded 76 % (by volume) hydrogen at 900 °C. These observed results were supported by elemental balance analysis. These findings highlight that two-stage microwave and catalysis assisted pyrolysis could be a promising method for the efficient management of waste coffee pods, particularly for producing clean energy.

Numerical Study on Chemical Kinetic Characteristics of Counterflow Diffusion Flame Extinction of Methane/Ammonia/Air Flame under High Pressure or Air Preheating Temperature

Green ammonia has become an increasingly popular fuel in recent years because of its combustion process without carbon oxide release. Adding ammonia to methane fuel for co-combustion has become one of the important research topics in the current combustion field. In the present study, the CH4/NH3/Air counterflow diffusion flame was taken as the research object, and Chemkin-2019 R3 software was used to explore and analyze the flame extinction limit and chemical kinetics characteristics under different ammonia mixing ratios, initial pressures, and air preheating temperatures. It was obtained that the flame extinction stretch rate was decreased by increasing the NH3 mole fraction in the CH4/NH3 mixed fuel. The increase in pressure or air preheating temperature would accelerate the chemical reaction rate of each component in the combustion process, increase the flame extinction limit, and counteract the “stretching effect” of the flame, thus restraining the flame extinguishing phenomenon. The results of a path analysis show that the formation and consumption of OH had an important influence on flame extinction in the chain reaction. The net reaction rate of OH increases with increasing the initial pressure or air preheating temperature, which leads to an increase in flame intensity, combustion stability, and the extinction limit. Furthermore, the function curve between the reaction influences the RIF factor and the stretch rate of the first-to-ten reactions, affected by the heat release of flame combustion, was drawn and quantitatively analyzed. Eventually, a sensitivity analysis of the flame under different working conditions was completed, which found that promoting the forward reaction R39 H + O2<=>O + OH also promotes the positive combustion as a whole when the flame was near extinction. The sensitivity coefficient of R39 in the CH4/NH3/Air flame increases with the growing initial pressure. The increasing air preheating temperature was capable of switching the reaction of R248 NH2 + OH<=>NH + H2O in the CH4/NH3/Air flame from an inhibiting reaction to a promoting reaction, while decreasing the sensitivity coefficient of inhibiting the forward reaction R10 O + CH3<=>H + CH2O, R88 OH + HO2<=>O2 + H2O, and R271 H + NO + M<=>HNO + M. Thus, the inhibition effect of flame extinction was weakened, and the positive progress of combustion was promoted.

Sulfur-doped Bi2O2CO3 nanosheet for enhanced visible-light-driven photocatalytic CO2 reduction to CO with ultra-high selectivity.

The photocatalytic reduction of carbon dioxide (CO2) has emerged as a compelling strategy for the conversion of renewable energy. However, the expeditious recombination of photogenerated charge carriers and the inadequate light absorption capabilities are currently predominant challenges. Herein, we developed a facile hydrothermal approach to synthesize a sulfur doped Bi2O2CO3 nanosheet with a tunable energy band structure designed to enhance visible light absorption. Our findings indicate that the incorporation of sulfur into the catalytic sites induces an electron sink effect, significantly improving the separation efficiency of photogenerated charge carriers. Consequently, this sulfur-doped Bi2O2CO3 catalyst exhibits a remarkable carbon monoxide (CO) yield of 16.64 μmol gcat-1 h-1 with nearly 100 % selectivity under illumination ranging from 420 to 780 nm. Through in-situ characterization techniques and theoretical calculations, it was revealed that sulfur-coordinated bismuth sites greatly enhance CO2 adsorption and decrease the energy barrier for critical intermediates formation (*COOH), thus selectively driving the reaction towards CO production. This work not only advances our understanding of mechanisms underlying photocatalytic reduction of CO2 on sulfur-doped bismuth-based catalysts but also sets a precedent for developing sophisticated photocatalytic systems for enhanced photoreduction reactions.

Transitioning to electric vehicles: Opportunities and challenges

The rapid improvements in India’s financial status and the inadequate transport system have significantly contributed to the surge in cars and two-wheelers. However, these motor vehicles, which predominantly run on petrol and diesel, pose a severe threat to the environment as they emit greenhouse gases such as carbon dioxide, carbon monooxide , Methane , sulphur oxides, and nitrous oxides and particulate matter etc.. These emissions contribute significantly to air pollution, posing a grave threat to human health, especially in urban areas. It is imperative to take action now to safeguard the planet from future catastrophes and ensure a safer environment for both current and future generations. One significant step we can take is transitioning to electric vehicles (EVs), which have far less environmental impact compared to those running on petrol and diesel. The Government of India has initiated several initiatives to promote EV usage. According to Statista, as of March 2023, there were 225,103,000 units operational EVs of all types in India .Electric vehicles emit significantly lower carbon emissions than gasoline vehicles, making them a crucial part of reducing environmental harm. According to recent studies, by 2030, EVs are expected to reduce nitrogen oxide by 17%, particulate matter by 18%, carbon monoxide by 18%, and carbon dioxide by 846.3 million tons. This paper high lights the transitioning towards zero emission public transport and the positive impacts of Electric vehicles on environment and the challenges before EV industry.

The environmental impact of Stubble burning

This paper aims to emphasize the environmental impacts of stubble burning, also known as 'parali' burning, and to raise awareness among farmers about its harmful effects. In Northern India, particularly after rice and wheat harvests, farmers often burn crop residue to clear fields quickly for the next season. This agricultural practice significantly contributes to air pollution and nutrient loss from the soil. Stubble burning releases greenhouse gases such as carbon dioxide, carbon monoxide, methane, nitrous oxides, and particulate matter into the atmosphere, posing various health risks to humans and animals. The stubble burning causes a significant increase in the air pollution and decrease in visibility. The government has implemented several policies and initiatives to educate farmers about the adverse effects of stubble burning. Recent studies have shown a decrease in stubble burning cases in 2024.

Mid-term outcomes of a smoking cessation program in hospitalized patients in Türkiye.

'Teachable moments', such as inpatient treatment periods, can be turned into opportunities for smokers to acquire healthy living behaviors. This study was conducted to evaluate the outcomes of smoking cessation interventions in an inpatient hospital setting. Data were collected for this single-arm prospective intervention cohort study between October 2021 and March 2022 from hospitalized patients at Recep Tayyip Erdoğan University Training and Research Hospital in Türkiye. Smoker patients received smoking cessation counseling and brief smoking cessation interventions during their hospitalization and were informed about how to apply to our hospital's smoking cessation outpatient clinic after discharge. They were followed via phone on the 3rd, 5th, and 7th day and the 1st, 3rd, 6th, and 12th month after their discharge, regarding their quit status as well as admissions to smoking cessation clinics. Quitters were confirmed by exhaled air carbon monoxide testing. Logistic regression analysis was performed to evaluate the presence of admission to the emergency department and family physicians at follow-up at 1st year. The model was adjusted in terms of age, sex, presence of malignancy, and education level. Of the 183 patients included in the study, 163 participants completed periodic follow-up during one year, with quit rate of 47.2%. The rate of anxiety was higher among non-quitters compared to quitters (9.4% vs 1.2%) (p=0.024). Non-quitters were 19 times more likely to have emergency department admissions (AOR=19.64; 95% CI: 8.08-47.68) and eight times more likely to have family doctor visits (AOR=8.43; 95% CI: 4.05-17.53) than quitters. This cessation program evaluated the quit rates of hospitalized patients in the first year and revealed that the rate of anxiety was higher in non-quitters compared to quitters. It would be an important approach to include psychiatric support in this practice.

Impact of the Ottawa model on opiate screening and smoking cessation in methadone-treated patients with opioid use disorder: A retrospective cohort analysis.

Approximately 60 million individuals worldwide used opioids in 2021, constituting 1.2% of the global adult population. This study aimed to evaluate the effectiveness of integrated treatment strategies for opioid use disorder and nicotine use disorder by assessing the impact of smoking cessation within a methadone treatment framework. In a retrospective cohort study, 53 methadone maintenance patients were divided into 16 treatment-seeking smokers (TSS) and 37 treatment-rejecting smokers (TRS) based on their participation in the Ottawa model for smoking cessation plus 16 weeks of varenicline treatment. Both groups received standard methadone treatment for 68 weeks. TSS were followed up for 44 weeks to assess smoking cessation outcomes, while TRS had none due to their lack of participation in smoking cessation treatment. The median age of the TSS group was 48 years, while that of the TRS group was 45.5 years. Males comprised 75% of TSS and 94.6% of the TRS. TSS exhibited an 83% decrease in positive opioid screen results compared to TRS (p=0.023). In TSS, peak smoking cessation success was observed at week 20, with 57% of participants maintaining carbon monoxide levels <5 ppm. The significant reduction in positive opioid screens and the high smoking cessation rate in the TSS group highlight the efficacy of combined treatment methods. This study underscores the advantages of integrating smoking cessation with methadone maintenance treatment, indicating that comprehensive approaches can substantially improve treatment outcomes.

Predicting air quality using random forest: A case study in Amman-Zarqa

The Spatiotemporal variability of air quality is influenced by various factors over time. The objectives of this research are to create prediction models for Carbon monoxide (CO) and Nitrogen dioxide (NO2) and determine the factors which that most impact CO and NO2 monthly using Random Forest Prediction. The methodology relies on Random Forest Prediction to predict air quality monthly in 2021, incorporating eight variables land surface temperature (LST), normalizeddifferencebuilt-upindex (NDBI), built-up index (BU index), normalized differencevegetation index (NDVI), digital elevation model (DEM), relative humidity (RH), wind speed (WS), and wind direction (WD). The results indicate that RH, elevation, WD, and LST are the most significant factors influencing CO concentrations, representing 33%, 24%, 12%, and 10% respectively at annual level in 2021. Similarly, WD, WS, RH, elevation and LST are the most importance factors impacting NO2 concentrations, representing 24%, 21%, 18%, 12%, and 10% respectively at an annual level in 2021. Furthermore, NDBI and BU index had the lowest impact in on both CO and NO2, with BU index showing a slightly higher percentage in NO2 models compared to CO models. Regarding cross-validation, the MAE values in CO models range from 0.11 to 0.18, and the RMSE values range from 0.14 to 0.23. Additionally, the MAE values in NO2 models ranges from 3.78 to 7.30, and RMSE values range from 4.93 to 9.23.

Cooperative Protein Dynamics of Heterotetrameric Hemoglobin from Scapharca inaequivalvis.

Hemoglobins achieve cooperative oxygen binding by diverse strategies based on different assemblies of globin subunits. Heterotetrameric hemoglobin from Scapharca inaequivalvis (HbII) consists of two AB-dimers, whose structure closely resembles that of homodimeric hemoglobin from the same organism (HbI). Herein, we investigated the structural dynamics of HbII following carbon monoxide (CO) dissociation using time-resolved resonance Raman (RR) spectroscopy. The observed spectra showed that the heme structure of the transient dissociated form of HbII was similar to that of HbI; however, the transition from the transient dissociated form to the equilibrium unligated form was faster for HbII than for HbI. Furthermore, the dependence of the time-resolved spectra on the yield of CO dissociation revealed that the transition became faster as the number of dissociated ligands increased from one to four. The positive correlation between the rate constants and number of dissociated ligands indicates that the structural transition of HbII following CO dissociation is cooperative.

5-Amino-1,2,4-triazol-3-one Degradation by Indirect Photolysis: A Density Functional Theory Study.

Sunlight irradiation induces formation of reactive oxygen species (superoxide, hydroperoxyl radical, singlet oxygen, etc.), which readily take part in degradation of environmental pollutants. Being a primary ingredient in a suite of insensitive munition formulations, NTO (5-nitro-1,2,4-triazol-3-one) can be released onto training range soils and reduced to ATO (5-amino-1,2,4-triazol-3-one) by soil bacteria or iron-contained minerals. ATO can be dissolved in surface water and groundwater due to its good water solubility and then undergo further decomposition. A detailed investigation of possible mechanisms for ATO decomposition in water induced by superoxide, hydroperoxyl radical, and singlet oxygen as pathways for ATO environmental degradation was performed by computational study at the PCM(Pauling)/M06-2X/6-311++G(d,p) level. Hydrolysis and degradation of ATO induced by superoxide are unlikely to occur due to the high activation energy or endergonicity of the processes. The hydroperoxyl radical causes rapid and reversible hydrogen transfer from ATO, while an attachment of the hydroperoxyl radical to ATO can induce decomposition of ATO, leading to its mineralization. Singlet oxygen shows a higher reactivity toward ATO than the hydroperoxyl radical. Decomposition of ATO was found to be a multistep process that begins with singlet oxygen attachment to the carbon atom of the C═N double bond. The intermediate that is formed undergoes recyclization, cycle opening, and sequential elimination of nitrogen gas, ammonia, and carbon(IV) oxide. Isocyanic acid, which arises intermediately, hydrolyzes into ammonia and carbon(IV) oxide. Calculated activation energies and high exergonicity of the studied processes support the contribution of singlet oxygen and the hydroperoxyl radical to ATO degradation into low-weight inorganic compounds in the environment.

Mimicking lightning-induced electrochemistry on the early Earth

To test the hypothesis that an abiotic Earth and its inert atmosphere could form chemically reactive carbon- and nitrogen-containing compounds, we designed a plasma electrochemical setup to mimic lightning-induced electrochemistry under steady-state conditions of the early Earth. Air-gap electrochemical reactions at air-water-ground interfaces lead to remarkable yields, with up to 40 moles of carbon dioxide being reduced into carbon monoxide and formic acid, and 3 moles of gaseous nitrogen being fixed into nitrate, nitrite, and ammonium ions, per mole of transmitted electrons. Interfaces enable reactants (e.g., minerals) that may have been on land, in lakes, and in oceans to participate in radical and redox reactions, leading to higher yields compared to gas-phase-only reactions. Cloud-to-ground lightning strikes could have generated high concentrations of reactive molecules locally, establishing diverse feedstocks for early life to emerge and survive globally.

Social cohesion as a modifier of joint air pollution exposure and incident dementia

Social cohesion can reduce stress, increase social interaction, and improve cognitive reserve. These social mechanisms may modify the effects of air pollution on dementia risk. This cohort study examines the potential moderating effect of social cohesion on associations between joint air pollution exposure and incident dementia leveraging data from 5112 community-dwelling adults ≥65 years of age enrolled in the National Health and Aging Trends Study (NHATS). Study participants were enrolled in 2011 and followed through 2018. We assigned 2010 residential census tract-level exposures to five air pollutants, particulate matter (PM) ≤ 10 μm in diameter, PM ≤ 2.5 μm in diameter, carbon monoxide, nitric oxide, and nitrogen dioxide, using the US Environmental Protection Agency's Community Multiscale Air Quality Modeling System. Dementia status was determined based on self- or proxy-reported dementia diagnosis or “probable dementia” according to NHATS cognitive screening tools. Participants' self-rated neighborhood social cohesion was evaluated based on three questions: neighbors knowing each other, being helpful, and trustworthy. Social cohesion was dichotomized at the median and stratified into high vs low social cohesion. Associations between air pollutants and incident dementia were assessed using quantile g-computation Cox proportional hazard models and stratified by high vs low social cohesion, adjusting for age, sex, education, partner status, urbanicity, annual income, race and ethnicity, years lived at current residence, neighborhood disadvantage index, and tract segregation. High social cohesion (HR = 1.20, 95 % CI = 0.98, 1.47). and air pollution (HR = 1.08, 95 % CI = 0.92, 1.28) were not associated with incident dementia alone. However, when stratified, greater joint air pollution exposure increased dementia risk among participants at low (HR = 1.34, 95 % CI = 1.04, 1.72), but not high (HR = 1.00, 95 % CI = 0.93, 1.06) social cohesion. Air pollution was a risk factor for dementia only when reported social cohesion was low, suggesting that social interaction may play a protective role, mitigating dementia risk via air pollution exposure.