Average Concentration Research Articles

Endothelial dysfunction in combination of occupational pathology of the respiratory system and atherosclerosis in coal industry workers

Introduction. The increasing prevalence of cardiovascular pathology among industrial workers determines the importance of studying not only occupational diseases, but also their combination with diseases of the circulatory system. Endothelial dysfunction is a key link in the pathogenesis of atherosclerosis. Evaluation of endothelial function indicators in occupational respiratory diseases in combination with atherosclerosis in workers of the coal mining industry is an urgent task. The study aims to consider the indicators of endothelial function in miners with occupational respiratory diseases in combination with atherosclerosis. Materials and methods. The authors have examined 88 miners with previously diagnosed occupational respiratory diseases (chronic dust bronchitis, anthracosilicosis, chronic obstructive pulmonary disease), 45 of them showed signs of atherosclerosis. There were two comparison groups without signs of atherosclerosis: 44 miners who work long-term in harmful working conditions, without lung pathology (control group) and 42 residents of Novokuznetsk who have never worked in harmful working conditions, and without lung pathology (unexposed group). Results. We found that miners with occupational respiratory diseases in combination with atherosclerosis had several forms of endothelial dysfunction: vasomotor (decreased synthesis of nitric oxide, increased endothelin-1 levels), hemostatic (increased levels of Willebrand factor), adhesive (increased levels of endothelial adhesion molecules sVCAM-1). The development of respiratory insufficiency in miners with occupational respiratory diseases increases endothelial dysfunction: miners with respiratory insufficiency have lower levels of nitric oxide (NO), higher levels of endothelin-1 and endothelial adhesion molecules sVCAM-1 than miners without respiratory insufficiency. There are correlations between indicators of endothelial function and production factors: with work experience in harmful working conditions, the level of the average concentration of coal-rock dust in the workplace and the frequency of exceeding the maximum permissible concentration of coal-rock dust. Limitations. The study is limited to a sample of workers in the main professions of coal mines who were examined at the Research Institute of Complex Hygiene Problems and Occupational Diseases, aged 40 to 54 years, with more than 15 years of experience working in underground dust conditions. Conclusion. Miners with occupational respiratory diseases in combination with atherosclerosis develop several forms of endothelial dysfunction: vasomotor, hemostatic, adhesive. The development of respiratory failure increases endothelial dysfunction. Ethics. This medical study involving a human as a subject was carried out in compliance with the Ethical principles presented in the latest version of the Helsinki Declaration, developed by the World Medical Association.

Radiological risk assessment of phosphate fertilizer application on farmlands in Ondo State, Nigeria

Abstract This study assesses the radiological risks associated with phosphate fertilizer application on farmlands in Ondo State, Nigeria. Soil samples from ten agricultural towns were analyzed for radionuclide concentrations using gamma-ray spectrometry. Primordial radionuclides such as 238U, 232Th, and 40K were examined, with 40K showing the highest concentration due to the potassium-rich nature of phosphate fertilizers. Spatial variability in radionuclide concentrations was observed, attributed to agricultural activities. Despite variations, mean activity concentrations were below global averages, indicating low radiological risks. Hazard indices, radium equivalent concentrations, and absorbed dose rates were all within safe limits. The annual effective dose equivalent was significantly lower than recommended levels, and excess lifetime cancer risk estimates were below the global average. The study emphasizes the importance of educating farmers on the potential adverse effects of radionuclides and recommends reducing the use of inorganic fertilizers to promote eco-friendly agricultural practices.

Chemical analysis and concentrations of cannabidiol substances used for refractory epilepsy in Chilean patients. An underestimated worldwide risk.

The purpose of this study is to analyze composition of HMS (homemade CBD), NLS (non-licensed commercial products), and bioequivalent CBD (BES) collected from Chilean patients that voluntary accepted to analyze the "CBD-substance." Samples were collected through an open invitation for different patients to anonymously and free of charge participate in the analysis of CBD oil. The analysis of the active principle was performed using High-Resolution Liquid Chromatography (HPLC). A total of 35 samples were collected between March 2020 and September 2021, including two BES, six NLS, and 27 HMS products. The BES had an average CBD concentration of 89.15 mg/mL and an average THC concentration of 0.015 mg/mL, which complied with the maximum THC levels required by regulatory authorities (<0.2% THC.). The NLS (six samples) exhibited significant variability in CBD concentrations, ranging from a maximum of 78.5 mg/mL to a minimum of 0.1 mg/mL, with an average of 25.41 mg/mL. The THC concentrations ranged from 0 mg/mL to 2.43 mg/mL with an average of 0.62 mg/mL. The HMS products exhibited even higher variations of CBD concentrations, ranging from 0 to a maximum of 6.6 mg/mL. THC concentrations were even more variable, ranging from 0 mg/mL to 388 mg/mL. The medical community and patients involved should be aware that Hemp products are not pure and/or innocuous. HMS are likely to have high levels of THC and very low CBD, far away from therapeutic doses of CBD. CBD used in epilepsy should be restricted to licensed products, especially in children where THC toxicity is much more harmful. The study analyzed three types of CBD (cannabidiol) oils: homemade, non-licensed, and bioequivalent. Homemade and non-licensed products showed nonacceptable variance of CBD and THC concentration (tetrahydrocannabinol), in some cases with 0 mgs of CBD and many beyond THC maximum accepted. The THC is another component found in cannabis and is responsible for the neurotoxic effects. Only bioequivalent products showed concentrations of CBD and THC acceptable for epilepsy treatment, therefore are the only products recommended for such purpose.

Clinical Study on the Induction of Psoriasis Flare-Ups by PM2.5 Air Pollutants via Immune Barrier Dysfunction.

This study explores the clinical correlation between the air pollutant PM2.5 and the induction of psoriasis flare-ups through the disruption of the immune barrier. Air quality data, the average mass concentration of the primary atmospheric pollutant PM2.5, and meteorological data spanning from November 2023 to March 2024 were gathered from 9 air quality monitoring stations situated within our city, courtesy of the local Meteorological Information Center. Psoriasis cases were sourced from our hospital's dermatology department, encompassing patients diagnosed and treated from November 2023 to March 2024 and residing within the city. From January 2023 to May 2024, aberrant expression of Th1 cells and Th2 cells was observed in psoriasis flare-up patients. Spearman correlation coefficient analysis revealed a positive correlation between PM2.5, PM10, and Th1 cells, and a negative correlation with Th2 cells, exhibiting significant differences (P < .05). Supplemental Figure 1 illustrates an increase in psoriasis flare-ups on the fifth day following a unit increase in PM2.5 concentration, with an excess risk (ER) value of 0.046 [95% confidence interval (CI): 0.137-0.893]. Conversely, after an increase of 1 unit of PM10, there was a decrease on the third and fourth days, followed by increases on the fifth, sixth, and seventh days, with ER values of 0.038 (95% CI: 0.013-0.067), 0.045 (95% CI: 0.019-0.073), 0.051 (95% CI: 0.034-0.078), 0.057 (95% CI: 0.045-0.083), and 0.061 (95% CI: 0.051-0.087), respectively. Air pollutant PM2.5 could potentially exacerbate psoriasis flare-ups by compromising the immune barrier, suggesting a plausible mechanism linked to the onset of this condition.

Temporal characterization of NOx and its relationship with O3 at a riverine site of Foshan

Nitrogen dioxide (NO2) is a crucial precursor of tropospheric O3. This study undertakes continuous measurements of nitric oxide (NO), nitrogen dioxide (NO2) and ozone (O3) at Shishan Port (SSP), a riverine site in Foshan, China. Oxides of nitrogen (NOx = NO + NO2) exhibit a distinct seasonality, with high concentrations in winter and low concentrations in summer. The daily average concentration of NOx is 30.5 ppb, with high concentrations in the evening and morning and low concentrations in the afternoon. The variation of the total oxidant (Ox = O3 + NO2) with the levels of NOx was examined to infer the atmospheric sources of Ox as the sum of a local contribution dependent on NOx and a regional contribution independent of NOx. The local contribution predominates during low wind speed and calm weather in winter. The case analysis of a typical NO2 pollution episode affirms that the increase of NO2 at night in SSP is significantly influenced by the exhaust emissions of passing ships, atmospheric diffusion conditions and the O3 concentration generated during the day. Due to the chemical coupling of NOx and O3, along with regional transport, the levels of NOx and O3 are inextricably linked yet complicated.

Machine Learning Based Inversion of Water Quality Parameters in Typical Reach of Rural Wetland by Unmanned Aerial Vehicle Images

Rural wetlands are complex landscapes where rivers, croplands, and villages coexist, making water quality monitoring crucial for the well-being of nearby residents. UAV-based imagery has proven effective in capturing detailed features of water bodies, making it a popular tool for water quality assessments. However, few studies have specifically focused on drone-based water quality monitoring in rural wetlands and their seasonal variations. In this study, Xiangfudang Rural Wetland Park, Jiaxin City, Zhejiang Province, China, was taken as the study area to evaluate water quality parameters, including total nitrogen (TN), total phosphors (TP), chemical oxygen demand (COD), and turbidity degree (TUB). We assessed these parameters across summer and winter seasons using UAV multispectral imagery and field sample data. Four machine learning algorithms were evaluated and compared for the inversion of the water quality parameters, based on the situ sample survey data and UAV multispectral images. The results show that ANN algorithm yielded the best results for estimating TN, COD, and TUB, with validation R2 of 0.78, 0.76, and 0.57, respectively; CatBoost performed best in TP estimation, with validation R2 and RMSE values of 0.72 and 0.05 mg/L. Based on spatial estimation results, the average COD concentration in the water body was 16.05 ± 9.87 mg/L in summer, higher than it was in winter (13.02 ± 8.22 mg/L). Additionally, mean TUB values were 18.39 Nephelometric Turbidity Units (NTU) in summer and 20.03 NTU in winter. This study demonstrates the novelty and effectiveness of using UAV multispectral imagery for water quality monitoring in rural wetlands, providing critical insights into seasonal water quality variations in these areas.

Assessment of the Environmental Impact of Fly Ash on the Concentration of Heavy Metals around Cement Company of Northern Nigeria

This study assessed the impact of Coal Fly Ash on the concentration of Heavy metals in water, soil, and vegetables (moringa and spinach) in the environment of Cement Company of Northern Nigeria. The samples collected were digested, and analysed for heavy metals concentration using Atomic Absorption Spectroscopy. The concentrations of heavy metals obtained in water samples were higher than the WHO/SON permissible limit, except for Cu and Zn which are below the standard limits. The average concentration of Pb, Mn, Cd, and Ni in all plant samples was higher than the permissible limit, except Cd in spinach sample. The roots of the spinach accumulate higher concentrations of heavy metals than the leaves and stem, while leaves of moringa accumulate higher than the roots and stem. The concentration of heavy metals in soil sample was below the WHO limit. Comparatively the plants samples have the highest concentrations of heavy metals than the water and soil samples. The coal fly ash from the Cement Company must have contributed to the significant concentration of Heavy metals in the environment making the water and plants from the study area unfit for human and animal consumption.

Assessment of dew harvesting as a sustainable water source and air quality indicator: a case study of Dhanbad, Jharkhand, India

ABSTRACT Dew formation takes place when atmospheric water vapor condenses on the surface which cools down due to radiation deficit. As it is a local phenomenon, its study gives information about the pollutants present in the atmosphere. Also, since dew formation is a natural phenomenon, and involves passive cooling, this can be a potential method for atmospheric water harvesting. The main intention of this present research work was the collection of dew samples and their analysis for yield and chemical composition. Dew samples were collected on a self-fabricated dew collection set up during the winter season. In total 30 dew samples were collected and analyzed for ionic constituents. The results were then compared to those of rain samples. The pH of dew was found to be in the range of 7-8.7, showing the neutral to alkaline nature of dew. Ionic compositions were higher in dew than in rain. While sulfate largely contributed to the ion composition of dew, nitrate was the least contributing ion. The average concentration for sulfate and nitrate in dew were found to be 0.55 and 0.03 meq/L, respectively. The average yield of dew was found to be 0.13L/m2. This yield value from the simplest of collection set-up ensures that dew can be considered as the potential water source with advanced condensing material and passive/active cooling in arid and semi-arid regions.

Prenatal exposure to ambient fine particulate matter and child lung function in the CANDLE cohort

Background Ambient fine particulate matter (PM2.5) exposure adversely impacts child airway health; however, research on prenatal PM2.5 exposure, and child lung function is limited. We investigated these associations in the ECHO-PATHWAYS Consortium, focusing on the role of exposure timing during different phases of fetal lung development. Methods We included 675 children in the CANDLE cohort born between 2007 and 2011 in Memphis, TN, USA. Prenatal exposure to ambient PM2.5 was estimated using a spatiotemporal model based on maternal residential history and averaged over established prenatal periods of lung development. Forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC) were measured by spirometry at age 8–9 years. We used linear regression and Bayesian Distributed Lag Interaction Models (BDLIM) to estimate associations between exposure and lung function z-scores, adjusting for maternal/child characteristics, prenatal/postnatal tobacco exposure, and birth year/season, and evaluating effect modification by child sex and allergic sensitization. Results The average ambient concentration of PM2.5 during pregnancy was 11.1 µg/m3 (standard deviation:1.0 µg/m3). In the adjusted linear regression and BDLIM models, adverse, but not statistically significant, associations were observed between exposure during the pseudoglandular (5–16 weeks of gestation) and saccular (24–36 weeks) phases of lung development and FEV1 and FVC. The strongest association was between a 2 μg/m3 higher concentration of PM2.5 during the saccular phase and FEV1 z-score (−0.176, 95% Confidence Interval [CI]: −0.361, 0.010). The FEV1/FVC ratio was not associated with PM2.5 in any exposure window. No effect modification by child sex or allergic sensitization was observed. Conclusions We did not find strong evidence of associations between prenatal ambient PM2.5 exposure and child lung function in a large, well-characterized study sample. However, there was a suggested adverse association between FEV1 and exposure during late pregnancy. The saccular phase of lung development might be an important window for exposure to PM2.5.

Pre-emptive use of glucose 5% as the standard drug solvent reduces hypernatremia in critically ill patients

Abstract Background Hypernatremia presents a common complication in ICU patients, associated with increased mortality and length of stay. This study investigates the effect of sodium chloride 0.9% compared with glucose 5% solution as the standard intravenous drug diluent on the prevalence of hypernatremia in a medical ICU. Methods This is a retrospective before-and-after study comparing two consecutive patient groups before- and after the standard drug solvent was changed from sodium chloride 0.9% to glucose 5% solution for compatible medications. A total of 265 adult COVID-19 patients admitted between October 2020 and March 2021 to the study intensive care unit were included, with 161 patients in the timeframe when sodium chloride 0.9% was employed as the standard drug solvent and 104 patients when glucose 5% was used. Routine sodium measurements from arterial and venous blood gases, along with heparinized lithium plasma, were analyzed. The daily sodium concentrations and the prevalence of severe hypernatremia (&amp;gt;150 mmol/l) were assessed during the first 8 days after ICU admission. Results Baseline characteristics were similar between the two groups. The cumulative volume of intravenous drug diluents was comparable. In the glucose 5% group, about half of the total drug diluent volume was glucose 5% (mean [SD]: 2251.6 [2355.4] mL), compared to 135.0 [746.9] mL (p &amp;lt; 0.001) in the control group. Average sodium concentrations diverged after day two, with the glucose 5% group consistently showing lower sodium levels (mean difference of approximately 2.5 mmol/L). Severe hypernatremia occurred less frequently in the glucose 5% group (6.6% vs. 20%). Conclusion Glucose 5% solution as the standard intravenous drug solvent significantly reduced sodium concentrations and the occurrence of severe hypernatremia. This simple modification in solvent choice may serve as a preventive strategy against hypernatremia in the ICU. Further prospective research is necessary to determine associated clinical outcomes. Trial registration: The trial was registered in the German Clinical Trials Register (DRKS00031877).

Source identification and human health risk to polychlorinated biphenyls in public parks and playground surface soils, southern zone of Ghana.

Polychlorinated biphenyls (PCBs) constitute a typical example of persistent organic pollutants (POPs) that have been detected globally in most environmental media. Soil serves as a critical reservoir for PCBs. This research is aimed at evaluating the potential exposure and associated health risks posed by soil-laden PCBs to humans during outdoor activities on public playgrounds and parks within the southern zone of Ghana where limited studies have been undertaken. Surface soils collected from 56 sites were processed and analyzed for seven indicator PCBs in soil particle sizes less than 63µm. A multi-residual analytical approach for the simultaneous analysis of PCBs and polycyclic aromatic hydrocarbons (PAHs) via gas chromatography tandem mass spectrometry was utilized. The results indicated that the concentration of PCBs ranged from 0.26 to 24.00µg/kg with an average total concentration of 1.86 ± 3.23µg/kg which is below the environment guideline threshold of 1.3mg/kg stipulated by the Canadian Council of Ministers for residential playgrounds/parkland soils. Multivariate analysis showed that the sources of the PCBs could be attributed predominantly to historical release, atmospheric transfer, and deposition. The excess lifetime cancer risks posed to children and adults are less than 10-6 thereby implying the existence of low carcinogenic health risk to the human populace within the southern zone of Ghana. Thus, the conduct of outdoor activities at the public playgrounds/parks within these highly populated areas poses no significant risk to human health.

Effects of gestational age on blood cortisol and prolactin levels during pregnancy in malaria endemic area.

The hormonal shift occurring in pregnant women is crucial for the outcome of pregnancy. We conducted a study in pregnant women living in a malaria endemic area to determine the potential effect of gestational age on the modulation of the endocrine system by cortisol and prolactin production during pregnancy. Primigravidae and multigravidae with a gestational age between 16-20 weeks were included in the study and followed up to delivery and 6-7 weeks thereafter. Venous blood was collected at scheduled visit: Visit 1 (V1; 16-20 weeks of amenorrhea), Visit 2 (V2; 28 ±1 weeks of pregnancy), Visit 3 (V3; 32 ±1 weeks of pregnancy), Visit4 (V4; delivery) and Visit5 (V5; 6-7 weeks after delivery). In addition, a cord blood sample was also collected during labour at delivery. Nulliparous and primiparous/multiparous non-pregnant women were enrolled in the control group. Cortisol and prolactin plasma concentrations were measured using ichroma II and i-chamber apparatus. Light microscopy was used to detect Plasmodium falciparum infections. A linear mixed-effects regression (LMER) model was used to assess the association between the variation of cortisol titres and prolactin levels during the pregnancy and the post-partum. Results showed that cortisol and prolactin levels in the peripheral blood were globally up-regulated during pregnancy. Concentrations of cortisol during follow-up was significantly higher in primigravidae than in multigravidae during the whole pregnancy (p<0.024). Moreover, the level of prolactin which was higher before delivery in primigravidae reversed at delivery and postpartum visit, but the difference was not statistically significant during the follow-up (V1 to V5) (p = 0.60). The cortisol level in peripheral blood at delivery was higher than that in the cord blood, and conversely for prolactin. Cortisol and prolactin levels decreased after delivery, though the level of prolactin was still higher than that at enrolment. An increase of one unit of prolactin was associated with the decrease of the average concentration of cortisol by 0.04 ng/ml (p = 0.009). However, when cortisol increases with one unit, the average concentration of prolactin decreases by 1.16 ng/ml (p = 0.013). These results showed that the up-regulation effects of cortisol and prolactin are related to gestational age. A The downward regulation effect that both hormones have on each other during the pregnancy when each increase to 1 unit (1.0 ng/ml) was also reported.

Analysis on pollutants removal and sludge characteristics of a novel two-phase anaerobic/aerobic/integrated deoxygenated and anoxic reactor associated with membrane process for treating pesticide wastewater

Most frequently used biological method was improved anaerobic/anoxic/aerobic (A/A/O) process for treating actual pesticide wastewater presently. However, the effluent results were far away from what the national standard expects due to pesticide wastewater characteristics of high COD concentration, high total nitrogen (TN) concentration and high toxicity. In this study, a novel two-phase anaerobic/aerobic/integrated deoxygenated and anoxic reactor associated with membrane process (P1) were regarded as excellent candidates for the treatment of pesticide wastewater, compared the removal efficiency of pollutants with improved A/A/O process (P2) under different hydraulic retention times (HRTs). Effluent ethylene thiourea (ETU) concentration was reduced effectively by 67.1 % in P1. The average cyanide (CN−) effluent concentration in P1 and P2 was 0.40 mg/L and 6.67 mg/L, respectively. During the entire HRT change period, P1 significantly increased the biological oxygen demand (BOD5) removal efficiency by 12.98 %. The average effluent COD concentration of P1 was 36.41 mg/L, while that of P2 was 984.42 mg/L. In addition, TN removal efficiency of P1 exhibited distinct superiority. When HRT was 72 h, the average TN effluent concentration of P1 and P2 was 12.67 mg/L and 67.66 mg/L. The sludge performance indicators have been determined and results showed that the sludge viscosity of the membrane reactor in P1 had merely 32.6 % higher than that of the secondary sedimentation tank in P2, and the average vertical displacement of sludge settleability in P1 was 23.0 % slight lower than that of P2. The overall sludge performance proved that higher sludge concentration was allowed in P1. Moreover, experiment improved nitrite reductase (NIR) and nitrate reductase (NAR) in P1 were less susceptible to be suppressed by ETU and CN− increase compared with P2. Finally, the positive correlation relationship of sludge settleability with ETU and CN− has been identified successfully in P1.

The behavioral dimension of CO2 fertilization effect: Evidence from US harvesting records

AbstractThe CO2 fertilization effect has been demonstrated to boost crop production by enhancing photosynthesis and reducing drought stress. In addition to this biological channel, there is also a behavioral margin for the CO2 fertilization effect that was previously unnoticed. I find evidence that an additional ppm of average CO2 concentration leads to increases in the corn and soybean harvested ratios of .57 and .75 percentage points, respectively. My predictions suggest that, without considering the adjustment in harvesting decision, the crop production benefits from CO2 fertilization effect would be biasedly estimated for both corn and soybeans, which broadens the understanding of farmers’ behavioral responses to environmental stimuli and extends the knowledge on how CO2 would benefit crop production.

The kinetics of a two-stage completely stirred tank reactor for treating tofu wastewater by anaerobic digestion

ABSTRACT Tofu wastewater is an inevitable by-product of the bean curd production process. In this study, we used a two-stage continuous stirred tank reactor (CSTR) to treat tofu wastewater. The kinetic analysis of two CSTR reactors was conducted utilizing the material accounting model, microbial accounting model, and first-order kinetic model. The results demonstrated that the methane production coefficient of reactor 1 was 0.00573 LCH4·mg−1 greater than that of reactor 2, which is 0.00533 L CH4·mg−1. The first-order kinetic constants of reactor 1 were poorer than those of reactor 2, and their values are 0.15700 d−1 and 0.11574 d−1, respectively. The microbial yield coefficients of reactors 1 and 2 were 0.009648 and 0.060704, respectively. Under different organic loading rates, the average microbial concentrations were 25.24000 and 2.706667 mg·L−1 for reactors 1 and 2, respectively. The operational performance of the two-stage CSTR anaerobic digestion system was evaluated in order to design a novel and unique method as well as provide a new perspective for enhancing the performance of anaerobic digestion.

Steady-State Drug Exposure of Repeated IV Bolus Administration for a One Compartment Pharmacokinetic Model with Sigmoidal Hill Elimination.

Drugs exhibiting nonlinear pharmacokinetics hold significant importance in drug research and development. However, evaluating drug exposure accurately is challenging with the current formulae established for linear pharmacokinetics. This article aims to investigate the steady-state drug exposure for a one-compartment pharmacokinetic (PK) model with sigmoidal Hill elimination, focusing on three key topics: the comparison between steady-state drug exposure of repeated intravenous (IV) bolus ( ) and total drug exposure after a single IV bolus ( ); the evolution of steady-state drug concentration with varying dosing frequencies; and the control of drug pharmacokinetics in multiple-dose therapeutic scenarios. For the first topic, we established conditions for the existence of , derived an explicit formula for its calculation, and compared it with . For the second, we identified the trending properties of steady-state average and trough concentrations concerning dosing frequency. For the third, we developed formulae to compute dose and dosing time for both regular and irregular dosing scenarios. As an example, our findings were applied to a real drug model of progesterone used in lactating dairy cows. In conclusion, these results provide a theoretical foundation for designing rational dosage regimens and conducting therapeutic trials.

Aircraft observation of aerosol and mixed-phase cloud microphysical over the North China Plain, China: Vertical distribution, size distribution, and effects of cloud seeding in two-layered clouds

Aerosol and clouds are essential to climate effects. Based on an aircraft observation in a mixed-phase cloud in Shijiazhuang, China, on November 21, 2020, analyzing the vertical and size distributions of cloud droplets, and ice crystal particles, and the effects of the similar to a “seeder-feeder” process after cloud seeding on cloud microphysics. The first seeding cloud (CS1) and second seeding cloud (CS2) were at 2600–2800 m and 1500–2300 m, respectively. Before seeding, the average number concentration of cloud droplets (Nc) was 236.91 cm−3 and 152.13 cm−3 in CS1 and CS2 from vertical observation. In CS1, the average number concentration of ice crystals (Ni) was 0.26 L−1 with dendritic ice crystals and graupel, while in CS2, the average Ni was 0.19 L−1, including rimed plate ice crystals, graupel, and needle ice crystals. After seeding, the average Nc decreased from 322.90 to 260.69 cm−3 and the spectrum of Nc broadened from 2.5 to 24 to 45 μm in CS1. The ice microphysics also had different responses in the layered cloud. Ni increased by 421 times in regions with high Nc and low LWC (Nc > 322.90 cm−3, LWC < 0.14 g∙m−3), including spoked and heavily rimed ice crystals and graupel (200–500 μm) in CS1. In CS2, the maximum Ni was 252.03 L−1 and the average Ni increased by 2 magnitudes (from 0.39 to 11.44 L−1). There were rimed needles and columnar ice crystals (200–300 μm) in regions with high Nc and high LWC (Nc > 92.78 cm−3, LWC > 0.13 g∙m−3), and high Nc and low LWC (Nc > 92.78 cm−3, LWC < 0.13 g∙m−3). Seeding in CS1 and CS2 formed a structure similar to the “seeder-feeder” process. Controlled by the downdraft (>1 m/s), these particles descended into the “feeder” region of CS2. Appropriate temperature and rimed crystals contributed to secondary ice crystal production (SIP), resulting in main columns (200–300 μm) observed in CS2. The “feeder” region generated more ice crystals than the “seeder” region.

A novel ensemble machine learning exposure model system for ground-level ozone at the national scale: A case of mainland China from 2013 to 2020

In epidemiological research, accurate estimation of historical ground-level ozone (O3) concentrations with enhanced spatiotemporal resolution is crucial for effective exposure assessment. The current state-of-the-art for estimating air pollutant concentrations is a two-stage ensemble method that integrates outputs from multiple machine learning algorithms. Despite its effectiveness, opportunities exist to refine this approach for more precise O3 estimation. In this study, we propose an enhanced ensemble method that incorporates four key strategies. First, we employ high-resolution spatiotemporal predictors derived from prior machine learning studies for refined secondary learning. Second, we use sophisticated algorithms, including categorical gradient boosting, deep neural network, random forest, stochastic variable Gaussian process, transformer, and a combination of convolutional neural network and long short-term memory neural network, as sublearners to enhance learning capabilities. Third, we spatiotemporally split the sample set and then train submodels separately on each subset to eliminate the unobserved spatiotemporal heterogeneity. Finally, we apply a complex machine learning algorithm, rather than the generalized additive model, for integrating sublearner predictions, enabling the capture of intricate nonlinear relationships beyond basic spatiotemporal linear weights. To validate these improvements, we estimated daily maximum 8-h moving average O3 concentrations ([O3]MDA8) across Chinese mainland from 2013 to 2020 at a 1 km spatial resolution. The proposed method demonstrated notable accuracy, achieving an out-of-station determination coefficient (R2) of 0.943 and a root-mean-square error (RMSE) of 10.197 μg/m3. This performance marks a nearly 15% improvement over the best existing Chinese O3 exposure model based on a single algorithm and also surpasses previous studies utilizing traditional ensemble methods for other air pollutants. Our enhanced ensemble approach significantly bolsters the reliability and robustness of future environmental epidemiological studies by further mitigating “misclassification” errors.

Association of long-term exposure to ozone with cardiovascular mortality and its metabolic mediators: evidence from a nationwide, population-based, prospective cohort study

Previous studies about chronic effects of ozone (O3) on cardiovascular mortality are scarce and inconclusive. We aimed to investigate the association between cardiovascular mortality and a broad range of long-term O3 exposure levels. This analysis included 3,206,871 participants aged 35-75 years enrolled in the ChinaHEART study. Participants were recruited from the 31 provinces of the Chinese mainland between January 2015 and December 2020. The five-year average O3 concentrations before baseline visits were calculated to represent long-term exposure. Over a median follow-up period of 4.7 (interquartile range: 3.7-6.2) years, 35,553 (1.1%) participants died from cardiovascular diseases (CVD). Following multivariable adjustment, nonlinear relationships were identified between O3 concentrations and CVD and ischemic heart disease (IHD) mortality, with inflection points at 85.44 and 88.15μg/m3, respectively. Above these points, a 10.0μg/m3 increase in the O3 level was associated with a 13.9% (hazard ratio [HR]: 1.139, 95% confidence interval [CI]: 1.096-1.184) and 25.0% (HR: 1.250, 95% CI: 1.151-1.357) greater risk of CVD and IHD mortality, respectively. Conversely, O3 exposure exhibited a linear relationship with ischemic stroke mortality. Moreover, the metabolic factors explained more than half of the association between O3 exposure and CVD mortality. Substantial influences of long-term O3 exposure on CVD mortality were identified, with notable mediation proportions attributed to metabolic factors. These findings could facilitate the air quality standard revisions and risk reduction strategy making in the future. This study was supported by the CAMS Innovation Fund for Medical Science (2021-1-I2M-011), the CAMS Innovation Fund for Medical Science (CIFMS, 2022-I2M-C&T-A-010), the National High Level Hospital Clinical Research Funding (2022-GSP-GG-4), the Ministry of Finance of China and National Health Commission of China, the 111 Project from the Ministry of Education of China (B16005).

Ethyl alcohol consumption characteristics of deceased individuals in Lithuania

The number of alcohol-related deaths in Lithuania has fallen by almost one-third in the last decade; however, the number of deaths has been on the rise since 2019. Data on the postmortem investigation of victims between 2018 and 2022 were obtained from the Lithuanian State Forensic Medicine Service database. This study analyzed data from 1,200 autopsies. The deceased victims were categorized based on their cause of death and blood alcohol concentration (sober, legally intoxicated, mild, medium, or heavy). The causes of death were diseases (54.17%, n=650), suicides (12.08%, n=145), homicides (2.5%, n=30), and accidents (31.25%, n=375). Toxicological tests for alcohol were performed in all cases. Alcohol levels in the blood and urine were measured using gas chromatography. A significant correlation was observed between blood alcohol concentration and age (r=-0.13, p=0.007). A statistically significant difference was observed in the proportions of men and women who were intoxicated. Among the causes of death, the group of individuals who died because of accidents exhibited the highest average blood alcohol concentration. Alcohol intoxication is undoubtedly a contributing factor to fatalities resulting from accidents and homicides. These findings assist in determining the intoxication level of victims and in assessing any potential links that may contribute to or predispose victims to lethal outcomes in cases of disease, suicide, homicide, or accident.