Average Concentration Research Articles

Numerical Simulation Study on the Stable Combustion of a 660 MW Supercritical Unit Boiler at Ultra-Low Load

To investigate the safe, stable, and economically viable operation of a boiler under ultra-low-load conditions during the deep peaking process of coal-fired units, a numerical simulation study was conducted on a 660 MW front- and rear-wall hedge cyclone burner boiler. The current research on low load conditions is limited to achieving stable combustion by adjusting the operating parameters, and few effective boiler operating parameter predictions are given for very low-load conditions, i.e., below 20%. Various burner operation modes under ultra-low load conditions were analyzed using computational fluid dynamics (CFDs) methods; this operation was successfully tested with six types of pulverized coal combustion in this paper, and fitting models for outlet flue gas temperature and NOx emissions were derived based on the combustion characteristics of different types of pulverized coal. The results indicate that under 20% ultra-low-load conditions, the use of lower burners leads to a uniform temperature distribution within the furnace, achieving a minimum NOx emission of 112 ppm and a flue gas temperature of 743 K. Coal type 3, with the highest carbon content and a calorific value of 22,440 kJ/kg, has the highest average section temperature of 1435.76 K. In contrast, coal type 1 has a higher nitrogen content, with a maximum cross-sectional average NOx concentration of 865.90 ppm and an exit NOx emission concentration of 800 ppm. The overall lower NOx emissions of coal type 3 are primarily attributed to its reduced nitrogen content and increased oxygen content, which enhance pulverized coal combustion and suppress NOx formation. The fitting models accurately capture the influence of pulverized coal composition on outlet flue gas temperature and NOx emissions. This control strategy can be extended to the stable combustion of many kinds of coal. For validation, the fitting error bar for the predicted outlet flue gas temperature based on the elemental composition of coal type 6 was 8.09%, whereas the fitting error bar for the outlet NOx emissions was only 1.45%.

Hemoglobin concentrations in early pregnancy and their associations with adverse pregnancy outcomes in Western China: a population-based study.

Despite the global standardization of hemoglobin (Hb) testing in early pregnancy, the impact of first trimester Hb concentrations on pregnancy outcomes remains inadequately understood. Also, the early pregnancy Hb concentrations have not been well documented in Western China. Therefore, this study aimed to assess the Hb concentrations during early pregnancy and their associations with adverse pregnancy outcomes in Western China. This cross-sectional study used data from the Chengdu Maternal and Child Health Information System for pregnant women who delivered between January 1, 2019, and December 31, 2023. A total of 454,815 Chinese females aged 15 to 49 years with available first trimester Hb data, including those with singleton or multiple gestations, were included in the analysis. Multivariable logistic regression models were performed to estimate the adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for associations between Hb categories and adverse pregnancy outcomes. The average first trimester Hb concentration was 126.0 (SD 10.5) g/L, with 5.8% of pregnant women experiencing anemia during early pregnancy. Multivariable logistic regression analyses revealed significantly increased odds of developing gestational diabetes mellitus (GDM) and gestational hypertensive disorders (GHD) across increasing Hb concentration categories. Compared to Hb concentrations of 110-119g/L, Hb ≥ 140g/L was associated with elevated risk of GDM (aOR: 1.57, 95% CI: 1.52, 1.62) and GHD (aOR: 1.87, 95% CI: 1.79, 1.96). Moreover, both Hb ≤ 99g/L (aOR: 1.15, 95% CI: 1.03, 1.29) and Hb ≥ 140g/L (aOR: 1.20, 95% CI: 1.13, 1.26) were associated with higher odds of preterm birth compared to Hb concentrations of 110-119g/L. In addition, the restricted cubic spline demonstrated a U-shaped relationship for cesarean delivery, low birthweight and small for gestational age (p < 0.001). However, no significant associations were found between first trimester Hb concentrations and the odds of stillbirth, Apgar score < 7 at 5min, or Apgar score < 7 at 10min (p > 0.05). Our research findings suggest associations between first trimester Hb concentrations and various adverse pregnancy outcomes. We recommend interventions for early pregnancy anemia, particularly moderate to severe cases, and emphasize monitoring females with high Hb concentrations to reduce adverse outcomes.

Evaluation of 210Po, 210Pb, and potentially toxic element concentrations in aquatic environments and polychaetes along the southeast coast of Chennai, Tamil Nadu: a baseline report

ABSTRACT The activity concentrations of radionuclides (210Po and 210Pb) and the concentrations of potentially toxic elements (PTEs) in water, sediment, and two polychaete species (Marphysa madrasi and Namalycastis jaya) collected from 12 stations, denoted as S1 to S12, along the coast of Tamil Nadu, Chennai, in southeast India has been investigated. The average activity concentrations of 210Po and 210Pb were 0.39 ± 0.01 mBq/L and 3.30 ± 0.06 mBq/L in water, and 0.80 ± 0.02 Bq/kg and 4.21 ± 0.19 Bq/kg in sediment, respectively. Marphysa madrasi exhibited higher 210Po and 210Pb activity concentrations (37.78 ± 0.43 Bq/kg and 17.25 ± 0.22 Bq/kg, respectively) compared to Namalycastis jaya (34.40 ± 0.42 Bq/kg and 15.91 ± 0.26 Bq/kg, respectively). Maximum activity concentrations for both radionuclides in water were observed at Kalpaakam (S11) and Nemmeli (S7), while maximum sediment activity concentrations were found at Nemmeli (S7). The elevated activity concentrations in polychaetes from Nemmeli (S7) likely reflect the significantly higher 210Po and 210Pb activity concentrations observed in sediments from this site when compared to other sites. Bioaccumulation values for 210Po and 210Pb averaged 6.89 × 101 and 4.20 for M. madrasi, and 6.17 × 101and 3.84 for N. jaya , respectively. Sediment PTE concentrations followed the order: Fe > Zn > Mn > Ni > Co > Cr > Pb > Cd > Cu. Risk assessment indicated alarming levels of PTE contamination in sediments, suggesting severe anthropogenic impacts. In contrast, average PTE concentrations in polychaetes followed the order: Fe > Cu > Zn > Mn> Cr > Ni > Co > Cd > Pb. Statistical analysis revealed strong and significant correlations (p < 0.05) between PTE concentrations in sediments and polychaetes. The present study offers baseline data for evaluatingthe levels of 210Po and 210Pb in water, sediment, and polychaetes in selected locations along Chennai, Tamil Nadu, India’s southeast coast. These findings lay the groundwork for further studies of polychaetes, specifically the ecological effects of PTEs and radionuclides on coastal creatures and biomagnification.

Risk assessment of uranium in water sources near coal mines and in human organs of Shahdol District, Madhya Pradesh, using biokinetic modelling.

This study concentrated on determining the levels of uranium present in drinking water samples obtained from various locations throughout the Shahdol district in Madhya Pradesh, India. In this assessment a LED fluorimeter Quantalase (LF-2a) was utilized. Uranium, being a radioactive substance, can be hazardous to health when consumed in significant quantities over extended durations. The study found that the average uranium concentration was 167.91µg/L. 82% of samples exceeded recommended limits, emphasizing the essential aspect of this study. The study utilizes the age-specific biokinetic model developed by the International Commission on Radiological Protection to examine uranium distribution across various organs. Using dosimetric model, the study provides a comprehensive health risk analysis by assessing the chemical toxicity and the radiation dosages received by particular organs. Longitudinal studies on uranium distribution across different organs and tissues showed that the kidneys, liver, non-exchangeable bone volume, and soft tissues are the primary locations where uranium accumulates.

HPLC-MS/MS monitoring and health risk assessment of carbosulfan and its metabolites in date palm fruit (Phoenix dactylifera).

This study investigated residual levels of carbosulfan and its metabolites in date palm fruit in the UAE using HPLC-MS/MS and QuEChERS method. The method demonstrated excellent linearity (R2 > 0.998), low LOD (0.001-0.04 μg/kg) and LOQ (0.003-0.1 μg/kg), and high recoveries (92-103%) with low RSD values (1-9%). The matrix effect was negligible (-16.43-17.09%), and uncertainty measurements did not exceed the 50% limit. Carbosulfan was present in all samples, exceeding its MRL in 46% of the samples. Carbofuran and 3-hydroxycarbofuran exceeded their MRL in 4.87% and 40% of the samples, respectively, while 3-ketocarbofuran levels were below the MRL. Dibutylamine was found in 82% of the samples, with an average concentration of 9.01µg/kg. The health risk assessment for children and adults showed that all HQ values were below the safety limit of 1.0, indicating that date consumption poses no adverse health risks for either adults or children.

Phthalate esters in baltic lagoons: Spatial distribution, ecological risks, and novel insights into their fate using transcriptomics.

Plasticizers such as phthalate esters (PAEs) are organic compounds widely used in various consumer and industrial products, raising strong environmental concerns due to their pervasive presence and potential adverse effects. Lagoon ecosystems are particularly vulnerable to PAE pollution as they are semi-enclosed and receive high loads of organic materials. The present study investigates the distribution of seven common PAEs in three large European lagoons (Curonian, Vistula and Szczecin) in the southern Baltic Sea. The concentration levels of PAEs in the water column, encompassing both the dissolved and particulate-bound phases, and in sediments were assessed to elucidate distribution patterns and potential ecological risks within these lagoon ecosystems. The average concentration of total PAEs in the water column ranged from 0.03 to 1.45 μg L-1, whereas sediment concentration varied from 0.008 to 1.06 μg g-1, levels comparable to or lower than those found in other European coastal areas. Distribution patterns of PAEs in sediment showed notable similarity across all three lagoons, whereas variations were observed in the water column. Notably, di(2-ethylhexyl) phthalate (DEHP), di-n-octyl phthalate (DOP) and dimethyl phthalate (DMP) emerged as the most concerning congeners in studied lagoons, all of which pose a moderate risk to aquatic organisms. This study applied shotgun transcriptomic analysis to field samples, revealing active microbial communities involved in PAEs degradation in the Baltic lagoons for the first time. The degradation of phthalic acid (PA) into intermediate compounds such as protocatechuate was not identified as a rate-limiting step in the studied environment. The degradation activity was primarily localized in the sediment layers, with Gram-negative bacteria playing a major role, while Gram-positive bacteria appeared incapable of degrading PA. These findings provide valuable insights into the distribution and transformation mechanisms of PAEs in estuarine environments.

Exploring Putative Kokumi Oligopeptides in Classic Sparkling Wines with a UHPLC-ESI-MS/MS Targeted Protocol.

Some oligopeptides can impart kokumi flavor to foods and beverages, a topic still not addressed in wine. A targeted ultra-high performance liquid-chromatography-mass spectrometry (UHPLC-MS/MS) metabolomics method capable of quantifying both amino acids and oligopeptides in wines was therefore developed and validated, confirming the presence of 50 oligopeptides in wine, most of which had been previously unexplored. In silico screening of the affinity of these oligopeptides to interact with CaSR, the protein necessary to activate kokumi sensations, highlighted 8 dipeptides and 3 tripeptides as putative kokumi compounds. These compounds were ubiquitous in a representative set of Trentodoc classic method sparkling wines, with an average concentration of kokumi oligopeptides of 19.8 mg/L, ranging between 9.1 and 33.3 mg/L. Half of the sparkling wine samples also contained glutamic acid at concentrations equal to or greater than the threshold for the umami taste in wine, namely, 48 mg/L. Sensory tests on the dipeptide Gly-Val confirmed the ability of this novel kokumi compound to significantly modify the perception of complex real wine matrices but not of the simple model one. Preliminary laboratory-scale fermentation tests showed that the oligopeptide profile in wines is linked to the starting grape matrix and that the patterns change by fermenting barley or apple juice with the same yeast.

Rhizosphere as a hotspot for microbial necromass deposition into the soil carbon pool

Abstract Microbial leftovers, known as necromass, are key players in storing carbon in the soil around plant roots (i.e. rhizosphere), a zone characterized by high‐efficiency microbial anabolism. Yet, the extent and mechanisms through which the rhizosphere contributes to soil organic carbon (SOC) via microbial necromass, especially under changing environments remain unclear. We aimed to evaluate the contributions of microbial necromass to SOC and influencing factors from the rhizosphere perspective. We collected the rhizosphere and bulk soil from 39 alpine coniferous forest sites on the eastern Tibetan Plateau to assess the extent of microbial necromass contribution to SOC in the rhizosphere from a dynamic perspective by calculating the ratio of increased amino sugars (AS) to increased SOC in the rhizosphere relative to that in bulk soil (RAS/SOC). We also collected climate data and determined nutrient concentrations and microbial physiological traits in rhizosphere soil to elucidate the factors affecting RAS/SOC. The results showed that across all sampling sites, the average concentrations of SOC‐normalized AS in the rhizosphere were significantly higher than those in the bulk soil. Furthermore, the average RAS/SOC was greater than 1, indicating a faster microbial necromass accumulation than SOC accumulation in the rhizosphere. These results implied that the rhizosphere sustains a greater capacity for microbial necromass contribution to the SOC pool than the bulk soil does. Soil nutrient availability was the primary factor affecting RAS/SOC, and precipitation indirectly affected microbial anabolism and RAS/SOC by changing soil nutrient status. Additionally, with increasing rhizosphere soil nutrient availability, microbial carbon‐use efficiency and growth rate increased but the biomass‐specific enzyme activity declined, indicating that microorganisms tended to exhibit high‐yield strategies with increasing soil nutrient availability. Synthesis. Our findings underpin the vital effect of microbial necromass in SOC accumulation from the rhizosphere perspective and offer valuable insights into mechanisms underlying microbial C metabolic processes in rhizosphere SOC accumulation under changing environments.

Exposure-Response Analyses of Sacituzumab Govitecan Efficacy and Safety in Patients With Metastatic Triple-Negative Breast Cancer.

Sacituzumab govitecan (SG), a Trop-2-directed antibody-drug conjugate, is approved for patients with metastatic triple-negative breast cancer (mTNBC) who received ≥2 prior systemic therapies (≥1 in metastatic setting). Exposure-response (E-R) relationships between SG exposure and efficacy and safety outcomes were characterized in 277 patients with mTNBC using data from the phase I/II IMMU-132-01 and phase III ASCENT (IMMU-132-05) studies. Evaluated endpoints included complete response (CR), objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and safety endpoints (individual first worst grade of select adverse events (AEs)). E-R analyses were also conducted for time to first dose reduction or delay. Patients received SG at 8 or 10 mg/kg intravenously on days 1 and 8 of a 21-day cycle. Average SG-related serum exposure over the treatment duration (until the event) was consistently the most significant exposure metric correlated with efficacy and safety endpoints. Higher average concentration over the treatment duration for SG (CAVGSG) was the best predictor of CR and ORR. The model-predicted proportions of patients with CR and ORR at 10 mg/kg were 4.26% and 32.6%, respectively. Higher CAVG for total antibody was the best predictor of OS and PFS. The model-predicted probability of OS at 12 months at median lactate dehydrogenase (227 IU/L) was 53%. The probability of grade ≥1 evaluated AEs and the risk of dose reductions and delays significantly increased with increasing CAVGSG. The model-predicted proportions of patients with any-grade AEs were 35.9%, 67.4%, 64.7%, and 67.1% for vomiting, diarrhea, nausea, and neutropenia, respectively (10 mg/kg dose group). Neutropenia was the only evaluated AE for which CAVGSG was significantly associated with grade ≥3 events. The clinically meaningful efficacy and manageable safety achieved with SG 10 mg/kg on days 1 and 8 of every 21-day cycle dosing regimen supports the appropriateness of this clinical dosage in patients with mTNBC.

Modelling of Carbon Monoxide and Suspended Particulate Matter Concentrations in a Rural Area Using Artificial Neural Networks

Air pollution is a growing concern in rural areas where agricultural production can be reduced by it. This article analyses data obtained as part of a research project. The aim of this study is to understand the influence of atmospheric pressure, air temperature, air relative humidity, longitude and latitude of the location, and indoor and outdoor environment on local rural workplace diversity of air pollutants such as carbon monoxide (CO) and suspended particulate matter (SPM), as well as the contribution of these variables to changes in such air pollutants. The focus is on four topics: motivation, innovation and creativity, leadership, and social responsibility. Furthermore, this study developed an artificial neural network (ANN) model to predict CO and SPM concentrations in the air based on data collected from the mentioned inputs. The related sensors were assembled on an Arduino Mega 2560 board to form a field-portable device to detect air pollutants and meteorological parameters. The sensors included an MQ7 sensor for CO concentration measurement, a Sharp GP2Y1010AU0F dust sensor for SPM concentration measurement, a DHT11 sensor for air temperature and air relative humidity measurement, and a BMP180 sensor for air pressure measurements. The longitude and latitude of the location were measured using a smartphone. Measurements were conducted from 20 December 2021 to 16 July 2022. Results showed that the overall average outdoor CO and SPM concentrations were 10.97 ppm and 231.14 μg/m3 air, respectively. The overall average indoor concentrations were 12.21 ppm and 233.91 μg/m3 air for CO and SPM, respectively. Results showed that the ANN model demonstrated acceptable performance in predicting CO and SPM in both the training and testing phases, exhibiting a coefficient of determination (R2) of 0.575, a root mean square error (RMSE) of 1.490 ppm, and a mean absolute error (MAE) of 0.994 ppm for CO concentrations when applying the testing dataset. For SPM concentrations, the R2, RMSE, and MAE using the test dataset were 0.497, 30.301 μg/m3 air, and 23.889 μg/m3 air, respectively. The most influential input variable was air pressure, with contribution rates of 22.88% and 22.82% in predicting CO and SPM concentrations, respectively. The acceptable performance of the developed ANN model provides potential advances in air quality management and agricultural planning, enabling a more accurate and informed decision-making process regarding air pollution. The results of short-term estimation of CO and SPM concentrations suggest that the accuracy of the ANN model needs to be improved through more comprehensive data collection or advanced machine learning algorithms to improve the prediction results of these two air pollutants. Moreover, as even lower cost devices can predict CO and SPM concentrations, this study could lead to the development some kind of virtual sensor, as other air pollutants can be estimated from measurements of particulate matters.

A comparison of statistical and machine learning models for spatio-temporal prediction of ambient air pollutant concentrations in Scotland

AbstractThe spatio-temporal prediction of air pollutant concentrations is vital for assessing regulatory compliance and for producing exposure estimates in epidemiological studies. Numerous approaches have been utilised for making such predictions, including land use regression models, additive models, spatio-temporal smoothing models and machine learning prediction algorithms. However, relatively few studies have compared the predictive performance of these models thoroughly, which is one of the novel contributions of this paper. For the specific challenge of predicting monthly average concentrations of NO$$_{2}$$ 2 , PM$$_{10}$$ 10 and $$\hbox {PM}_{2.5}$$ PM 2.5 in Scotland, we find that random forests typically outperform (or are as good as) more traditional statistical prediction approaches. Additionally, we utilise the best performing model to provide a new data resource, namely, predictions of monthly average concentrations (with uncertainty quantification) of the above pollutants on a regular 1 km$$^{2}$$ 2 grid for all of Scotland between 2016 and 2020.

Radiation dose estimation for indoor radon, thoron and their progenies using a stochastic method-a small-scale survey in Wuhan, China.

Passive radon monitors with CR-39s are widely used in major epidemiological surveys. However, the conventional CR-39 track density determining strategy makes it difficult to accurately estimate the concentration because of the heterogeneity of tracks on CR-39s. This study introduced a stochastic method, Latin hypercube sampling, to improve the track density determining strategy and provide the probability distribution of 222Rn concentration and equilibrium equivalent thoron concentration. The first 222Rn and 220Rn discriminated survey was conducted in Wuhan, China, in 2018 using RADUET® and deposition-based passive 220Rn progeny monitors and applying the stochastic method to the measurement. The results indicate that the stochastic method could decrease the effects of the track heterogeneity on the CR-39s and provide reliable results. The 220Rn progeny contributed more than 40% of the total inhalation dose in the survey, which cannot be ignored in urban family dwellings.

Characterization of the Elemental Composition of Aerosols Emitted in the Dry Season of the Pantanal Wetland, Brazil

The Brazilian Pantanal region experiences intense biomass burning during the dry season, releasing large quantities of gasses and particles into the atmosphere, which have serious implications on both the climate system and public health. Understanding the dynamics of these emissions is crucial for mitigating the impact on the ecosystem, its functioning, and potential anthropogenic disturbances. This study focused on analyzing emissions in the northern Pantanal during the 2022 drought. Concentrations of fine particulate matter (PM2.5), black carbon (BC), and 25 chemical elements were measured using gravimetry, reflectance analysis, and X-Ray fluorescence, respectively, from samples collected between August and October 2022. The average concentrations of PM2.5 and BC increased approximately 4-fold and 2.5-fold, respectively, compared to averages from a decade ago. Significant increases were also observed in elements such as sulfur (S), potassium (K), iron (Fe), and silicon (Si). The maximum concentrations were comparable to values typical of the southern Amazon, a region known for high deforestation rates and land use changes. Elemental analysis revealed substantial shifts in concentrations, primarily associated with biomass burning (BB) and soil suspension. Additionally, enrichment factor (Ef) analysis showed that lead (Pb) levels, correlated with human activities, were 200 times higher than those found under clean atmospheric conditions.

Vitamin D Status in Supplemented Hemodialysis Patients

Introduction: Chronic kidney disease (CKD) causes decreased activity of the enzyme 1-alpha-hydroxylase and calcitriol deficiency with mineral and bone metabolism disorders or secondary hyperparathyroidism. Anticipation of the occurrence of these complications implies the systematic supplementation of all hemodialysis patients, with monitoring of biological parameters. It is in this context that this study was carried out, the general objective of which was to establish the profile of vitamin D concentration in hemodialysis and Ivorian public sector supplemented patients in Abidjan. Patients and Methods: In a cross-sectional study conducted from September to December 2022, we included 89 patients with end-stage CKD treated with hemodialysis at the CNPTIR in Cocody. The collection of epidemio-clinical data was done on the basis of a questionnaire on the one hand and the patients' medical records on the other. The vitamin D concentration was determined by the ELFA immunoassay method on mini Vidas (BIOMERIEUX). Results: The mean age of the patients was 45 ± 13 and 65.17% of them were men. 55.06% of the patients had been treated with dialysis for at least 5 years. 48.31% of the patients had regular supplementation treatment. Of the two types of vitamin D supplementation, 94.38% of the study population was supplemented with cholecalciferol compared to 18% for alfacalcidol with 12% of patients included, using both types. From a biological point of view, it appears that the average concentration of vitamin D in the patients was 26.9 ng/mL, and only 16% have a concentration of less than 20 mg/mL, corresponding to an deficiency vitamin D status. Conclusion: At the end of this cross-sectional study, it emerged that the average in adult hemodialysis subjects followed at the CNPTIR in Cocody had an insufficient vitamin D status. And 37% of the study population with normal vitamin D status. However, these results could be improved by better accessibility to the products, and regular compliance with supplementation.

Ecological Health Hazards and Multivariate Assessment of Contamination Sources of Potentially Toxic Elements from Al-Lith Coastal Sediments, Saudi Arabia

To assess the contamination levels, sources, and ecological health risks of potentially toxic elements (PTEs) in the sediments of Al Lith on the Saudi Red Sea coast, 25 samples were collected and analyzed for Zn, V, Cr, Cu, Ni, As, Pb, and Fe using inductively coupled plasma-atomic emission spectrometry. The average concentrations of PTEs (μg/g) were obtained in the following order: Fe (14,259) &gt; V (28.30) &gt; Zn (22.74) &gt; Cr (16.81) &gt; Cu (12.41) &gt; Ni (10.63) &gt; As (2.66) &gt; Pb (2.46). The average values of enrichment factor were in the following order: As (1.12) &gt; Zn (0.75) &gt; V (0.70) &gt; Cr (0.69) &gt; Cu (0.69) &gt; Pb (0.67) &gt; Ni (0.46). This indicated that the Al Lith sediments exhibited either no or minimal enrichment of PTEs, with concentrations below the low effect range. This suggests that the primary source of these PTEs is the minerals associated with the basement rocks of the Arabian Shield (sphalerite, vanadiferous magnetite, chromite, pentlandite, arsenopyrite, and galena) and that they are unlikely to pose a substantial risk to benthic communities. The hazard index (HI) values for the PTEs in both adults and children were below 1.0, indicating no significant non-carcinogenic risk. The lifetime cancer risk (LCR) values for Pb, As, and Cr in both adults and children were within acceptable or tolerable levels, posing no significant health threats. However, a few samples showed LCR values exceeding 1 × 10−4, which may indicate potential risks.

Occurrence, spatiotemporal distribution, and health risk of antibiotics in the Wuhan section of the Yangtze River, China.

The occurrence, spatiotemporal changes, and health hazard of antibiotics in source water and finished water in the Wuhan section of the Yangtze River are not well understood. In this study, 43 source water and finished water samples were collected from 11 water plants in Wuhan in August 2021 and May 2022. Fifty-one antibiotics from eight categories were measured. A total of 41 antibiotics were detected in the source water samples, and 24 in the finished water samples. The total antibiotic concentration in source water ranged from 1.68 to 437.18 ng/L, which is significantly higher than that in finished water (2.04-87.25 ng/L). Sulfonamides and lincosamides were predominant, accounting for nearly 80% of the total antibiotic concentration. Lincomycin constituted nearly 30% of the total antibiotic concentration in the source water. In August 2021, the average total antibiotic concentration in source water was 107.12 ng/L, higher than in May 2022 (63.13 ng/L). Spatially, the total antibiotic concentrations in samples collected from the Han River, a tributary of the Yangtze River, were higher than those in the main stream of the Yangtze River. Ecological risk assessment indicated that the hazard posed by most antibiotics were negligible. Lincomycin potentially posed a high health hazard, and clarithromycin and roxithromycin posed a moderate hazard to infants.

Abstract 4138321: Marine Microplastic Levels and the Prevalence of Cardio-Metabolic Diseases in Coastline Counties: An Ecological Analysis

Background: Micro- and nanoplastics are an emerging risk factor for the development of cardiovascular diseases. The association of marine microplastic levels (MMLs) with the burden of cardiometabolic diseases at a population level remains unexplored. Aim: To investigate the association between the average microplastic concentration in the ocean water body within 200 nautical miles of US coastline surveyed between 2015 and 2020, assigned to its most adjacent coastline county, and the prevalence of type 2 diabetes (T2D), coronary artery disease (CAD), and stroke in those counties. Methods: Microplastic concentration data within 200 nautical miles of the US coastline was spatially analyzed in ArcGIS Online to calculate mean MMLs. The coastal counties were stratified into four categories based on MMLs in the adjacent ocean water body: low (0-0.005 pieces/m 3 ), medium (0.005-1 pieces/m 3 ), high (1-10 pieces/m 3 ), or very high (≥10 pieces/m 3 ). BRFSS 2019-2020 survey data was used to correlate with the prevalence of type 2 diabetes (T2D), coronary artery disease (CAD), and stroke in these counties. Univariate and population-weighted multivariate quasi-Poisson regression adjusted for median county age, sex, physician access, and baseline community vulnerability theme of the US climate vulnerability index (CVI) was used to evaluate unadjusted and adjusted associations between disease prevalence and MMLs. Results: The mean age of the population was 43 ± 6 years. The mean prevalence of T2D, CAD, and stroke was significantly higher in counties with very high MMLs (13.03%, 8.94%, and 4.17%, respectively) compared to low MMLs (11.23%, 7.43%, and 3.51%, respectively, p &lt; 0.001). The counties with very high MMLs exhibited an 18% higher adjusted prevalence of T2D (PR: 1.18 [1.13 – 1.23], p &lt; 0.001), 7% higher adjusted prevalence of CAD (PR: 1.07, [1.03 – 1.11], p &lt; 0.001), and 9% higher adjusted prevalence of stroke (PR: 1.09, 95% CI: 1.05 – 1.13, p &lt; 0.001) compared to those with low levels. Conclusion: Our study establishes a significant association between marine microplastic levels and cardiometabolic disease prevalence in coastal counties.

Ecological risks caused by neonicotinoid pesticides in sediments: A case study of freshwater basins in China.

Neonicotinoid insecticides (NNIs) are extensively used in agricultural production in China due to their selective neurotoxicity towards target insects. In recent years, the rapid development of agriculture has increased the use and residue of NNIs. Consequently, the sediment environment, serving as the ultimate sink, is significantly impacted by NNIs. Upon release into the environment, NNIs can enter the human body through the food chain, posing potential ecological and human health risks. This study analyzed 79 sediment samples from two major river basins in North and South China, the Liaohe River basin in Liaoning Province and the Jianjiang River basin in Guangdong Province. The content, composition, distribution, and source of eight NNIs were analyzed, and assess the ecological and human health risks of the target compounds in these regions. The results indicated that the average concentration of NNIs in the sediments of the Jianjiang River basin (2.34 μg/kg) is slightly higher than that of the Liaohe River basin (2.32 μg/kg), and the sources of NNIs in the two areas were different, with differences in the sources of NNIs likely attributable to varying types of agricultural production. The risk assessment revealed that the ecotoxicological and public health risks were more pronounced in the Jianjiang River basin compared to the Liaohe River basin, underscoring the critical need for surveillance and management of hazardous substances like NNIs. The insights findings from this study can provide scientific guidance for the risk evaluation and environmental management of NNIs.

Chemical Analysis and Flavour Distribution of Electronic Cigarettes in Australian Schools.

Adolescent usage of electronic cigarettes has increased globally. Inconsistent, or absent, labelling of nicotine and other ingredients requires chemical analysis to accurately determine the chemical composition of these products. Electronic cigarettes confiscated from public and private high school students (N=598) were provided for analysis from three regions in New South Wales, Australia. The products were examined for brand, model and flavour and a subset were further analysed for chemical composition (n=410) quantifying nicotine, synthetic cooling agents, flavouring chemicals and prohibited ingredients by gas chromatography-mass spectrometry (GC-MS). The majority of samples provided were fruity-flavoured disposable e-cigarettes across three main brands (IGET, HQD and Gunnpod). Nicotine was quantified in 97.3% of disposable samples with an average concentration of 40.0mg/mL while one refill e-liquid was found to contain nicotine at a low concentration. Almost all samples contained the coolant WS-23 in relatively high concentrations compared to other flavouring chemicals present. Chemicals prohibited under the TGO110 (Australian e-cigarette product standard) were identified in 3.4% of the samples which were chemically analysed. This included the presence of ethylene glycol in moderately high concentrations (up to 13.2mg/mL). Australian students' preferences for fruity, disposable e-cigarettes were identified regardless of region with the vast majority containing high concentrations of nicotine. WS-23 was found in most disposable e-cigarettes, potentially to reduce the throat irritation from nicotine and other flavouring chemicals. The inhalational safety of the samples is of concern due to health risks associated with detected prohibited compounds, particularly ethylene glycol. This is the first study to quantify nicotine, coolants and flavouring chemicals in ecigarette products seized from Australian high school students and has significant implications for future policy development. Students appear to be almost exclusively using disposable ecigarettes with high nicotine concentrations and predominately fruity flavours. WS-23 may potentially be added to disposable e-cigarettes to facilitate the uptake of these products by adolescents unaccustomed to the throat irritation from nicotine and intense flavours. The ecigarette coils were found to have degraded over time, potentially affecting the composition of the aerosol and leaching of metals.

Assessment of the air pollutants on automobiles emission dispersion: the effects of barrier height and the road surface temperature.

In the paper, a mathematical model was constructed that describes the specifications of the wind flow and the dispersion of pollutants, taking into account the variable temperature on the roadway surface, which varies depending on the time for some quarter of the city of Almaty. The impact of the traffic tidal flow was studied based on the data of measuring passing vehicles as a source of pollution by the CFD and on the spatial distribution of pollutants for various types of pollution. A test problem was performed to validate the numerical algorithm and the mathematical model. From the obtained numerical solutions, it was determined that the existing barriers along the road have a positive effect on pedestrian zones regardless of the type of pollution. It was also found that, taking into account the variable temperature on the carriageway, the presence of barriers with a height of 4 m shows favorable behavior on the adjacent areas, in which the average concentration value drops by 6.4 times for the pedestrian zone, which is located on the left side and 2.9 times for the pedestrian zone, which is on the right side compared to the option without a barrier.