Average Concentration Research Articles

Study of spatiotemporal evolution of coupled airflow–gas–dust multi-field diffusion at low-gas tunnel

The increasing level of mechanization in coal mining means more dust and gas are generated during excavation operations in tunnels. The high concentrations of dust and gas severely affect production efficiency and the physical and mental health of workers. Here, Ansys Fluent simulations were performed to derive the spatiotemporal evolution of coupled airflow–dust–gas diffusion in a low-gas excavation face. The aim was to optimize pollution control by determining the optimal duct distance, L, from the working face in the excavation tunnel. Our results showed that the airflow field affects the coupled diffusion and transport of dust and gas. According to a comparison of the effects of different duct distances from the working face, when L = 6 m, the average dust concentration in the tunnel is low (257.6 mg/m3), and the average gas concentration in the tunnel is 0.28 %, which does not exceed the safety limit. Accordingly, the optimal distance of the duct for pollution control is 6 m. The results of field measurements supported the validity of the simulation. Our findings can be used to improve the air quality in tunnels, thereby keeping miners safe and the working area clean.

Copper (II) Ion Detection in Food and Water Harnessing Schiff Base-Enabled Electrochemical Sensor

A copper (II) ion-selective sensor was generated using a processed membrane that included 4-(2-(2,4-Dinitrophenylhydrazono) Methyl)Benzene-1,3-diol (L). The sensor’s efficacy was tested using a variety of plasticizers, comprising sodium tetraphenylborate (NaTPB), O-Nitrophenyloctyl ether (ONPOE), benzyl acetate (BA), dibutyl phthalate (DBP), and dibutyl sebacate (DBS). Membrane layers comprised of L:DBS:OA:PVC in a ratio of 5:55:10:30 (w/w,%) provided optimum sensing effectiveness. The detection system performed well in an average concentration that ranged from 5.3×10−8 to 1.0×10−1 mol L−1, with a Nernstian slope of 29.1±0.5 mV decade-1 for Cu(II) ions. The sensor’s minimal detection limit of 2.1×10−8 mol, broad pH range (3.1–8.2), quick reaction time (9 s), strong non-aqueous resistance (up to 25% v/v), and good retention time (2 months) demonstrates its value. Potentiometric selectivity coefficients revealed an exclusive exposure for Cu(II) ions under the influence of intervening ions, allowing for accurate identification of copper in a variety of materials such as food oils, tomato plant material, and river water. The proposed sensor is a promising means for accurately detecting Cu(II) ions in environmental and food specimens, with potential utilization in quality assurance and environmental surveillance.

Cordycepin in the fruiting body of Cordyceps militaris cultured from 5 different materials in Vietnam: Analysis and comparison

Cordyceps militaris is frequently employed in pharmacology and nutrition for its well-documented health benefits. The advancement of Cordyceps militaris farming technology has facilitated the establishment of a reliable supply source capable of effectively meeting the expanding market demand. This study aimed to analyze and compare cordycepin concentrations in the fruiting bodies of Cordyceps militaris cultivated from five raw material sources in Vietnam. The results revealed significant variations in cordycepin concentrations among the samples, with average concentrations (measured in mg/g) as follows: Sample 1 (0.8), Sample 2 (1.2), Sample 3 (0.6), Sample 4 (1.0), and Sample 5 (0.9). Notably, Cordyceps militaris from Sample 2 exhibited the highest cordycepin concentration, while Sample 3 had the lowest. Differences in cordycepin content between Cordyceps militaris samples from different raw material sources may be attributed to variations in manufacturing technology. The results of this study provided the necessary information to evaluate the quality of Cordyceps militaris products on the market and propose quality standards for raw materials in the food and pharmaceutical industries.

Comparative study of air quality index of two metropolitan cities (Lucknow and Kanpur) in Year-2023

In 2023, it was declared that the Bangladesh at the first place and then Pakistan, after which the most polluted country is India at the third place. Polluted air is becoming a very considerate issue all over the world. This study is all about comparing the air quality of two metro cities, Lucknow and Kanpur during (November 2022- October,2023) buy monitoring and assessment of few selective basic AQI air pollutants namely Particulate Matter (PM10) , Sulphur dioxide (SO2), Nitrogen dioxide (NO2) concentrations and also AQI of Lucknow and Kanpur at 5 representative locations categorized as residential, commercial and industrial areas. Residential area in Lucknow (Mahanagar and Aliganj) and in Kanpur (Kidwai Nagar and Shastri Nagar), Commercial areas in Lucknow (Hazarat Ganj and Ansal T.C.) and in Kanpur (Zareeb Chauki and Ramadevi), Industrial area Talkatora in Lucknow and Panki in Kanpur have been taken under consideration. The result found that 24 hours concentration of PM10 were in the range of 76.40 to 261.19 µg/m3 in Lucknow and 74.68 to 400.67 µg/m3 in Kanpur with an average of 174.34 and 160.36 µg/m3, respectively. The average value of PM10 was above as per the guideline of WHO and permissible limit prescribed by NAAQ in both the cities. Similarly, 24 hours average concentration of SO2 was below the prescribed level of NAAQ in Lucknow and Kanpur which was in the range of 5.33 to 12.70 µg/m3 in Lucknow and 2.00 to 9.53 µg/m3 in Kanpur with an average of 8.71 and 7.19 µg/m3, respectively. The 24 hours average concentration of Nitrogen dioxide (NO2) was below prescribed level of NAAQ in Lucknow and Kanpur. In Lucknow it was in the range of 13.83 to 48.01 µg/m3 and in Kanpur 21.45 to 64.02 µg/m3 with an average of 29.45 and 50.14 µg/m3, respectively. The 24 hours AQI was reported in the range of 76 to 211 in Lucknow and 75 to 363 in Kanpur with an average of 150.84 and 142.76 respectively which is greater moderate to severe by NAAQ and WHO guideline throughout the year. Ultimately, this entire study is related to human health because polluted air gives rise to various hazardous diseases such as asthma cancer, premature death cardiovascular diseases, respiratory tract diseases etc.

Insight Study of Trace Elements in PM2.5 During Nine Years in Delhi, India: Seasonal Variation, Source Apportionment, and Health Risks Assessment.

This study investigated the concentrations, seasonal variations, sources, and human health risks associated with exposure to heavy elements (As, Al, Pb, Cr, Mn, Cu, Zn, and Ni) of PM2.5 at an urban location of Delhi (28° 38' N, 77° 10' E; 218m amsl), India, from January 2013 to December 2021. The average mass concentration of PM2.5 throughout the study period was estimated as 127 ± 77µgm-3, which is exceeding the National Ambient Air Quality Standards (NAAQS) limit (annual: 40µgm-3; 24h: 60µgm-3). The seasonal mass concentrations of PM2.5 exhibited at the order of post-monsoon (192 ± 110 µgm-3) > winter (158 ± 70 µgm-3) > summer (92 ± 44 µgm-3) and> monsoon (67 ± 32 µgm-3). The heavy elements, Al (1.19µgm-3), Zn (0.49µgm-3), Pb (0.43µgm-3), Cr (0.21µgm-3), Cu (0.21µgm-3), Mn (0.07µgm-3), and Ni (0.14µgm-3) exhibited varying concentrations in PM2.5, with the highest levels observed in the post-monsoon season, followed by winter, summer, and monsoon seasons. Six primary sources throughout the study period, contributing to PM2.5 were identified by positive matrix factorization (PMF), such as dust (paved/crustal/soil dust: 29.9%), vehicular emissions (17.2%), biomass burning (15.4%), combustion (14%), industrial emissions (14.2%), and Br-rich sources (9.2%). Health risk assessments, including hazard quotient(HQ), hazard index(HI), and carcinogenic risk(CR), were computed based on heavy elements concentrations in PM2.5. Elevated HQvalues for Cr and Mn linked with adverse health impacts in both adults and children. High carcinogenic risk values were observed for Cr in both adults and children during the winter and post-monsoon seasons, as well as in adults during the summer and monsoon seasons. The combined HIvalue exceeding one suggests appreciable non-carcinogenic risks associated with the examined elements. The findings of this study provide valuable insights into the behaviour and risk mitigation of heavy elements in PM2.5, contributing to the understanding of air quality and public health in the urban environment of Delhi.

Assessment of Natural Radioactivity and Associated Radiological Indicators in Water and Surface Soils Around Beta Glass Plc and Its Environs, Ughelli, Delta State, Nigeria

A radiometric assessment was conducted around Beta Glass plc using sodium iodide detector (3×3-inch NaI (TI)). The study collected 14 soil and 13 water samples from June to July 2022, analyzing radioactivity concentrations of 40K, 238U, and 232Th. The mean specific activity concentrations of 40K, 238U, and 232Th were 184.00±29.73 Bqkg-1, 14.55±2.50 Bqkg-1, and 8.60±1.04 Bqkg-1, respectively, in soil samples, but these elements' concentrations in water were 27.429±5.633 BqL-1, 6.661±1.421 BqL-1, and 2.518±0.361 BqL-1, respectively. The average activity concentrations of 40K, 238U, and 232Th were lower than the safe limit, and the corresponding radiation hazard indices for soil samples were all below the UNSCEAR-recommended acceptable limits. The mean activity concentrations of radionuclides in water samples were higher than the UNSCEAR's recommended international limits for 40K, 238U, and 232Th. Nonetheless, elevated radiological health hazards imply that cumulative dosages may cause cancer, even though these values might not pose an immediate health concern to the local community's people or the workforce.

Evaluation and health risk assessment of arsenic and potentially toxic elements pollution in groundwater of Majha Belt, Punjab, India.

Concentrations of potentially toxic elements (PTEs) like arsenic, uranium, iron, and nitrate in the groundwater of the Majha Belt (including Tarn Taran, Amritsar, Gurdaspur, and Pathankot districts) in Punjab, India were measured to evaluate the health risks associated with its consumption and daily use. The average concentrations of these elements in some locations exceeded the WHO-recommended values. Arsenic and iron toxicity levels were found to be higher in the Amritsar district, while uranium toxicity was more prevalent in Tarn Taran. The Trace Element Evaluation Index suggests that Amritsar is one of the districts most affected by toxic elements. According to the US Environmental Protection Agency's (USEPA) guidelines, the HQ values of U, Fe, and nitrate were less than one, indicating that there is no non-carcinogenic health risk for adults and children. However, the hazard quotient (HQ) value for arsenic was greater than one, indicating a higher possibility of health risk due to arsenic in the study area. The total hazard index values of 44.10% of samples were greater than four for arsenic, indicating that people in the Majha Belt are at a very high health risk due to the usage of water for drinking and domestic purposes. The cancer risk assessment values for arsenic in children (5.69E + 0) and adults (4.07E + 0) were higher than the accepted limit of USEPA (10-4 to 10-6) in the Majha Belt. The average radiological cancer risk values of U for children and adults were 8.68E-07 and 9.45E-06, respectively, which are well below the permissible limit of 1.67 × 10-4 suggested by the Atomic Energy Regulatory Board of DAE, India. The results of this study confirm that the residents of the Majha Belt who use contaminated groundwater are at a serious risk of exposure to arsenic in the Amritsar district and uranium in Tarn Taran district.

Concentration and variation of traffic-related air pollution as measured by carbon monoxide in Hawassa City, Ethiopia

Air pollution is a pressing problem and causes millions of deaths each year related to its effects on respiratory health worldwide. Despite its significant impact, information on air pollution in many cities, including Hawassa city, remains limited. The aim of this study was to determine the concentrations and variations of traffic-related air pollution, as measured by carbon monoxide, and its relationship with temperature, relative humidity, traffic flow, and road routing in Hawassa City. We monitored carbon monoxide (CO) concentrations in Hawassa city, Ethiopia, for 24 days using real-time monitors with carbon monoxide sensor head. A total of 24 different roads (12 high-traffic congested roads and 12 low-traffic congested roads) were included as monitoring sites. We conducted 1 hour monitoring at each monitoring site in the morning and afternoon to characterize the temporal variations. Accordingly, the average carbon monoxide concentrations varied temporally at different times. In addition, the average carbon monoxide concentrations on paved main roads, traffic light roads and low-traffic flow roads were 4.87 ± 0.6 ppm, 5.38 ± 0.8 ppm and 1.62 ± 0.53 ppm, respectively. The study also identified factors that correlated positively with carbon monoxide concentration, including temperature, relative humidity, traffic flow and road routing. The study concludes that long-term monitoring of carbon monoxide concentrations is necessary to fully characterize the health effects. The study also provides valuable insights for urban planners when implementing measures to mitigate the negative effects.

Investigation of the pollutant load of artisanal-refined gasoline in the Niger Delta region of Nigeria and its implications on air quality

In order to examine the gaseous pollutants generated by artisanal refined gasoline and the contribution to air pollution associated with such combustion in the Niger-Delta region of Nigeria, this study collected a sample of indigenously refined gasoline product each from thirty (30) different randomly selected artisanal camps in the Niger-Delta region and subjected all the collected samples to combustion. Fifty (50) ml of each gasoline sample was combusted at controlled conditions, and the concentrations of gaseous emissions from the process were measured using a combustion emission analyser. Pollutants characterised by the Department of Petroleum Resources which include sulphur dioxide (SO2), carbon monoxide (CO), oxides of nitrogen (NOx), hydrocarbons (HC) and carbon dioxide (CO2) were characterised. The average concentrations of the emissions were 211.50 mg/m3, 7.18 mg/m3, 17.51 mg/m3, 3011.33 mg/m3, and 500.39 mg/m3 for CO, NOx, SO2, CO2, and HC respectively. The concentrations of SO2 and NOx measured were within the Federal Environmental Protection Agency (FEPA) set limits for combustion emissions from stationary sources but breached World Health Organization (WHO), World Bank and Environmental Guidelines and Standard for Petroleum Industry in Nigeria (EGASPIN) set limits. The concentrations of CO and HC exceeded FEPA, WHO, World Bank and EGASPIN set limits and hazardous on Air Quality Index (AQI) classification. Elevated concentrations of CO and HC in the atmosphere pose a major threat to ambient air quality and human health, especially in locations where artisanal-refined fuel is predominantly utilised. Associated risks include poor visibility, occurrence of acid rain, blood poisoning and cancer-related diseases. In addition to these effects are the worsening global warming crises associated with CO2 emission, a major product of fossil fuel combustion.

Spatial distribution of NORMs concentrations and assessing potential risk to inhabitants in western Chattogram, Bangladesh

ABSTRACT This study represents a pioneering endeavour in consolidating previous measurements of naturally occurring radioactive materials (NORMs) within the Chattogram division, Bangladesh. Employing a meticulous approach, data was overlaid onto a comprehensive grid map covering the entire Chattogram region, comprising 523 grids, each of 8.05 km x 8.05 km. The analysis revealed numerous areas where NORMs concentrations had not been previously measured. To bridge this gap, soil samples were collected from 56 previously unmeasured locations across Cumilla and Chandpur districts and analysed using high purity Germanium (HPGe) detector technology. Results indicated average activity concentrations of Ra-226, Th-232, and K-40 at 27.30 ± 5.41, 46.09 ± 7.88, and 362.50 ± 48.10 Bq.kg−1 respectively, with no detectable presence of Cs-137 or other anthropogenic radionuclides, affirming the region’s absence of fallout or accidental releases. Additionally, measured values for radiation hazard indices are well within acceptable limits set by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Spatial distribution maps of radionuclide concentrations and absorbed dose rates were generated not only for the immediate study area but also for the entire Chattogram division, integrating previously collected data for the first time. These distribution maps, alongside the comprehensive findings of this study, establish a pivotal dataset for future research and regulatory efforts, providing invaluable insights into the region’s radiological landscape.

The Transformation of Per- and Polyfluoroalkyl Substances in the Aquatic Environment of a Fluorochemical Industrial Park

Jiangsu High-Tech Fluorochemical Industrial Park in Changshu City, Jiangsu Province, is the largest fluorochemical industrial park in Asia. The occurrence of per- and polyfluoroalkyl substances (PFASs) in surface water and widespread local plants was investigated in Jiangsu High-Tech Fluorochemical Industrial Park. Thirty-two target PFASs were detected in dissolved-phase, particle-phase and plant samples. The concentrations of total PFASs ranged from 1650 to 8250 ng/L in the dissolved-phase samples, 132 to 6810 ng/g dw in the particle-phase samples and 25.8 to 9460 ng/g dw in different plant tissues. Perfluorohexanoic acid (PFHxA), Perfluorooctanoate acid (PFOA) and 6:2 fluorotelomer carboxylic acid (6:2 FTCA) were predominant PFASs and contributed 80−91% to ΣPFAS in water samples. A total of 67 emerging PFAS were identified in all samples using nontargeted analysis. Typha orientalis showed better accumulation ability, with an average ΣPFAS concentration of 3450 ng/g dw and the highest root concentration factor (RCF) of 171. Typha orientalis, Eichhornia crassipes and Alternanthera sessilis have potential for use in PFAS phytostabilization.

Investigating ground-level ozone pollution in semi-arid and arid regions of Arizona using WRF-Chem v4.4 modeling

Abstract. Ground-level ozone (O3) pollution is a persistent environmental concern, even in regions that have made efforts to reduce emissions. This study focuses on the state of Arizona, which has experienced elevated O3 concentrations over past decades and contains two non-attainment areas as designated by the U.S. Environmental Protection Agency. Using the Weather Research and Forecasting with Chemistry (WRF-Chem) model, we examine O3 levels in the semi-arid and arid regions of Arizona. Our analysis focuses on the month of June between 2017 and 2021, a period characterized by high O3 levels before the onset of the North American Monsoon (NAM). Our evaluation of the WRF-Chem model against surface Air Quality System (AQS) observations reveals that the model adeptly captures the diurnal variation of hourly O3 levels and the episodes of O3 exceedance through the maximum daily 8 h average (MDA8) O3 concentrations. However, the model tends to overestimate surface NO2 concentrations, particularly during nighttime hours. Among the three cities studied, Phoenix (PHX) and Tucson (TUS) exhibit a negative bias in both hourly and MDA8 O3 levels, while Yuma demonstrates a relatively large positive bias. The simulated mean hourly and MDA8 O3 concentrations in Phoenix are 44.6 and 64.7 parts per billion (ppb), respectively, compared to observed values of 47.5 and 65.7 ppb, resulting in mean negative biases of −2.9 and −1.0 ppb, respectively. Furthermore, the analysis of the simulated ratio of formaldehyde (HCHO) to NO2 (HCHO/NO2; FNR), reveals interesting insights of the sensitivity of O3 to its precursors. In Phoenix, the FNR varies from a VOC (volatile organic compound)-limited regime in the most populated areas to a transition between VOC-limited and NOx-limited regimes throughout the metro area, with an average FNR of 1.15. In conclusion, this study sheds light on the persistent challenge of ground-level O3 pollution in semi-arid and arid regions, using the state of Arizona as a case study.

Net escape velocity, transfer probability, and travel time distributions within a cross-ventilated room model sheltered by urban-like block array

Natural ventilation offers significant advantages, especially in terms of energy conservation. However, most published articles have focused on the ventilation flow rate to determine the average contaminant concentration, while few have examined local ventilation distributions. Therefore, isothermal steady-state Reynolds-averaged Navier–Stokes simulations were conducted to analyze the airflow and scalar concentration fields of a cross-ventilation model sheltered by buildings. Based on these fields, we generated the spatial distributions of ventilation indices, namely, the net escape velocity (NEV), point-to-point indices transfer probability (TP), and travel time (TT), to discuss the dispersion of scalars emitted from local points in a room with natural ventilation. The NEV, which indicates the direction of the scalar discharge from each cell, exhibited a distribution distinct from the advection velocity because of concentration gradient effect. Higher TPs were observed when evaluated from a contaminant source to a target point following the NEV streamlines. Meanwhile, lower TTs were observed when evaluated in a point near the source and also from a contaminant source to a target point following the NEV streamlines. Although TP and TT are independent ventilation indices, a negative correlation between them was observed. Instead of the ventilation flow rate, the detailed structure of scalar dispersion can now be described by simultaneously analyzing the ventilation efficiency indices, which provide information on the general contaminant transport direction, and the probability and duration of transfer from a source to a target point. This potentially helps in the design of ventilation system especially in room lay-out to avoid cross-contamination.

Evaluation of consumer digital radon measurement devices: a comparative analysis

Kansas State University (KSU) Engineering Extension conducted an abridged evaluation of eight consumer grade digital radon monitors. Using the KSU secondary radon chamber, these devices were exposed to three different radon concentrations for 7 d in average household temperature and relative humidity conditions. The three different radon concentration ranges used were: 12.8 pCi L−1 to 15.5 pCi L−1 (473.6 Bq m−3–573.5 Bq m−3), 27.7 pCi L−1 to 29.4 pCi L−1 (1024.9–10 857.8 Bq m−3), and ambient room level average radon concentration of 0.6 pCi L−1 (22.2 Bq m−3). The American National Standards Institute/American Academy of Radon Scientists and Technologists Performance Specifications for Instrumentation Systems Designed to Measure Radon Gas in Air (ANSI/AARST MS-PC) (ANSI/AARST MS-PC 2022 Performance Specifications for Instrumentation Systems Designed to Measure Radon Gas in Air (AARST Radon Standards)) minimum performance metrics were used to evaluate the accuracy and precision of each model type for each radon concentration tested. The eight different device models performed within the 0 ± 25% requirement for the individual percent error (IPE) for radon concentrations between 27.7 pCi L−1 and 29.4 pCi L−1 (1024.9–10 857.8 Bq m−3). For radon concentrations between 12.8 pCi L−1 and 15.5 pCi L−1 (444–592 Bq m−3) seven of the eight monitors fell within the IPE requirement and for ambient room radon concentrations six of the eight monitors fell within the IPE requirement for the ANSI/AARST MS-PC minimum performance requirement (ANSI/AARST MS-PC 2022 Performance Specifications for Instrumentation Systems Designed to Measure Radon Gas in Air (AARST Radon Standards)) ranges. All eight device models fell within the ± 15% ANSI/AARST MS-PC minimum performance requirement (ANSI/AARST MS-PC 2022 Performance Specifications for Instrumentation Systems Designed to Measure Radon Gas in Air (AARST Radon Standards)) coefficient of variation (CV) range for radon concentrations between 12.8 pCi L−1 and 15.5 pCi L−1 (444–592 Bq m−3) and for radon concentrations between 27.7 pCi L−1 and 29.4 pCi L−1 (1024.9–10 857.8 Bq m−3). In the future, evaluating the performance of these models over time to observe their long term accuracy and precision is anticipated.

Contamination, morphological and chemical characterization, and hazard risk analyses of microplastics in drinking water sourced from groundwater in a developing nation

Groundwater (GW) plays a crucial role as the primary source of potable water in numerous developing nations. However, the increasing presence of microplastics (MPs) represents a concealed danger, threatening activities that guarantee safe drinking water in these countries. Despite this, there is limited awareness about the widespread existence of MPs in these regions of the world. In this study, we investigated the contamination levels, distribution, morphological characteristics, chemical composition, and associated public health risk of MPs in groundwater samples from six coastal districts of Bangladesh using stereomicroscopy and Fourier transform infrared spectroscopy (FTIR). MPs were prevalent at all sampling stations, with average concentrations of 24.63 ± 16.13 items/L and a range of 4–75 items/L. The majority of MPs (97.6%) were fibers, indicating a likely origin from fabric disintegration during drying, washing, discarded fishing nets, personal care items, and municipal waste. Smaller-sized MPs (<0.5 mm), transparent and violet-colored, were predominantly observed. Additionally, FTIR confirmed the presence of plastic polymers, including low-density polyethylene (LDPE), high-density polyethylene (HDPE), ethylene vinyl acetate (EVA), and polyethylene terephthalate (PETE). Despite the high visibility observed or focus given for PETE, PE was found to be abundant. These are thought to have come from runoff from agricultural fields, seeping from landfills where plastic trash is disposed of, synthetic fabrics, and inappropriate plastic product disposal. Estimated dietary intake was recorded as 1.85 particles/person/day (i.e., 675 particles/year), suggesting the possible health risk to consumers. Hazard analyses based on the polymeric risk score revealed diverse risks associated with polymer levels, with PETE indicating a medium risk and other polymers, e.g., HDPE, LDPE, and EVA at 39%, 31%, and 17%, respectively, showing a minor risk to human health from drinking water from the studied sources. This is the first study from the regions, and the findings will be valuable for identifying sources, implementing control measures, shaping policies, and safeguarding public health against plastic pollution.

37 years after the chernobyl: the current radiation status in Kocaeli, Turkey

AbstractThis study aims to assess the artificial and natural radiation dose levels in certain districts of Kocaeli province within the Marmara region, 37 years after the Chernobyl nuclear accident, and evaluate the current status prior to potential nuclear leakage events from Zaporijya or other nuclear power plants. Radioactive concentrations of 232Th, 238U, 40K and 137Cs were determined using HPGe gamma spectrometry in 26 soil samples collected from the region of interest. The average concentrations were found to be 22.35 Bqkg−1 for 238U, 26.36 Bqkg−1 for 232Th, 368.34 Bqkg−1 for 40K, and 2.44 Bqkg−1 for 137Cs. Furthermore, the study revealed an absorbed dose rate of 41.73 nGyh−1, an annual effective dose equivalent of 51.18 µSvy−1, and an excess lifetime cancer risk of 0.00018.

#2063 Safety and efficacy of vadadustat vs darbepoetin alfa in patients on maintenance dialysis by prespecified subgroups of baseline ESA dose

Abstract Background and Aims Vadadustat is an oral hypoxia-inducible factor prolyl hydroxylase inhibitor approved in Europe, Australia, Japan for the treatment of anemia in patients with dialysis-dependent (DD)-CKD. In the INNO2VATE global phase 3 trials in patients with DD-CKD, including 2 separate trials in patients new to dialysis [NCT02865850] and on maintenance dialysis [NCT02892149], vadadustat was noninferior to the erythropoiesis -stimulating agent (ESA) darbepoetin alfa for cardiovascular safety and hemoglobin efficacy. Among patients with DD-CKD, high ESA dose requirements have been associated with an increased risk of cardiovascular complications. In this secondary analysis, we compared cardiovascular safety and hematological efficacy of vadadustat and darbepoetin alfa across baseline ESA dose categories. Method In the INNO2VATE trials, 3554 patients on maintenance dialysis were randomized 1:1 to vadadustat or darbepoetin alfa, stratified according to geographic region, New York Heart Association heart failure classification, and hemoglobin concentration at trial entry. Data were analyzed for prespecified subgroups of patients categorized by their baseline ESA (epoetin alfa/equivalents) dose: low (<90 U/kg/week), intermediate (90-299 U/kg/week), or high (≥300 U/kg/week). Within these dose subgroups, the key safety endpoint was the first occurrence of an adjudicated major adverse cardiovascular event (MACE: first occurrence of all-cause mortality, nonfatal myocardial infarction [MI], or nonfatal stroke) using a time-to-event analysis. Primary and secondary efficacy endpoints were mean change in hemoglobin concentration from baseline during the primary (weeks 24-36) and secondary (weeks 40-52) evaluation periods, respectively. Results More participants were in the low (vadadustat: n = 916 [53%], darbepoetin alfa: n = 968 [55%]) and intermediate (vadadustat: n = 724 [42%], darbepoetin alfa: n = 693 [39%]) than in the high (vadadustat: n = 102 [6%], darbepoetin alfa: n = 98 [6%]) baseline ESA dose subgroups. Hazard ratios for the occurrence of first MACE between vadadustat and darbepoetin alfa in the 3 baseline ESA dose subgroups were as follows: low dose, 0.99 (95% CI, 0.81 to 1.23); intermediate dose, 0.93 (95% CI, 0.74 to 1.18); and high dose, 0.62 (95% CI, 0.34 to 1.14) (Fig.). Similar results were observed for other key MACE-related endpoints, including all-cause mortality, MACE plus hospitalizations for heart failure or thromboembolic events, cardiovascular MACE (first occurrence of cardiovascular mortality, nonfatal MI, or nonfatal stroke), and cardiovascular death. Mean hemoglobin concentrations increased in both treatment groups throughout the trial period. The least squares mean treatment difference (vadadustat compared to darbepoetin alfa) for change in hemoglobin concentration from baseline to the primary efficacy period was –0.10 g/dL (95% CI, –0.19 to –0.02), –0.20 g/dL (95% CI, –0.30 to –0.09), and –0.39 g/dL (95% CI, –0.67 to –0.11) for the low, intermediate, and high baseline ESA dose subgroups, respectively. Similar results were observed for the secondary efficacy period. Across baseline ESA dose subgroups, the proportion of patients whose average hemoglobin concentration was within target range was similar between the vadadustat and darbepoetin alfa arms during the primary efficacy period (low: odds ratio [OR], 0.89; 95% CI, 0.74, 1.08; intermediate: OR, 0.87; 95% CI, 0.70, 1.09; high: OR, 0.90; 95% CI 0.49, 1.64). Similar results were observed during the secondary efficacy period. Conclusion The cardiovascular safety and efficacy of vadadustat was similar to darbepoetin alfa in patients with DD-CKD irrespective of baseline ESA dose. In patients requiring higher ESA doses at baseline, the risk of MACE was numerically (but not significantly) lower in vadadustat-treated patients. Further investigation is required to confirm or refute this trend.

Associations between PM2.5 Components and Mortality of Ischemic Stroke, Chronic Obstructive Pulmonary Disease and Diabetes in Beijing, China

Ischemic stroke (IS), chronic obstructive pulmonary disease (COPD) and diabetes mellitus (DM) account for a large burden of premature deaths. However, few studies have investigated the associations between fine particular matter (PM2.5) components and mortality of IS, COPD and DM. We aimed to examine these associations in Beijing, China. Data on daily mortality, air pollutants and meteorological factors from 2008 to 2011 in Beijing were collected. Daily concentrations of five PM2.5 components, namely, sulfate ion (SO42−), ammonium ion (NH4+), nitrate ion (NO3−), organic matter (OM) and black carbon (BC), were obtained from the Tracking Air Pollution (TAP) database in China. The association between PM2.5 components and daily deaths was explored using a quasi-Poisson regression with the distributed lag nonlinear model (DLNM). The average daily concentrations of SO42−, NH4+, NO3−, OM and BC were 11.24, 8.37, 12.00, 17.34 and 3.32 μg/m3, respectively. After adjusting for temperature, relative humidity, pressure, particulate matter less than 10 μm in aerodynamic diameter (PM10), nitrogen dioxide (NO2) and sulfur dioxide (SO2), an IQR increase in OM at lag day 2 and lag day 6 was associated with an increased DM mortality risk (RR 1.038; 95% CI: 1.005–1.071) and COPD mortality risk (RR 1.013; 95% CI: 1.001–1.026). An IQR increase in BC at lag day 0 and lag day 6 was associated with increased COPD mortality risk (RR 1.228; 95% CI: 1.017–1.48, RR 1.059; 95% CI: 1.001–1.121). Cumulative exposure to SO42− and NH4+ was associated with an increased mortality risk for IS, with the highest effect found for lag of 0–7 days (RR 1.085; 95% CI: 1.010–1.167, RR 1.083; 95% CI: 1.003–1.169). These effects varied by sex and age group. This study demonstrated associations of short-term exposure to PM2.5 components with increased risk of IS, COPD and DM mortality in the general population. Our study also highlighted susceptible subgroups.

Soil and Urine Mercury Levels in Secocha: A Case Study of Artisanal and Small-Scale Gold Mining in Peru

In recent decades, artisanal and small-scale gold mining (ASGM) has spurred population and economic growth in the small rural communities in which it is located, along with causing contamination of the soil, air, and water with grave effects on human health due to the uncontrolled use of mercury for gold processing activities. This study analyzes the levels of mercury in Secocha, an ASGM community in Arequipa, Peru. A total of 44 soil samples were taken from two ASGM commercial-extractive zones (n = 18) and non-processing urban zones (n = 26). Soil mercury analysis with atomic absorption spectrometry revealed average mercury levels of 86.11 mg/kg in commercial-extractive zone I, where ore processing has occurred for about 17 years, and mercury levels of 43.81 mg/kg in commercial-extractive zone II, where processing has occurred for about 7 years. In the urban zone, the average mercury level was 9.53 mg/kg. The average mercury concentrations for each zone exceed the relevant environmental quality standards established by the Peruvian Ministry of the Environment. In addition, urine samples were obtained from 15 miners and 15 people from the general urban population (non-miners). The average mercury level in the urine of miners was 7.04 µg/L, and in the urine of non-miners it was 0.49 µg/L. In both cases, the mercury urine level did not exceed the limits established by WHO and the Peruvian Ministry of Health, though miners’ elevated levels do raise concerns.

Melanoidin Content Determines the Primary Pathways in Glucose Dark Fermentation: A Preliminary Assessment of Kinetic and Microbial Aspects

Melanoidins are heterogeneous polymers with a high molecular weight and brown color formed during the Maillard reaction by the combination of sugars and amino acids at high temperatures with the potential to inhibit the microbial activity in bioprocesses. This study assessed the impacts of melanoidins on the kinetic of substrate conversion and production of organic acids via dark fermentation using microbial consortia as inoculum. The investigations were carried out in fed-batch reactors using synthetic melanoidins following glucose-to-melanoidin ratios (G/M; g-glucose g−1 melanoidins) of 0.50, 1.50, 1.62, 1.67, and 5.00, also considering a melanoidin-free control reactor. The results showed that melanoidins negatively impacted the kinetics of glucose fermentation by decreasing the first-order decay constant (k1): when dosing equivalent initial concentrations of glucose (ca. 3 g L−1), the absence of melanoidins led to a k1 of 0.62 d−1, whilst dosing 2 g L−1 (G/M = 1.5) and 6.0 g L−1 (G/M = 0.5) of melanoidins produced k1 values of 0.37 d−1 and 0.27 d−1, respectively. The production of butyric and acetic acids was also negatively impacted by melanoidins, whilst the lactic activity was not impaired by the presence of these compounds. Lactate production reached ca. 1000 mg L−1 in G/M = 1.67, whilst no lactate was detected in the control reactor. The presence of melanoidins was demonstrated to be a selective metabolic driver, decreasing the microbial diversity compared to the control reactor and favoring the growth of Lactobacillus. These results highlight the importance of further understanding the impacts of melanoidins on melanoidin-rich organic wastewater bioconversion, such as sugarcane vinasse, which are abundantly available in biorefineries.