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The concentrations of heavy metals (HMs) can be increased by various anthropogenic activities such as mining, fuel combustion, pesticide use, and urban development, which can alter the mechanisms determining their spatial variability in the environment. Determining natural concentrations, monitoring, and assessing potential ecological risks are essential in the management of pollution prevention policies and soil conservation in watersheds. The aim of this study was to determine HMs natural concentrations, establish quality reference values (QRVs), and evaluate pollution indices in a watershed-scale. Composite surface soil samples (n = 115) were collected from areas: native vegetation, pasture, perennial crops, urbanization, planted forest, annual crops, and desertification. The soil samples digestion followed the EPA 3051A, and metals determination in ICP-OES. The data were subjected to the Kruskal–Wallis test, Spearman's correlation, multivariate clustering analysis and. geostatistics. The QRVs established (75th) for the Gurgueia River watershed in descending order were (mg kg−1): V (26.16) > Cr (18.06) > Pb (6.24) > Zn (3.86) > Cu (2.66) > Ni (1.45) > Co (0.57) > Mo (0.46) > Cd (0.07). The concentrations of Cd, Co, Cr, Mo, Ni, V, and Zn in types of land and management practices were significantly increased compared to those in natural vegetation. Overall, the watershed falls into the categories of minimal to moderate enrichment, moderate to considerable contamination, and low to moderate potential ecological risk, with Cd presenting elevated values. The percentages of polluted samples ranged from 14.3 to 82.5%, indicating the need for monitoring these areas to ensure environmental quality and food safety. [ABSTRACT FROM AUTHOR]

Heavy metal pollution is a silent killer and has become a pervasive issue in various regions worldwide, particularly within developing nations such as Nigeria. This study undertook a thorough examination of 120 scholarly articles published from 2000 to 2019, aimed at evaluating the prevalence of heavy metal pollution in soils, aquatic environments, and food sources including crops, meat, and dairy products. Methodologies employed for sample collection and metal quantification were critically assessed, alongside an extensive discussion on the concentrations, sources, and levels of contamination observed. The investigation revealed elevated concentrations of cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb), zinc (Zn), cobalt (Co), chromium (Cr), iron (Fe), and arsenic (As) across all examined locales, with average metal concentrations surpassing World Health Organization/Food and Agriculture Organization (WHO/FAO) guidelines for soil. Furthermore, higher metal concentrations were detected in surface and well waters, whereas borehole groundwaters were relatively pollution-free. Analysis of food crops, meat, and milk demonstrated metal concentrations exceeding WHO/FAO standards across all urban areas studied. Contrary to expectations of lithogenic toxicity, the primary sources of contamination were identified as anthropogenic, stemming from dumpsites, landfill sites, mining operations, runoff and seepage from automotive repair workshops, petroleum hydrocarbon spills, and effluents from industrial plants. The geo-accumulation index (Igeo) analysis revealed significant soil contamination with Fe and Cd, classified under extremely serious and moderate contamination levels, respectively. This comprehensive review highlights the necessity for viable and clear policy interventions to mitigate heavy metal pollution and advocates for the rigorous monitoring and control of industrial activities. [ABSTRACT FROM AUTHOR]

Surface soils in urban regions play a crucial role in controlling regional climatic patterns and sustaining ecological equilibrium. This study evaluates the contamination status, distribution patterns and ecological risks of trace metals (TMs) in the soil. Twenty-two sets of surface soils were collected and analyzed using X-ray fluorescence spectrometry, to estimate the levels of TMs, including As, Ba, Co, Cr, Cu, Ni, Pb, Rb, Sr, V, Y, and Zn. The study reveals a high degree of spatial variability in the distribution of TMs, attributable to the influence of various contamination sources. Simultaneously, descriptive statistical analyses unveil that contents of Cu, V, Co, Ni, Cr, Ba, Y, Zn and Sr in the soils were higher than the local background values. Furthermore, most of the surface soil sampling demonstrated moderate to heavily pollution with a few indicating light pollution. The northern, north-western and central parts in the surveyed zone, particularly in the vicinity of Kabelmal, Naimatabad, and Waddi County, were found to be heavily contaminated. The presence of As, Pb, and Zn was primarily influenced by anthropogenic sources, including agricultural and traffic emissions, while Cr and Y were mainly due to industrial emissions. In addition, Ni, Cr and Co were largely attributed to human activities. This provides fundamental information on TMs in surface soils and underscores the necessity for long-term monitoring to safeguard soil and environmental health. [ABSTRACT FROM AUTHOR]

This research investigates the arsenic concentrations in 96 soil samples from a regency in Indonesia using a statistical approach. Soil samples were collected from three depth layers (topsoil [10–20 cm], subsoil [50–60 cm], and deep soil [90–100 cm]), with each layer consisting of 32 samples. Statistical analysis using SPSS was employed to analyze potential arsenic sources based on the proximity of study locations to geothermal system areas, land use, distance from industry, and the presence of study locations on fault lines.The findings indicate that the potential source of arsenic contamination in the soil are suspected to be associated with geothermal system activities and the presence of soil samples on fault lines. The arsenic concentration in locations near to the geothermal system (5-10 km) was 45 times higher (OR = 45, 95% CI = 45–362.57, p topsoil > deep soil, whereas in residential soil, it was subsoil > deep soil > topsoil. The arsenic concentration variation at near distances from industrial areas was topsoil > subsoil > deep soil, contrasting with medium to far distances from industry (subsoil > deep soil > topsoil). Therefore, these findings can be utilized to prioritize remediation efforts and provide input for future research on arsenic contamination in the region.

Methane is the second largest anthropogenic greenhouse gas, and changes in atmospheric methane concentrations can reflect the dynamic balance between its emissions and sinks. Therefore, the monitoring of CH 4 concentration changes and the assessment of underlying driving factors can provide scientific basis for the government's policy making and evaluation. China is the world's largest emitter of anthropogenic methane. However, due to the lack of ground-based observation sites, little work has been done on the spatial-temporal variations for the past decades and influencing factors in China, especially for areas with high anthropogenic emissions as Central and Eastern China. Here to quantify atmospheric CH 4 enhancements trends and its driving factors in Central and Eastern China, we combined the most up-to-date TROPOMI satellite-based column CH 4 (xCH 4) concentration from 2018 to 2022, anthropogenic and natural emissions, and a random forest-based machine learning approach, to simulate atmospheric xCH 4 enhancements from 2001 to 2018. The results showed that (1) the random forest model was able to accurately establish the relationship between emission sources and xCH 4 enhancement with a correlation coefficient (R²) of 0.89 and a root mean-square error (RMSE) of 11.98 ppb; (2)The xCH 4 enhancement only increased from 48.21±2.02 ppb to 49.79±1.87 ppb from the year of 2001 to 2018, with a relative change of 3.27%±0.13%; (3) The simulation results showed that the energy activities and waste treatment were the main contributors to the increase in xCH 4 enhancement, contributing 68.00% and 31.21%, respectively, and the decrease of animal ruminants contributed -6.70% of its enhancement trend. [Display omitted] [ABSTRACT FROM AUTHOR]

China is among the top nitrous oxide (N2O)-emitting countries, but existing national inventories do not provide full-scale emissions including both natural and anthropogenic sources. We conducted a four-decade (1980 – 2020) of comprehensive quantification of Chinese N2O inventory using empirical emission factor method for anthropogenic sources and two up-to-date process-based models for natural sources. Total N2O emissions peaked at 2287.4 (1774.8 – 2799.9) Gg N2O yr−1 in 2018, and agriculture-developed regions, like the East, Northeast, and Central, were the top N2O-emitting regions. Agricultural N2O emissions have started to decrease after 2016 due to the decline of nitrogen fertilization applications, while, industrial and energetic sources have been dramatically increasing after 2005. N2O emissions from agriculture, industry, energy, and waste represented 49.3%, 26.4%, 17.5%, and 6.7% of the anthropogenic emissions in 2020, respectively, which revealed that it is imperative to prioritize N2O emission mitigation in agriculture, industry, and energy. Natural N2O sources, dominated by forests, have been steadily growing from 317.3 (290.3 – 344.1) Gg N2O yr−1 in 1980 to 376.2 (335.5 – 407.2) Gg N2O yr−1 in 2020. Our study produces a Full-scale Annual N2O dataset in China (FAN2020), providing emergent counting to refine the current national N2O inventories. [ABSTRACT FROM AUTHOR]

Air pollution is a significant environmental problem in Isfahan City, Iran, with detrimental effects on human health and ecosystems. It comes from various sources, including the asphalt industry, motor vehicles, power plants, industry, and natural events such as forest fires and dust storms. The data used in the study was obtained through a combination of different methods and strategies. Reliable laboratory information besides reports from the European Environmental Protection Organization, American Environmental Protection Organization, and Australian Environmental Protection Organization, standards from environmental organizations were used to determine emission coefficients. Questionnaires were prepared and referred to trade and industrial units to gather information on production and air pollutant emissions. Finally, statistical analysis and grouping methods were used to analyze the data. Based on average data of emission rate of different sources, prioritizing resulted in the identification of five main sources of gaseous pollutant including chemical industries, synthetic textiles, and pharmaceutical industries (7.36%), burning garden waste outdoors (7.68), brick kilns (12.43%), garbage center (15.78), and digestion of humans (45.68). Other 30 sources contribute less than 3%. Based on the results, it is obvious that CH4 only contributes 44% in gas emissions of Isfahan City followed by CO (23%), TSP (13%), MVOCS (9%), PM10 (2.17%), NH3 (1.96%), non-methane volatile organic compounds (1.89%), Nox (1.70%), PM2.5 (1.36%), SOx (0.89%), VOC (0.76%), and PM (0.03%).The results of the paper provide information on the major sources of air pollutant emissions in Isfahan City, including chemical industries, burning garden waste outdoors, brick kilns, garbage centers, and digestion of humans. It presents the average data of emission rates from different sources, helping in prioritizing and targeting specific sectors for reducing emissions. The study highlights the importance of considering both natural and anthropogenic sources of air pollution and the need for implementing strategies to obtain accurate information on emissions. The research contributes to the understanding of air pollution sources in Isfahan City, which can aid in developing effective measures for reducing pollution and improving air quality. [ABSTRACT FROM AUTHOR]

The prevalence of brown carbon (BrC) in the atmosphere has experienced a notable upsurge owing to human activities of anthropogenic origin. This study aims to examine the optical characteristics of BrC in both deionized (DI) water and organic solvents (OS), alongside the identification of BrC chromophores within the ambient atmosphere of Dhaka, Bangladesh. Particulate matter (PM) samples were collected on quartz filters using a low-volume sampler from December 2021 to May 2022 at Mukarram Hussain Khundker Bhaban, University of Dhaka. The concentration of BrC was measured using soot analyzer, optical properties of BrC were determined using UV–Vis spectrometer, and BrC chromophores were identified with GC-MS. Average concentration of BrC was 19.13 ± 5.71 μgm−3. The average of absorption coefficient (babs_365), mass absorption efficiency (MAE), absorption angstrom exponent (AAE), and refractive index (kabs_365) of BrC_DI have been observed to be 38.75 ± 21.90 Mm−1, 2.16 ± 1.42 m2 g-1, 1.51 ± 0.08, 0.06 ± 0.04, respectively. The absorption coefficient and MAE of BrC_OS are 1.3 and 1.36 times, respectively higher than that of BrC_DI. Thirty chromophores of BrC have been identified, predominantly consisting of oxygenated compounds. Derivatives of Bisphenol A (C27H44O2Si2) were detected in all samples of oxygenated compounds, primarily originating from the combustion of plastic and the incineration of e-waste. Additionally, compounds containing nitrogen and sulfur, such as C14H26N2O, C31H55N, and C31H49NO3S, were identified, largely attributed to biomass combustion and traffic emissions. These chromophores play a significant role in the absorption of solar radiation, thus influencing atmospheric photochemistry.

Abstract This study presents geophysical data from two passive seismic measurements conducted at two different sites in Antarctica. We analyzed the signals mainly in the frequency domain through the multitaper method to extract some spectral characteristics of the signals that would have been out of reach through the usual FFT approach. The power spectral density of the signals carries information about the processes that generated them, allowing its correlation with their source origin and type, either natural or anthropogenic. We deal with three different source types: calving, wind, and anthropogenic origins. The former is closely related to glacier dynamics, being modulated by the prevailing atmospheric processes. At both locations the wind noise is prevalent, complicating the analysis of other events like calving. We have used data classification, estimation of the source azimuth, and seismic apparent velocity to demonstrate the viability of using geophysical methods to study glacier elastic parameters and dynamics. Moreover, the calving rate can yield a wider and more independent understanding of glacier hydrodynamics and may help to estimate the future response of the polar areas to a changing environment.

Street dust enters the urban environments due to the resuspension of particles smaller than 100 micrometers. The magnetic properties of street dust and their relationship with the concentration of heavy metals have received less attention from researchers worldwide, and not much study has been performed on this issue in Iran. The objectives of this study were: (i) to investigate the spatial and seasonal changes in street dust, and (ii) to determine their relationships with the concentration of selected heavy metals in several cities in the Isfahan province. Sampling was carried out in the first half of the second month of each season including 20 samples from Isfahan city and 10 samples from Natanz, Shahreza, Falavarjan, Khomeinishahr, and Najafabad. The concentration of selected heavy metals was measured using an atomic absorption spectrometer. Also, the magnetic susceptibility values of the samples at low and high frequencies were determined and frequency-dependent magnetic susceptibility was calculated. The results showed that the presence of ferromagnesian minerals in the parent materials could be the reason for the high values of magnetic receptivity in Natanz City. However, the high level of this characteristic in the street dust of other cities could be due to human activities, especially in Isfahan city. Based on the results of principal component analysis, the high correlation of the first component with magnetic susceptibility and the concentration of zinc, copper, and chromium elements most likely indicates the absorption of these elements by particles close to superparamagnetic (SP). The high correlation of the second component with frequency-dependent magnetic susceptibility and concentration of nickel and cobalt is most likely related to the adsorption of magnetic elements and heavy metals into coarse polyhedral particles that remained on the street floor after the re-deposition of street dust particles. Also, the high correlations between magnetic parameters and the concentration of copper and zinc confirm their anthropogenic origin. On the other hand, low or negative correlations of Pb, Ni, Cr, and Co concentrations with magnetic susceptibility might confirm their natural or non-anthropogenic origin. The higher values of magnetic parameters of street dust in the spring season reflect the significant contribution of magnetic minerals in this season, compared to autumn and winter, and indicate the higher influence of human activities.

The One World, One Health concept implies that antibiotic resistance (AR) in the soil-microbe-plant resistome is intricately linked to the human resistome. However, the literature is mainly confined to sources and types of AR in soils or microbes, but comprehensive reviews tracking AR in the soil-microbe-plant resistome are limited. The present review applies the source-pathway-receptor concept to understand the sources, behaviour, and health hazards of the soil-microbe-plant resistome. The results showed that the soil-microbe-plant system harbours various antibiotic-resistance genes (ARGs), antibiotic-resistant bacteria (ARB), and mobile genetic elements (MGEs). Anthropogenic sources and drivers include soil application of solid waste, wastewater, biosolids, and industrial waste. Water-, wind-, and human-driven processes and horizontal gene transfer circulate AR in the soil-microbe-plant resistome. The AR in bulk soil, soil components that include soil microorganisms, soil meso- and macro-organisms, and possible mechanisms of AR transfer to soil components and ultimately to plants are discussed. The health risks of the soil-microbe-plant resistome are less studied, but potential impacts include (1) the transfer of AR to previously susceptible organisms and other resistomes, including the human resistome. Overall, the study tracks the behaviour and health risks of AR in the soil–plant system. Future research should focus on (1) ecological risks of AR at different levels of biological organization, (2) partitioning of AR among various phases of the soil–plant system, (3) physico-chemical parameters controlling the fate of AR, and (4) increasing research from low-income regions particularly Africa as most of the available literature is from developed countries. [ABSTRACT FROM AUTHOR]

Street dust enters the urban environments due to the resuspension of particles smaller than 100 micrometers. The magnetic properties of street dust and their relationship with the concentration of heavy metals have received less attention from researchers worldwide, and not much study has been performed on this issue in Iran. The objectives of this study were: (i) to investigate the spatial and seasonal changes in street dust, and (ii) to determine their relationships with the concentration of selected heavy metals in several cities in the Isfahan province. Sampling was carried out in the first half of the second month of each season including 20 samples from Isfahan city and 10 samples from Natanz, Shahreza, Falavarjan, Khomeinishahr, and Najafabad. The concentration of selected heavy metals was measured using an atomic absorption spectrometer. Also, the magnetic susceptibility values of the samples at low and high frequencies were determined and frequency-dependent magnetic susceptibility was calculated. The results showed that the presence of ferromagnesian minerals in the parent materials could be the reason for the high values of magnetic receptivity in Natanz City. However, the high level of this characteristic in the street dust of other cities could be due to human activities, especially in Isfahan city. Based on the results of principal component analysis, the high correlation of the first component with magnetic susceptibility and the concentration of zinc, copper, and chromium elements most likely indicates the absorption of these elements by particles close to superparamagnetic (SP). The high correlation of the second component with frequency-dependent magnetic susceptibility and concentration of nickel and cobalt is most likely related to the adsorption of magnetic elements and heavy metals into coarse polyhedral particles that remained on the street floor after the re-deposition of street dust particles. Also, the high correlations between magnetic parameters and the concentration of copper and zinc confirm their anthropogenic origin. On the other hand, low or negative correlations of Pb, Ni, Cr, and Co concentrations with magnetic susceptibility might confirm their natural or nonanthropogenic origin. The higher values of magnetic parameters of street dust in the spring season reflect the significant contribution of magnetic minerals in this season, compared to autumn and winter, and indicate the higher influence of human activities. [ABSTRACT FROM AUTHOR]

Different anthropogenic sources can have a significant influence on bacterial populations and their antimicrobial activities. In this study, the impact of anthropogenic activities on Enterococcus species was studied in an urban watershed in southern California affected by concentrated animal feeding operations (CAFOs), recreational activities, wastewater treatment plants (WWTPs), urban runoff, and control sites. Water samples were collected quarterly for two years for the enumeration of Enterococcus species based on the Enterolert most probable-number (MPN) assay. Concentrations of enterococci were higher in the sediment compared to surface water (4.5 × 106 CFU/g of sediment vs. 2.3 × 105 MPN/100 mL of water). The species diversity was dominated by E. mundtii (32%), E. faecalis (27%), and E. faecium (25%). E. faecium exhibited the highest antibiotic-resistant phenotype. Resistances were mostly to ciprofloxacin, erythromycin, and tetracycline. Tetracycline and erythromycin resistance genes, encoded by tet (C, K, O, S) and ermB, respectively, were more common in isolates from sediment (42.9%) compared to water (12.7%). E. mundtii was sensitive to ampicillin, chloramphenicol, gentamicin, and high levels of vancomycin. A significant percentage of E. faecalis were also resistant to these antibiotics. E. faecium and E. faecalis exhibited resistance to multiple antibiotics. Our data suggest that resistant Enterococcus species within the watershed might provide some useful data to determine pollutant types and sources in that watershed. Therefore, the widespread occurrence and abundance of E. faecium and E. faecalis, and their resistance genes associated with multiple antibiotics may potentially pose risks to the local populations exposed to these water sources during recreational activities. [ABSTRACT FROM AUTHOR]

In this study, PM2.5 aerosols were collected from the campus of the University of Jammu situated along the Shivalik foothills of the North‐western Himalayas in the Jammu urban area to understand the seasonal variability of PM2.5 mass concentrations and associated water‐soluble inorganic ions (WSIIs). Results showed that the annual average PM2.5 mass concentrations were average 65.02 μg/m3 which significantly exceeded the annual National Ambient Air Quality Standards (40 μg/m3) by ~1.6 times. In addition, PM2.5 and WSIIs mass concentrations exhibited significant seasonal variability with the highest average concentrations observed during winter and the least during monsoon. Furthermore, WSIIs accounted for 24.56% of PM2.5 mass annually. Cl−, Na+, Ca2+ and Mg2+ depicted higher concentrations in summer whereas higher mass concentrations of SO42−, NO3− and NH4+ observed during winter pointed to their formation from gas to particulate conversion mechanisms. The variability of source strength during peak tourist seasons in holidays, festivities and new year appears to have significantly accounted for high PM2.5 in the study area. Additionally, meteorological conditions also appear to have played an important role in secondary aerosol formation which is noticeable from the high correlation observed among SO42−–NO3− (0.97), NH4+–SO42− (0.69), K+–Cl− (0.85), NH4+–NO3− (0.64), SO42−–K+ (0.63), NH4+–Cl− (0.65) at p <.05 during winter. On the other hand, significant correlations (p <.01) observed between Ca2+–Mg2+ (0.94), SO42−–Ca2+ (0.78) and SO42−–Mg2+ (0.89) during summer indicated their primary origin as crustal‐based sources. [ABSTRACT FROM AUTHOR]

Assessment of pollutants and groundwater quality has attracted much attention worldwide as it is directly linked to human health. In view of this, groundwater samples were collected from a part of Guntur district, Andhra Pradesh, India, to assess groundwater pollution levels and groundwater quality, using Water Pollution Index (WPI) and Water Quality Index (WQI), respectively. Groundwater chemical composition results indicated that groundwater quality was characterized by alkaline and very hard categories with Na+ > Mg2+ > Ca2+ > K+: HCO3 - > Cl - > SO42 - > NO3 - > F - facies. TDS, TH, Ca2+, Mg2+, Na+, K+, HCO3 - , Cl - , NO3 - , and F - were above the recommended threshold limits in 100%, 100%, 35%, 100%, 100%, 100%, 100%, 95%, 85%, and 75% of groundwater samples, respectively, for drinking purposes. The geochemical diagram showed base exchange water type (Na+–HCO3 - ) in 50% of groundwater samples resulting from weathering and dissolution of plagioclase feldspars under the influence of soil CO2 and ion exchange process. The remaining groundwater samples showed saline water type (Na+–Cl - ) due to the influence of evaporation, sewage sludge, septic tank leaks, irrigation-return flows, agrochemicals, etc. Ionic relationships of Ca2+/Na+vs HCO3 - /Na+, Ca2+/Na+vs Mg2+/Na+, higher Na+ than Ca2+, and occurrence of CaCO3 concretions further supported geogenic processes that alter groundwater chemistry. The positive linear trend of TDS vs Cl - + NO3 - /HCO3 - and the relationship of TDS with TH showed anthropogenic input as the main factor, causing groundwater contamination. The WPI indicated two categories of water quality: moderately polluted water (WPI: 0.75–1.00) and highly polluted water (WPI: > 1.00) in 60% and 40% of groundwater samples, which were 81.49% and 18.51% of the study area, respectively. Hierarchical cluster analysis identified three clusters: Cluster I (pH, F - , Ca2+, K+, NO3 - , Na+, and SO42−), Cluster II (TH, Mg2+, Cl - , and HCO3 - ), and Cluster III (TDS) support WPI. Following WQI, 75% and 25% of groundwater samples fell under poor groundwater quality type (WQI: 100–200) and very poor groundwater quality type (> 200), respectively, especially due to the increased concentrations of Mg2+, Na+, K+, HCO32−, Cl - , NO3 - , and F - ions, thereby increasing salinity (TDS) and hardness (TH) in groundwater. Spatially, they covered 85.84% and 14.06% of the study area. The quality of this groundwater is not suitable for drinking purposes. Therefore, the present study suggests preventive measures (safe drinking water supply, desalinization, defluoridation, denitrification, calcium food, and rainwater harvesting) to protect human health. [ABSTRACT FROM AUTHOR]

This paper provides an overview of the various sources of air pollution and their impact on the environment and human health, distinguishing between natural and anthropogenic (man-made) sources. The study assessed the environmental impact of these sources – the overall level of air pollution, taking into account the predominant anthropo-genic source, such as emissions from vehicles and industrial activities. The important role of geographic information systems (GIS) in monitoring air pollution, performing spatial data analysis, and identifying pollution hotspots is emphasized. This method proposes to analyze the impact of the air quality result on public health and the environment. The main focus of the study is on the predominant pollutants in the atmosphere such as particulate matter (PM), nitrogen oxides (NOx), and sulfur dioxide (SO2). The object of the study was the Old Town of the city of Vilnius. A calculation model was created in the MatLab environment to determine the pollution. The results reveal trends in environmental indicators. In the Old Town, decreasing pollution levels of PM10 and CO are observed, and NO2 remained relatively constant from 2020 the month of January until 2022 December. The primary importance of environmental monitoring depends on government regulation, technological advancements, and public participation to effectively reduce air pollution and protect the environment. Article in English. Oro taršos šaltiniai ir jų poveikis aplinkai Santrauka Šiame darbe pateikiama įvairių oro taršos šaltinių ir jų poveikio aplinkai ir žmonių sveikatai apžvalga, išskiriant natūralius ir antropogeninius (žmogaus sukurtus) šaltinius. Tyrime įvertinta šių šaltinių įtaka aplinkai – bendras oro taršos lygis, atsižvelgiant į vyraujantį antropogeninį šaltinį, pvz., transporto priemonių išmetamus teršalus ir pramoninės veiklos atliekas. Pabrėžtas svarbus geografinės informacijos sistemų (GIS) vaidmuo stebint oro taršą, atliekant duomenų erdvinę analizę ir nustatant taršos židinius. Šiuo metodu siūloma analizuoti oro kokybės rezultato poveikį visuomenės sveikatai ir aplinkai. Atliekant tyrimą pagrindinis dėmesys skirtas vyraujantiems atmosferoje teršalams, tokiems kaip kietosios dalelės (PM), azoto oksidai (NOx) ir sieros dioksidas (SO2). Tyrimo objektu pasirinktas Vilniaus miesto senamiestis, taršai nustatyti sudarytas skaičiavimo modelis MatLab programos aplinkoje. Rezultatai atskleidžia aplinkosaugos rodiklių tendencijas. Senamiestyje pastebimas mažėjantis PM10 ir CO taršos lygis, o NO2 kiekis nuo 2020 m. sausio mėn. iki 2022 m. gruodžio mėn. išliko gana pastovus. Aplinkos stebėsenos svarba labiausiai priklauso nuo vyriausybės reguliavimo, technologijų pažangos ir visuomenės dalyvavimo siekiant veiksmingai sumažinti oro taršą ir apsaugoti aplinką. Reikšminiai žodžiai: oro tarša, antropogeniniai šaltiniai, kietosios dalelės (PM), azoto oksidas (NOx), sieros dioksidas (SO2), ozonas (O₃), geografinės informacinės sistemos (GIS).

Multiple environmental problems are caused by the accumulation of nitrogen (N) and phosphorus (P) in river water on its way to the ocean. The objective of this work was to determine the N and P loads in 12 hydrographic basins that flow into estuaries along the northeastern coast of Brazil using established methods. Additionally, natural and anthropogenic loads trends in the hydrographic basins of 12 tropical rivers in northeastern Brazil over 27 years (1990-2016) were evaluated. The results indicated an annual average increase of +1.1% in population density, while precipitation showed no significant trend. The anthropogenic loads were 21 and 112 times higher than natural inputs for N and P, respectively. Anthropogenic sources accounted for ~ 96% of all contributions. The positive trends of these loads (mainly wastewater) represented an annual average increase of 1.1% for N and 1.2% for P, for all river basins included in this study. These percentages represent average annual loads of 251 t N yr-1 and 54.8 t P yr-1. The time series of N and P in the study region showed trends that point to a constant increase, implying a greater contribution of these loads to the adjacent coastal region year after year.

Based on a shipboard observation conducted in winter 2018, we reported the aerosol chemical properties and their differences in offshore and remote oceans over the Western Pacific Ocean (WPO). It's found that the chemical compositions over the WPO have significant spatial heterogeneity due to the influences of regional transport of anthropogenic aerosols and long‐path transport of dust aerosols. The average concentration of water soluble ions during the whole sampling period followed Cl− > OC > Na+ > SO42− ${{\text{SO}}_{4}}^{2-}$ > NO3− ${{\text{NO}}_{3}}^{-}$ > Ca2+ > Mg2+ > EC > K+ > NH4+ ${{\text{NH}}_{4}}^{+}$. Crustal elements of Ca (980.41 ng/m3), Na (971.55 ng/m3), and Al (781.16 ng/m3) were uniformly distributed in offshore area, but high proportion of Na elements dominated in remote regions. The total concentration of heavy metals including Zn, Cu, Cr, Pb and others originating from anthropogenic sources were 208 ng/m3 along the coastal region, about 10 times higher than that of 20.2 ng/m3 in the offshore and remote seas. For the reconstructed components, we found an increase of sea‐salt aerosol ranged from 3% to 72%, and a decrease of black carbon, organic matter and secondary inorganic salts, indicating a transformation from anthropogenic influence to marine environment. The rapidly increased secondary organic matter during dust event revealed that the transport of dust serves as catalysts to promote multi‐phase reactions. Cl− photochemical reaction rate in offshore area was mainly affected by sulfate from anthropogenic emissions, with an average chlorine loss rate of 18%, whereas it was inverse Cl− excess in the remote oceans. Plain Language Summary: The Institute of Oceanography, Chinese Academy of Sciences, organized a shipboard scientific observation over the Western Pacific Ocean (WPO) in winter 2018 to explore the chemical compositions of marine aerosols. The results showed that the chemical compositions over the WPO have significant spatial heterogeneity due to the different pollutants from various sources. Anthropogenic elements such as SO42− ${{\text{SO}}_{4}}^{2-}$, NO3− ${{\text{NO}}_{3}}^{-}$, and OC dominated in offshore waters, whereas the sea salt components of Na and Cl took a high proportion in remote oceans. In addition, dust aerosol originating from the North Africa also affected the WPO regions by long‐distance transport. The photochemical reaction rate of Cl− in offshore area was mainly affected by sulfate concentration from anthropogenic emissions, with an overall chlorine loss rate of 18%, but it exhibited an inversely Cl− excess phenomenon in the remote oceans. Key Points: The compositions of aerosol presented a significant change from anthropogenic source to marine sea salt from coast to remote oceansDust from North Africa acted as catalyst to promote the intensive formation of secondary organic aerosols in equatorial areaThere was a significant chlorine loss in the offshore coast, and a pronounced chlorine excess in remote seas [ABSTRACT FROM AUTHOR]

The widespread presence of organic aerosols (OA) in the atmosphere and their dominant role in climate forcing are increasingly recognized. Measurements from the high‐altitude region provide insights into the natural processes and long‐range transport of aerosols. We studied water‐soluble organic compounds in PM1.1 during January‐March 2020 and February‐April 2021 at Ponmudi (8.8°N and 77.1°E), a tropical hill station (960 m a.s.l.) located on the Western Ghats of India. The 5‐day backward trajectories of air masses presented that continental and marine sources impacted the site during the campaign, and thus we classified samples as mixed and marine air masses. Their molecular fingerprints revealed the prevalence of oxalic acid (C2), followed by terephthalic acid in mixed air mass and malonic (C3) or succinic (C4) acid in maritime air mass aerosol samples. This feature and the phthalic to azelaic acid ratio, as well as the C3 to C4 and fumaric to maleic acid ratios, evidenced that water‐soluble OA were of anthropogenic origin and less photochemically aged in mixed air mass samples, whereas they derived from biogenic sources and more photochemical aging in marine air mass samples. However, we found their comparable contributions in water‐soluble organic carbon under mixed and marine air masses. Linear correlations between C2 relative abundance and its ratios with the precursor compounds implied that the oxidation of precursors to oxalic acid occurs during atmospheric transport. The results revealed that the input of anthropogenic and biogenic precursors followed by atmospheric processing controlled the burden of water‐soluble OA across the Western Ghats. Plain Language Summary: Dicarboxylic acids (DCAs), oxocarboxylic acids and dicarbonyls are ubiquitous water‐soluble components of organic aerosol (OA) that can serve as cloud condensation nuclei and affect the climate of the Earth. We reveal for the first time the molecular fingerprints and sources as well as formation processes of water‐soluble OA in PM1.1 at a tropical hill station in Western Ghats of India. Significant differences in the molecular fingerprints and atmospheric processes of water‐soluble OA were found due to the influence of different air masses. DCAs and related compounds in mixed air mass aerosols originated from anthropogenic sources and produced in the atmosphere by photooxidation during long‐range transport whereas they were of biogenic origin followed by intense photochemical aging of biogenic volatile organic compounds such as isoprene and unsaturated fatty acids during atmospheric transport in marine air mass aerosols. The results revealed that DCAs substantially contribute to water‐soluble OA not only in mixed air mass aerosols but also in marine air mass aerosols at the tropical hill station in the Western Ghats. These findings have implications for assessing climate‐forcing feedback of secondary OA over the Western Ghats that is driven by anthropogenic and biogenic sources followed by photochemical processes. Key Points: Mixed and marine air masses drive the molecular fingerprints of atmospheric water‐soluble organic compounds over the Western GhatsAerosols of mixed air masses comprised dicarboxylic acids (DCAs) of anthropogenic origin and less photochemically processedDCAs were produced from biogenic sources followed by intense photochemical aging in marine air mass aerosols [ABSTRACT FROM AUTHOR]

The District of Bani Kenanah is home to natural reserves, forests, local agricultural practices, and a multitude of historical and cultural sites. The majority of the population in the study area is employed in the agricultural sector, which is dominated by olive tree cultivation and the production of premium olive oil. The current study aimed to assess the degree of roadside soil pollution and predict the potential ecological impacts of Pb, Cd, Zn, Cr, Ni, Mn, Cu, Fe, and Co. Therefore, 30 soil samples were collected and analyzed with a Flame atomic absorption spectrophotometer for the aforementioned metals. The spatial distribution maps of these metals were generated by inverse distance weighted (IDW) interpolation in ArcGIS 10.3. The values of heavy metals (HMs) in the study were lower than the international standards for soil quality. The soil was classified as moderately to substantially enriched with Cd, Pb, and Zn based on the EF values. However, the indices of geo-accumulation (Igeo), contamination factor (CF), and potential ecological risk (RI) generally revealed minor metallic contamination. The traffic and agricultural activities were the potential sources of Cd, Pb, and Zn in the study area. Incorporating HMs analysis with GIS maps was beneficial for assessing soil pollution. [ABSTRACT FROM AUTHOR]

Abstract The widespread presence of organic aerosols (OA) in the atmosphere and their dominant role in climate forcing are increasingly recognized. Measurements from the high‐altitude region provide insights into the natural processes and long‐range transport of aerosols. We studied water‐soluble organic compounds in PM1.1 during January‐March 2020 and February‐April 2021 at Ponmudi (8.8°N and 77.1°E), a tropical hill station (960 m a.s.l.) located on the Western Ghats of India. The 5‐day backward trajectories of air masses presented that continental and marine sources impacted the site during the campaign, and thus we classified samples as mixed and marine air masses. Their molecular fingerprints revealed the prevalence of oxalic acid (C2), followed by terephthalic acid in mixed air mass and malonic (C3) or succinic (C4) acid in maritime air mass aerosol samples. This feature and the phthalic to azelaic acid ratio, as well as the C3 to C4 and fumaric to maleic acid ratios, evidenced that water‐soluble OA were of anthropogenic origin and less photochemically aged in mixed air mass samples, whereas they derived from biogenic sources and more photochemical aging in marine air mass samples. However, we found their comparable contributions in water‐soluble organic carbon under mixed and marine air masses. Linear correlations between C2 relative abundance and its ratios with the precursor compounds implied that the oxidation of precursors to oxalic acid occurs during atmospheric transport. The results revealed that the input of anthropogenic and biogenic precursors followed by atmospheric processing controlled the burden of water‐soluble OA across the Western Ghats.

Lead (Pb) isotopes are less fractionated than those from different sources, and thus were used to trace the sources of Pb in the environment. To investigate the sources of Pb in the atmosphere of the Tibetan Plateau, stable Pb isotopes (206Pb, 207Pb and 208Pb) in acidified snow pit samples collected from five glaciers (i.e., Qiyi-QY, Meikuang-MK, Yuzhufeng-YZF, Hariqin-HRQ and Xiaodongkemadi-XDKMD) in May 2016 of the northern and central Tibetan Plateau were measured. The results showed narrow ranges of 1.158–1.187 for 206Pb/207Pb and 2.450–2.489 for 208Pb/207Pb respectively. The 206Pb/207Pb ratios in all samples were obviously lower than the environmental background value of 1.196, indicating the primary contributions of anthropogenic sources. At least 60% of Pb was contributed by various human activities, which was supported by the Pb isotopes in the snow pit samples from the QY, MK, YZF, HRQ and XDKMD glaciers. By comparing Pb isotope data, we found that the primary anthropogenic sources are coal combustion, mining and smelting activities in northwestern China and mixed emissions from cities located in western China and close to the glaciers. These sources contributed to the Pb in the northern glaciers (QY and MK) in particular. Coal combustion in India probably contributes to the central glaciers (HRQ and XDKMD). Another potential source could be parts of central Asia (e.g., Kyrgyzstan and Uzbekistan) through long range transport. The above potential source areas of contaminants were traced further by the air mass back-trajectory tracing method.

Heavy metal-polluted soils have grown ubiquitous worldwide due to increased geologic and anthropogenic activity, and the plants growing in these soils exhibit decreased growth, performance, and yield. Contaminated soil with heavy metals has become a concern for agricultural scientists because of the progress made in agricultural product safety. Heavy metals are metalloids with biological toxicity. The most common are arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), lead (Pb), and zinc (Zn). These metals exist throughout the terrestrial environment and have spread out due to anthropogenic and natural activities. Soil heavy metal pollution leads to human health risks, groundwater pollution, plant phytotoxicity, and a decline in crop and soil production. Bioremediation is an effective method of treating heavy metal-polluted soils. It is a widely accepted method that is mostly carried out in situ; hence it is suitable for the establishment/reestablishment of crops on treated soils. Using plants in the treatment of polluted soils is a more common approach in the bioremediation of heavy metal-polluted soils. Bioremediation ensures a more efficient clean-up of heavy metal-polluted soils. However, the success of this approach largely depends on the species of organisms. This paper is aimed to review the hazardous effects of heavy metal toxicity on soil and plants and their bioremediation. This paper also discusses numerous strategies for addressing heavy metal contamination in soil. [ABSTRACT FROM AUTHOR]

The coastal lagoons of the Gulf of California support important traditional fisheries and mollusc cultures (generally oysters) and receive important volumes of agricultural, industrial and urban effluents, consumption of the oysters could pose risk to human health. The concentrations of arsenic (As), cadmium (Cd), copper (Cu), iron (Fe), lead (Pb), and zinc (Zn) in the oysters Saccostrea palmula and Crassostrea corteziensis, from four coastal lagoons (Altata, AL; Macapule, ML; Navachiste, NL; El Colorado, ECL) in the Southeast Gulf of California, were seasonally evaluated (summer 2019–spring 2020). The order of magnitude of potentially toxic elements concentrations in the soft tissue in both oyster species and at all sites was Zn > Fe > Cu > As > Cd > Pb. Cadmium, Cu, Pb, and Zn exceeded the maximum permissible limits in more than one sampling site. The highest concentrations (mg kg–1, wet weight) of As (4.2 ± 1.1, spring) and Cd (3.3 ± 0.7, autumn) were registered in S. palmula et al. and NL sampling sites, respectively. Crassostrea corteziensis presented higher levels of Cu (40.5 ± 6.7, spring), Pb (2.0 ± 0.4, spring), and Zn (96.9 ± 20.4, spring) in ECL and Fe (62.2 ± 25.4, autumn) in ML. The hazard quotient (HQ) values exceeded the safe level of 1 for Cd in S. palmula and C. corteziensis in NL for children (~ 16 kg weight). In addition, in children, the hazard index (HI) values in both species of oysters ranged from 0.7 to 2.1 and 0.6 to 1.9, respectively. On the other hand, the intake of the studied elements through the consumption of oysters would not induce adverse effects to human health (men and women weighing 70 and 60 kg, respectively); HQ and HI values were < 1. [ABSTRACT FROM AUTHOR]

Fine atmospheric particles have physiological toxicity affecting human health. This study investigates the compositional and morphological properties of the particulate matter smaller than 10 µm (PM10) collected from five different monitoring stations in Chelyabinsk, Russia. We used scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) for the investigation of PM10. In order to determine the possible sources of emissions of atmospheric particulate matter, a principal component analysis (PCA) was performed. The results revealed the presence of atmospheric PM10, such as aluminosilicates, calcium particles, sulfates, and metallic particles differentiated on the basis of the chemical composition and morphological parameters. Sulfate PM10 with metal inclusions contained Mn, Ti, Zn, Cu, and Cr. It obtained a higher content of potentially toxic elements in traffic-related S-rich particles compared with industrial-related PM10. It was the result of the solubilization of metals in airborne particles and increased toxicity. We obtained new coatings based on titanium nanooxide synthesized by the peroxy method for air purification from PM2.5 and PM10. They were macroporous and very effective means against industrial dust and PM air pollution. [ABSTRACT FROM AUTHOR]

Different anthropogenic sources can have a significant influence on bacterial populations and their antimicrobial activities. In this study, the impact of anthropogenic activities on Enterococcus species was studied in an urban watershed in southern California affected by concentrated animal feeding operations (CAFOs), recreational activities, wastewater treatment plants (WWTPs), urban runoff, and control sites. Water samples were collected quarterly for two years for the enumeration of Enterococcus species based on the Enterolert most probable-number (MPN) assay. Concentrations of enterococci were higher in the sediment compared to surface water (4.5 × 106 CFU/g of sediment vs. 2.3 × 105 MPN/100 mL of water). The species diversity was dominated by E. mundtii (32%), E. faecalis (27%), and E. faecium (25%). E. faecium exhibited the highest antibiotic-resistant phenotype. Resistances were mostly to ciprofloxacin, erythromycin, and tetracycline. Tetracycline and erythromycin resistance genes, encoded by tet (C, K, O, S) and ermB, respectively, were more common in isolates from sediment (42.9%) compared to water (12.7%). E. mundtii was sensitive to ampicillin, chloramphenicol, gentamicin, and high levels of vancomycin. A significant percentage of E. faecalis were also resistant to these antibiotics. E. faecium and E. faecalis exhibited resistance to multiple antibiotics. Our data suggest that resistant Enterococcus species within the watershed might provide some useful data to determine pollutant types and sources in that watershed. Therefore, the widespread occurrence and abundance of E. faecium and E. faecalis, and their resistance genes associated with multiple antibiotics may potentially pose risks to the local populations exposed to these water sources during recreational activities.

Lakes are sensitive ecosystems and respond quickly to any natural or anthropogenic contamination, particularly in urban areas due to poor planning and mismanagement in urban settlement, encroachment, and anthropogenic pollution. In the current study, water and sediment geochemistry are used along with available time series of geospatial data sets to assess: a) provenance and sources of pollution in the lake sediment and water, b) health risk using various sediment and water quality indices, and c) the key drivers of lake shrinkage. Chemical index of alteration (CIA) of lake sediment is higher (>85) with an atypical cluster of samples (CIA = 50–75) towards the south and west of the lake. Further, samples in this cluster show granodioritic provenance which is contrary to the overall mafic provenance of lake sediment. The unusual decrease in CIA in the southern and western side of the lake is attributed to anthropogenically induced fresh sediment in the lake. The results indicate that the sediment is highly polluted by cadmium (Cd) and moderately polluted by copper (Cu), molybdenum (Mo), lead (Pb), and boron (B). Higher Metal Index (MI) values for most of the water samples (>70%) and Hazard Index (HI) for chromium (Cr), nickel (Ni), and cadmium (Cd) towards west and south of the lake reflect the deterioration of water quality in the lake. Moreover, land use change detection attained from available time series of geospatial data sets indicate a drastic transformation of the open water area into other land use classes particularly human settlement, shrinking the lake open water area by 13 km2 since 1859. The current study will help policy makers and managers to restore and conserve the lake. • Dal Lake has lost 52% of its open water area due to the human activities. • Unusual decrease in CIA (50-75) in the south/west of the lake is attributed to encroachment by filling of fresh sediment. • The lake sediment is strongly to moderately contaminated for some trace elements. • High metal and hazard indices reflect the deterioration of water quality in the lake. [ABSTRACT FROM AUTHOR]

Abstract In this study, we present a first-ever effort made to develop an ultra-high-resolution gridded emission inventory (i.e. ~ 0.4 km × ~ 0.4 km) for the Indian megacity Kolkata. As the rising demand for fossil fuels based energy along with the spread of urban corridors have forced the anthropogenic activities to a mounting level, therefore determining the sources responsible is of paramount importance. This has worsened not only the regional air quality but also has an indirect effect on the global air quality. The spatial and temporal variation of the source requires an accurate estimation of the surface emission which is the most essential parameter to study the air quality, that positively has been fulfilled in this study. The annual emission for 2020 is calculated to be 37.2 Gg/yr of PM2.5, 61.4 Gg/yr of PM10, 222.6 Gg/yr of CO, 131.3 Gg/yr of NOx, 60.3 Gg/yr of SO2, 120.4 Gg/yr of VOC, 9.5 Gg/yr of BC and 16.8 Gg/yr of OC that prevails in the toxic air of megacity Kolkata. The present surface chemistry dataset will be the first line of detailed information regarding emission hotspots in the megacity that could be used as important tool for clean air mitigation strategies, input into the air quality modeling study to tackle environmental issues, and public health. Article Highlights Identification of sources of pollutants through spatially resolved high-resolution inventory in megacity Kolkata. Unlike transport and industrial sector, municipal solid waste burning has emerged as another big source. Present information is vital for policy making to mitigate air quality issues and modeling studies.

Ammonia (NH 3) acts as a key precursor of the particulate matter, could reduce visibility, deplete stratospheric ozone, and trigger perturbation in ecosystems. Being an agrarian country with a large livestock population and uncontrolled fertilizer application, India could be accountable as a major stakeholder of global NH 3 emissions. This study developed a comprehensive gridded (0.1° x 0.1°) ammonia inventory for India considering 24 types of sources. The total NH 3 emission is estimated to be 10.54 Tg/yr in 2022, where synthetic fertilizer application accounts for ∼47 % followed by livestock (∼34 %). Minor unattended sectors such as biomass burning, agricultural soil, human excrement, waste disposal, etc. contribute 0.68 Tg/yr, 0.32 Tg/yr, 0.3 Tg/yr, and 0.14 Tg/yr, respectively. The overall uncertainty of the inventory ranges around ± 55 %. These emission datasets are essential for atmospheric chemistry models and could be a crucial tool for policymakers to combat ammonia pollution. [Display omitted] • Total NH 3 emission for India is estimated to be 10.54 Tg/yr in 2022. • Fertilizer application is the highest contributor (47 %), followed by livestock (34 %). • Biomass burning, open defecation and agricultural soil are the emerging sectors. • Only 11 % area accounts for 50 % of total NH 3 emissions. • Indo-Gangetic plains, Western and Southern India are the prominent hotspots. [ABSTRACT FROM AUTHOR]

Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) have been recognized as novel hazardous pollutants; however, the dominant sources remain unclear. This study investigates the occurrences of ClPAHs in five stages of size-segregated particles collected from an urban site and evaluates the sources and factors affecting the concentrations using organic and inorganic source tracers. ClPAHs are the most frequently detected in the finest particle fraction (less than 1.1 µm; PM1.1), similar to polycyclic aromatic hydrocarbons (PAHs), hopanes, and levoglucosan (LEV). The concentrations of total ClPAHs in PM1.1 shows a significant correlation (p

Source water nutrient management to prevent eutrophication requires critical strategies to reduce watershed phosphorus (P) loadings. Shanxi Drinking-Water Source Area (SDWSA) in eastern China experienced severe water quality deterioration before 2010, but showed considerable improvement following application of several watershed management actions to reduce P. This paper assessed the changes in total phosphorus (TP) concentrations and fluxes at the SDWSA outlet relative to watershed anthropogenic P sources during 2005⁻2016. Overall anthropogenic P inputs decreased by 21.5% over the study period. Domestic sewage, livestock, and fertilizer accounted for (mean ± SD) 18.4 ± 0.6%, 30.1 ± 1.9%, and 51.5 ± 1.5% of total anthropogenic P inputs during 2005⁻2010, compared to 24.3 ± 2.7%, 8.8 ± 10.7%, and 66.9 ± 8.0% for the 2011⁻2016 period, respectively. Annual average TP concentrations in SDWSA decreased from 0.041 ± 0.019 mg/L in 2009 to 0.025 ± 0.013 mg/L in 2016, a total decrease of 38.2%. Annual P flux exported from SDWSA decreased from 0.46 ± 0.04 kg P/(ha·a) in 2010 to 0.25 ± 0.02 kg P/(ha·a) in 2016, a decrease of 44.9%. The success in reducing TP concentrations was mainly due to the development of domestic sewage/refuse collection/treatment and improved livestock management. These P management practices have prevented harmful algal blooms, providing for safe drinking water.

Heavy metal concentrations were investigated for 30 sediments collected from different regions of Mighan playa/lake. The means of Cr, Cu, Ni, Pb, Zn and Cd in sediments of playa/lake were much lower than the soil guideline values of Iran and background values of region (BVR). However, the maximum concentrations of Cr, Cu, Ni, Pb, Zn and Cd were higher than BVR. Only 7% of Cr, Cu, Zn, 27% of Ni, 14% of Pb and 38% of Cd concentration exceeded the BVR. The heavy metal Cr, Zn, Ni and Cd are the most important metals in different land use. About 11% of the samples in the lake land use contain Cr, Ni, Pb and Zn has concentration higher than BVR. The concentration of Cu and Pb in 33% and 67% samples is exceeded the BVR in Tail of Mineral Salts Company. The spatial distribution patterns of Cr, Cu, Ni, Pb, Zn and Cd were generally similar and increase from Mighan playa/lake to the Arak city and mainly affected by anthropogenic sources. Among the six types of land use, the concentrations of Cr, Ni, Zn and Cd in the range land and wastewater sludge were significantly higher than those in the other land use (p

Solubility largely determines the impacts of aerosol Fe on marine ecosystems and human health. Currently, modeling studies have large uncertainties in aerosol Fe solubility due to inadequate understanding of the sources of dissolved Fe. This work investigated seasonal variations of Fe solubility in coarse and fine aerosols in Qingdao, a coastal city in the Northwest Pacific, and utilized a receptor model for source apportionment of total and dissolved aerosol Fe. Desert dust was found to be the main source of total Fe, contributing 65 and 81% annually to total Fe in coarse and fine particles, respectively; in contrast, dissolved aerosol Fe originated primarily from combustion, industrial, and secondary sources. The annual average contributions to dissolved Fe in coarse and fine particles were 68 and 47% for the secondary source and 32 and 33% for the combustion source, respectively. Aerosol Fe solubility was found to be highest in summer and lowest in spring, showing seasonal patterns similar to those of aerosol acidity. Increase in Fe solubility in atmospheric particles, when compared to desert dust, was mainly caused by secondary processing and combustion emission, and the effect of secondary processes was dictated by aerosol acidity and liquid water content.

Abstract: Aim Estimate the input of loads of N and P emitted by natural (atmospheric deposition and soil denudation) and anthropogenic (agriculture, livestock and sewage) factors for the hydrographic basins of two reservoirs in the Brazilian semiarid region (Mendubim and Umari). Methods In the present work, we use georeferenced data provided by official agencies, data presented in academic papers, field samples and laboratory analysis of emission factors in the estimates of nitrogen and phosphorus inputs in reservoir basins of Brazilian semiarid region. Results Soil denudation was identified as the main natural source of N and atmospheric deposition as the main source of P in both basins. Among the anthropogenic sources, the main source of N and P, for the two basins, was livestock. The total loads (natural and anthropogenic) of N (579.01 tonne. year-1) and P (136.35 tonne. year-1) received by the Umari basin was, respectively, 43.90% and 22.10% higher than those received by Mendubim, with a predominance of anthropogenic sources in both nitrogen and phosphorus emission. Conclusions The results showed the importance of monitoring human activities that can enhance nutrient inputs, such as nitrogen and phosphorus, in basins of the Brazilian semiarid region. The quantification of the emission factors analyzed here can be a tool in the development of strategies to mitigate the problems that high concentrations of N and P can bring to the quality and use of water in semiarid reservoirs.

Currently, all the technology used for seismic monitoring is based on sensors in the electrical domain. There are, however, other physical principles that may enable and fully replace existing devices in the future. This paper introduces one of these approaches, namely the field of fiber optics, which has great potential to be fully applied in the field of vibration measurement. The proposed solution uses a Michelson fiber-optic interferometer designed without polarization fading and with an operationally passive demodulation technique using three mutually phase-shifted optical outputs. Standard instrumentation commonly used in the field of seismic monitoring in geotechnical engineering was used as a reference. Comparative measurements were carried out during the implementation of gravel piles, which represents a significant source of vibration. For the correlation of the data obtained, the linear dependence previously verified in laboratory measurements was used. The presented results show that the correlation is also highly favorable (correlation coefficient in excess of 0.9) from the values measured in situ, with an average deviation for the oscillation velocity amplitude of the optical sensor not exceeding 0.0052. [ABSTRACT FROM AUTHOR]

Suspended particulate matter (SPM) is a major source of contamination in urban rivers as it serves as a carrier for pollutants, such as heavy metals. In this study, the Beiyun River, northern China, was used as a case study to determine the characteristics of SPM-associated heavy metal spatial distribution, to evaluate the potential ecological risks and identify heavy metal sources. The concentrations of seven heavy metals and other associated indicators (TC, TN, TP, and OM) were measured at 12 sites and analyzed by Pearson correlation (PC) and principal component analyses (PCA). The average concentrations of Cr, Ni, Cu, Zn, As, Cd, and Pb were 70.72, 27.88, 31.35, 115.70, 27.77, 0.23, and 29.62 mg/kg, respectively, with significant spatial differences occurring between some elements. Igeo values established the ranked order of heavy metal pollutant concentrations in SPM as As > Cd > Zn > Cu > Pb > Cr > Ni. E r i analysis demonstrated that the ranked order of potential ecological risk from the seven metals was Cd > As > Cu > Pb > Ni > Cr > Zn. Potential ecological risk index (RI) results confirmed the high potential ecological risk in the study area. Among the measured heavy metals, Cd represented the highest pollution risk, as shown by its highest E r i value. Correlation analysis (CA) showed that Zn had a strong correlation with Cu and Pb. Significant positive correlations were found between TC, TN, TP, and Cu. Three element pairs, Zn-Cd, Cr-Cu, and Cr-Ni, were also found to have strong correlations. Zn, Cu, and Ni were mainly introduced by human activities including urban industrial sewage discharge (such as metallurgy and electroplating industrial wastewater), agricultural drainage, and landfill wastewater, while Cr mainly originated from natural processes like mineral weathering and atmospheric precipitation. This information on the concentration, risk, and sources of SPM in Beiyun River provides an important reference for the reduction of heavy metal pollution in SPM in a typical river in the Haihe River Basin (China). [ABSTRACT FROM AUTHOR]