High Enrichment Factor Values Research Articles

The Added Value of Urban Trees (Tilia tomentosa Moench, Fraxinus excelsior L. and Pinus nigra J.F. Arnold) in Terms of Air Pollutant Removal

The serious densification of human settlements necessitates an increase in the role and importance of green infrastructures in the overall functioning of urban ecosystems. Accordingly, the aim of the present study was to (1) assess the efficiency of air pollutant removal (potentially toxic elements) of three common ornamental trees (Tilia tomentosa Moench, Fraxinus excelsior L. and Pinus nigra J.F. Arnold) and (2) model the air quality regulatory services (removal of PM10, PM2.5 and NO2). Three different approaches were applied—enrichment factor (EF) and metal accumulation factor (MAI) per tree species, as well as simulation modeling for the whole urban forest. The MAI values of the three studied species were found to be very similar, in the range of 22.35 to 23.08, which suggests that these species could be a good choice for planting in urban areas with worsened air quality. The highest EF values were observed for U (3–18), followed by As (1.6–2.56) and Sr (0.87–2.46). The potential of urban forests in countering air pollution was highlighted by three simulated scenarios for PM10, PM2.5 and NO2 removal. The highest removal efficiency was calculated for evergreen species, followed by the mixed composition of deciduous (90%) and evergreen trees (10%), and the scenario with wholly deciduous trees had the lowest one. The contribution of nature-based solutions in meeting air quality standards and enhancing resilience in urban areas was clearly demonstrated. The functional complementarity of the different functional tree groups (coniferous, evergreen and deciduous broad-leaved species) was proven to be crucial for the support of both functional stabilities of the phytocenosis under diverse climatic conditions and during the change of seasonal cycles in the vegetation.

Trace-metal enrichment mechanisms in Bakken Formation black shales, Williston Basin, North Dakota, USA

The Bakken black shales represent a unique sedimentary system characterized by high total organic carbon contents (TOC; Lower Bakken shale = 10.8 and Upper Bakken shale = 11.8 avg. wt%) and enrichment factors (EF) of various trace metals (TMs) such as Cu (6.2–7.7), Mo (219.7–237.8), Ni (9.4–10.2), U (20.6–29.3), V (9.9–14.2), and Zn (10.4–12.2) that are considerably higher than many other Devonian-Mississippian (D–M) black shales. In this study, raw distributions of elemental concentrations combined with bivariate and principal component analysis (PCA) were used to clarify processes that contributed to high TM EF values in the Bakken shales. Total organic carbon shares heavier PCA component loadings (>0.445) and stronger Pearson correlation coefficients (r) with Cu, Mo, Ni, U, V, and Zn than with pyrite-associated (As, Co, Fe, and S) elements, suggesting that organic matter (OM) played a primary role in the scavenging and accumulation of TMs in the sediments. Reducing conditions within bottom waters or sediment pore waters may have accelerated the accumulation of redox-sensitive Cu, Mo, Ni, V, and Zn introduced into the sediments via an OM detritus host and most likely played a secondary role in their enrichment. Deep-water renewal times for the Bakken have been estimated to be ∼10–30 yrs. based on Mo/TOC results. The high TM EF values observed in the Bakken shales may reflect frequent resupply of TMs into basin waters, enhanced primary productivity that is necessary in scavenging TMs from the water column, the presence of H2S within sediment pore or bottom waters, or possibly secondary processes associated with basin-wide fluid and hydrocarbon migration. High TOC concentrations may be the result of a possible shallow water column (∼150 m), which would limit exposure time of OM to oxidation and degradation, coupled with intermittent fluctuations between dysoxic and anoxic/euxinic bottom-water redox conditions, the latter of which would reduce rates of OM degradation by benthic organisms.

Chemical characteristics with attention on toxic metals content in sediments of the urban tropical ecosystem Río Almendares, Havana, Cuba: Pollution risk assessment

Anthropogenic disturbances have dramatically impacted surface water quality worldwide. There is no restriction placed on waste disposal in developing countries, so micropollutants, including metals, are of major concern to soil and water. A tropical river ecosystem was selected as a model for this study: Almendares River (Havana, Cuba). We investigated the occurrence of 15 toxic metals in surface sediment for ecological risk analysis. Results indicated that sediments of a silty loam type had higher concentrations of four metals (Cr concentration range: 3.59–7.35 mg kg−1, Cu: 6.23–14.82 mg kg−1, Zn: 22.64–27.40 mg kg−1, and Pb:3.85–6.72 mg kg−1), than Cuban norms. Further, the contamination indices including Enrichment Factor (EF), Geo-accumulation, Contamination Factor, Contamination Degree, Ecological Risk Factor and Potential Ecological Risk were calculated. 10 elements presented significant enrichment at the sampling stations of the 15 metals examined; Zn, Cd, Pb, Cu, and Ag had the highest EF values. Anthropogenic activities and polymetallic contamination could be the main source of these five heavy metals. The correlation analysis revealed that domestic, agricultural, and industrial sources were the main sources of contamination, along with an unregulated landfill. In terms of the extent of metal contamination in the urban site (Zone II) of Almendares River, this study constitutes the most comprehensive and extensive. The study contributes to the knowledge of the region and is crucial for the sustainable management of the Almendares River. There must be efforts made to control metal pollution in this river and ensure that metal levels are monitored.

Chemical Characteristics and Sources Analysis of PM2.5 in Shaoxing in Winter

By analyzing the mass concentrations and compositions of atmospheric PM2.5 in Shaoxing from December 2019 to February 2020, the characteristics of carbon-containing components, water-soluble ions and metal elements were obtained. NO3−, OC, SO42− and NH4+ were the main components of PM2.5 in winter. The OC/EC ratio was 3.27, which proved the existence of SOC. The proportion of SOC in OC was 47.3%, which showed that secondary sources made a significant contribution. The values of OC/EC and NO3−/SO42− indicated that vehicle exhaust emissions also made a significant contribution to PM2.5. Trace elements of Na, Ca, K and Cd had higher enrichment factor values and were enriched due to human activities. Finally, PM2.5 sources analysis was performed by the positive matrix factorization model. The results showed that secondary inorganic salts (49.3%), motor vehicles and industrial sources (21.3%) and dust sources (17.0%) were the important sources of PM2.5 pollution.

Spatiotemporal records of major historical events and human activities in river sediments: A coupled study of heavy metals distribution and lead isotopic dating

Thirty sediment samples (11 on the surface and 19 from a 55 cm core) collected in the Dadu River, upstream of the Yangtze River, China, were analyzed by ICP-MS and Laser diffraction particle size techniques to determine heavy metal spatial-temporal distribution and particle size characteristics, respectively. The intent was to clarify the impact of human activities such as Pb-Zn mining and exploration on the distribution of potentially toxic elements (As, Cd, Cr, Cu, Pb and Zn) in adjacent fluvial deposits. Moreover, 210Pb isotope dating was applied to study the historical variation and distribution of heavy metal pollution in a sedimentary profile in the middle section of the Dadu River. Results suggest that Cd concentration is notably high, exceeding by 16.3 times the soil background value in Sichuan Province, China, which can be intensified by Pb-Zn ore smelting. Surface sediments are mainly composed of silt, accounting for 79% on average, and relatively minor amounts of clay and sand. The fraction of clay in the downstream segments of the Dadu River is significantly higher than that upstream, indicating that the hydrodynamic force in the downstream region is relatively low compared with the upstream flow. Samples in the sedimentary profile, collected at 3 cm intervals, are mainly composed of silty sand, accounting for 75.6%, which comprehensively reflects the strong hydrodynamic force in this area. The results of 210Pb dating of these samples indicate three intervals of historical fluctuation in heavy metal concentrations: 1950–1966, 1988–1991 and 1996–2006, respectively, which coincide to significant historical events (the Cultural Revolution, the construction of Pubugou reservoir and local smelting activities, and the implementation of environmental protection policies). Enrichment factor (EF) values of all heavy metals in the profile began to increase after 1994, and relatively high EF values of Cr and Cd indicated a significant enrichment due to increasing anthropogenic activities during this period. Our study demonstrates that anthropogenic activities can be well recorded in sedimentary profiles and provide new insights to retrieving the history of human developments.

Historical trends and pollution assessment of heavy metals in core sediments from the Jiangsu offshore area, China

To assess the historical changes and pollution status of heavy metals, core sediments from the Jiangsu offshore area of China were systematically sampled and analyzed to determine the concentrations of Cu, Pb, Zn, Cr, Cd, As, Hg, Li, Ni, and Co. The stratigraphic framework of the SYS-1501 core was identified based on sedimentary structures, sedimentary facies, grain size, and comparison with seismic reflections and other well-studied cores from adjacent areas. The Pearson’s correlation coefficient, enrichment factor (EF), geoaccumulation index (Igeo), and principal component analysis (PCA) were used to distinguish the sources and assess the pollution risk of heavy metals. The results showed no elemental enrichment or contamination in the core sediments, and the high EF and Igeo values of Pb, As, Hg, and Li may be related to the selected background values of these metals. Except for Mn, all other metals and TOC exhibited similar vertical distribution patterns that were closely related to the mean grain size (Mz). Almost all the heavy metals were positively correlated with Al, Fe, and Mz, and all had high loadings on PC1, indicating that they are naturally sourced. Manganese (Mn) had a high loading on PC2, mainly representing the effect of marine authigenic elements on the sediments. Historical changes in the heavy metals in the core sediments were predominantly related to the sedimentary environment, sediment sources, and Mz.

The national maize hybrid as a potential mediator in the contamination of the food chain with heavy metals

ABSTRACT The ability of the maize hybrid ZP666 to uptake cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), and lead (Pb) from artificially contaminated soil in a pot experiment was investigated. The applied ICP-OES methods are of satisfactory accuracy (Recovery values from 88.9 to 103.0%) and negligible matrix effect (slope ratio from 0.95 to 1.11). The determined contents of the investigated heavy metals in plant parts of maize, the mass of roots, stems and leaves, the height of the aboveground parts as well as the BCF (Biological Concentration Factor), MR (Mobility Ratio), TF (Translocation Factor) and EF (Enrichment Factor) values show the highest influence of Cd. The strongest negative effect on mass (roots 59.7%, stems 56.6%, and leaves 42.5%) and on the height of aboveground parts (13.5%) was observed in the unit treated with Cd. Also, BCF and TF (stem/root) are higher than 1 only for Cd (1.65 and 1.07, respectively) and the highest EF values are for Cd in roots in units treated with Cd and with a mixture of heavy metals (37.30 and 24.04, respectively ZP 666). MR values were less than 1 in all cases. The results obtained are useful for tracing the migration of heavy metals from the roots to the aboveground parts as well as the potential of plant parts for the enrichment of added heavy metals through possible synergistic or antagonistic interactions.

Temporospatial Variation, Chemical Composition, and Source Resolution of PM2.5 in the Southeastern Taiwan Island

This study investigated the temporospatial variation, chemical composition, and source resolution of fine particles (PM2.5) in the southeastern seas of the Taiwan Island. 24-hr PM2.5 was sampled simultaneously at two remote sites, the Green Island (West Pacific Ocean; WPO) and the Kenting Peninsula (northern Bashi Channel; BC), in four seasons. After sampling, the chemical fingerprints of PM2.5 were characterized and further applied to resolve the potential sources of PM2.5 and their contribution by using a receptor model on the basis of chemical mass balance (CMB), enrichment factor (EF), and backward trajectory simulation. It showed that PM2.5 concentrations in winter (10.8 µg m–3) and spring (12.0 µg m–3) (i.e., during the period of Asian Northeastern Monsoons; ANMs) were higher than those in summer (4.0 µg m–3) and fall (6.6 µg m–3). In terms of chemical composition of PM2.5, secondary inorganic aerosols (SIAs = NO3–, SO42–, and NH4+) (56.7–67.2%) were the dominant component of water-soluble ions (WSIs) in PM2.5, while crustal elements (Mg, Al, Ca, Fe, and K) (44.0–61.2%) dominated the metallic contents in PM2.5. High EF values (> 10) showed that V, Mn, Ni, Cu, and Zn were potentially contributed from anthropogenic sources. Moreover, organic carbon (OC) (0.6 µg m–3) was superior to elemental carbon (EC) (0.3 µg m–3) in PM2.5. The OC/EC ratios higher than 2.0 showed the potential chemical formation of secondary organic aerosols (SOAs) in the atmosphere in winter and spring. Trajectory simulation indicated that high PM2.5 concentrations were mostly originated from North and Central China, Japan islands, and Korea Peninsula. Major sources of PM2.5 resolved by CMB receptor modeling were ordered as: sea salts (19.9%) > fugitive dust (19.8%) > industrial boilers (oil-fired) (10.8%) > secondary sulfate (9.8%) > mobile sources (8.0%).

Characterization of trace elements and Pb isotopes in PM2.5 and isotopic source identification during haze episodes in Seoul, Korea

Trace elements in fine particulate matter (PM2.5) exacerbate human health problems owing to exposure to PM2.5 and its toxic components. Samples of PM2.5 collected in Seoul, Republic of Korea, during typical haze episodes between November 2017 and April 2018, were analyzed for trace elements and Pb isotopes to characterize PM2.5 trace elements and their sources. The concentrations of Cu, Zn, As, Cd, Sb, Tl, and Pb showed statistically significant increases with ambient PM2.5 levels under their negative relationships with wind speed. High enrichment factor values provided evidence of significant inputs from anthropogenic sources. We assigned the dominant source regions of PM2.5 mass and chemical composition during individual sampling periods by coupling the Pb isotopic composition with the air mass back trajectories. The results identified three major categories of domestic, Chinese, and mixed domestic/Chinese source contributions, accounting for about 39%, 38%, and 21%, respectively, during the entire sampling period, which reflects a significant Chinese contribution. Principal component analysis (PCA) identified the major domestic sources for individual elements: coal/oil combustion and vehicle exhaust (Zn, As, Cd, Sb, Tl, and Pb), non-exhaust traffic emissions (Cu and Sb), and soil/road dust (Fe and Mn). Using a Pb isotopic mixing model, the relative contributions from coal combustion, oil combustion, and vehicle exhaust to associated trace elements were estimated to be 35 ± 11%, 35 ± 8%, and 29 ± 16%, respectively. Our results highlight that beyond addressing climate change, driving the transition from fossil fuels to renewable energy sources in the power, heat, and road transport sectors can help greatly reduce air pollution and achieve healthy environment.

The spatial–temporal impact on dissolved and particulate metals in Brunei Bay, Malaysia: Spectrometric and chemometrics approach

The concentrations of metals in the waters of Brunei Bay, Malaysia were determined to define the current level and changes of its distribution. Discriminant analysis showed that metals distribution was spatially influenced by anthropogenic activities, whereas the distribution of cadmium (Cd) and zinc (Zn) was temporally influenced by the seasonal changes. High concentration of particulate metals in the coastal region during the wet season was presumably affected by freshwater intrusion and strong current disturbance. Generally, the enrichment factor of the aluminium (Al), Cd, copper (Cu), lead (Pb), and Zn proved enrichment by anthropogenic sources, except for iron (Fe). Furthermore, Cd has the highest enrichment factor value, signifying the potential risk of Cd on the Brunei Bay waters even at a low level. However, the Malaysia Marine Water Quality Criteria and Standard have classified the Brunei Bay waters as unpolluted.

Seasonal and spatial variations of atmospheric depositions-bound elements over Tehran megacity, Iran: Pollution levels, PMF-based source apportionment and risks assessment

A total of 32 atmospheric depositions (ADs) samples were collected from eight sampling sites from April 2018 to March 2019 in the Tehran megacity. Elemental concentration, pollution characteristics, ecological and human health risks, and source apportionment of ADs in the < 63 μm fraction were investigated. Descriptive statistical analysis revealed that the average concentration of Zn, Cd, Pb, and Cu had the highest values over the upper continental crust (UCC). The influence of anthropogenic activities on the level of elements pollution was determined using the Geo-accumulation index (Igeo), Enrichment factor (EF), and Pollution index (PI). The findings revealed the highest Igeo values for Cd at the “extremely contaminated” level due to great influence from Cd emission sources, especially in spring. The extremely high EF values for Zn in 18.8% of samples could be attributed to the low distance of these sampling sites from the nearby industrial areas and adjacent road traffic density. PI values in the range of “considerable to extremely high” pollution were in the order of Zn > Cd > Pb > Cu > Ni > Cr. Eventually, The pollution load index (PLI) indicated the higher than unity of PLI values for all sampling sites reflecting considerable polluted sites across the study area. The ecological risk index (RI) indicated a considerable ecological risk, with the highest monomial risk values for Cd and Pb. The cumulative hazard index (HI) results showed that children encounter higher non-carcinogenic (NCR) risks than adults. However, the cumulative carcinogenic risk (CCR) of adults was 2.25 times higher than for children. The positive matrix factorization (PMF) model extracted four factors, including traffic-related sources (29.7%), local soils and crustal dust resuspension sources (24.8%), demolition and construction activities (23.5%), and industry-related emissions (22%). Among the identified sources, traffic-related sources showed the largest contribution to elements and ecological risks.

REVIEW: APPLICATION OF MAGNETIC SOLID-PHASE EXTRACTION (MSPE) IN VARIOUS TYPES OF SAMPLES

This review aimed to inform about the magnetic nanoparticle functionalization and solid magnetic phase extraction application to separate analytes in various types of samples. The review was conducted by analyzing several articles published in 2010 until 2021 obtained through search engines, such as Science Direct, Google Scholar and PubMed, using the keyword “magnetic phase extraction” and “magnetic nanoparticle”. The magnetic nanoparticle can be functionalized with organic, inorganic, and metal-organic framework compounds to obtain good selectivity and extraction capability. The Magnetic Solid Phase Extraction (MSPE) can be applied to separate analytes in biological, food, environmental samples. The MSPE can be used in various biological, food, and environmental samples resulting in high enrichment factor value, good recovery, and the magnetic adsorbent has excellent reusability.

Diagenetic Barite-Pyrite-Wurtzite Formation and Redox Signatures in Triassic Mudstone, Brooks Range, Northern Alaska

Mineralogical and geochemical studies of interbedded black and gray mudstones in the Triassic part of the Triassic-Jurassic Otuk Formation (northern Alaska) document locally abundant barite and pyrite plus diverse redox signatures. These strata, deposited in an outer shelf setting at paleolatitudes of ~45 to 60°N, show widespread sedimentological evidence for bioturbation. Barite occurs preferentially in black mudstones (TOC = 0.93–6.46 wt%), forming displacive euhedral crystals with pyrite inclusions and rims, and late albite inclusions or intergrowths. Pyrite also occurs as small (3–20 μm) framboids, discontinuous laminae, euhedral and anhedral crystals, and replacements of barite and fossils (mainly radiolarians). Paragenetically early wurtzite is present as clusters of very small (1–3 μm) aggregates of radiating crystals 0.5 to 1.0 μm long with cores of organic matter that overgrow framboidal pyrite; later wurtzite forms 10- to 30-μm bladed crystals. Equant grains (3–30 μm) and small (20 μm) angular clusters of zinc sulfide that include <1-μm-long, comb-like structures are sphalerite or wurtzite, or both. Minor siderite forms euhedral crystals intergrown with albite that enclose wurtzite and barite. Illite shows intergrowths with sphalerite; rare K-feldspar is intergrown with barite. Formation of these minerals and assemblages is attributed to early diagenetic processes.Whole-rock geochemical data for 15 samples show large ranges in redox proxies including Post Archean Average Shale (PAAS)-normalized enrichment factors (EFs) for V, U, Mo, and Re, and Al-normalized ratios for V, U, and Mo. Results for most black mudstones, with or without abundant barite and/or pyrite, suggest deposition within an oxygen minimum zone. Cerium anomalies, PAAS-normalized and calculated on a detrital-free basis, range widely from 0.49 to 0.96 and may reflect diagenetic overprinting by Ce-depleted fluids. Considering data for both black and gray mudstones, the overall geochemical pattern together with evidence from pyrite framboid sizes suggest that redox conditions fluctuated greatly from euxinic to oxic, like the redox profiles reported for modern shelf sediments offshore Peru and Namibia. The euxinic redox signatures in some Otuk black mudstones may correlate with widespread Early to Middle Triassic ocean anoxic events proposed for other regions.Calculations of median EFs for trace elements in Otuk black mudstones reveal both enrichments and depletions. Normalizations to the median composition of the three least-mineralized black mudstones show that barite- and/or pyrite-rich samples display large (>50%) positive changes for Li (+80.4%), V (+75.6%), Sr (+75.9%), Ba (+790%), Cu (+92.1%), Ni (+169%), Ag (+156%), Au (+3091%), As (+109%), Sb (+476%), and Se (+205%); Zn shows a moderate positive change of +42.1%. Moderate negative changes are evident only for Ge (−47.2%) and W (−30.6%). The local enrichments may reflect one or more factors including redox variations in bottom waters and pore fluids, element mobility during diagenesis, and selective fractionation into minerals such as barite, pyrite, and wurtzite. Anomalously low U/Al and UEF values, compared to those for other modern and ancient organic-rich sediments and sedimentary rocks, are attributed to increased solubility and loss of U during bioturbation-related oxygenation in the subsurface.Physicochemical constraints on barite, pyrite, and wurtzite formation are informed by use of a pH-fO2 plot constructed at 10 °C. Based on paragenetic evidence for multistage deposition of these three minerals, together with the presence of illite intergrown with ZnS and K-feldspar with barite, proposed diagenetic trends involve an increase in pH and fO2 related to the ingress of sulfate-rich pore fluids during bioturbation, followed by a return to lower then higher pH and fO2 conditions linked to carbon, sulfur, barium, and iron cycling during diagenesis. Labile Ba of marine pelagic origin was mobilized from organic-rich sediment upward to the sulfate-methane transition zone where barite precipitated during the interaction of reduced Ba- and CH4-rich fluids with sulfate-bearing pore fluids. The formation of paragenetically early wurtzite (ZnS) crystals, as well as locally high EF values for Cu, Ni, Ag, and Au, is attributed to metal enrichment of pore fluids, with sources being derived in part from water-column deposition from hydrothermal plumes related to coeval Triassic seafloor vent systems including a volcanogenic massive sulfide deposit in British Columbia and the Wrangellia Large Igneous Province in Alaska.

Mercury, Platinum, Antimony and Other Trace Elements in the Atmospheric Environment of the Urban Area of Mexico City: Use of Ficus benjamina as Biomonitor.

The application of Sb, Pt and Hg in the development of new strategic technologies has increased significantly in recent years. This study evaluates the impact of vehicular traffic on the rise in emission of Sb, Pt and Hg in the atmospheric environmen of Mexico City and their correlation to Co, Cr, Cu, Ni, Pb, V and Zn. Ficus benjamina leaves were collected as biomonitor of atmospheric metals deposited in areas exposed to heavy vehicular traffic. High enrichment factor values (metal(loid) concentration/background values) were calculated: 146 (Sb), 52.8 (Pb), 29.7 (Pt) and 25.1 (Cr). Enrichment factors of Ni, Zn, Co, V, Cu and Hg decrease in that order and are <10. Principal component analysis allows recognize that most of the analyzed metal(loids) are related to traffic sources; Ni and Cr are also attributable to an additional anthropogenic source. No relationship was found relating Pb to vehicular sources.

Heavy metal transport and evolution of atmospheric aerosols in the Antarctic region

Suspended particulate matter (SPM) measurements and backward air mass trajectory analysis using the HYSPLIT model were performed to better understand the main sources and transport pathways of heavy metals in atmospheric aerosols reaching the Antarctic region. Field campaigns were carried out during the austral summer 2016–2017 at the “Gabriel de Castilla” Spanish Antarctic Research Station, located on Deception Island. Aerosols were deposited in an air filter through a low-volume sampler and chemically analysed using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The study of air masses and high enrichment factor values of several elements (Hf, Zr, As, Cu, Sn, Zn, Pb) together with their correlations (Hf/Zr, V/As, Ti/Mn and Cu/Sn) suggests a potentially significant role of three main sources in this area: remote maritime traffic, local petrol combustion (generators and/or tourist cruises), and remote/local crust. Additionally, the investigation of atmospheric flow patterns through backward trajectory analysis revealed that Hf/Zr correlation was related to a remote crustal origin, V/As to anthropogenic local pollution, Ti/Mn to terrestrial inputs on the island and Cu/Sn to remote anthropogenic sources. Overall, the present study demonstrates the existence of anthropogenic pollution at this remote site from distant as well as local sources following the Antarctic circumpolar wind pattern.

Heavy Metal Pollution Characteristics and Ecological and Health Risk Assessment of Atmospheric PM2.5 in a Living Area of Zhengzhou City

To study the pollution characteristics of atmospheric heavy metal elements in a living area of Zhengzhou City, assess the potential ecological risks, and determine risks to resident health in this city, the Wuhan Tianhong TH-16A Airborne Particles Intelligent Sampler was used to collect atmospheric PM2.5 in Zhengzhou City. The mass concentrations of 17 metal elements were analyzed by ambient air determination of inorganic elements by ambient particle matter wavelength dispersive X-ray fluorescence spectrometry. The source of heavy metals was analyzed by the enrichment factor method and principal component analysis. The ecological risk index method and the US Environmental Protection Agency's health risk assessment method were used to evaluate the potential ecological risks and residents' health risks from Cr, Cd, Cu, Zn, Ni, Pb, As, and other elements. The results showed that metals with higher enrichment factor values were Cd, Sb, Pb, and As, and Cd had the highest enrichment factor value. The sources of metal elements in a living area of Zhengzhou City were mainly crust/burning coal, fuel, garbage burning, metallurgical dust, and vehicle emission. The single factor potential ecological hazard index values of Cd, Pb, Zn, As, Cu, Ni, and Cr were 70420.2, 255.3, 204.6, 71.5, 36.9, 24.0, and 5.1, respectively. Cd, As, and Cr in a living area of Zhengzhou City posed a cancer risk, and Cd was the most harmful. Mn had a non-carcinogenic risk.

Quantitative identification of anthropogenic trace metal sources in surface river sediments from a hilly agricultural watershed, East China.

Quantitative identification of anthropogenic trace metal sources in surface river sediments is vital for watershed pollution control and environmental safety. In this study, we developed a reliable approach by integrating enrichment factor (EF), multiple linear regression of absolute principal component scores (MLR-APCS), and Pb stable isotopes, and applied it to a typical hilly agricultural watershed in Eastern China. Results showed that trace metals have accumulated in the river sediments during long-term agricultural development, with special concern of Cu, Ni, Pb, and Cr that may pose adverse biological effects. Among them, Pb was the most anthropogenically impacted trace metal due to its high EF value, but its excessive concentration still did not exceed background concentration. Based on the excessive trace metal concentrations, atmospheric deposition, livestock manure, and chemical fertilizer were identified as the three major anthropogenic pollution sources, and their respective contributions were further estimated by using MLR-APCS model. Together with natural contributions, atmospheric deposition contributed on average 35.3%, 43.1%, and 30.4% of total Ni, Pb, and Cr concentrations in the sediments, respectively. Similarly, livestock manure contributed 41.0% of total Cu and 40.6% of total Zn concentrations, while chemical fertilizer was responsible for 44.3% of total Cd concentration. For Pb, the source contribution of atmospheric deposition to sediment pollution was also quantitatively assessed by isotopic analysis, which was generally close to the value of 43.1% and therefore verified the EF and MLR-APCS results.

Seasonal Variation and Quality Assessment of the Major and Trace Elements of Atmospheric Dust in a Typical Karst City, Southwest China

Atmospheric dust plays an important role in bio-geochemical cycling and the ecological environment. In urban areas, atmospheric dust is more likely to be the carrier of pollutants, thus affecting the air quality of cities. In this study, samples of atmospheric dust were collected monthly for one year in Guiyang City, and the contents of major and trace elements in the dust were determined. The results showed that the major and trace elements in the atmospheric dust of Guiyang city vary with the seasons. The concentrations of trace elements in the dust of autumn and winter were significantly higher than those in spring and summer. Most of the major elements in dust were higher than those in the corresponding topsoil, while most trace elements were similar to those in the topsoil except for Pb. The enrichment factor (EF) values calculated by topsoil as background showed that the Ca and Pb have higher EF values than the rest elements, indicating that some dust may be contaminated by Ca and Pb. The high content of Ca in the dust might be derived from concrete buildings in urban areas, while Pb might be closely related to motor vehicle emissions. The relationship between La and Yb of the atmospheric dust showed that the dust in Guiyang have the same pattern as those of Libo, it also revealed that these dust probably come mainly from natural sources and are less affected by human activities.

Applying of Modified Constant Rate of Supply Model to Lake Sediments in &lt;sup&gt;210&lt;/sup&gt;Pb Dating and Assessment of Some Heavy Metals

In present study, Lead-210 (Polonium-210) activity concentrations were indirectly obtained by utilizing alpha spectrometry. Sediment chronology was determined by using modified CRS model. Average sediment accumulation rates are 0.351, 0.324, 0.222 g cm -2 y -1 in S-1, S-2, S-3 stations respectively. With reference to atmospheric 210 Pb flux (29 mBq cm -2 y -1 ) Lake Karagol has extra outer 210 Pb input (soil erosion) from the catchment area. In terms of Enrichment Factor (EF), heavy metal concentrations are lower than the anthropogenic values. So it can be said that the elements except Au originate from the continental supply. Au has unexpectedly too high level EF value (58.22) in northern station (S-1) of the Lake Karagol. It corresponds to time interval from 2004 to nowadays. However Pollution Load Index (PLI) says different consequences from the EF values. PLI value has only baseline levels of pollutants in northern part of the Lake Karagol as it shows progressive deterioration of the site for southern part of the Lake Karagol.

Temporal evolution of lead isotope ratios and metal concentrations in sediments of the north Aegean Sea, in Turkish coast

In present research, fifteen surficial and two profile sediment samples were studied in terms of sediment chronology and pollution degree on the ground of pollution indexes such as enrichment factor (EF), contamination factor (CF), Pollution Load Index (PLI) and lead isotope ratios (206Pb/207Pb, 208Pb/206Pb). Lead-210 (polonium-210) activity concentrations were measured by utilizing alpha spectrometry. Sediment chronology was determined via modified CRS mathematical model. Average mass accumulation rates are 0.301 and 0.227 g cm−2 year−1 in Bakircay River mouth and Ayvalik offshore stations respectively. Mass accumulation rates do not display the systematic increases along the cores from bottom layers to top layers. In Bakircay River mouth station 210Pb flux is higher than the range of global atmospheric 210Pb flux value. Due to the high CF and EF values of Sr both of stations have hydrothermal features. Ayvalik offshore station has displayed Na, Cd pollution since 1945, but Na, Cd, As, Mo, Ag pollutions have existed in Bakircay River mouth station since 1983 in terms of CF and EF values. According to PLI index, Bakircay River mouth station has “starting level pollution” degree and it displayed an “acute corruption” in 1981. 206Pb/207Pb ratios range from 1.17 to 1.25, 208Pb/206Pb ratios range from 1.99 to 2.16 in study area. When 206Pb/207Pb and 208Pb/206Pb ratios are evaluated with together, it is seen that both of the stations have had the natural (geologic) sediments since 2011.