Concentrations Of Most Elements Research Articles

Distribution and accumulation of inorganic elements in Ligusticum chuanxiong

Aiming at the phenomenon of heavy metal Cd exceeding the standard of Chuanxiong medicinal materials,the accumulation of 12 inorganic elements,including heavy metals,in Ligusticum chuanxiong was studied in this paper. It was found that the contents and distribution of most inorganic elements in the stems and leaves of L. chuanxiong were higher than those in the rhizomes at seedling and shooting stages. The content of most elements in rhizome reached the highest at harvest stage,and the distribution ratio of some elements in rhizome was higher than that in stem and leaf at harvest stage. But rhizome,stem and leaf of L. chuanxiong have relatively stable absorption capacity and enrichment effect on different elements,and are less affected by growth period and position. Rhizomes and stems and leaves of L. chuanxiong were enriched with Cd,and stems and leaves also accumulated Pb at seedling stage and stem stage. The absorption capacity of Pb in stems and leaves of L. chuanxiong was higher than that of rhizomes,and the ability of absorbing Cd was less than that of rhizomes at harvest time. The total uptake of Cd and Pb by L. chuanxiong decreased with the prolongation of growth time,but the proportion of Cd and Pb in rhizome increased,so that the content of Cd and Pb increased with the prolongation of growth time.

Chemical and boron isotope compositions of tourmaline in the Hadamiao porphyry gold deposit, Inner Mongolia, China

The Hadamiao porphyry gold deposit in Inner Mongolia, China, is located in the northern margin of the North China Craton (NCC). Tourmaline is a common mineral in hydrothermal veins and granitic rocks contemporaneous with the mineralized granite porphyry in this deposit. The tourmaline can be divided into six types, including magmatic tourmaline (Tur-M1) in granite porphyry dikes, magmatic-hydrothermal transitional tourmaline (Tur-M2) in nodular granitic rocks, and hydrothermal tourmalines in early tourmaline veins (Tur-V1), gold-bearing quartz-tourmaline-chalcopyrite veins (Tur-V2), breccia cements (Tur-V3) and late carbonate-quartz veins (Tur-V4). The gold mineralization is closely related to the occurrence of Tur-V2.Almost all the tourmalines from the Hadamiao deposit belong to the alkali group and show a schorlitic–dravitic composition, except for some Tur-M1 belonging to uvite. The concentrations of most elements in different tourmaline types overlap. Tur-M1 has higher Ca, W, Th, U, Pb, Mn, and Zr contents than other types, and the hydrothermal tourmalines (V1–V4) show slightly higher Ba, Cu and Y contents than Tur-M1 and Tur-M2. The concentration of Au in Tur-M1 and Tur-M2 can reach up to 80 ppb and is higher than that in Tur-V1; the Au content in Tur-V2 is an order of magnitude higher than that in other stages of tourmaline. Systematic contrasts in major and trace element compositions between magmatic and hydrothermal tourmalines are attributed to the assimilation of the country rock by the magmatic-hydrothermal system.The six types of tourmaline exhibit variable δ11B values ranging from −8.7‰ to +21.2‰. Tur-M1 shows the highest δ11B values of +15.1‰ to +21.2‰, and Tur-V2 yields the lowest values ranging from−8.7‰ to −5.4‰. The boron probably came from two sources with different isotopic compositions, one with high positive δ11B values and the other with negative δ11B values. Magmatic hydrothermal fluids could have provided isotopically light boron for hydrothermal tourmalines, whereas the heavy boron in magmatic tourmaline was probably derived from marine carbonates that are widespread in the study area. The magma related to the mineralization and the one containing magmatic tourmaline may have experienced different degrees of interaction with wall rocks, resulting in the diversity of δ11B values in Hadamiao tourmaline.

Grinding Methods Influence Nutrient Analysis of Bahiagrass and St. Augustinegrass

Particle reduction is a necessary step during turfgrass tissue analysis and may result in contamination of the sample with one or more elements. Metals such as W or Zr may reduce contamination because the metals are void of any plant essential elements. The objective of this study was to determine the nutrient content of turfgrass tissue submitted to eight grinding methods. Leaf tissue from bahiagrass (Paspalum notatum Flügge) and ‘Floratam’ St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] was collected and ground using one of the following eight methods: unground, Wiley mill, Cyclone mill, alumina beads, ceramic beads, stainless steel beads, tungsten carbide beads, and zirconium oxide beads. Tissue was analyzed for N, P, K, Ca, Mg, S, Al, Cu, Fe, Mn, Na, and Zn. Each method influenced turfgrass nutrient analysis by increasing, and in some cases decreasing, the concentration of one or more elements compared with unground tissue. Alumina and ceramic beads resulted in a decreased concentration of most elements, whereas the Wiley mill and tungsten beads resulted in an increase in N and Cu, and N and Mn, respectively. Grinding methods did not influence the concentration of P, K, S, Mn, or Na in bahiagrass but did alter their concentration in St. Augustinegrass. To minimize inaccurate analysis, the grinding method must account for additions or subtractions of elements resulting from the turfgrass species and the element analyzed.

Indoor air quality in schools of a highly polluted south Mediterranean area.

This study aimed at surveying lower secondary schools in southern Italy, in a highly polluted area. A community close to an industrial area and three villages in rural areas was investigated. Indoor temperature, relative humidity (RH), gaseous pollutants (CO2 and NO2 ), selected biological pollutants in indoor dust, and the indoor/outdoor mass concentration and elemental composition of PM2.5 were ascertained. Temperature and RH were within, or close to, the comfort range, while CO2 frequently exceeded the threshold of 1000ppm, indicating inadequate air exchange rate. In all the classrooms, median NO2 levels were above the WHO threshold value. Dermatophagoides p. allergen concentration was below the sensitizing threshold, while high endotoxin levels were detected in the classrooms, suggesting schools may produce significant risks of endotoxin exposure. Concentration and solubility of PM2.5 elements were used to identify the sources of indoor particles. Indoor concentration of most elements was higher than outdoors. Resuspension was responsible for the indoor increase in soil components. For elements from industrial emission (Cd, Co, Ni, Pb, Sb, Tl, V), the indoor concentration depended on penetration from the outside. For these elements, differences in rural vs industrial concentrations were found, suggesting industrial sources may influence indoor air quality nearby schools.

Quantification and Characterization of Particulate Matter Generated from Unpaved Roads in the Oil Development Area of Western North Dakota

Abstract. Heavy vehicle traffic on unpaved roads in western North Dakota, due to increasing oil extraction activities, is generating coarse particulate matter (PM10) and fine PM (PM2.5), and total suspended particles (TSP), potentially raising concerns for animal and human health and impacts on crop and plant growth. However, limited quantification and characterization are available for PM from unpaved roads next to oil activities. Therefore, a study was conducted to characterize and quantify the PM concentrations from heavy traffic on unpaved roads due to increasing oil activities in western North Dakota. Three unpaved road sites were selected and paired with application of two dust suppressants (brine and magnesium chloride). MiniVol air samplers were used to quantify PM, scanning electron microscopy (SEM) was used to characterize the minerals in PM samples, and inductively coupled plasma mass spectrometry (ICP-MS) was used to analyze the chemical composition of soil samples. The average PM10 and PM2.5 concentrations were higher at site 2 (untreated loose gravel road) than at site 1 (periodically treated with dust suppressants) during the study period (2015-2016). In addition, the PM concentrations were lower in 2016 because of decreased oil activities at site 2. Statistical analyses revealed that the PM concentrations were mostly correlated with vehicle count in addition to temperature, wind direction, and rainfall. Magnesium chloride was the most effective treatment for reducing PM. The SEM analyses of PM samples revealed that most particulates were quartz, other silicates, or biogenic particles. Soil sample analyses revealed that the concentrations of most elements were lower than the threshold values set by the USGS National Geochemical Survey. Keywords: Air pollution, Air quality, Dust, North Dakota, Oil development, Particulate matter.

Environmental impact assessment of industrial activities on heavy metals distribution in street dust and soil

Street dust and soil are important materials for evaluating the contaminants level in industrial areas. Detailed size-resolved distribution of metal(loid)s in street dusts and soils influenced by industrial activities has rarely been investigated. This study was carried out to understand how industrialization might affect the size distribution of metal(loid)s concentration and contamination level in the street dust and soil from Murcia, southern Spain. An industrial and a natural areas were selected and surface soil and street dust samples were taken. They were fractionated into eleven size classes and total concentrations of Pb, Zn, Cu, Cd, Cr, Ni, As and Fe were determined in both the bulk samples and their fractions. Enrichment factor, geoaccumulation index, and mass loading of different heavy metal(loids) were calculated. The results indicated that the street dust from natural and industrial areas had almost the same particle size distribution, both containing higher percentage of coarse-sized particles than the soil. Industrialization seems to have only slightly affected the concentration of most elements studied in the soil. In contrast, the concentrations of the heavy elements in bulk industrial dust samples and all their size fractions were extremely higher than those from the natural area. This means that the industrial activities only affected the size dependency of the concentration (contamination level) of certain elements (Pb, Zn, Cu, Cd, and Cr) in the street dust, but not in the soil.

WATER QUALITY EVALUATION OF THE TIEN RIVER BY MEANS OF WATER QUALITY INDEX (WQI) AND STATISTICAL TECHNIQUES

This study aimed to evaluate the Tien River’s water quality by using Water Quality Index (WQI) and statistical techniques. Water samples were collected from six monitoring stations along Tien River. At each station, samples were taken in dry season and wet season during three years (2014-2016). Physicochemical parameters of surface water samples including pH, DO, COD, BOD, total coliforms, TSS, NH4+-N, and PO43- were analyzed to evaluate the water quality. The results illustrated that surface water of the river was gradually polluted from year to year. In addition, the water quality insignificantly varied between monitoring sites. Furthermore, the seasonal feature was not a principal factor to impact water quality during the years. The concentrations of most elements in the studied water samples were much higher than the permissible levels for river water. This integrated technique has been pointed out to be an effective approach to set up a correlation between water quality and the sustainable wastewater management in the Tien river basin.

Trace Element Concentrations in European Pond Turtles (Emys orbicularis) from Brenne Natural Park, France.

We assessed trace elements concentration in European pond turtle (Emys orbicularis) from Brenne Natural Park (France). We sampled road-killed turtles (N = 46) to measure the concentrations of 4 non-essential (Ag, Cd, Hg, and Pb) and 10 essential (As, Co, Cr, Cu, Fe, Mn, Ni, Se, V, and Zn) elements in muscle, skin, liver and claws. Body size or sex did not influence the concentrations of most elements; except for Hg (liver, skin and claws) and Zn (muscle) which increased with body size. We found relatively high concentrations of Hg and Zn, possibly linked to fish farming. This result deserves future investigations to evaluate possible ecotoxicological effects on E. orbicularis.

Occupational Exposure to Metals in Shooting Ranges: A Biomonitoring Study.

BackgroundLead (Pb) exposure in shooting ranges has been reduced by various measures such as jacketed ammunition and lead-free primers. Nevertheless, this may lead to exposure to other metals, potentially resulting in adverse health effects.MethodsIn a cross-sectional study, 35 subjects from seven different shooting ranges were studied: four shooting instructors, 10 police officers, 15 Special Forces, and six maintenance staff members. Metals and metalloids were determined in blood and urine by inductively coupled plasma–mass spectrometry.ResultsThe concentrations of most elements did not differ significantly between groups or compared to reference values, except for Sb and Pt in urine and Pb in blood. Mean values for Sb were considerably higher in urine from the Special Forces (0.34 μg/L), the maintenance staff (0.13 μg/L), and shooting instructors (0.32 μg/L) compared to the police officers before shooting (0.06 μg/L) and a Belgian reference value (0.04 μg/L). For Pt, the Special Forces showed higher mean urinary concentrations (0.078 μg/L) compared to a Belgian reference value (<0.061 μg/L). Mean values for blood lead were markedly higher in the Special Forces (3.9 μg/dL), maintenance staff (5.7 μg/dL), and instructors (11.7 μg/dL) compared to police officers (1.4 μg/dL). One instructor exceeded the biological exposure index for blood Pb (38.8 μg/dL).ConclusionSince both Pb and Sb were found to be higher in shooting range employees, especially among frequent shooters, it is advisable to provide appropriate protective equipment, education, and medical follow-up for shooting range personnel in addition to careful choice of ammunition.

Palynological and Geochemical Records of Environmental Changes in a Taxodium Swamp near Lake Pontchartrain in Southern Louisiana (USA) during the Last 150 Years

Ryu, J.; Bianchette, T.A.; Liu, K.-B.; Yao, Q., and Maiti, K.D., 2018. Palynological and Geochemical Records of Environmental Changes in a Taxodium Swamp near Lake Pontchartrain in Southern Louisiana (USA) during the Last 150 Years. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 381–385. Coconut Creek (Florida), ISSN 0749-0208.The hydrological and environmental histories of estuarine wetlands in southern Louisiana are not well-documented. To better understand their local developmental processes, a 59 cm sediment core (WMA-1) was extracted from a bald cypress (Taxodium distichum) swamp located approximately 800 m west of Lake Pontchartrain. This area has been heavily influenced by human activities, and is susceptible to inundation from storm surges from Lake Pontchartrain as well as fluvial and lacustrine processes. 210Pb analysis indicates that WMA-1 has a sedimentation rate of 0.39 cm/year, consistent with the detection of a 137Cs peak at 18 cm depth. Sedimentological and geochemical analyses reveal two distinct sedimentological facies: an organic-rich dark brown peat unit from 0 to 29 cm containing low concentrations of terrestrial elements (e.g., Ti, and Fe), and a clay unit from 29 to 59 cm with elevated concentrations of most elements (e.g., Sr, Cl, Ti, Mn, and Fe). The pollen assemblage in the clay section is dominated by TCT (mainly Taxodium), but it is replaced by Salix and wetland herbaceous taxa in the overlying peat. The Taxodium swamp was present at the site at least 150 years ago, and was replaced by Salix and other bottomland hardwood trees and wetland herbs due to a decrease in water level around AD 1940. While climate may have played a role, this hydrological change was most likely caused by the significant regional human activities during the last 100 years. Two thin clay layers (at 3–5 cm, 14–19 cm) embedded in the upper peat section were likely deposited from hurricanes Isaac (2012) and Betsy (1969): two events responsible for heavy rain and significant storm-surge flooding. Our findings suggest that human activities are capable of altering local wetland hydrology and ecology, while the clay layers represent hurricane-induced floods at the site during the past century.

Chemico‐mineralogical changes of ultramafic topsoil during stockpiling: implications for post‐mining restoration

AbstractLateritic topsoils, which are usually removed and stored apart before mining operations take place, play an essential role in the success of post‐mining restoration. They contain elements to recover chemical (organic matter, nutrients) and biological (seed and bud banks, microorganisms) fertility of the soil. Conserving topsoil fertility during storage time is essential for a successful use of topsoil during restoration. In this study, different chemico‐mineralogical properties of a lateritic topsoil from the Goro nickel mine (New Caledonia) were monitored from its original in situ emplacement on the soil profile, immediately after its stockpiling and after 24 months of storage. Our analyses show that topsoil experienced noticeable changes immediately after storage, mostly produced by mixing of different soil profiles. Cation Exchange Capacities and concentrations of most elements did not vary even after 24 months of storage. However, a slight reduction of Ni, Cr, K, Na and of the C:N ratio, and an increase of Ca have been observed. Stockpiling has not affected negatively the chemical fertility of the topsoil, although biological parameters should be considered to have a complete view of stockpiling sustainability.

The geochemical estimation of the geoecological state left in flows of Podolsk part of the Dnister river

A research object is water, ground sedimentations and soils from the banks of the left tributaries of Podolsk part of the river Dnister (Ukraine). One of problem places of this research is absence of the analogical complex watching maintenance in water, ground sedimentations and soil from the banks of the left tributaries of Podolsk part of Dnister of the investigated area. It hampers finding out of geochemical features of the ground sedimentations and soils. The tests of soils from the banks of currents for ecogeochemical researches were selected for GOST 17.4.4.02-84 and investigational with the use of quantitative spectrology of gross maintenance of elements. It allowed to compare inter se maintenance of elements in soils and ground sedimentations. It is set that on mechanical composition prevail psammites among the ground fallouts of the rivers, and insignificant maintenance of argillaceous-silt constituent in the ground sedimentations does not assist an accumulation in them contaminents. It is set that on mechanical composition prevail psammites among the ground fallouts of the rivers, and insignificant maintenance of argillaceous-silt constituent in the ground sedimentations does not assist an accumulation in them contaminents. The table of contents of most elements in water of the rivers does not exceed possible concentrations maximum. Only in the district of Mogilev-Podolsky in Derlo maintenance of potassium and iron in 13 . 28 and 7 . 4 times exceeds MPC accordingly. In general maintenance of the investigated elements in water is ordinary does not exceed not only, and and considerably less MPC both sanitary requirements and MPC of standard of Worldwide organization of health protection. Research of maintenance of Cr and Pb in the ground sedimentations of the rivers of Zhvan , Lyadova, Nemiya, Derlo and Dnister, and soils of their banks allowed to find out that maintenance of lead and chrome in the investigated standards usually does not exceed a median value for the investigated currents. In general maintenance of the investigated elements in water is ordinary not only does not exceed but also considerably less MPC , both sanitary requirements and MPC of standard of Worldwide organization of health protection. In general the geoecological state of the left tributaries of Podolsk part of the river Dnister is satisfactory. Contamination chemical elements has point character. It is recommended to create the joint international program of realization of the geoecological monitoring not only Dnister but also his left and right tributaries within the limits of Podolsk part.

Surface Water Quality Monitoring for River Nile, Egypt Using GIS-Techniques

Egypt faces a severe water scarcity in the last years. Increasing population cause rising in water demands and fast economic growth leads to ecosystem degradation. In addition, ineffective irrigation methods with water misuse result in water quality degradation. River Nile is the main fresh water source in Egypt. This study evaluates, one of River Nile branches; Rosetta water quality through Geographical Information System (GIS) techniques. Fifteen water samples were analyzed for their chemical and biological properties. A mathematical model of Water Quality Index (WQI) has been built to integrate biochemical data as input parameters. This model describes the spatial distribution. On the other hand, the temporal of water quality status has been defined. A spatial variation of water quality index was generalized for the study area. The average water quality index values range between 58.8 and 67.2. Generally, the water quality index values within the study area were about the critical pollution level. The concentrations of most elements in the studied water samples were above the permissible levels for drinking water standards. This study concludes that Rosetta water is not suitable for drinking. Furthermore, it can be used for irrigation and domestic uses with specified treatments.

Towards a better understanding of long-term wood-chemistry variations in old-growth forests: A case study on ancient Pinus uncinata trees from the Pyrenees

Dendrochemical studies in old forests are still underdeveloped. Old trees growing in remote high-elevation areas far from direct human influence constitute a promising biological proxy for the long-term reconstructions of environmental changes using tree-rings. Furthermore, centennial-long chronologies of multi-elemental chemistry at inter- and intra-annual resolution are scarce. Here, we use a novel non-destructive method by applying Micro X-ray fluorescence (μXRF) to wood samples of old Pinus uncinata trees from two Pyrenean high-elevation forests growing on acidic and basic soils. To disentangle ontogenetic (changes in tree age and diameter) from environmental influences (e.g., climate warming) we compared element patterns in sapwood (SW) and heartwood (HW) during the pre-industrial (1700–1849) and industrial (1850–2008) periods. We quantified tree-ring growth, wood density and relative element concentrations at annual (TRW, tree-ring) to seasonal resolution (EW, earlywood; LW, latewood) and related them to climate variables (temperature and precipitation) and volcanic eruptions in the 18th and 19th centuries. We detected differences for most studied elements between SW and HW along the stem and also between EW and LW within rings. Long-term positive and negative trends were observed for Ca and K, respectively. Cl, P and S showed positive trends during the industrial period. However, differences between sites were also notable. Higher values of Mg, Al, Si and the Ca/Mn ratio were observed at the site with acidic soil. Growing-season temperatures were positively related to growth, maximum wood density and to the concentration of most elements. Peaks in S, Fe, Cl, Zn and Ca were linked to major volcanic eruptions (e.g., Tambora in 1815). Our results reveal the potential of long-term wood-chemistry studies based on the μXRF non-destructive technique to reconstruct environmental changes.

Levels, Sources, Markers and Health Risks of Heavy Metals in PM2.5 Over a Typical Mining and Metallurgical City of Central China

To investigate the pollution characteristics, sources and health risk assessment of various elements in PM2.5 of Huangshi city, 54 samples were collected from March 2012 to February 2013. The composition and characteristic of sixteen elements (Mg, Al, Ca, Ti, Cr, Mn, Cu, Zn, V, Fe, As, Pb, Cd, Co, Ni and W) were analyzed by high-sensitivity X-ray fluorescence (XRF). The result showed that the annual mean concentration of PM2.5 was 104.4 μg/m3, far exceeding the secondary level of Ambient Air Quality Standard of China (annual average limit 35 μg/m3). Element W has the highest annual concentration, followed by Zn, Pb and As. Compared with the concentration limit of National Ambient Air Quality Standard of China, Cd and As in Huangshi were 4.3 times and 32.8 times higher, respectively, than national standard. The concentration of most elements has distinct seasonal characteristic which is higher in winter and lower in summer. Enrichment factor (EF) analysis indicates that W, Fe, Cd, As, Pb, Zn, Cu, Cr, Co and Ni are extremely enriched in PM2.5, Ca, Mg and Mn are highly enriched, and V is significant enriched. EF of Ti is less than 2, suggesting minimal pollution. Positive matrix factorization (PMF) analysis indicates that Ca, Ti and Al are associated with fugitive dust, and As is associated with coal-fired industrial activity. W, Cr, Cd, V and Ni are originated from chemical and metallurgical industry activities. Pb, Zn, Cu and Mg are derived from vehicle emissions. The results of the human health risk assessment model show that As may pose great non-carcinogenic risk to children and adults. Cr and As have a higher carcinogenic risk for adults, and Cr has a higher carcinogenic risk for children, and other toxic metals are in relatively safe range.

Evidence for contrasting accumulation pattern of cadmium in relation to other elements in Senilia senilis and Tagelus adansoni from the Bijagós archipelago, Guinea-Bissau.

Shellfish harvesting in intertidal areas is a widespread and economically important activity in many countries across West Africa. However, in some areas, there is virtually no information concerning the levels of contaminants (and other elements related to nutritional aspects) in the harvested species. We collected sediments and several individuals of the West African bloody cockle Senilia senilis and of the razor clam Tagelus adansoni during the dry season of 2015 nearby three islands in the Bijagós archipelago, Guinea-Bissau. Aluminium, Ca, Fe, Mg, As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn were determined in sediments and whole soft tissues of the two bivalves. Sediments showed uniformly low trace element concentrations, pointing to an ecosystem with low levels of trace element contamination. T. adansoni presented higher concentrations of most elements than S. senilis, with the exception of Cd that showed up to 40 times higher values in S. senilis than in T. adansoni from the same sites. Furthermore, Cd concentrations (25±8.7mgkg-1, dw) in S. senilis are clearly above the maximum level established for human consumption. Future studies should clarify whether biological factors are the major responsible for this unusual situation.

Below‐ and above‐ground effects of deadwood and termites in plantation forests

AbstractDeadwood is an important legacy structure in managed forests, providing continuity in shelter and resource availability for many organisms and acting as a vehicle by which nutrients can be passed from one stand to the next following a harvest. Despite existing at the interface between below‐ and above‐ground systems, however, much remains unknown about the role woody debris plays in linking these zones. Moreover, it remains untested whether the accelerative effects of wood‐feeding insects on wood decomposition influence tree growth or nutritional status in forests. In this study, we added different quantities of pine logs to the bases of saplings in two‐year‐old loblolly pine (Pinus taedaL.) plantations in Mississippi,USA. We included a treatment in which subterranean termites (Blattodea: Rhinotermitidae:Reticulitermes) were excluded from logs to determine how these insects affect the release of nutrients from wood and, in turn, tree growth. After 51 months of decomposition, we quantified below‐ground effects by measuring microbial biomass, plant‐available forms of N, and ectomycorrhizal diversity associated with fine tree roots. Meanwhile, above‐ground measurements focused on the elemental concentrations in decomposing wood either protected or unprotected from termites and tree metrics related to growth and nutrient status. We found additions of wood to significantly increase nitrate and potential net nitrification relative to reference treatments but detected no significant effects on tree growth, needle nitrogen concentrations, or ectomycorrhizal diversity. Soil nitrate and potential net nitrification were higher under protected vs. unprotected logs, and plant‐available forms of N were mostly more abundant short distances away from both protected and unprotected logs than directly under them. The wood of logs protected from termites had significantly lower concentrations of most elements compared to that of unprotected logs, largely due to the large amounts of soil imported into unprotected logs by termites. Termite exclusion had no measurable effect on tree growth, nutritional status, or ectomycorrhizal diversity, however. Our findings indicate that deadwood and termites both contribute to the spatial heterogeneity of soil properties but may have limited short‐term local effects on tree growth. Longer‐term studies and studies on less fertile sites are needed.

Potential Influence of Ocean Acidification on Deep-Sea Fe–Mn Nodules: Results from Leaching Experiments

With the continuous rise in CO2 emissions, the pH of seawater may decrease extensively in the coming centuries. Deep-sea environments are more vulnerable to decreasing pH since sediments in deep oceans below the carbonate compensation depth (CCD) are often completely devoid of carbonate particles. In order to assess the potential risk of heavy metal release from deep-sea deposits, the mobility of elements from ferromanganese (Fe–Mn) nodules and pelagic clays was examined by means of leaching experiments using phosphate buffer solutions ranging in pH from 7.1 to 8.6 (NBS scale). With decreasing pH, the results showed an enhanced leaching of elements such as Li, B, Mg, Si, Sc, Sr, Ba, Tl, and U, but a reduced leaching of V, Cu, Mo, Cd, and W. Elements in leachates originate mainly from exchangeable fractions, and tend to be affected by sorption–desorption processes. Concentrations of most elements did not exceed widely used international water quality criteria, indicating that changes in pH caused by future ocean acidification may not increase the risk of heavy metal release during deep-sea nodule mining operations.

Pollution history of Neva Bay bottom sediments (eastern Gulf of Finland, Baltic Sea)

Neva Bay is the shallowest and easternmost part of the Gulf of Finland (Baltic Sea). St. Petersburg, Russia’s second largest city, occupies the coastal area where the Neva River debouches into Neva Bay. St. Petersburg has a protracted history of industrial, transportation and urban related activity that have affected Neva Bay. By the sealing off the bay from the eastern Gulf of Finland, the St. Petersburg Flood Protective Facility, which was constructed from the 1970‘s to 2011, transformed Neva Bay into a “technogenic” lagoon. Neva Bay sediments record a unique history of pollution near the metropolis. Heavy metal concentrations of most elements studied varied consistently throughout sediment cores. Temporal trends indicate that metals started to accumulate abruptly in the first half of the 20th century. Zinc, lead and copper were the first metals to reach contaminant thresholds implicating the regional base metal industry as a source. Significant increase in cadmium levels a decade or two later suggests pollution from the regional chemical industry. Comparison of geochemical data collected from sediment cores and recent annual sediment surveys highlighted the temporal history and potential sources of pollution in Neva Bay. Intensive dredging in 2007–2008 resuspended and redistributed contaminated sediment around Neva Bay causing a dramatic increase in benthic sediment heavy metal concentrations. Concentrations of all measured metals subsequently declined from 2009–2014 relative to the elevated values observed for 2007–2008. Pollution history of Neva Bay bottom sediments is closely linked with changing of sedimentation conditions. Analyses of sedimentological data collected by 20th and 21st century scientific surveys reveal dramatic shifts in Neva Bay sedimentation processes over the last three centuries. The western part of Neva Bay has transitioned from a sanddominated system to one of mud accumulation with the aerial extent of mud deposition expanding significantly during the 20th century. This inventory coupled with an understanding of primary natural and anthropogenic processes can help inform decision makers to support the overall ecological health of the bay.

Isolation and quantitative analysis of road dust nanoparticles

Nanoparticles are capable of preconcentrating various elements, including toxic ones; they have high mobility in the environment and can easily penetrate into a human body. The study of the chemical composition and properties of road dust nanoparticles is an urgent task of analytical chemistry, which needs to be addressed in the monitoring of the anthropogenic load on the environment and the assessment of the potential danger of pollution to human health. In the present paper, we propose a new approach for the isolation, characterization, and quantitative elemental analysis of road dust nanoparticles. Conditions are selected for the separation of nanoparticles from Moscow dust samples by field-flow fractionation in a rotating coiled column; the resulting fractions are characterized by independent methods (using static light scattering and electron microscopy); the method for calculating the concentration of elements in the nanoparticle fraction according to inductively coupled plasma atomic emission spectrometry and mass spectrometry is improved; elements in a water-soluble form are isolated and determined; and the role of soluble organic matter in the binding of trace elements is discussed. It is shown that the total concentration of most elements in the samples of Moscow dust is comparable to the average values for urban soils. Abnormally high concentrations of several elements (Cu, Zn, Ag, Cd, Sn, Sb, Hg, Pb, Tl, and Bi) are revealed in the fraction of nanoparticles; the enrichment factor with respect to the total concentration ranges from 10 to 450. The source of contamination of road dust nanoparticles with copper, zinc, antimony, and cadmium is highly probable wearing-off of brake pads and car tires. The developed procedure of separation, characterization, and analysis of nanoparticles can be used for other polydisperse environmental samples (for example, volcanic ash).