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Effect of soil properties, heavy metals and emerging contaminants in the soil nematodes diversity
2016
Gutiérrez, Carmen | Fernández, Carlos | Escuer, Miguel | Campos-Herrera, Raquel | Beltrán Rodríguez, Mª Eulalia | Carbonell, Gregoria | Rodríguez Martín, Jose Antonio
Among soil organisms, nematodes are seen as the most promising candidates for bioindications of soil health. We hypothesized that the soil nematode community structure would differ in three land use areas (agricultural, forest and industrial soils), be modulated by soil parameters (N, P, K, pH, SOM, CaCO3, granulometric fraction, etc.), and strongly affected by high levels of heavy metals (Cd, Pb, Zn, Cr, Ni, Cu, and Hg) and emerging contaminants (pharmaceuticals and personal care products, PPCPs). Although these pollutants did not significantly affect the total number of free-living nematodes, diversity and structure community indices vastly altered. Our data showed that whereas nematodes with r-strategy were tolerant, genera with k-strategy were negatively affected by the selected pollutants. These effects diminished in soils with high levels of heavy metals given their adaptation to the historical pollution in this area, but not to emerging pollutants like PPCPs.
Show more [+] Less [-]Spatial pattern of heavy metals accumulation risk in urban soils of Beijing and its influencing factors
2016
Liu, Rui | Wang, Meie | Chen, Weiping | Peng, Chi
Accumulations of heavy metals in urban soils are highly spatial heterogeneity and affected by multiple factors including soil properties, land use and pattern, population and climatic conditions. We studied accumulation risks of Cd, Cu, Pb and Zn in unban soils of Beijing and their influencing based on the regression tree analysis and a GIS-based overlay model. Result shows that Zinc causes the most extensive soil pollution and Cu result in the most acute soil pollution. The soil's organic carbon content and CEC and population growth are the most significant factors affecting heavy metal accumulation. Other influence factors in land use pattern, urban landscape, and wind speed also contributed, but less pronounced. The soils in areas with higher degree of urbanization and surrounded by intense vehicular traffics have higher accumulation risk of Cd, Cu, Pb, and Zn.
Show more [+] Less [-]Soil pollution indices conditioned by medieval metallurgical activity – A case study from Krakow (Poland)
2016
Kowalska, Joanna | Mazurek, Ryszard | Gąsiorek, Michał | Setlak, Marcin | Zaleski, Tomasz | Waroszewski, Jaroslaw
The studied soil profile under the Main Market Square (MMS) in Krakow was characterised by the influence of medieval metallurgical activity. In the presented soil section lithological discontinuity (LD) was found, which manifests itself in the form of cultural layers (CLs). Moreover, in this paper LD detection methods based on soil texture are presented. For the first time, three different ways to identify the presence of LD in the urban soils are suggested. The presence of LD had an influence on the content and distribution of heavy metals within the soil profile. The content of heavy metals in the CLs under the MMS in Krakow was significantly higher than the content in natural horizons. In addition, there were distinct differences in the content of heavy metals within CLs. Profile variability and differences in the content of heavy metals and phosphorus within the CLs under the MMS were activity indicators of Krakow inhabitants in the past. This paper presents alternative methods for the assessment of the degree of heavy metal contamination in urban soils using selected pollution indices. On the basis of the studied total concentration of heavy metals (Zn, Pb, Cu, Mn, Cr, Cd, Ni, Sn, Ag) and total phosphorus content, the Geoaccumulation Index (Igeo), Enrichment Factor (EF), Sum of Pollution Index (PIsum), Single Pollution Index (PI), Nemerow Pollution Index (PINemerow) and Potential Ecological Risk (RI) were calculated using different local and reference geochemical backgrounds. The use of various geochemical backgrounds is helpful to evaluate the assessment of soil pollution. The individual CLs differed from each other according to the degree of pollution. The different values of pollution indices within the studied soil profile showed that LDS should not be evaluated in terms of contamination as one, homogeneous soil profile but each separate CL should be treated individually.
Show more [+] Less [-]Elevated CO2 increases glomalin-related soil protein (GRSP) in the rhizosphere of Robinia pseudoacacia L. seedlings in Pb- and Cd-contaminated soils
2016
Jia, Xia | Zhao, Yonghua | Liu, Tuo | Huang, Shuping | Chang, Yafei
Glomalin-related soil protein (GRSP), which contains glycoproteins produced by arbuscular mycorrhizal fungi (AMF), as well as non-mycorrhizal-related heat-stable proteins, lipids, and humic materials, is generally categorized into two fractions: easily extractable GRSP (EE-GRSP) and total GRSP (T-GRSP). GRSP plays an important role in soil carbon (C) sequestration and can stabilize heavy metals such as lead (Pb), cadmium (Cd), and manganese (Mn). Soil contamination by heavy metals is occurring in conjunction with rising atmospheric CO2 in natural ecosystems due to human activities. However, the response of GRSP to elevated CO2 combined with heavy metal contamination has not been widely reported. Here, we investigated the response of GRSP to elevated CO2 in the rhizosphere of Robinia pseudoacacia L. seedlings in Pb- and Cd-contaminated soils. Elevated CO2 (700 μmol mol−1) significantly increased T- and EE- GRSP concentrations in soils contaminated with Cd, Pb or Cd + Pb. GRSP contributed more carbon to the rhizosphere soil organic carbon pool under elevated CO2 + heavy metals than under ambient CO2. The amount of Cd and Pb bound to GRSP was significantly higher under elevated (compared to ambient) CO2; and elevated CO2 increased the ratio of GRSP-bound Cd and Pb to total Cd and Pb. However, available Cd and Pb in rhizosphere soil under increased elevated CO2 compared to ambient CO2. The combination of both metals and elevated CO2 led to a significant increase in available Pb in rhizosphere soil compared to the Pb treatment alone. In conclusion, increased GRSP produced under elevated CO2 could contribute to sequestration of soil pollutants by adsorption of Cd and Pb.
Show more [+] Less [-]Combination of geo- pedo- and technogenic magnetic and geochemical signals in soil profiles – Diversification and its interpretation: A new approach
2016
Szuszkiewicz, Marcin | Łukasik, Adam | Magiera, Tadeusz | Mendakiewicz, Maria
Magnetic and geochemical parameters of soils are determined with respect to geology, pedogenesis and anthropopression. Depending on local conditions these factors affect magnetic and geochemical signals simultaneously or in various configurations. We examined four type of soils (Entic Podzol, Eutric Cambisol, Humic Cambisol and Dystric Cambisol) developed on various bedrock (the Tumlin Sandstone, basaltoid, amphibolite and serpentinite, respectively). Our primary aim was to characterize the origin and diversification of the magnetic and geochemical signal in soils in order to distinguish the most reliable methods for correct interpretation of measured parameters. Presented data include selected parameters, both magnetic (mass magnetic susceptibility – χ, frequency-dependent magnetic susceptibility – χfd and thermomagnetic susceptibility measurement – TSM), and geochemical (selected heavy metal contents: Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn). Additionally, the enrichment factor (EF) and index of geoaccumulation (Igeo) were calculated. Our results suggest the following: (1) the χ/Fe ratio may be a reliable indicator for determining changes of magnetic signal origin in soil profiles; (2) magnetic and geochemical signals are simultaneously higher (the increment of χ and lead and zinc was noted) in topsoil horizons because of the deposition of technogenic magnetic particles (TMPs); (3) EF and Igeo evaluated for lead and zinc unambiguously showed anthropogenic influence in terms of increasing heavy metal contents in topsoil regardless of bedrock or soil type; (4) magnetic susceptibility measurements supported by TSM curves for soil samples of different genetic horizons are a helpful tool for interpreting the origin and nature of the mineral phases responsible for the changes of magnetic susceptibility values.
Show more [+] Less [-]Soil pollution at outdoor shooting ranges: Health effects, bioavailability and best management practices
2016
Fayiga, A.O. | Saha, U.K.
The total lead (Pb) concentrations of the surface soil, sub surface soil, vegetation and surface waters of outdoor shooting ranges are extremely high and above regulatory limits. Lead is dangerous at high concentrations and can cause a variety of serious health problems. Shooters and range workers are exposed to lead dust and can even take Pb dust home to their families while some animals around the shooting range can ingest the Pb bullets. The toxicity of Pb depends on its bioavailability which has been determined to be influenced greatly by the geochemical properties of each site. The bioavailability of Pb in shooting ranges has been found to be higher than other metal contaminated soils probably because of its very low residual Pb (<1%). Despite being an immobile element in the soil, migration of Pb within shooting ranges and offsite has been reported in literature. Best management practices to reduce mobility of Pb in shooting ranges involve an integrated Pb management program which has been described in the paper. The adoption of the non-toxic “green bullet” which has been developed to replace Pb bullets may reduce or prevent environmental pollution at shooting ranges. However, the contaminated soil resulting from decades of operation of several shooting ranges still needs to be restored to its natural state.
Show more [+] Less [-]Modelling cadmium contamination in paddy soils under long-term remediation measures: Model development and stochastic simulations
2016
Peng, Chi | Wang, Meie | Chen, Weiping
A pollutant accumulation model (PAM) based on the mass balance theory was developed to simulate long-term changes of heavy metal concentrations in soil. When combined with Monte Carlo simulation, the model can predict the probability distributions of heavy metals in a soil–water–plant system with fluctuating environmental parameters and inputs from multiple pathways. The model was used for evaluating different remediation measures to deal with Cd contamination of paddy soils in Youxian county (Hunan province), China, under five scenarios, namely the default scenario (A), not returning paddy straw to the soil (B), reducing the deposition of Cd (C), liming (D), and integrating several remediation measures (E). The model predicted that the Cd contents of soil can lowered significantly by (B) and those of the plants by (D). However, in the long run, (D) will increase soil Cd. The concentrations of Cd in both soils and rice grains can be effectively reduced by (E), although it will take decades of effort. The history of Cd pollution and the major causes of Cd accumulation in soil were studied by means of sensitivity analysis and retrospective simulation.
Show more [+] Less [-]PCDD/Fs in soil and air and their possible sources in the vicinity of municipal solid waste incinerators in northeastern China
2016
Meng, Bo | Ma, Wanli | Liu, Li-Yan | Zhu, Ning-Zheng | Song, Wei-Wei | Lo, Ching Yee | Li, James | Kannan, Kurunthachalam | Li, Yi-Fan
Fly ash, flue gas, ambient air, and soil samples were collected to investigate concentrations, profiles, gas–particle partitioning, and air–soil exchange of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the vicinity of two municipal solid waste incinerators (MSWIs) in Harbin in northeastern China. The PCDD/F concentrations were 11 600–12 300 pg g−1 (597–615 pg WHO-TEQ g−1) in fly ash and 873–1120 fg m−3 (51.2–61.9 fg WHO-TEQ m−3) in air. The results of gas–particle partitioning possibly indicated the equilibrium state of PCDD/F during sampling period. For soil samples, both Enzyme-linked immuno-sorbent assay (ELISA) and high-resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) were used. Significant correlations between the results from these two methods indicated that both methods are useful for PCDD/Fs analysis in soil. PCDD/Fs concentrations in soil samples ranged from 17.2 to 157 pg g−1 (0.59–8.81 pg WHO-TEQ g−1). Both Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) suggested the sources of the emission from MSWIs and the historical emission from a petroleum refinery to PCDD/Fs in adjacent soils. The air–soil exchange analysis showed a net flux of PCDD/F from air to soil at all soil-sampling sites.
Show more [+] Less [-]Rare Earth Elements in the Soil Environment
2016
Ramos, Silvio J. | Dinali, Guilherme S. | Oliveira, Cynthia | Martins, Gabriel C. | Moreira, Cristiano G. | Siqueira, José O. | Guilherme, Luiz R. G.
Rare earth elements (REE) are a homogenous group of 17 chemical elements in the periodic table that are key to many modern industries including chemicals, consumer electronics, clean energy, transportation, health care, aviation, and defense. Moreover, in recent years, they have been used in agriculture. One of the consequences of their worldwide use is the possible increase of their levels in various environmental compartments. This review addresses major topics concerning the study of REE in the soil environment, with special attention to the latest research findings. The main sources of REE to soils, the contents of REE in soils worldwide, and relevant information on the effects of REE to plants were explored. Ecological and human health risk issues related to the presence of REE in soils were also discussed. Although several findings reported positive effects of REE on plant growth, many questions about their biological role remain unanswered. Therefore, studies concerning the actual mechanism of action of these elements on cellular and physiological processes should be further refined. Even more urgent is to unveil their chemical behavior in soils and the ecological and human health risks that might be associated with the widespread use of REE in our modern society.
Show more [+] Less [-]Chemical Processes Affecting the Mobility of Heavy Metals and Metalloids in Soil Environments
2016
Caporale, Antonio G. | Violante, Antonio
The mobility, bioavailability, and toxicity of metal(loid)s are influenced by their interactions with phyllosilicates, organic matter, variable charge minerals, and microorganisms. Physicochemical processes influencing the chemistry of metal(loid)s in soil environments include sorption/desorption, solution complexation, oxidation-reduction, and precipitation-dissolution reactions. In particular, the sorption/desorption reactions of metal(loid)s on/from soil sorbents are influenced by pH, nature of soil components, and presence and concentrations of cations and inorganic anions. In recent years, many extraction tests have been used for assessing trace elements mobility and phytoavailability. Chemical speciation of toxic elements may be achieved by spectroscopic analyses (XAS), which provide information about oxidation state, symmetry, and identity of the coordinating ligand environment, and possible solid phases.
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