Toxic Elements In Soils Research Articles

Harmful Effects of Potentially Toxic Elements in Soils of Cerrado Biomes

Harmful Effects of Potentially Toxic Elements in Soils of Cerrado Biomes

A global meta-analysis of the correlation between soil physicochemical properties and lead bioaccessibility

Soil physiochemical properties play a vital role in bioaccessibility-based health risk assessment as it can determine the bioaccessibility and the true risk of potentially toxic elements in soil. However, the effects of soil properties on bioaccessibility still remains unclear. In this paper, 17 of the 1454 literatures with 474 samples were identified, screened and reviewed for exploring the correlation between soil physicochemical properties and lead bioaccessibility (BAcPb) through a meta-analysis approach. Five soil physicochemical parameters including pH, SOM, Clay, CEC and T-Pb were systematically analyzed using Principal component analysis, Pearson correlation analysis and survival analysis. The results showed that pH of simulated gastric juice is a major source of heterogeneity of the correlation between soil pH and BAcPb. In the gastric phase, the effect of alkaline soil on high BAcPb (BAc >50%) is more sensitive, and the effect of acidic soil on low BAcPb (BAc <50%) is more sensitive. However, in the small intestinal phase, soil pH displays little impacts on BAcPb in acidic, alkaline and neutral soils. Although three principal components explained 66.2% and 64.9% of the total variance of the urban, agricultural, and mining soils in gastric and small intestinal phases, respectively, there was no strong evidence that soil type can influence the BAcPb. The results of present study provide insights into the correlation between soil properties and BAcPb, and prediction of the bioaccessibility and bioavailability of Pb in different types of soil.

Physiological responses of wild grass Holcus lanatus L. to potentially toxic elements in soils: a review.

Potentially toxic elements (PTEs) in soils accumulate in plants, obstruct their growth, and pose hazards to the consumer via the food chain. Many kinds of grass, grass-like plants, and other higher plant species have evolved a tolerance to PTEs. Holcus lanatus L., a wild grass, is also tolerant (an excluder) of PTEs, such as arsenic (As), cadmium (Cd), lead (Pb), and zinc (Zn). However, the extent of tolerance varies among ecotypes and genotypes. The PTE tolerance mechanism of H. lanatus curtails the typical uptake process and causes a reduced translocation of PTEs from the roots to the shoots, while such a characteristic is useful for contaminated land management. The ecology and response patterns of Holcus lanatus L. to PTEs, along with the associated mechanisms, are reviewed in the current work.

Characterization and chemical fractionation of potentially toxic elements in soils of a pre-mining mineralized area; an evaluation of mobility and environmental risk.

The environmental geochemical characterization of mineralized areas prior to mining does not receive adequate attention. This study shows trace element distribution in soils of two unexploited porphyry copper deposits located in Darreh-Zereshk and Ali-Abad in central Iran. The study was carried out using a compositional data analysis (CoDa) approach and combination of multivariate statistics and clustering techniques, which made it possible to identify the geochemical associations representing the different areas of the mineral deposits. The results of the chemical analyses, performed by ICP-MS, revealed high concentrations of those elements typically associated with porphyry deposits (As, Co, Cu, Mo, Ni, Pb, and Zn). The typical zonal pattern with an anomaly of Cu in central parts of the system and the prevalence of epithermal elements (Ag, Cd, Pb, and Zn) toward the peripheral propylitic alteration zone were recognized. The XRD analysis of selected soil samples allowed us to determine the distribution of elements within the different carrier minerals. Afterward, geochemical speciation patterns were investigated by a four-step sequential extraction procedure based on BCR protocol. The residual fraction consisting of primary resistant minerals was found to be the main host for As (73-93.4%), Cr (65.1-79.6%), Cu (54.3-81.4%), Ni (58.9-80.6%), V (75.9-88%), and Zn (56.5-60.5%) in the studied soils. Even though these elements are not readily leachable, their behavior and distribution could be largely affected by the mining operation and consequent changes in the physicochemical properties of the soil. The soluble-exchangeable phase was only less than 15% of the total extractions for all elements, except for Cd. With respect to the mobility factor (MF), Cd was the most mobile element followed by Sb and Pb. The measured risk assessment code (RAC) presented the following risk order: Cd > Sb > Ni > Co > Pb > Cr > As > Zn > Cu > V. This study reveals that the acquisition of pre-mining geo-environmental data of trace elements is very important to establish pre-mining backgrounds and baselines for evaluating post-mining or post-reclamation geochemical signatures.

Appraisal and health risk assessment of potential toxic element in fruits and vegetables from three markets in Anambra state, Nigeria

Abstract The influence of anthropogenic activities has led to increase of potential toxic elements (PTEs) present in plant-based food sources, even in trace amounts; thus, it is known to pose a threat to human health over an extended period. The concentration levels of PTEs (Pb, Cu, Zn, Cd, Co and Ni) in soils and fruits and vegetables from three markets (Atani, Omor and Eke Awka) in Anambra state, Southeastern Nigeria were quantified and assessed using Atomic Absorption Spectrophotometer (AAS) instrument. The result of PTE (mg/kg) studied was in the order Zn &gt; Cu &gt; Pb &gt; Ni &gt; Co &gt; Cd with the highest value for Zn (13.61 mg/kg) recorded in soil sample at Omor market. The mean concentrations of PTEs in soil of both evaluated studied areas were lower than the WHO permissible limits for PTEs in soil. Among the fruits and vegetables, Bitter leaf had highest PTE from Eke Awka followed by banana, fluted pumpkin, water leaf and onion. Fluted pumpkin had the highest PTE content from Omor followed by watermelon, water leaf, onion and cucumber, while water leaf had the highest metal concentration from Atani followed by bitter leaf, fluted pumpkin, cucumber, lettuce and carrot. Health risk assessment showed that hazard index (HI) in decreasing order was Eke – Awka market &gt; Omor market &gt; Atani market across all fruits and vegetables, as adverse health effect is not expected. The present study recommends containment measures of potential toxic elements in soils and fruits/vegetables to prevent excessive accumulation in food value chain.

Contamination and health risk assessment of potentially toxic elements in soils of different kinds of land use in Lithuania

Using the case of five different kinds of land use from different territories of Lithuania, this study assesses the level of contamination and human health risk assessment of arsenic (As), and heavy metals (HMs) such as cadmium (Cd), copper (Cu), zinc (Zn) and chromium (Cr) in the surface soil of the study areas. Geo-accumulation index (Igeo) analysis indicated that heavy Cd contamination occurred in agricultural territory (AT), while for As, no contamination to mild contamination occurred in all territories. For living territory (LT), green territory (GT) and technical territory (TT), Igeo readings for Cu showed no pollution to moderate pollution, while there was no pollution for natural territory (NT) and AT. For AT, there is no contamination from Zn or Cr. By contrast, Igeo values for Zn and Cu represent minimal to no pollution in the remaining territories. As in LT and Cd in AT, two of the HMs discovered, were deemed to be of medium risk, whereas other components fell into the permitted range. Among three different routes to exposure, it was discovered that the ingestion pathway was the main health risk. The Hazard quotient (HQ) and hazard index (HI) values for As, Cd, Cu, Zn, and Cr were lower than the suggested limit (HI = 1), indicating minimal non-carcinogenic risk to inhabitants in the study regions. The carcinogenic risk values for As (1.12E-04 children), Cd (2.20E-04 children), and Cr (2.35E-04 children) in AT pose a risk to children’s health when ingested. The GT’s carcinogenic readings for Cr (1.02 E+00 adult), put adults at risk of developing cancer, whereas As (1.89E-04) and Cr (2.28E-04) in LT put children at risk of cancer and for TT, both adults and children were at risk due to Cr’s higher carcinogenic values (1.93E-04 for adults and 5.21E-04 for children).

Pollution and risk assessment of potentially toxic elements in soils from industrial and mining sites across China

Potentially toxic elements in soils (SPTEs) from industrial and mining sites (IMSs) often cause public health issues. However, previous studies have either focused on SPTEs in agricultural or urban areas, or in a single or few IMSs. A systematic assessment of the pollution and risk levels of SPTEs from IMS at the national scale is lacking. Here, we obtained SPTE (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) concentrations from IMSs across China based on 188 peer-reviewed articles published between 2004 and 2022 and quantified their pollution and risk levels using the pollution index and risk assessment model, respectively. The results indicated that the average concentrations of the eight SPTEs were 4.42–270.50 times the corresponding background values, and 19.58% of As, 14.39% of Zn, 12.79% of Pb, and 8.03% of Cd exceeded the corresponding soil risk screening values in these IMSs. In addition, 27.13% of the examined IMS had one or more SPTE pollution, mainly distributed in the southwest and south central China. On the examined IMSs, 81.91% had moderate or severe ecological risks, which were mainly caused by Cd, Hg, As, and Pb; 23.40% showed non-carcinogenic risk and 11.70% demonstrated carcinogenic risk. The primary exposure pathways of the former were ingestion and inhalation, while that for the latter was ingestion. A Monte Carlo simulation also confirmed the health risk assessment results. As, Cd, Hg, and Pb were identified as priority control SPTEs, and Hunan, Guangxi, Guangdong, Yunnan, and Guizhou were selected as the key control provinces. Our results provide valuable information for public health and soil environment management in China.

Effect of freshwater and wastewater irrigation on buildup of toxic elements in soil and maize crop.

Untreated wastewater is routinely used for agricultural activities in water-stressed regions, thereby causing severe ecological risks by various pollutants. Hence, management strategies are needed to cope with the environmental issues related to wastewater use in agriculture. This pot study evaluates the effect of mixing either freshwater (FW) or groundwater (GW) with sewage water (SW) on the buildup of potentially toxic elements (PTEs) in soil and maize crop. Results revealed that SW of Vehari contains high levels of Cd (0.08mg L-1) and Cr (2.3mg L-1). Mixing of FW and GW with SW increased soil contents of As (22%) and decreased Cd (1%), Cu (1%), Fe (3%), Mn (9%), Ni (9%), Pb (10%), and Zn (4%) than SW "alone" treatment. Risk indices showed high-degree of soil-contamination and very-high ecological risks. Maize accumulated considerable concentrations of PTEs in roots and shoot with bioconcentration factor > 1 for Cd, Cu, and Pb and transfer factor > 1 for As, Fe, Mn, and Ni. Overall, mixed treatments increased plant contents of As (118%), Cu (7%), Mn (8%), Ni (55%), and Zn (1%), while decreased those of Cd (7%), Fe (5%), and Pb (1%) compared to SW "alone" treatments. Risk indices predicted possible carcinogenic risks to cow (CR 0.003 > 0.0001) and sheep (CR 0.0121 > 0.0001) due to consumption of maize fodder containing PTEs. Hence, to minimize possible environmental/health hazards, mixing of FW and GW with SW can be an effective strategy. However, the recommendation greatly depends on the composition of mixing waters.

Characteristics of Soil DOM and Its Effect on the Transformation of Potentially Toxic Elements (PTE) Forms under Organic Fertilizer Return Conditions

In order to explore the effects of the composition and structure of soil’s dissolved organic matter (DOM) and its electron transfer capacity (ETC) on the bioavailability of the potential toxic elements chromium (Cr), lead (Pb) and cadmium (Cd) after the application of decomposed pig manure organic fertilizer, three-dimensional fluorescence spectroscopy (3D-EEMs), parallel factor analysis (PARAFAC) and electrochemical methods were used to analyze the composition characteristics of DOM in soil solution and the changes in the ETC, and the dynamic relationship between the relative content of DOM, ETC and various forms of potential toxic elements was explored by means of a Pearson correlation analysis and redundancy analysis (RDA). Among them, Cr, Pb and Cd were the elements with significant biological toxicity in farmland soil. The results indicated the following: (1) The soil DOM before and after returning the organic fertilizer to the field contained four components: UV and UVA humic-like (C1), tryptophan-like and UVA humic-like (C2), Exogenous and visible humic-like (C3) and tyrosine-like (C4). Humus-like was the main component. (2) After applying organic fertilizer, the relative contents of the DOM humus and tyrosine-like components in the soil increased by 8% and 8.73%, respectively. In this process, the DOM electron-accepting capacity (EAC) and electron-donating capacity (EDC) increased by 39.98% and 27.91%, respectively. (3) The humic-like fraction showed a highly significant positive correlation with ETC (p &lt; 0.01), and the tyrosine-like fraction showed a significant negative correlation with ETC (p &lt; 0.05). (4) The humus-like substance and ETC were positively correlated with the total amount, reducible state and oxidizable state of the potential toxic elements and negatively correlated with the weak acid extracted state and residue state; this showed that the humus-like components and ETC were more helpful for the transformation of the weak acid extracted state to the reducible state, oxidizable state and residue state in the interaction between the DOM components and Cr, Pb and Cd. In summary, the reasonable application of organic fertilizer could improve the relative content of DOM and ETC in soil, inhibit the biological toxicity of potential toxic elements in soil and provide a theoretical basis for the safe use of organic fertilizer.

Evaluation of Environmental Contamination by Toxic Elements in Agricultural Soils and Their Health Risks in the City of Arequipa, Peru

This study evaluated the concentration of toxic elements in soil samples from agricultural fields in the districts of Sachaca, Socabaya, Hunter, Quequeña, Yarabamba, Characato and Tiabaya in the city of Arequipa, Peru. The ecological risk, enrichment factor (EF), geo-accumulation index (Igeo) and integrated ecological risk index (RI) were estimated, while the health risk was determined with hazard coefficient (HQ) and hazard index (HI) values. Seven soil samples were collected in July 2019 and 17 toxic elements were analyzed in an accredited laboratory using the inductively coupled plasma-mass spectrometry (ICP-MS) methodology. The results were compared with environmental samples where no element exceeded what is established in the standard. The enrichment factor (EF), according to the background of Wedepohl, indicated that As (12.26 ± 3.66) presented a severe enrichment (high) in agricultural soils, while Cd (6.87 ± 3.25) presented moderate values. As, Cd, Pb, Cu and Zn (2.85 ± 0.85; 3.53 ± 1.67; 2.71 ± 1.25; 3.83 ± 0.81; 2.55 ± 0.79) presented low to moderate enrichment in agricultural soils, while Cr did not present enrichment in soils. The Igeo for As in Sachaca, Socabaya, Quequeña and Characato showed moderate contamination, Cu also showed moderate contamination in all the districts evaluated, and Cd showed the same contamination in the districts of Sachaca, Hunter, Quequeña and Tiabaya. The ecological risk in the districts evaluated showed a low degree of risk due to contamination by toxic elements. Finally, the health hazard index for toxic elements present in agricultural soils was evaluated, where the HQ values were negligible and the HI was less than 0.1 (H1 &lt; 0.1) for children and adults.

Environmental and Health Risk Assessment Due to Potentially Toxic Elements in Soil near Former Antimony Mine in Western Serbia

Background: Anthropogenic activities have clearly affected the environment, with irreversible and destructive consequences. Mining activities have a significant negative impact, primarily on soil, and then on human health. The negative impact of the first mining activities is represented even today in the soils of those localities. Research shows that, for different types of mines, the concentrations of potentially toxic elements (PTEs) are high, especially in antimony, multi-metal and lead–zinc mines, which have adverse effects on the environment and then on human health and the economy. A large flood in 2014 in Western Serbia resulted in the breaking of the dam of the processed antimony ore dump of the former antimony mine, causing toxic tailings to spill and pollute the downstream area. Due to this accident, tailings material flooded the area downstream of the dump, and severely affected the local agriculture and population. Methods: Potentially toxic elements content, pollution indices and health indices were determined in soil samples from the flooded area, using referenced methodologies. The sources and routes of pollutants and risks were determined and quantified using statistical principal component analysis, positive matrix factorisation, and a Monte Carlo simulation. Results: The main source of As, Cd, Hg, Pb, Sb and Zn in the upper part of the study area was the tailing material. Based on the pollution indices, about 72% of the studied samples show a high risk of contamination and are mainly distributed immediately downstream of the tailings dump that was spilled due to heavy rainfall. Conclusions: Although the content of the PTEs is high, there is no non-carcinogenic risk for any PTEs except As, for which a threshold risk was determined. There is no carcinogenic risk in the study area.

Trace element geochemical imprints and multi-path health risk assessment of potentially toxic elements in soils from the polymetallic area of tashan-jatau, northwestern nigeria

The occurrence of Potentially toxic elements (PTEs) in the soil phase may portend environmental, ecological and health-related risks. Hence, this study has combined high-precision geochemical analyses (X-ray fluorescence (XRF) and inductively Coupled Plasma Mass Spectrometry (ICP-MS)), quantitative soil pollution indices and health risk assessment modelling for a holistic and precise assessment of the intrinsic vulnerability of the soil system to contamination. Geochemical analysis showed that the soils are highly enriched with PTEs such as V (mean = 449.5 mg/L), Cr (mean = 529.9 mg/L), Cu (mean = 374.4 mg/L), Sr (mean = 1365.3 mg/L), Zr (mean = 2703 mg/L), Zn (mean = 282.5 mg/L), and Pb (mean = 127.3 mg/L). Quantitative soil pollution assessment (contamination factor and enrichment factor) revealed that besides mining, the distribution and association between trace elements and oxides were from surface environmental conditions (including mobility potential, leaching metal-complexation, weathering and oxidation of parent material). Health risk assessment based on hazard quotient and hazard index revealed that the inhabitants are generally more exposed to risks from toxic elements ingestion than dermal contact and inhalation; the children are vulnerable to risks than adults. The cancer risks from ingestion and dermal contact of As and Cr for both children and adults are relatively higher (&gt; 1.0E−04) than the acceptable range; although the children population seems to be more susceptible to cancer risks due to lower body weight.&#x0D;

Identification of sources and their potential health risk of potential toxic elements in soils from a mercury‑thallium polymetallic mining area in Southwest China: Insight from mercury isotopes and PMF model

Identification of potential toxic element (PTE) sources and their specific human health risk is critical to the management of PTEs in soils. In this study, multi-medium were collected from a mercury‑thallium polymetallic mining area in Southwestern China. Hg isotope technique together with positive matrix factorization (PMF) model was used to identify PTE sources and assess their source-oriented health risk. Results showed that among the studied PTEs, this study area presented high pollution of Hg, Tl and As, with higher concentrations than their corresponding background values of Guizhou province, yet their average concentrations in covering soils were significantly lower than those in the natural soils. The Tl in coix grains should also be paid more attention due to its high concentration. Both natural and covering soils had different Hg isotope composition with tailings, while sediments have similar Hg isotope fractionation with covering soils. According to the PMF model, three sources in both natural and covering soils were apportioned and Hg, Tl and As were mainly influenced by the historical mining activities, which also confirmed by their Hg isotope signatures. The contributions of historical mining activities accounted for 40 % and 20 % of the PTEs in natural and covering soils, respectively. The assessment of source-specific health risks suggested that the non-carcinogenic risk of Hg, Tl and As was much higher than other elements. Historical mining activities were regarded as the major contributor to health risks (79 % and 76 % for natural soils and 50 % and 59 % for covering soils, respectively). This indicated that the restoration of coveing soils indeed decreased the health risk in this study area. These findings thus highlight the importance of ongoing monitoring of covering soils in the polymetallic mining area, which is imperative for preferably assessing the health risk of PTEs in similar mining area worldwide.

A baseline survey of potentially toxic elements in the soil of north-west Syria following a decade of conflict

The first regional topsoil sampling campaign since 2011 maps elevated background concentrations of potentially toxic elements in soils across north-west Syria following more than a decade of conflict.

Geochemistry of Potentially Toxic Elements in Soil and Sediments of a Tanzanian Small-Scale Gold Mining Area

Geochemistry of Potentially Toxic Elements in Soil and Sediments of a Tanzanian Small-Scale Gold Mining Area

Contamination and Environmental Risk Assessment of Potentially Toxic Elements in Soils of Palm Farms in Northwest Riyadh, Saudi Arabia

Thirty-four surface soil samples were collected from the palm farms of the Al-Ammariah area, northwest Riyadh, Saudi Arabia to assess the contamination and environmental risk of potentially toxic elements (PTEs). Aluminum (Al), arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), antimony (Sb), strontium (Sr), uranium (U), vanadium (V), and zinc (Zn) were analyzed using inductively coupled plasma–atomic emission spectroscopy (ICP–AES). Several pollution indices were employed to assess contamination and to evaluate the environmental risks of these PTEs. Average values (mg/kg) for Cr (19.97), Pb (5.08), Cu (11.36), Zn (52.16), Ni (26.94), Co (3.89), and V (18.94) were under the values recorded for soils globally, while the average values of Hg (0.50) and U (8.06) were greater than the average values of worldwide soils. Pollution indices indicated that the studied soils exhibited indications of severe enrichment and significant contamination with Hg, and moderately severe enrichment with U and As. The potential ecological (RI) findings indicated a moderate level of risk posed by PTEs in the study area. The potentially toxic elements originated from both natural and human sources, largely due to chemical weathering of the neighboring mountains, in addition to the widespread utilization of insecticides and fertilizers.

Contamination, Source Identification, Ecological and Human Health Risks Assessment of Potentially Toxic-Elements in Soils of Typical Rare-Earth Mining Areas.

The mining and leaching processes of rare-earth mines can include the entry of potentially toxic elements (PTEs) into the environment, causing ecological risks and endangering human health. However, the identification of ecological risks and sources of PTEs in rare-earth mining areas is less comprehensive. Hence, we determine the PTE (Co, Cr, Cu, Mn, Ni, Pb, Zn, V) content in soils around rare-earth mining areas in the south and analyze the ecological health risks, distribution characteristics, and sources of PTEs in the study area using various indices and models. The results showed that the average concentrations of Co, Mn, Ni, Pb and Zn were higher than the soil background values, with a maximum of 1.62 times. The spatial distribution of PTEs was not homogeneous and the hot spots were mostly located near roads and mining areas. The ecological risk index and the non-carcinogenic index showed that the contribution was mainly from Co, Pb, and Cr, which accounted for more than 90%. Correlation analysis and PMF models indicated that eight PTEs were positively correlated, and rare-earth mining operations (concentration of 22.85%) may have caused Pb and Cu enrichment in soils in the area, while other anthropogenic sources of pollution were industrial emissions and agricultural pollution. The results of the study can provide a scientific basis for environmental-pollution assessment and prevention in rare-earth mining cities.

Bibliometrics-Based: Trends in Phytoremediation of Potentially Toxic Elements in Soil

Land purity is of central importance to crop production. The accumulation of toxic elements in soil seriously affects crop safety. Phytoremediation is a widely used technology to clean soil pollution because of its low cost, simple implementation, and lack of secondary pollution. This investigation includes data from 4787 articles on phytoremediation of heavy metals in soil from the period between 2008 and 2021, acquired from Web of Science databases. VOSviewer was utilized to conduct statistical analysis of countries (regions), institutions, journals, cited literature, and keywords. According to the statistical data, the use of phytoremediation for cleaning soil with heavy metals has matured in recent years, showing a trend of rapid growth. There were also few collaborative studies on this subject between institutions, and China has the most extensive research in this field and, therefore, has the highest number of publications, followed by India and the United States. Publications from Pakistan are very in-depth and have the highest average number of citations. It was discovered that many researchers are now publishing articles on Environmental Science and Pollution Research. Chemosphere was revealed as the most influential journal, whereas The Journal of Hazardous Materials was the most cited. In-depth research on keywords such as metal enrichment, super-enrichment plants, phytoremediation, Cd, Pb, etc. have been conducted by many scientists; however, the research content for different countries was different. The review analysis revealed that in the future it will be possible to breed trees with high heavy metal accumulation, or to use transgenic plants and ornamental plants with high tolerance to prevent and control heavy metal pollution in soil. This paper aims to provide references for scholars in this field and to allow them quick access to summarized knowledge on this topic.

Impact of bare and CMC-coated Fe oxide nanoparticles on microbial activity and immobilising zinc, lead, and cadmium in a contaminated soil

ABSTRACT The potential of bare and carboxymethyl cellulose (CMC)-coated iron oxide nanoparticles (FeONPs), including goethite, hematite, and magnetite, for stabilisation of lead (Pb), zinc (Zn), and cadmium (Cd) in contaminated soil was investigated in a greenhouse experiment. The results showed that FeONPs application decreased the availability of potentially toxic elements in soil, and CMC-coated NPs were more effective than bare NPs. CMC-coated goethite proved to be the most effective treatment in reducing the Zn and Cd availability. Its application decreased the diethylenetriaminepentaacetic acid (DTPA) extractable Zn and Cd concentrations by 49% and 56%, respectively. CMC-coated magnetite was the most effective treatment for the stabilisation of Pb. Its application decreased the DTPA-extractable Pb by 56%. Carbon dioxide (CO2) emission and microbial biomass carbon (MBC) were higher in samples treated with CMC-coated FeONPs than bare FeONPs-treated samples, indicating that CMC coating NPs enhanced microbial activity. CO2 emission and MBC were approximately three and five times higher, respectively, in samples treated with CMC-coated goethite than the control. This study suggests that coating of bare FeONPs with CMC improves the adsorption capacity of NPs, making them more chemically reactive, and is a possible technique to reduce the likely antibacterial effects of bare FeONPs.

Geochemical baseline assessment and ecological risk evaluation of potentially toxic elements in soils: a case in Han River, China

Geochemical baseline assessment and ecological risk evaluation of potentially toxic elements in soils: a case in Han River, China