Elements In Soils Research Articles

Investigation of Lunar Shallow Subsurface Water Content and Soil Elemental Composition via Active Neutron Detection

The detection of planetary water and soil elements is a pivotal area of research due to its implications for understanding celestial bodies. Within the realm of planetary sampling missions, attention is predominantly directed toward the shallow surface layers, typically to a depth of 1 m. This paper examines the Moon as a case study, employing Monte Carlo simulations to introduce an active detection methodology that integrates high-energy neutron pulse generators with neutron and gamma detectors. Simulations were made of the albedo neutrons and prompt gamma counts after mitigating the interference of secondary neutrons and gamma rays, which result from the interaction between galactic cosmic rays and the lunar surface. The depth limit of active neutron detection on the shallow surface is about 100 cm. The cadmium ratio (CdR), the ratio between total neutron counts and counts caused by nonthermal neutrons, facilitates the rapid and accurate water content calculation using a fitted CdR curve. Standard gamma spectra of the associated elements, derived through Monte Carlo simulations, along with the mixed gamma spectra requiring resolution, form the foundation for the spectral analysis. Utilizing the weighted least-squares method to invert gamma spectra facilitates the identification of the content of associated elements. Integrating the analysis of albedo neutron energy spectra with prompt gamma spectra allows for the rapid assessment of the region’s water content and soil conditions. Moreover, this study also explores the impact of variations in the content of associated elements on the determination of water content.

Microplastics and their interaction with microorganisms in Bosten Lake sediment

Microplastics (MPs), discovered in oceans, lakes, and rivers, can infiltrate the food chain through ingestion by organisms, potentially posing health risks. Our research is the first to study the composition and distribution of MPs in Bosten Lake's sediment. In May, the average abundance of MPs was 0.95±0.72 particles per 10 gs, and in October, it was 0.90±0.61 particles per 10 gs. Bohu Town had the highest MP abundance, with 1.75±0.35 particles per 10 gs in spring and 2 ± 0 particles per 10 gs in autumn. In May, 53 % of the MPs were transparent, while in October, black MPs constituted 58 %. The predominant morphology was fibrous, accounting for 61 % of the total. MPs in the size range of 0.2–1 mm made up 91 % and 66 % of the total in May and October, respectively. The most common types of MPs in May were polyethylene terephthalate (PET) at 40 % and polyethylene (PE) at 26 %. In October, PET was the most prevalent at 71 %, followed by poly(ether-ether-ketone)(PEEK) at 11 %. Certain microbial taxa, such as Actinobacteriota, Pseudomonas, and Vicinamibacteraceae, associated with MP degradation or complex carbon chain breakdown, were notably enriched in sediment areas with high MP concentrations. A significant positive correlation was observed between the abundance of MPs in sediments and Actinobacteriota. Additionally, the abundance of Thiobacillus, Ca.competibacter, and other bacteria involved in soil element cycling showed a significant positive correlation with the organic matter content in the sediments. Anaerobic bacteria like Thermoanaerobacterium displayed a significant positive correlation with water depth. Our study reveals the presence, composition, and distribution of MPs in Bosten Lake's sediments, shedding light on their potential ecological impact.

In the Qaidam Basin, Soil Nutrients Directly or Indirectly Affect Desert Ecosystem Stability under Drought Stress through Plant Nutrients.

The low nutrient content of soil in desert ecosystems results in unique physiological and ecological characteristics of plants under long-term water and nutrient stress, which is the basis for the productivity and stability maintenance of the desert ecosystem. However, the relationship between the soil and the plant nutrient elements in the desert ecosystem and its mechanism for maintaining ecosystem stability is still unclear. In this study, 35 sampling sites were established in an area with typical desert vegetation in the Qaidam Basin, based on a drought gradient. A total of 90 soil samples and 100 plant samples were collected, and the soil's physico-chemical properties, as well as the nutrient elements in the plant leaves, were measured. Regression analysis, redundancy analysis (RDA), the Theil-Sen Median and Mann-Kendall methods, the structural equation model (SEM), and other methods were employed to analyze the distribution characteristics of the soil and plant nutrient elements along the drought gradient and the relationship between the soil and leaf nutrient elements and its impact on ecosystem stability. The results provided the following conclusions: Compared with the nutrient elements in plant leaves, the soil's nutrient elements had a more obvious regularity of distribution along the drought gradient. A strong correlation was observed between the soil and leaf nutrient elements, with soil organic carbon and alkali-hydrolyzed nitrogen identified as important factors influencing the leaf nutrient content. The SEM showed that the soil's organic carbon had a positive effect on ecosystem stability by influencing the leaf carbon, while the soil's available phosphorus and the mean annual temperature had a direct positive effect on stability, and the soil's total nitrogen had a negative effect on stability. In general, the soil nutrient content was high in areas with a low mean annual temperature and high precipitation, and the ecosystem stability in the area distribution of typical desert vegetation in the Qaidam Basin was low. These findings reveal that soil nutrients affect the stability of desert ecosystems directly or indirectly through plant nutrients in the Qaidam Basin, which is crucial for maintaining the stability of desert ecosystems with the background of climate change.

Black shale bedrock control of soil heavy metal typical high geological background in China Loushao Basin: Pollution characteristics, source and Influence assessment based on spatial analysis

During the process of black shale weathering, multiple heavy metal elements are concentrated in the soil, causing pollution. This study selected soil and black shale bedrock samples from high geological background areas to investigate the control of heavy metal element pollution by bedrock using spatial analysis. The research results indicate that the heavy metal content in black shale bedrock is extremely high, ranging from 2.3 to 13.1 times the background values of rock heavy metal elements. The heavy metal content in the soil formed through weathering is positively correlated with the bedrock, ranging from 1.1 to 21.3 times the background values. The coefficient of variation of rock samples ranges from 1.09 to 7.18, indicating significant variability.The analysis reveals that the control ability of pure rock over heavy metal elements is mainly moderate and high, accounting for over 70 %, with d being the most affected metal element. Except for As, the other seven elements exhibit strong spatial autocorrelation, showing distinct regional distribution characteristics. The soil elements demonstrate high homogeneity, with heavy metal elements from black shale bedrock primarily released through weathering serving as the main source of these elements.

Distribution Characteristics, Risk Assessment, and Source Analysis of Heavy Metals in Farmland Soil of a Karst Area in Southwest China

Soil environmental quality related to the residents’ life, health, and safety, has been the hotspot issues in science of ecological environment protection. Evaluating the distribution characteristics, ecological risk, and source of heavy metals in farmland is important for protecting soil resources. The agricultural area of Lianhua town, Gongcheng County, Guilin is a typical karst landform. In response to the problem of heavy metal pollution and complex sources in the soil of this area, the characteristics and sources of heavy metal pollution in the soil profiles from farmland, abandoned land, and forest were studied using the single-factor index method, the geoaccumulation index (Igeo) principal component analysis (PCA) and positive matrix factorization (PMF) model. The results showed that: (1) that the contents of cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) in the soil profile of the study area were higher than that of the soil elements background values in Guangxi. The total and available forms contents of all heavy metal elements exhibited the characteristics of accumulation in the surface profile; (2) among the six heavy elements, the contents of Cd were in a moderately to heavily polluted state. The contents of Cd in some soil profiles exceeded the control standard for agricultural land soil pollution. The contents of Zn and Ni were from slightly to moderately polluted in areas with frequent agricultural activities; (3) according to the PCA and PMF model, there were three main sources of heavy metals in the study area. Among them, Cd, Cu, Ni, and Zn are related to agricultural activities; the elements As, Cd, Cr, and Hg are closely related to geological background; Pb and Zn are mainly affected by atmospheric sedimentation of transportation. Agricultural activities and natural geological background are the main contribution sources of heavy metals in soil. Human activities are the main factors that cause the accumulation of heavy metals in soil. This research has theoretical guidance and practical significance for the prevention and control of soil heavy metal pollution and the protection of farmland environmental quality in the region.

Impact of Metals Scrap Yard on the Presence of some Heavy Metals Concentration within Gombe Metropolis, Gombe State, Nigeria, using Atomic Absorption Spectrometry

The Metal scrap yards play a crucial role in the recycling and reuse of metals, contributing significantly to the economy and conservation of natural resources. However, the processing and storage of metal scraps can lead to the release of heavy metals such as lead, chromium and cadmium, into the environment. The presence of heavy metals in metal scrap yards poses a significant risk to nearby communities, workers and the environment, also causing air and water pollution, soil contamination, and health problem. Study of impact of metals scrap yard on the presence some of some heavy metals in soil samples was done using Atomic Absorption Spectrometer (AAS). Top soil sample were collected from eight metals scrap yards and their corresponding control areas. One gram (1 g) each of the soil samples was digested and then heated slowly and steadily, the solution appears colorless. The samples were allowed to cool and ready for analysis. The result obtained was, the mean elemental concentration element was of the order ofMn (41.022±41.202)> Cu (4.416±4.274) >Pb (2.685±1.399) > Mg (0.500±10.122) > Cr (0.460±0.187) > Cd (0.125±0.027) > Co (0.04±0.000)> Ni (0.000±0.000). The comparison of the elemental concentration of the heavy metals of (Mn, Mg, Cu, Pd, Cr, Cd, Co and Ni) in the study area ware shows the metal scrap yard has impact in the presence of heavy metals in soil. In addition, the Contamination factor (CF), and Pollution load index (PLI) of each trace element in soil of the study area and their respective control area were all < 1 which implies that they all have low contamination factors, less polluted and low contaminated.

DYNAMIC SOIL PROPERTIES AFFECT THE ACIDITY OF ARTIFICIAL WETLANDS: A CASE STUDY IN THUNG YIEW PAK PHLI OF NAKHON NAYOK PROVINCE, THAILAND

This study examined the soil elements and properties of an area becoming an artificial wetland and compared them with those of an agricultural area. The study site is an artificial wetland in Nakhon Nayok Province, Thailand. Its soil properties and element content were compared with a nearby agricultural area using a one-way analysis of variance (ANOVA). The results of the study found this artificial wetland to be within the soil acidity zone of central Thailand, with an average soil pH above 3.99 ± 0.49 and a topsoil organic matter average of 17090 ± 2685 mg kg-1, with aluminium (Al) and iron (Fe) as the major soil minerals. Compared to the agricultural area, the soil properties of the artificial wetland had slightly lower topsoil pH but significantly lower pH in the soil layer 100 cm deep in the agricultural area, and the EC in the artificial wetland was higher than in the agricultural area. However, there are three distinct patterns in the elemental composition of the artificial wetland: (1) A lower-quantity soil surface that improves with depth, (2) a high-quantity of topsoil that worsens with depth, and (3) highly variable soil quality below 50-100 cm. In the soil, the organic carbon in artificial wetlands has a ratio of 1:0.17:0.51 to reference area 1 and reference area 2, indicating that wetlands can store carbon in the soil. The element content of the topsoil and 50 cm soil layer is potentially influenced by land use and beneficial microbial activity, and the soil 100-150 cm layer has an element quantity shared with its parent soil. In this study, we sought to understand the physics and chemical composition of soil in an area transitioning to an artificial wetland over approximately 30 years.

Concentrations and Health Risk Valuation of Possibly Toxic Metals in Soil and Sediment in Parts of Ona River, Ibadan, Nigeria

The accumulation of contaminants in the soils and sediments may negatively affects people within the vicinity of Ona River and increase potential of human health risk. This study appraised the concentration status, probable origins and human health risks of some possibly toxic elements (Fe, Cu, Zn, Mn, Pb and Cd) in the riverbank soils (RBK) and riverbed sediments (RBS) of Ona River section bordering residential community in Ibadan, Southwest Nigeria. Therefore, six composite samples of RBK and RBD were analyzed for heavy metals using atomic absorption spectrophotometry (AAS). Enrichment factor (EF) and quantification of contamination (QoC) are used to examine potential origins of tested metals. Furthermore, hazard index (HI) and total cancer risk (TCR) have been utilized to evaluate the extent of non-carcinogenic and cancer risks of studied metals to inhabitants of the study site. The results of metal contamination assessment revealed low concentration <1.0 mg/kg for each analyzed metal in both RBK and RBD while EF and QoC advocate lithogenic origins of assessed metals with little or none anthropogenic inputs in both studied soils and sediments. The computed HI values were lower than 1.0 and thus no adversative health effects on adults and children via ingestion, skin contact and inhalation routes. The CR computation exposed that adults and children are at growing risk of developing cancer over a lifetime when exposed to RBK and RBD via ingestion and dermal pathways. Cadmium contributed largely to TCRs among the assessed metals. The study indicates the inevitability of initiating actions that reduce exposure of residents to nearby soil and sediment and safeguard their health, particularly the children.

Mobilization Of Metal Elements Against The Incidence Of Dermatitis Is Seen From Community Knowledge In The Mining Circle In Amonggedo Sub-District, Konawe District

Background: Mining activities in Amonggedo sub-district have an impact on public health and environmental conditions, including data on the 10 highest diseases in the Amonggedo Health Center work area after the presence of mining activities showing 2 types of diseases due to metal distribution that have continued to increase in the last 3 years, namely Skin Disease and Underground Tissue. Methods: The study was conducted with the Mix Method, namely descriptive analysis with water and metal quality checks carried out at the Health Laboratory of Southeast Sulawesi province and Cross Sectional research was carried out on the people of Amonggedo District, Konawe Regency. Results: The results showed that the knowledge variable obtained the value of X2 calculated > X2 table (25.235 > 3.841) which means that there is a relationship between knowledge and the incidence of dermatitis in the Working Area of the Amonggedo Health Center, Amonggedo District, Konawe Regency. Conclusions: Metal content in dominant soil elements exceeds the threshold value both at the inlet and outlet, namely Ni, Fe, Mg, Al, Si, Ca, Cr, Metal content in some elements exceeds the threshold value both at the inlet and outlet, namely TSS, Fe, Ni, Co, Pb, There is a moderate relationship between knowledge and the incidence of dermatitis in the Working Area of the Amonggedo Health Center, Amonggedo District, Konawe Regency.

Оценка химического состава сапропелей различных месторождений

Complex chemical composition and wide mining opportunities determine the use of sapropels and sapropel-based products in various sectors of national economy. The fullest potential of sapropel is revealed in agriculture, where it is used as fertilizer, a component of soils, raw materials for humic preparations production etc. The aim was to study the sapropels’ suitability for the production of humic fertilizers. Using validated methods we analyze chemical composition of sapropel sediments from 4 freshwater lakes located within the latitudinal section of 53–56° N in the temperate climate. Microbiological parameters of all studied samples are within the normal range. Dry matter content in the range of 46.1–51.3% corresponds to the normative indicators. The mass fraction of organic matter varies in the range of 31.8–39.9% DM. This allows classifying all samples as organo-clay, and determines the possibility of their use for soils of light granulometric composition. The relatively high content of humic (18.3–22.9% DM) and fulvic acids (3.7–6.4% DM) makes it possible to use the studied sapropel samples for the manufacture of humic preparations (especially, a sapropel sample of the lake Chervonoe, Belarus). Low P and K content (0.24–0.36% DM and 0.32–0.42% DM, respectively) can negatively affect the efficiency of fertilizers from these sapropel species; this can be avoided by mixing sapropel with manure or enrichment with mineral fertilizers. Indicators of heavy metal (Cu, Mn, Zn, Co, Pb and Cd) content in all studied samples meet the safety requirements. Samples from deeper layers of the Rusaki Lake (Altai Territory) and the Beloe Lake (Novosibirsk Region) refer to the 1st class of suitability, the rest (according to a number of indicators) – to the 2nd class. The content of trace elements in the studied sapropels is within the established norms and makes it possible to use them for replenishing the deficit of trace elements in soils. In general, all the studied samples can be used as environmentally friendly organomineral fertilizers, as well as production of humic preparations to increase in the biological and energy capacity of agrocenoses and to reproduce the soil fertility.

The Effect of Manganese and Sulfur Applications on the Rocket (Eruca vesicaria subsp. Sativa) Plant Grown in Lime Soils

Due to the high lime and pH in the soil, sulfur and micro element deficiencies are observed in green vegetable plants. Rocket, one of the green vegetables and a member of the Brassicaceae family, is widely produced in our country. It is noteworthy that rocket is grown by producers almost everywhere and that this plant grown in our region also has a deficiency of microelements. For this reason, in this study were investigated that the sulfur and manganese requirement of rocket, which is one of the vegetable plants grown in Konya calcareous soil, and the effect of the interaction between these two elements on plant growth and yield. In our study, sulfur (S) fertilizer was applied in three doses (0- 40- 80 kg S da-1) and manganese (Mn) fertilizer in three doses (0- 1- 2 kg Mn da-1) was applied to the rocket plant. The experiment was carried out in the greenhouse conditions according to the randomized plots factorial design. At the end of the experiment, the average leaf height, chlorophyll SPAD value, plant fresh weight, plant height and plant Mn concentration did not differ with different doses of fertilizer applications in the rocket plant. On the other hand, the sulfur concentration in the plant and soil increased significantly with sulfur fertilization (p

Wykorzystanie testów kontaktowych do oceny gleb rolniczych

A soil has been of great concern throughout the world due to increasing environmental awareness and interest in the quality and management of such soils. Košice, the city in eastern Slovakia, is exposed to typical urban contamination sources such, furthermore, being the largest steel producer in Central Europe, it is long-term environmentally loaded by the iron and steel works that represent the largest source of (metallic elements) contamination in Slovakia. Five sampling sites located in the surrounding of U.S.Steel Košice (Slovakia), were selected, where almost all the agricultural soils were polluted by the metallic elements (Fe3+, Al3+, Mn2+, Cu2+, As3+). Agricultural soils toxicity was assessed with the toxicity bioassay -Phytotoxkit. Tests of limit concentrations of the elements (Fe3+, Al3+, Mn2+, Cu2+ and As3+) and Tests of soil concentration series (100-50-25-12.5%) - screening tests mustard Sinapis alba and Lepidium sativum were performed. The testing of the concentration range was performed in order to determine the values of 14d/EC50 and the possibility of comparing the ecotoxicity of metallic elements in agricultural soils (ISO 11269-2 Soil quality). Four concentrations were prepared in test plates: 12.5 - 25 - 50 - 100% soil samples. Concentration of metals in the soil samples ranged from 24400 to 39000 mg/kg for iron; 54000 to 85000 mg/kg for aluminum; 381 to 1035 mg/kg for manganese; 27 to 59 mg/kg for copper; and 7 to 36 mg/kg for arsenic. Based on the median concentration, the metals in the soils were arranged in the following decreasing order: Al3+ > Fe3+ > Mn2+ > Cu2+ > As3+. In the agricultural soils (4USS-PW) showed high contamination values for the iron with a median 35300 mg/kg, aluminum with a median 82500 mg/kg, manganese with a median 1027 mg/kg. The median level of arsenic in the soil (4USS-PW) was 34 mg/kg, this indicate higher concentration as the limit concentration is 25 mg/kg (Law No. 220/2004-2). Agricultural soils 1-3USS and 5USS showed less than 50% inhibition of the seed germination and root growth in the S.alba and L. sativum tests compared to the control, excepting of soil from 4USS plant west (values of the EC50 to 65%). Thus, the results of phytotoxicity tests were consistent with the chemical data. The rapid increase in urbanization, industrialization, human population, and traffic flow has resulted in the environment surrounding farmland ecosystems being critically contaminated by metallic elements.

Sorption of ciprofloxacin and enrofloxacin on alkaline cropland soil in semiarid regions: Roles of pH, ionic strength, and ion type

Animals manure and chemical fertilizers are widely applied to agricultural soils to mitigate soil fertility decline resulting from intensive farming practices. However, the use of antibiotics such as ciprofloxacin (CIP) and enrofloxacin (ENR) in these manures introduces certain environmental risks. The sorption of CIP and ENR in soil is influenced by various factors. Soil cations (i.e., Na+, K+, Mg2+, and Ca2+) and artificially introduced ions (NH4+) can affect the sorption behavior of CIP and ENR in alkaline agricultural soils through mechanisms such as ion exchange and competitive sorption. To investigate the effects of ionic strength and ion type on the sorption of antibiotics in alkaline agricultural soil, batch equilibrium experiments were conducted in this study. The results showed that the affinity of alkaline farmland soil to CIP and ENR was poor, and Kd was only 159 L/kg and 89 L/kg, respectively. Increases in temperature and pH inhibited CIP and ENR sorption on soil. Mineral elements in the soil strongly inhibited CIP and ENR sorption. Conversely, NH4+ promoted the Kd values of CIP and ENR by 46% and 221%, respectively. Additionally, under different influencing factors, both the sorption affinity (Kd) and sorption amount of ENR were lower than those of CIP. These findings indicate that ENR has a greater migration potential and poses a greater environmental risk in agricultural soils. Alkaline soil and mineral elements increase the migration potential of CIP, ENR, but the introduction of NH4+ in agricultural production can weaken the migration potential of them.

Exploring the potential of biochar for the remediation of microbial communities and element cycling in microplastic-contaminated soil

The detrimental effects of microplastics (MPs) on soil microbial and elemental raise significant environmental concerns. The potential of remediation with biochar to mitigate these negative impacts remains an open question. The remediation effects of biochar derived from corn and cotton straw on MPs concerning soil microorganisms and element cycling were investigated. Specifically, biochar induced substantial remediations in microbial community structure following MP exposure, restoring and fortifying the symbiotic network while exerting dominance over microbial community changes. A combined treatment of biochar and MPs exhibited a noteworthy increase in the abundance of NH4+, NO3−, and available phosphorous by 0.46–2.1 times, reversing the declining trend of dissolved organic carbon, showing a remarkable increase by 0.36 times. This combined treatment also led to a reduction in the abundance of the nitrogen fixation gene nifH by 0.46 times, while significantly increasing the expression of nitrification genes (amoA and amoB) and denitrification genes (nirS and nirK) by 22.5 times and 1.7 times, respectively. Additionally, the carbon cycle cbbLG gene showed a 2.3-fold increase, and the phosphorus cycle gene phoD increased by 0.1-fold. The mixed treatment enriched element-cycling microorganisms by 4.8–9.6 times. In summary, the addition of biochar repaired the negative effects of MPs in terms of microbial community dynamics, element content, gene expression, and functional microbiota. These findings underscore the crucial role of biochar in alleviating the adverse effects of MPs on microbial communities and elemental cycling, providing valuable insights into sustainable environmental remediation strategies.

Quantitative source apportionment and health risk assessment of trace elements in surface soils around the Shazand chemical industrial district, northwestern of Iran

A comprehensive study aimed at measuring trace elements pollution in the Shazand chemical industrial district, located in northwestern Iran, was conducted. Employing principal component analysis (PCA) and positive matrix factorization (PMF), we identified sources of trace elements and assessed associated health risks for inhabitants. The results showed that the mean concentrations of Pb, Cd, Ni, Zn, and As of 190 topsoil samples exceeded the background values, except for Cu. The total noncancer risk values for adults and children were 0.72 and 7.95, respectively, and the total carcinogenic risks were 8.46 E – 05 and 2.69 E – 04, respectively. The noncarcinogenic risk for children was above the threshold level, but low for adults. The total potential carcinogenic health risks for children exceeded the threshold of 1 E – 04 indicating a high carcinogenic risk for them, whereas the risk for adults was considered acceptable. Furthermore, As was the primary hazardous metal to human health, followed by Cd and Ni. According to the results of the PMF model, four factors were extracted for trace elements, including natural source, transportation sources, industrial sources, and agricultural sources, which contributed about 27.9%, 17.51%, 29.15%, and 25.44% to pollution of the area, respectively. Anthropogenic sources contributed far more to the potential health risks posed to inhabitants of the study area. These findings can assist governmental agencies in implementing targeted control strategies to prevent the contamination of heavy metals.

Oral bioaccessibility of potentially toxic elements in various urban environmental media

An important aspect of geochemical studies is determining health hazard of potentially toxic elements (PTEs). Key information on PTEs behaviour in the human body in case of their ingestion is provided with the use of in vitro bioaccessibility tests. We analysed and compared oral bioaccessibility of a wide range of PTEs (As, Cd, Ce, Cr, Cu, Hg, La, Li, Ni, Pb, Sb, Sn, Zn), including some that are not often studied but might pose a human health hazard, in soil, attic dust, street dust, and household dust, using Unified BARGE Method (UBM). Additionally, feasibility of usage of scanning electron microscope techniques in analyses of solid residuals of UBM phases was tested. Results show that bioaccessible fractions (BAFs) of PTEs vary significantly between individual samples of the same medium, between different media and between the gastric and gastro-intestinal phases. In soil, attic dust and street dust, bioaccessibility of individual PTE is mostly higher in gastric than in gastro-intestinal phase. The opposite is true for PTEs in household dust. In all four media, with the exception of Pb in household dust, among the most bioaccessible PTEs in gastric phase are Cd, Cu, Pb, and Zn. During the transition from the stomach to small intestine, the mean BAFs of most elements in soil, attic dust, and street dust decreases. The most bioaccessible PTEs in gastro-intestinal phase are Cu, Cd, Ni, and As. Micromorphological and chemical characterisation at individual particle level before and after bioaccessibility test contribute significantly to the understanding of oral bioaccessibility.

Rapid and High-Performance Analysis of Total Nitrogen in Coco-Peat Substrate by Coupling Laser-Induced Breakdown Spectroscopy with Multi-Chemometrics

Nitrogen is an important nutrient element for crop growth. Rapid and accurate acquisition of nitrogen content in cultivation substrate is the key to precise fertilization. In this study, laser-induced breakdown spectroscopy (LIBS) was used to detect the total nitrogen (TN) of coco-peat substrate. A LIBS spectrum acquisition system was established to collect the spectral line signal of samples with wavelengths ranging from 200 nm to 860 nm. Synergy interval partial least squares (Si-PLS) algorithm and elimination of uninformative variables (UVE) algorithm were used to select the spectral data of TN characteristic lines in coco-peat substrate. Univariate calibration curve and partial least squares regression (PLSR) were used to build mathematical models for the relationship between the spectral data of univariate characteristic spectral lines, full variables and screened multi-variable characteristic spectral lines of samples and reference measurement values of TN. By comparing the detection performance of calibration curves and multivariate spectral prediction models, it was concluded that UVE was used to simplify the number of spectral input variables for the model and PLSR was applied to construct the simplest multivariate model for the measurement of TN in the substrate samples. The model provided the best measurement performance, with the calibration set determination coefficient () and calibration set root mean square error (RMSEC) values of 0.9944 and 0.0382%, respectively; the prediction set determination coefficient () and prediction set root mean square error (RMSEP) had values of 0.9902 and 0.0513%, respectively. These results indicated that the combination of UVE and PLSR could make full use of the variable information related to TN detection in the LIBS spectrum and realize the rapid and high-performance measurement of TN in coco-peat substrate. It would provide a reference for the rapid and quantitative assessment of nutrient elements in other substrate and soil.

Occupational and human health risks of exposure to potentially toxic elements (PTEs) in top soils from steel fabrication workshops

IntroductionEnvironmental pollution caused by potentially toxic elements (PTEs) from anthropogenic sources has become a global concern due to its deleterious effect on humans and ecosystem health. Therefore, this study evaluated the concentrations of PTEs, pollution level and human health risk in topsoil from ten (10) steel fabrication workshops in Abeokuta, Ogun State, Nigeria. Materials and methodsTen (10) composite soil samples were collected in November 2023, from 10 different steel fabrication workshops in proximity to residence in Abeokuta, Ogun State, Nigeria. One (1) gram of processed sample was digested using aqua regia and PTE concentration estimated using atomic absorption spectrophotometer (AAS). Pollution index assessment was determined using enrichment factor (EF) and geo-accumulation index (I-geo) while descriptive statistics and correlation were subjected to statistical package for social sciences (SPSS). ResultsThe result showed that Iron (Fe) (11,500 – 42,100 mg kg−1), Lead (Pb) (10.7 – 583 mg kg−1), Chromium (Cr) (16.3 - 49.7 mg kg−1), Zinc (Zn) (34.6 – 343 mg kg−1), Manganese (Mn) (109 – 840 mg kg−1), Nickel (Ni) (2.23 - 25.3 mg kg−1), Copper (Cu) (16.6 -107 mg kg−1) and Cadmium (Cd) (2.23 - 25.3 mg kg−1) were present. Mean concentration for Pb (179±202 mg kg−1) is higher than the Canada soil guideline value (CSGV) (140 mg kg−1) while other PTEs are within the recommended limit. Pollution indices revealed EF (Cd and Pb) and I-geo (Cd) as the primary pollutants in the soil while the strong significant correlation between Cr, Cu and Mn p < 0.05. Cr, Ni, Pb and that of Cu, Mn, Ni, Pb, Zn p < 0.01 suggest an emanation from both geogenic and anthropogenic sources. Human health risk assessment revealed Fe as the most dosed PTE and ingestion as the major pathways of exposure especially to children being the most susceptible. Hazard index (HI) and total cancer risk (TCR) values for PTEs were <1 and within the acceptable threshold (1 × 10−6 – 1 × 10−4) except for Pb (3.93E+01; 1.16E-03) in adults respectively. ConclusionThe study showed that the topsoil from the steel fabrication workshop is polluted with Pb and Cu toxicity and the adult (residents and workers) population exposed to the soil is potentially at a non-cancer and cancer risk.

Assessing the impact of climate and crop diversity on regional greenhouse gas emissions and water demand of cropland

To tackle the challenges of climate warming and freshwater scarcity, evaluating greenhouse gas (GHG) emissions and water demand in agricultural production can contribute positively to sustainable agricultural practices. This study aims to quantify the GHG emissions and water requirements of three major grains in diverse environmental regions in China, with a specific focus on exploring their spatial heterogeneity due to regional differences. The parameterized DNDC model was used to quantify crop GHG emissions, while the Penman-Monteith equation was utilized to assess crop water demand. The result showed that the total GHG emission of major grain in China was 372.43 Tg/yr (CO2), 11.68 Tg/yr (CH4), 475.56 Gg/yr (N2O) respectively; and the water demand was 473.60 Gm3, in 2015. The Middle-lower Yangtze Plain (MLYP) had the highest emission and water demand. High-temperature and high-precipitation regions had greater GHG emission intensity; the intensity of different GHG emissions was significantly influenced by the type of crops. Late rice had the highest emission intensity. The geospatial distribution of GHG emissions and water demand displayed opposite patterns, with meteorological conditions and crop types as the main reasons. Soil bulk density was the most significant soil element influencing regional emissions. These results will help to assess the spatial heterogeneity of agricultural “water and carbon”, and the quantitative results can be used as evaluation indicators to establish resource- and environment- friendly agricultural cropping patterns suitable for different cropping regions.

Inorganic mineral elements in sandy soil, and their effect on agricultural crops "The soil of the Libyan Kufra Oasis as a model"

Inorganic mineral elements in sandy soil, and their effect on agricultural crops "The soil of the Libyan Kufra Oasis as a model"