Agricultural Soil Samples Research Articles

Natural deep eutectic solvents as sustainable alternative for the Ultrasound-Assisted extraction of triazines from agricultural soils

Natural deep eutectic solvents (NADES) have gained much attention as a viable and sustainable alternative to traditional organic solvents in multiple areas of analytical chemistry, including extraction of contaminants from samples of environmental concern. In this work, a total of 68 potential NADES have been assayed and further evaluated as sustainable solvents in the development of an ultrasound (US)-assisted extraction method for triazinic herbicides from agricultural soil samples and final determination by HPLC-UV. Choline chloride (ChCl) was used as hydrogen bond acceptor (HBA), and different carboxylic acids, alcohols and amines were tested as hydrogen bond donors (HBDs) in different molar ratios in order to find the optimum combination able to form appropriated NADES for the extraction of triazines. Among the different ChCl:carboxylic acids mixtures tested, those consisting of ChCl:formic acid and ChCl:acetic acid, both in a molar ratio 1:2, presented the better physico-chemical properties (pH, stability at room temperature, water miscibility, etc.). Concerning amines, NADES could not be obtained at any of the combination assayed whereas, among the alcohols tested, 2,3-butanediol was found to be the most appropriated for NADES formation. A three-level factorial design was then used to further evaluate the effect of time and temperature on the ability of these selected optimum NADES for the US-assisted extraction of triazines from agricultural soil samples. Under optimal conditions, the developed US-assisted extraction method provided quantitative recoveries (from 87 to 104 %) with good reproducibility (RSDs lower than 12 %) and limits of detection (LODs) lower than 0.05 μg g−1 for all target triazines.

Agricultural soil contamination and degradation near a mining area in an arid region

Industrial and mining activities release toxic substances and heavy metals into the soil of the surrounding environment and result in soil degradation and desertification. The contaminated residential areas near mines can endanger the health of residents, and the agricultural lands at the fringes of mines contaminate agricultural products with heavy metals. In this study, in order to determine the rate of soil degradation and its contamination at the margins of Koushk Pb-Zn mine, the surface of the agricultural soil adjacent to the mine was sampled. Surface soil samples were also prepared from around two villages in the vicinity of the mine and along the roadside. The samples were digested using four acid methods and analyzed by ICP-OES, and the concentrations of Pb, Zn, Cr, Co, Sb, and Ba were measured in the samples. The difference between the concentrations of heavy metals in the agricultural and rangeland soil samples was assessed with a t-test, and the corresponding contamination maps were plotted. The results showed that the agricultural soil in both villages was more polluted than the rangeland soil around the villages. Indeed, the lead and zinc concentrations in the agricultural soil of Koushk were several times higher than environmental standards. Also, despite the equal distance of the villages from the mine, the average amounts of barium, lead, and zinc in Koushk soil were 1.5, 26, and 11 times higher than those in Seyyedabad, respectively. As a result, the parent materials geochemistry is a major source of variation in soil pollution in two villages. In addition the agriculture management style can play a role in elemental content of the samples.

Estimation of Background Radiation from A Soil Sample from A Barley Farm Area and Malt Factory in East Arsi, Ethiopia

The aim of this work is to estimate the background radiation of a soil sample from the barley farm area and Malt factory in East Arsi, Ethiopia. The technique of gamma-ray spectrometry with a high-purity germanium (HPGe) gamma-ray detector and a PC-based MCA was used. The activity concentration levels due to 40K, 137Cs, 238U, and 232Th were measured within the study area at a depth of 30 cm. The soils of the study region are used as construction material by many farmers. The measured specific activity of those radionuclides was compared with the data reported worldwide. The specific activity of radionuclides was estimated in both study locations. The specific activity 238U of soil samples ranged from 41.0 Bq kg-1 to 30.7 Bq kg-1 in the barley farm, with a mean value of 37.7 Bq kg-1, and for malt ranged from 23.8 Bq kg-1 to 40.6 Bq kg-1, with a mean value of 32.5 Bq kg-1. The specific activity of 232Th in soil samples ranged from 89.9 Bq kg-1 to 156.0 Bq kg-1, with a mean value of 118.6 Bq kg-1, whereas for the Malt factory ranged from 121.0 Bq kg-1 to 128.0 Bq kg-1, with a mean value of 123.7 Bq kg-1. In barley soil samples, the specific activity of 40K ranged from 401.0 Bq kg-1 to 530.0 Bq kg-1 with a mean value at the Malt plant ranged from 518 Bq kg-1 to 598.0 Bq kg-1, with a mean value of 553.6 Bq kg-1. Similarly, the specific activity of 137Cs was determined in both the barley farm and the malt Factory. In barley farm soil samples, it ranged from 3.3 ±0.6 Bq kg-1 to 5.34±0.6 Bq kg-1, and with a mean value of 4.3 Bq kg-1 whereas, in the Malt factory it varied from 3.1 ±0.7 Bq kg-1 to 5.3 ±0.7 Bq kg-1, and with a mean value of 4.5 Bq kg-1. The absorbed dose rate within the barley farm ranged from 24.6 ±2.9 nGyh-1 to 34.1 ±2.9 nGy h-1, and with a mean value of 30.6 nGyh-1, whereas, in the Malt factory, it varied from 31.3 ±1.3 nGy h-1 to 35.5 ±1.3 nGyh-1, and with a mean value of 33.5 nGy h-1. The annual effective radiation dose for BSS and MFSS was calculated to be 37.6 mSv y-1and 41.1mSv y-1. This study revealed that this region lies within a medium radiation background when compared with the world's average. The marginal value of dose is higher within the Malt factory area because of fertilizer consumption for cultivation. Since these estimated background and radiological impact factors are below the recommended values, it seems that there is no potential radiological health hazard related to the soils from both BSS and MFSS in Arsi Asella, Oromia, Ethiopia.

Analysis, Optimization and Molecular Characterization of PHB Positive Bacteria Isolated from Agricultural Soil Sample

Polyhydroxybutyrates are the widely studied biopolymer because of its biodegradability and non-toxic effect in the environment. This work focused on the isolation, screening, characterization and optimization of the PHB producing bacteria from agricultural soil. About eighty percentage of the isolated bacteria were identified as PHB producing bacteria after Sudan Black Blue staining. Among them three colonies were randomly selected and their morphologically and biochemically characterized. The biopolymer was extracted using sodium hypochlorite method. Potent PHB producer (WJSP1) (13.5µg/ml) was identified by crotonic acid assay. The functional groups of the produced PHB were identified by Fourier Transform Infra-Red spectroscopy (FTIR). The presence of functional groups like carbon group, C=O ester group, CH group, carbonyl group, carboxyl group which was corelated with the peak values1454.33cm-1, 1724.36 cm-1, 1274.95 cm-1, 1049.28 cm-1, 1280-1053 cm-1 indicates the presence of PHB. The potent producer (WJSP1) was optimized under different conditions to achieve the best condition for the production of PHB. The maximum production was obtained at the temperature - 37˚C, the carbon source - glucose, pH - 7 and at a time period of 72 hours. 16SrRNA sequencing was performed and the organism was identified as Bacillus cereus from the BLST (Basic Local Alignment Search Tool). A phylogenetic tree was constructed and the sequence was submitted in GENBANK (Accession No: OR192860). The isolated bacteria Bacillus cereus is an efficient producer of PHB under laboratory condition in presence of glucose as a chief carbon source. Large scale production of PHB can be done in large scale fermenters in industries. Large scale production of PHB will help the environment to get rid of the petroleum-based bioplastics.

Analysis of the radiological dose and hazards assessment around swampy agricultural soil in Keffi, Nasarawa State, Nigeria

The present study analyzes radiological dose and hazard around the swampy agricultural soil in Keffi Local Government Area of Nasarawa State, using determined activity concentration (AC) of 238U, 232Th and 40K obtained from swampy agricultural soil samples, systematically collected from Ten (10) sampled points. Samples collected were further analyzed using a sodium iodide detector for activity concentrations of 238U, 232Th and 40K. The average AC of 238U, 232Th and 40K were 26.73±4.64, 9.77±2.57 and 1115.52 ±67.43 Bq/kg, respectively. The gamma absorbed dose rate (Dabs) ranges from 6.37E-01 to 2.33E+01 nGy/hr with a mean value of 6.10E+00 nGy/hr. The annual effective dose equivalent (AEDE) ranges from 8.12E-03 to 2.97E-01 mSv/yr with an estimated mean value of 7.77E-02 mSv/yr. The annual gonadal dose equivalent ranges from 4.48E-02 to 1.72E+01 mSv/yr with a mean value of 4.49E-01 mSv/yr. The calculated radium equivalent activity ranges from 1.44E+01 to 4.49E+02 Bq/kg with a mean value of 1.18E+02 Bq/kg, which falls below the recommended standard value of 3.7E+02 Bq/kg. The external and internal hazard index ranges from 3.89E-02 to 1.21E+00 mSv/yr with a mean value of 3.20E-01 mSv/yr, and 3.90E-02 to 1.41E+00 mSv/yr with a mean value of 3.70E-01 mSv/yr. The gamma hazard index ranges from 5.24E-02 to 1.84E+00 mSv/yr with a mean value of 4.83E-01 mSv/yr. The activity utilization index ranges from 8.65E-02 to 1.34E+00 mSv/yr with a mean value of 3.82E-01 mSv/yr, excess life cancer risk (ELCR) for both adult and child was found to be 1.94E-01 and 2.72E-01, respectively, higher than the recommended world average value of 0.29E-03. The high value of ELCR implies that residents around the study area have a high chance of developing cancer over a lifetime. Hence periodic radiological dose and hazard analysis is recommended to keep the exposure as low as reasonably achievable.

Rhizosphere shapes the associations between protistan predators and bacteria within microbiomes through the deterministic selection on bacterial communities.

The assembly of bacterial communities in the rhizosphere is well-documented and plays a crucial role in supporting plant performance. However, we have limited knowledge of how plant rhizosphere determines the assembly of protistan predators and whether the potential associations between protistan predators and bacterial communities shift due to rhizosphere selection. To address this, we examined bacterial and protistan taxa from 443 agricultural soil samples including bulk and rhizosphere soils. Our results presented distinct patterns of bacteria and protistan predators in rhizosphere microbiome assembly. Community assembly of protistan predators was determined by a stochastic process in the rhizosphere and the diversity of protistan predators was reduced in the rhizosphere compared to bulk soils, these may be attributed to the indirect impacts from the altered bacterial communities that showed deterministic process assembly in the rhizosphere. Interestingly, we observed that the plant rhizosphere facilitates more close interrelationships between protistan predators and bacterial communities, which might promote a healthy rhizosphere microbial community for plant growth. Overall, our findings indicate that the potential predator-prey relationships within the microbiome, mediated by plant rhizosphere, might contribute to plant performance in agricultural ecosystems.

Myconanosynthesis of Copper Oxide Nanoparticles from Talaromyces versatilis against Human Bacterial Pathogens

Globally, there is a clinical problem caused by rising antibiotic resistance. The latest advances in biosynthesis have intrigued scientists and researchers as they investigate its potential against dangerous bacteria. The current emphasis is on myconanosynthesis, copper oxide nanoparticle (CuO NPs) characterization, and antibacterial efficacy. The extracellular biosynthetic approach we employed to create the CuO NPs was friendly to the environment. From agricultural soil samples, Talaromyces versatilis was isolated. They were comparing its 18s rDNA sequencing allowed for identification. Culture filtrate extracts of fungi were used as the reducing agents to synthesis the nanoparticles. XRD and DLS analysis were used to determine copper oxide nanoparticles (CuO NPs) size and material characteristics. When tested against Gram-positive and Gram-negative bacteria from that Salmonella paratyphi, Serratia sp., and Enterococcus fecalis myconanosynthesized copper oxide nanoparticles (CuO NPs) demonstrated a maximal zone of inhibition. Additionally, molecular in vivo research will aid in the creation of a novel wide-spectrum antibacterial drug.

Exploring Microeukaryote Community Characteristics and Niche Differentiation in Arid Farmland Soil at the Northeastern Edge of the Tibetan Plateau.

The northeastern edge of the Tibetan Plateau exhibits diverse climate and landform variations, and has experienced substantial recent environmental changes, which may significantly impact local agricultural practices. Understanding the microeukaryote community structure within agricultural soils is crucial for finding out the biological responses to such changes and may guide future agricultural practices. In this study, we employed high-throughput amplicon sequencing to examine 29 agricultural soil samples from seven research areas around the northeastern edge of the Tibetan Plateau. The findings revealed that the predominant biological communities in these soils were characterized by a high abundance of Alveolata, Amoebozoa, and Rhizaria. Ascomycota displayed the highest relative abundance among fungal communities. Moreover, notable distinctions in microeukaryote community composition were observed among the study sites. Co-occurrence network analysis highlighted interactions between the biological communities. Furthermore, our results elucidated that deterministic and stochastic processes exerted diverse influences on the distribution of protozoan and fungal communities. This study provides valuable insight into the microeukaryote structure in the agricultural soils of the northeastern edge of the Tibetan Plateau, shedding light on the intricate relationships between environmental factors, microeukaryote communities, and agricultural productivity.

Condition of composted microplastics after they have been buried for 30 years: Vertical distribution in the soil and degree of degradation

Microplastics in soils are a growing concern. Composting household wastes can introduce microplastics to agroecosystems, because when unsorted compost is used as a fertilizer, the plastic debris it contains degrades to microplastics. This paper examines the distribution and degradation of microplastics in agricultural soil samples to investigate their potential mobility. The source of microplastics was a household waste compost added to the soil more than 30 years before the study. The microplastics were sorted from a plot-composite soil and characterised by Attenuated Total Reflectance combined with Fourier transform infrared spectroscopy (ATR-FTIR). The microplastics are present in the cultivated depth but have not been transferred deeper (2.9 g kg-1 in the 0–5 cm soil depth against 0.9 g kg-1 in the 30–35 cm soil depth). Polyethylene (PE), polypropylene (PP), polystyrene (PS) and Polyvinylchloride (PVC) were identified in the forms of heterogeneous fragments, films, and fibres and accounted for 90% of the total microplastics. Advanced degradation observed was mainly assumed to be due to composting, though the plastic may have degraded further in the soil matrix. Highly degraded plastics are a greater danger for further leaching of contaminants into soil and our food supply.

Contamination of Agricultural Soils in Some Baghdad Areas with Antibiotics Resistant Pathogenic Fecal Bacteria

Background: Early studies have shown that agricultural soil contains various types of microorganisms, especially bacteria, including coliform bacteria (Salmonella, Shigella, Klebsiella, Escherichia coli, and Enterobacter) with fecal Gram-positive bacteria like Enterococcus faecalis. Therefore, the current study aimed to investigate the contamination of Iraqi agricultural soils with pathogenic fecal bacteria (Escherichia coli and Enterococcus faecalis) and study the antibiotic sensitivity patterns of soil-isolated bacteria because it is a dangerous indicator when transmitted to humans. Methods: Soil samples were collected from six locations (farms) in the capital, Baghdad, which were AL-Jadria, AL-Latifia, Diyala River, AL-Jazera, and AL-Zafraniya (block 1 and block 2) during the study period from the end of November 2021 to August 2022; then were compared with the control samples (house garden). These bacteria were isolated by selective culture media and identified using the VITEK® 2 Compact system, and antibiotic sensitivity tests were carried out against 18 different antibiotics by the Kirby Power method. The t-test was used for the statistical analysis. Results: The bacteriological study of agricultural soil showed the presence of fecal bacteria, and this is evidence of contamination of agricultural soil samples with these bacteria. The highest E. coli count was in the AL-Latifia farm (1. 48× 103), while the highest E. faecalis count was in the Diyala River farm (2.63 × 103). The antibiotic sensitivity profile illustrated that E. coli was resistant to ampicillin, ceftriaxone, cefoxitin, piperacillin, ceftazidime, and Teicoplanin but was sensitive to the rest of the antibiotics used, while E. faecalis was only resistant to levofloxacin and linezolid and highly sensitive to the other tested antibiotics. Conclusion: The current study documented the presence of fecal coliform bacteria in studied soil samples, with markedly high resistance rates toward used antibiotics. These facts might be the result of irrigation with sewage water and the use of organic fertilizers Received:March 2023 Accepted: May 2023 Published: Oct. 2023

Bioplastic (Polyhydroxyalkanoate) producing Indigenous Bacteria from Agricultural Soil Samples

Polyhydroxyalkanoate (PHA) is the naturally occurring biopolymer produced by the microorganisms. It is biodegradable and having physicochemical properties similar to conventional synthetic plastics and it can be used as an alternative to plastics. PHA is produced by microorganisms including bacteria, archaea and fungi. It gets accumulated inside the microorganisms as crystal in the presence of excess source of carbon, nitrogen, sulphur, oxygen and limited source of other nutrients. In this study PHA producing strain was isolated from agricultural soil sample. All the isolates obtained were screened for PHA production by using Nile red and Sudan black dyes. The potential isolate was characterized by biochemical tests and identified using 16S rRNA sequencing. The isolate showed sequence similarity with Priestia aryabhattai B8W22 and was designated as Priestia aryabhattai VITJK01. For PHA production, seed culture was prepared and inoculated in mineral salt medium containing glucose as a carbon source. PHA was extracted from cell dry weight biomass using methanolysis. It produced polyhydroxybutyrate (PHB) compounds including dodecane, penta decanoic acid, octadecanoic acid and heptadecanoic acid identified by Gas Chromatography Mass Spectrometry. Based on the results, it can be concluded that Priestia aryabhattai VITJK01 is a potential source for PHA/PHB production.

GEMAS: Chemical weathering of silicate parent materials revealed by agricultural soil of Europe

The chemical composition of soil represents to a large extent the primary mineralogy and geochemistry of the source bedrock, the effects of pre- and post-depositional weathering and element mobility, either by leaching or mineral sorting with the addition of secondary products such as clays. Agricultural soil in Europe (0–20 cm, 33 countries, 5.6 million km2) was sampled during the continental-scale soil mapping project (GEochemical Mapping of Agricultural and grazing land Soil - GEMAS). Total element concentrations were determined by wavelength dispersive X-ray fluorescence spectrometry. Bulk content of major elements (SiO2, TiO2, Al2O3, Fe2O3, MgO, CaO, Na2O, K2O, P2O5) in soil has been used to calculate weathering indices such as chemical index of alteration (CIA), reductive and oxidative mafic indices of alteration (MIA), the change in mass balance (τ calculation relative to immobile Nb) for soil derived from silicate bedrocks (granite, gneiss and schist) at the European continental-scale, which are useful tools for evaluating chemical weathering trends.The greatest variation of CIA values is exhibited by soil derived from granite, followed by soil derived from schist. The CIA results show clearly that Ca and Na are removed from agricultural soil (0–20 cm) during soil development. Geographical distribution of weathering indices shows that weak chemical weathering of agricultural soil samples, sourced from gneissic and granitic bedrock, occurs in the Fennoscandian Shield; intermediate chemical weathering in granite, schist and gneiss occurring in the Iberian Peninsula and France, and intense chemical weathering in schist sourced agricultural soil occurring in areas with intense rainfall and moderate temperature (Wales, England, Ireland and western Iberia). In addition, values of CIA and MIA, higher than those for standard rock compositions, suggest more active enrichment/depletion processes during soil formation and subsequent soil weathering/maturation.The range of the elemental mass transfer coefficient τ is wide for agricultural soil derived from gneiss and granite, and narrow for agricultural soil sourced from schist parent rocks. The weathering behaviour of chemical elements, assessed by using the τ mass transport model, suggests an order of susceptibility of K ≈ Na > Al > Fe > Ca > Mg > Ti.Weathering indices and gain-loss mass transfer coefficients, tested on agricultural soil samples, provide an insight to the weathering processes affecting the silicate parent rocks and their impact on soil development at the European scale. This can have further implications for evaluation of soil nutritional conditions and mitigating of soil erosion and deprivation.

Using Soil Testing Data to Monitor Changes in Maine Agricultural Soil Organic Carbon from 1995 to 2021

ABSTRACT Estimates of soil organic matter (SOM) are commonly part of soil testing, and typically use the loss-on-ignition (LOI) method. To explore the utility of existing soil testing databases as a resource for estimating soil organic carbon (SOC) concentrations over time, we determined the relationship between SOM estimated by LOI and SOC measured using IR detection of CO2 for Maine soils. We then examined trends in SOC concentrations in Maine agricultural soils over the past 27 years using data from 97,713 standard soil samples received by the Maine Soil Testing Service. For 91 agricultural soil samples representative of Maine cropping systems, we found that the standard LOI temperature used by the Maine Soil Testing Service, 375°C, produced LOI values that correlated more strongly with SOC measured by IR detection of CO2 than the three higher temperatures we studied, although all temperatures produced data that was well correlated (R2 values from 0.95 to 0.98). Soil texture did not influence the correlation. Our analysis of soil testing data from 1995 to 2021 suggested increases in SOC concentrations in soils planted to grain and hay, and possibly corn, broadly corresponding with changing agricultural practices occurring over this time frame. Of our four focal crop categories, only potato soils decreased in SOC concentration from 1995 to 2021, underscoring the unique challenges associated with potato soil management relative to other cropping systems in Maine. Our study confirms the potential utility of soil testing databases in assessing changes in SOC concentrations in agricultural soils over decades.

Antibiotic resistome and associated bacterial communities in agricultural soil following the amendments of swine manure-derived fermentation bed waste.

The practice of utilizing animal manures on land is widespread in agriculture, but it has raised concerns about the possible spread of antibiotic resistance genes (ARGs) and thepotential risk it poses to public health through food production. Fermentation bed culture is an effective circular agricultural practice commonly utilized in pig farming that minimizes the environmental impact of livestock farming. However, this method generates a significant amount of fermentation bed waste (FBW), which can be turned into organic fertilizer for land application. The objective of this research was to examine the impacts of amending agricultural soil samples with swine manure-derived FBW on microbial communities, mobile genetic elements (MGEs), and ARG profiles over different periods. The study findings indicated that the amendment of swine manure-derived FBW significantly increased the diversity and abundance of ARGs and MGEs during the early stages of amendment, but this effect diminished over time, and after 12months of FBW amendments, the levels returned to those comparable to control samples. The shift in the bacterial communities played a significant role in shaping the patterns of ARGs. Actinobacteriota, Proteobacteria, and Bacteroidetes were identified as the primary potential hosts of ARGs through metagenomic binning analysis. Furthermore, thepH of soil samples was identified as the most important property in driving the composition of the bacterial community and soil resistome. These findings provided valuable insights into the temporal patterns and dissemination risks of ARGs in FBW-amended agriculture soil, which could contribute to the development of effective strategies to manage the dissemination risks of FBW-derived ARGs.

Photocatalytic fuel cell self-powered sensor for Cu2+ detection in water and soil: Signal amplification of biomass induced carbon-rich carbon nitride photoanode

The development of an accurate, selective, sensitive, and quantitative monitoring method for copper ion (Cu2+) in water and soil is crucial for addressing environmental pollution. Herein, a photocatalytic fuel cell self-powered sensor (PFC-SPS) platform was proposed by carbon-rich carbon nitride photoanode for Cu2+ determination. Carbon-rich carbon nitride is formed by replacing nitrogen atoms of tertiary nitrogen with carbon generated through the thermal decomposition of biomass chitosan. The carbon-rich structure enhances the π delocalization in the carbon nitride skeleton, improving the optical absorption and accelerating the transmission of charge, endowing the photoanode with high and stable output signal. The formed Cu2+-aptamer complex increases the surface resistance of electrode, hindering the catalytic reaction of H2O2 oxidation and leading to the decrease in the output power density signal. This PFC-SPS platform detected Cu2+ with a wide range of 1.0 ∼ 1.5 × 103 nM, a low limit of 0.40 nM, excellent selectivity, stability and accuracy for real river water and agricultural soil samples. It is expected that the platform can achieve low-cost and portable monitoring by a digital multimeter, and this work also proposes a strategy for detecting heavy metal ions based on the synergism of a photocatalytic fuel and self-powered platform.

Pollution level, source, and health risk assessment of PAHs in food products and environmental media in Nantong, China: A pilot case

The following study is an analysis of the pollution characteristics, dietary intake levels, and health effects of 16 polycyclic aromatic hydrocarbons (PAHs) in vegetables, fruits, and meat products in Nantong City, China. The PAHs content, pollution level, carcinogenic risk, and correlation of soil and local atmospheric environment in the crop irrigation area were determined. A total of agricultural products (n = 42), soil samples (n = 18), and air samples (n = 42) were freshly collected from selected irrigation areas in Nantong to detect the content of 16 US EPA PAHs. The total contents of PAHs in vegetables, fruits, and meat products were 16.4 − 136.5 ng/g, 86.0 − 225.1 ng/g, and 0.1 − 23.4 ng/g, respectively. Phe (32.00 −37.24%) and Pyr (27.25 −28.79%) were two PAHs with the highest pollution. The total contents of 16 PAHs in both soil and air were 31.5 − 288.2 ng/g and 1.08 − 28.85 ng/m3, respectively. The single PAHs with the highest pollution were BaP (36.48%) and Flu (21.45%). The characteristic ratio analysis method was used to trace the source of PAHs. Accordingly, PAHs in the three types of food sources primarily originated from the burning of coal, oil or biomass, and was consistent with the air or soil pollution sources. The total exposure to PAHs in vegetables, fruits, and meat products was 18.81 − 66.82 ng/d, 5.69 − 8.62 ng/d, and 0.82 − 2.45 ng/d, respectively. The lifetime incremental carcinogenic risk was 4.20 × 10−7 − 6.41 × 10−6, 1.0 × 10−7 − 7.8 × 10−7, and 1.9 × 10−8 − 2.0 × 10−7, which corresponds to a relatively low−risk level. In comparison, the total exposure of soil and air were 4.15 × 10−7 − 1.54 × 10−6 mg·kg−1·d−1 and 2.71 × 10−6 − 1.40 × 10−5 mg·kg−1·d−1, respectively, and the non−carcinogenic and carcinogenic risk of soil were 3.07 × 10−5 − 1.21 × 10−4 and 1.09 × 10−8 − 3.98 × 10−8, respectively. The carcinogenic risk of air was 8.42 × 10−6 − 4.35 × 10−5, indicating that the risk of cancer is within the acceptable range; however, it cannot be ignored.

Occurrence of microplastics in agricultural soils in ecologically fragile areas of China

The pollution caused by microplastics (MPs), an emerging pollutant, has been receiving continuous concern. However, the distribution characteristics of MPs in ecologically fragile areas (EFAs), which are sensitive to environmental change and pollution, are still unclear. Here, the abundance and pollution characteristics of MPs in agricultural soils in four typical EFAs in China, namely semiarid farming-pastoral area (SFPA), desert-oasis interlaced area (DOIA), plateau composite erosion area (PCEA) and southwest karst area (SWKA) were investigated. MPs were detected in all agricultural soil samples with a mean abundance of 2685 ± 938 n/kg. DOIA (3193 ± 630 n/kg) had the largest abundance of MPs in agricultural soils, followed by SWKA (2948 ± 819 n/kg), SFPA (2920 ± 935 n/kg), and PCEA (1680 ± 320 n/kg). MPs in four EFAs were mostly small size (0–0.49 mm), accounted for 81.71 %. Fragmented and pelleted MPs were the main shapes, occupying for 51.26 % and 28.53 %, respectively. In addition, Fourier transform infrared (FTIR) was applied to determine the polymer types of MPs and to assess the pollution risk of MPs, which ranged from 157 to 938, indicating a moderate to high risk. The results revealed that EFAs located in remote inland areas were considerably polluted by MPs, close to the developed coastal areas. This study provided systematic data on MPs pollution of EFAs, which is crucial in preventing further environmental degradation and promoting ecological restoration.

Sporadic Detection of Escherichia coli O104:H4 Strain C227/11Φcu in the Edible Parts of Lamb's Lettuce Cultured in Contaminated Agricultural Soil Samples.

In the current study, we demonstrate that E. coli O104:H4 strain C227/11Φcu, a derivative of the 2011 enterohemorrhagic/enteroaggregative (EHEC/EAEC) E. coli outbreak strain, migrated into the edible portion of lamb's lettuce plants upon contamination of the surrounding soil. Seeds were surface-sterilized and cultivated on Murashige-Skoog agar or in autoclaved agricultural soil. Migration into the edible portions was investigated by inoculating the agar or soil close to the plants with 108 colony-forming units (CFU). The edible parts, which did not come into contact with the contaminated medium or soil, were quantitatively analyzed for the presence of bacteria after 2, 4 and 8 weeks. Strain C227/11Φcu could colonize lamb's lettuce when contamination of medium or soil occurs. The highest recovery rate (27%) was found for lettuce cultivated in agar, and up to 1.6 × 103 CFU/g lettuce was detected. The recovery rate was lower for the soil samples (9% and 13.5%). Although the used contamination levels were high, migration of C227/11Φcu from the soil into the edible parts was demonstrated. This study further highlights the risk of crop plant contamination with pathogenic E. coli upon soil contamination.

Preliminary results on microplastic pollution from agricultural soil in Vietnam: Distribution, characterization, and ecological risk assessment

Microplastics (MPs) have been extensively studied in aquatic systems; however, their presence in general agricultural systems and in particular, soil still needs comprehensive understanding. This study conducted a field survey at 25 sites to investigate the abundance of MPs in agricultural soil. The MPs in these soil samples were separated using sieves and filters by the density separation method with NaCl solution (d = 1.2 g/cm3). The density of MPs in agricultural soils ranged from 1,700 items/kg to 38,800 items/kg, with an average of 11,716 ±10,726 items/kg. The black-colored MPs were found to be dominant, followed by white, purple, red, and blue. The fibers represented most of the MPs' shapes observed in this research (77.9±17.4%). MPs in agricultural soil samples were tiny particles with sizes of <1,000 µm and 1,000-2,000 µm. A significant difference was observed in the concentration of MPs in locations near and far from residential areas and manufacturing facilities. The average concentration of MPs in the soils adjacent to the residential and manufacturing facilities and near the agricultural solid waste collection sites was 21,471±12,729 items/kg and 20,188±4,403 items/kg, much higher than in distant these locations at 4,418±1,573 items/kg. These results suggest that domestic, industrial, and agricultural activities could contribute to MP pollution in agricultural soil. The ecological dangers MPs pose in terrestrial and aquatic environments have drawn much attention from the scientific community. This work represented the first effort to comprehend the ecological risk of MPs on selected samples of Vietnamese agricultural soil. According to the Pollution Load Index (PLI) values, most agricultural soil samples in this study were contaminated with MPs at hazard level IV. The potential ecological risk index (PERI) values of agricultural soil samples from nearby residential, industrial, or agricultural solid waste areas indicated a higher ecological risk.

New and legacy pesticidal persistent organic pollutants in the agricultural region of the Sultanate of Oman

Comprehensive air and surface soil monitoring was conducted for new and legacy organochlorine pesticides (OCPs) to fill the knowledge and data gap on the sources and fate of pesticidal persistent organic pollutants (POPs) in the Sultanate of Oman. DDTs in agricultural soil samples ranged from 0.013 to 95.80 ng/g (mean: 8.4 ± 25.06 ng/g), with a median value of 0.07 ng/g. The highest concentration was observed at Shinas, where intensive agricultural practice is prevalent. The dominance of p,p′-DDT in soil and air reflected technical DDT formulation usage in Oman. Among newly enlisted POPs, pentachlorobenzene had the maximum detection frequency in air (47%) and soil (41%). Over 90% of sites reflected extensive past use of hexachlorobenzene. Major OCP isomers and metabolites showed net volatilisation from the agricultural soil, thereby indicating concurrent emission and re-emission processes from the soil of Oman. However, the cleansing effect of oceanic air mass is the possible reason for relatively lower atmospheric OCP levels from a previous study. Although DDT displayed maximum cancer risk, the level is below the permissible limit. DDT primarily stemmed from obsolete stock and inadequate management practices. Hence, we suggest there is a need for DDT regulation in Oman.