Contamination Of Agricultural Soils Research Articles

Protective mechanisms of sulfur against arsenic phytotoxicity in Brassica napus by regulating thiol biosynthesis, sulfur-assimilation, photosynthesis, and antioxidant response

The contamination of agricultural soils with Arsenic (As) is a significant environmental stress that restricts plant growth, metabolism, and productivity worldwide. The present study examined the role of elemental sulfur (S0) in protecting Brassica napus plants from Arsenic (As) toxicity. Arsenic (100, and 200 mg As kg−1 soil) in soil caused detrimental effects on five Brassica napus cultivars (Neelam, Teri-Uttam Jawahar, Him Sarson, GSC-101, and NUDB 26–11). The As toxicity inhibited the growth and photosynthesis indices in all cultivars with more deterioration effects in NUDB 26–11. Plant absorption and uptake of As caused the generation of oxidative injury by accumulating the reactive oxygen species (ROS), which simultaneously decreased the plant defence capability and ultimately the photosynthesis. Application of sulfur (S0, 100 or 200 mg S kg−1 soil) alleviated the negative impacts and toxicity of As on the photosynthesis and growth matrices of plants, especially under high S level. S0 also boosted the antioxidant potential of plants and toned-down lipid peroxidation and ROS aggravation such as superoxide anion (O2•−) and H2O2, hydrogen peroxide, in As affected plants. In general, S0 at 200 mg kg−1 soil more perceptibly increased the functionality of antioxidant enzymes, and non-enzymatic antioxidants, metal chelators and non-protein thiols. Further amendment of soil with S0 at fifteen days before seed sowing affected by As-induced toxic effects (added to soil at the time of sowing) considerably intensified the endogenous hydrogen sulfide (H2S) content and its regenerating enzymes D-cysteine desulfhydrase (DCD) and L-cysteine desulfhydrase (LCD) that further strengthened the defense capability of plants to withstand As-stress. Our results suggest the role of H2S in the S-induced defense operation of the B. napus plants in restraining As toxicity. The current study shows that S0 as a source of S might be used to promote the growth of B. napus plants in polluted agricultural soils.

Accumulation and Health Risk Assessment of Heavy Metal(loid)s in Soil-Crop Systems from Central Guizhou, Southwest China

Heavy metal(loid)s (HMs) contamination in agricultural soil and crops is related to the quality and safety of agricultural products and public health and has attracted worldwide attention. This study systematically investigated the bioaccumulation of HMs including Cd, Pb, Cr, Hg, As and Se in soil and associated crops (Tea, Plum and Corn) in Guizhou Province, China, and assessed the health risks of the edible part of the crops using the bioconcentration factor (BCF), geoaccumulation index (Igeo), and target hazard quotient (THQ). The results indicate that the mean concentrations of Pb (39.54 ± 16.56 mg/kg), Cr (122.50 ± 33.36 mg/kg), Hg (0.26 ± 0.33 mg/kg), As (25.40 ± 21.34 mg/kg), and Se (0.90 ± 0.46 mg/kg) in cultivated soil exceed the background values of Guizhou Province by 1.12, 1.28, 2.36, 1.27, and 2.4 times, respectively. However, the average concentration of Cd is 0.49 ± 0.49 mg/kg, which is lower than the corresponding background value. The average Igeo values of Pb, Cd, Cr, and As in the soil samples were lower than 1, indicating a relatively low degree of enrichment, whereas the enrichment of Hg was relatively obvious, as approximately 32.9% of the samples were at moderate and above enrichment levels. The contents of HMs in samples of corn, plum, and tea were lower than the corresponding pollutant limit. The BCF values of Cd, Hg, and Se in the three crops were relatively high, indicating a strong migration ability, and the average BCF values of tea in the soil-crop system were higher than those of corn and plum. Correlation analysis showed that the soil pH and concentrations of K2O, Fe2O3, and Al2O3 were negatively correlated with the BCF of Pb, Cr, and Hg in the soil-crop system, indicating that they were affected by macro-oxidation in the soil, whereas Cd and As were basically not affected. The human health risk assessment of THQ values demonstrated that the health risks to local residents from eating corn and drinking tea were low.

Sulfhydryl grafted palygorskite amendment with varying loading rates: Characteristic differences and dose-effect relationship for immobilizing soil Cd

Heavy metal contamination in agricultural soil and immobilization remediation have generated widespread concern in all areas of society. Sulfhydryl-functionalized materials as emerging amendments exhibit application potential, but the dose-effect relationship and immobilization mechanism are poorly understood. To understand the relationship between the immobilization effect and total sulfhydryl content, sulfhydryl-grafted palygorskite (SGP) with three sulfhydryl loading rates (0.88 mmol/g, 1.83 mmol/g, and 2.77 mmol/g) was prepared and characterized in the current study. The Cd immobilization efficiency and the dose-effect relationship were investigated via sorption in solutions, soil incubation, and field-scale wheat cultivation. 29Si nuclear magnetic resonance, X-ray diffraction, differential scanning calorimetry, X-ray photoelectron spectroscopy, zeta potential, and potentiometric titration analyses confirmed that the sulfhydryl loading rates had little impact on the mineral structure but had a significant effect on the SGP surface properties. The sorption process of Cd2+ on SGP can be described by the 2nd order kinetic model and the Langmuir isotherm. The maximal sorption capacities had a linear relationship with the experimental sulfhydryl content in SGP. Meanwhile, SGP with three loading rates under different doses reduced available Cd concentrations in alkaline soil by 28.40 %–87.78 % in soil incubation and wheat grain Cd by 21.95 %–80.19 % in field-scale demonstration The relationship between immobilization efficiency and the total sulfhydryl group could be adequately described using the Michaelis-Menten equation. The sulfhydryl group was the key site for SGP amendments, which when added to the soil, reduced the bioavailability of soil Cd. Clarification of the dose-effect relationship will provide theoretical support for the accurate regulation of safe utilization of Cd-contaminated farmland.

Greenhouse farming as a source of macroplastic and microplastics contamination in agricultural soils: a case study from Southeast-Hungary

Greenhouse plastic contaminations in agricultural soils were studied to quantify and examine the macroplastic and microplastic contaminants on the soil surface, soil profile, and groundwater under greenhouse farmland. Random sampling was used to select three areas in a greenhouse farm where macroplastic and microplastic data were collected. Four composite samples were collected from shallow (0–20 cm) and deep (20–40 cm) soils for each sampling point, respectively. Three soil profiles were dug, and samples were collected at intervals of 20 cm. Groundwater samples were also collected from the same profiles at a depth of 100 cm. Microplastics were extracted using predigestion of organic matter with 30% H2O2 and density separation with ZnCl2. The total mass of macroplastics in the greenhouse farmland was 6.4 kg ha–1. Polyethylene and polyvinyl chloride were the dominant plastic structures, and the dominant sizes were 1–5 and 0.5–1.0 cm, respectively. Overall, the average abundance of microplastics in the greenhouse soil was 225 ± 61.69 pieces/kg, and the dominant size structure was 2–3 mm. The average microplastic concentrations at depths of 0–20 and 20–40 cm were 300 ± 93 and 150.0 ± 76.3 pieces/kg, respectively. The average microplastic concentration in the groundwater was 2.3 pieces/l, and fibers were the dominant plastic structure. Given that microplastics were found in greenhouse soil, soil profiles, and groundwater, we recommend the careful cleaning and disposal of plastics on greenhouse farmland and further research to shed light on the level of microplastic contamination in the soil profiles and groundwater.

Automated identification and quantification of invisible microplastics in agricultural soils

Microplastics in agricultural soils have become the research hotspot in recent years, however, the quantitative methods based on the traditional visual inspection may have a high false detection rate. Here we combined the laser direct infrared (LDIR) and Fourier–transform infrared (FTIR) methods to investigate the microplastics in farmland with long–term agricultural activities. The results showed that the total abundance of microplastics reached 1.98 ± 0.41 × 105, 1.57 ± 0.28 × 105, 1.78 ± 0.27 × 105, and 3.20 ± 0.41 × 105 particles/kg soil in cotton fields with film mulching of 5, 10, 20, and >30 years, respectively. LDIR results indicated that microplastics ranging from 10 to 500 μm accounted for 96.5–99.9 % of the total microplastic amounts in the soils. Additionally, a total of 26 polymer types of microplastics were detected, among which polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyamide (PA), and polytetrafluoroethylene (PTFE) were dominantly observed. For the microplastics detected by FTIR (500 μm–5 mm), PE polymer was majorly observed (88.0–98.9 %). Most microplastics were films (88.2 %), while fibers and pellets were also found. The reclaimed water from sewage treatment plants, the drip irrigation utilities, and the residual plastic film are the potential sources of microplastics in the farmland soils. By using the automated quantitative and identifiable approaches, this study suggested that the commonly used visual counting method may underestimate the microplastic contamination in agricultural soils.

Big data research on agricultural soil contamination by zeolite application

Big data research on agricultural soil contamination by zeolite application

Biorecovery of Agricultural Soil Impacted by Waste Motor Oil with Phaseolus vulgaris and Xanthobacter autotrophicus.

Agricultural soil contamination by waste motor oil (WMO) is a worldwide environmental problem. The phytotoxicity of WMO hydrocarbons limits agricultural production; therefore, Mexican standard NOM-138-SEMARNAT/SSA1-2012 (NOM-138) establishes a maximum permissible limit of 4400 ppm for hydrocarbons in soil. The objectives of this study are to (a) biostimulate, (b) bioaugment, and (c) phytoremediate soil impacted by 60,000 ppm of WMO, to decrease it to a concentration lower than the maximum allowed by NOM-138. Soil contaminated with WMO was biostimulated, bioaugmented, and phytoremediated, and the response variables were WMO concentration, germination, phenology, and biomass of Phaseolus vulgaris. The experimental data were validated by Tukey HSD ANOVA. The maximum decrease in WMO was recorded in the soil biostimulated, bioaugmented, and phytoremediated by P. vulgaris from 60,000 ppm to 190 ppm, which was considerably lower than the maximum allowable limit of 4400 ppm of NOM-138 after five months. Biostimulation of WMO-impacted soil by detergent, mineral solution and bioaugmentation with Xanthobacter autotrophicus accelerated the reduction in WMO concentration, which allowed phytoremediation with P. vulgaris to oxidize aromatic hydrocarbons and recover WMO-impacted agricultural soil faster than other bioremediation strategies.

Distribution and ecological risk assessment of trace elements in the paddy soil-rice ecosystem of Punjab, Pakistan

Trace elements (TEs) contamination of agricultural soils requires suitable criteria for regulating their toxicity limits in soil and food crops, which depends on their potential ecological risk spanning regional to global scales. However, no comprehensive study is available that links TE concentrations in paddy soil with ecological and human health risks in less developed regions like Pakistan. Here we evaluated the data set to establish standard guidelines for defining the hazard levels of various potentially toxic TEs (such as As, Cd, Co, Cu, Cr, Fe, Mn, Ni, Pb, Se, Zn) in agricultural paddy soils of Punjab, Pakistan. In total, 100 topsoils (at 0–15 cm depth) and 204 rice plant (shoot and grain) samples were collected from five ecological zones of Punjab (Gujranwala, Hafizabad, Vehari, Mailsi, and Burewala), representing the major rice growing regions in Pakistan. The degree of contamination (Cd) and potential ecological risk index (PERI) established from ecological risk models were substantially higher in 100% and 97% of samples, respectively. The positive matrix factorization (PMF) model revealed that the elevated TEs concentration, notably Cd, As, Cr, Ni, and Pb, in the agricultural paddy soil was attributed to the anthropogenic activities and groundwater irrigation. Moreover, the concentration of these TEs in rice grains was higher than the FAO/WHO's safe limits. This study provided a baseline, albeit critical knowledge, on the impact of TE-allied ecological and human health risks in the paddy soil-rice system in Pakistan; and it opens new avenues for setting TEs guidelines in agro-ecological zones globally, especially in underdeveloped regions.

Effects of soil amendments, foliar sprayings of silicon and selenium and their combinations on the reduction of cadmium accumulation in rice

Agricultural soil contamination by cadmium (Cd) is becoming one of the most serious environmental issues and public concerns. In this study, factorial arrangements of treatments were designed to explore the effects of two soil amendments, sodium sulfide-biofuel ash (SSBA) and lime (0.1%), and three foliar applications, silicon (Si, 2.5 mmol L-1), selenium (Se, 40 mg L-1), and their combination (SS), on Cd reduction in rice (Oryza sativa L.) in a pot experiment, which were then verified in a field experiment. Compared with the control without amendment but with spraying of deionized water, both SSBA and lime significantly reduced concentrations of CaCl2-extractable Cd in soil by 30%–39% and 31%–40% and Cd in brown rice by 44%–63% and 53%–72% in the pot and field experiments, respectively. Foliar Si, Se, and SS applications significantly reduced Cd accumulation in brown rice by 62%–64%, 72%–83%, and 39%–73%, respectively, increased rice grain yield, and improved antioxidant enzyme activities in rice leaves but with different trends in the pot and field experiments. Combinations of SSBA and lime with Si, Se, and SS had a non-significant synergistic effect on Cd reduction in brown rice compared to only foliar spraying or soil amendment in both pot and field experiments, although SSBA + Se and SSBA + Si reduced Cd concentration in brown rice by 16%–34% and 14%–24% compared to only foliar Si and Se and soil SSBA applications, respectively. Soil lime application and foliar Si spraying were the most cost-effective strategies to reduce Cd accumulation in brown rice in the field and pot experiments, respectively. Although soil amendments and foliar treatments were individually effective, their combinations failed to generate a significant synergistic reduction of Cd concentration in brown rice.

Heavy Metal Contamination in Agricultural Soils: A Case Study in Mohammedia Benslimane Region (Morocco)

Heavy Metal Contamination in Agricultural Soils: A Case Study in Mohammedia Benslimane Region (Morocco)

Health risk assessment of heavy metal(loid)s in the farmland of megalopolis in China by using APCS-MLR and PMF receptor models: Taking Huairou District of Beijing as an example

The quality of agricultural soils is important for agricultural production and food safety. The contamination of agricultural soils by heavy metal(loid)s (HMs) has aroused global attention. Fifty-two topsoil samples with 8 HMs were gathered to assess the health risks of farmland soil in Huairou District, Beijing. As a significantly enriched pollutant, the results revealed that Hg had greater ecological risks relative to other HMs. We found that the positive matrix factorization (PMF) model appears to be more physically plausible in identifying complex pollution sources compared to the absolute principal components score-multiple linear regression (APCS-MLR) model, which had a higher fit coefficient (r2 = 0.69–0.99). Five HMs from pollution sources, including agricultural activities, traffic source, natural source, fuel burning, and industrial production, were identified by integrating the PMF model with Pearson's correlation analysis, revealing corresponding contribution rates of 29.40%, 22.54%, 20.16%, 15.20%, and 12.70%, respectively. The probabilistic health risk evaluation results showed an absence of non-carcinogenic risks in all populations, but the carcinogenic risk could not be ignored, especially in children. In addition, the source-oriented health risks showed that agricultural activities made the largest contribution to the health risks of all populations. This research provides scientific evidence for preventing HMs contamination and control of farmland.

Regional and Global Scale Challenges for Controlling Arsenic Contamination in Agricultural Soil, Water Supplies, Foods and Ayurvedic Medicines

Arsenic is naturally present at high concentration levels in aquifers adversely affecting the life of some 200 million people in a number of countries on four continents. Human exposure to As from dietary sources such as marine fish, seafood, poultry, cereals is generally much lower compared to exposure through drinking contaminated water, using contaminated water in food preparation and irrigation of crops. Arsenic toxicity depends on its four valences [As(-III), As0, As(III) and As(V)] and chemical compounds. Thus, in seafood, As is mainly found in its less toxic organic forms. The qualitative and quantitative determinations of individual As species are crucial to understand the environmental fate and behavior of As. The aim of the present review is to give a brief overview on the main As speciation methods and to present how to control As contamination at local and global scales in several environmental (soil, waters) and biological (crops, basic and processed food) samples, as well as complementary and alternative medicinal products marketed as food supplements. In terms of chromatographic separation, emphasis is placed on separation by thin layer chromatography and solid phase extraction. Some approaches to address As contamination (e.g., stabilization in soil, provision of a safe water supply in affected communities) at global and regional scales are also presented.

Amelioration of cadmium toxicity by enhancing nitrogen assimilation and photosynthetic activity by two different nitrogen supplements in rice (Oryza sativa L.) cv. Lalat

Rapid industrialization and over-use of agrochemicals may lead to cadmium (Cd) contamination in agricultural soil, posing serious threat to human health. In recent times, application of plant nutrients and other growth promoting substances, like, nanoparticles (nZVI), silicon, salicylic acid were reported to have ameliorated Cd toxicity, in this regard, nitrogen (N) amendment can be a promising technique to ameliorate Cd toxicity as, N is an essential macronutrient responsible for plant growth and development. In the present study, seven days old seedlings of Oryza sativa L. cv. Lalat were co-treated with 10 µM CdCl2 and two different nitrogen supplements (Calcium nitrate and Ammonium acetate) separately to evaluate its ameliorating potential. It was observed that, Cd stress impaired plant vigor, biomass, RWC, nitrogen-containing components and non-enzymatic antioxidants causing significant reduction in photosynthesis and N-assimilation, indicating sensitivity of the cultivar to Cd stress. Cd stress also enhanced lipid peroxidation, enzymatic-antioxidant activity, proline and non-protein thiol accumulation. N-supplementation to Cd stressed plants rescued plant growth, biomass, protein content and nitrogen containing compounds leading to the upregulation of photosynthesis and nitrogen assimilation. N amendment was found to downregulate lipid peroxidation, enzymatic antioxidant activity, proline and non-protein thiol content and upregulate non-enzymatic antioxidant. Agronomical parameters and yield also improved significantly by N supplementation as compared to Cd stressed plants. Supplementation with N salts also improved grain quality by enhancing grain nutrients and reduced grain Cd by decreasing bioavailable Cd in soil, thereby reducing daily Cd intake and cancer risk. Among the two N-supplements, ammonium acetate showed better ameliorating effect compared to calcium nitrate.

Calcium Oxide Nanoparticles Have the Role of Alleviating Arsenic Toxicity of Barley.

Arsenic (As) contamination in agricultural soils has become a great threat to the sustainable development of agriculture and food safety. Although a lot of approaches have been proposed for dealing with soil As contamination, they are not practical in crop production due to high cost, time-taking, or operational complexity. The rapid development of nanotechnology appears to provide a novel solution to soil As contamination. This study investigated the roles of calcium oxide nanoparticles (CaO NPs) in alleviating As toxicity in two barley genotypes (LJZ and Pu-9) differing in As tolerance. The exposure of barley seedlings to As stress showed a significant reduction in plant growth, calcium and chlorophyll content (SPAD value), fluorescence efficiency (Fv/m), and a dramatic increase in the contents of reactive oxygen species (ROS), malondialdehyde (MDA) and As, with LJZ being more affected than Pu-9. The exogenous supply of CaO NPs notably alleviated the toxic effect caused by As in the two barley genotypes. Moreover, the expression of As transporter genes, that is, HvPHT1;1, HvPHT1;3, HvPHT1;4 and HvPHT1;6, was dramatically enhanced when barley seedlings were exposed to As stress and significantly reduced in the treatment of CaO NPs addition. It may be concluded that the roles of CaO NPs in alleviating As toxicity could be attributed to its enhancement of Ca uptake, ROS scavenging ability, and reduction of As uptake and transportation from roots to shoots.

Macroplastic Fragment Contamination of Agricultural Soils Supports a Distinct Microbial Hotspot

Agricultural plastics support crop production and quality by reducing weeds, improving irrigation efficiency, and regulating soil conditions, but can also become a soil pollutant. While microplastic effects on soil function are increasingly well-understood, the impacts of agricultural macroplastic (>5 mm) contamination on soils are poorly documented. Prolonged exposure to plastic macrofragments may alter microbial decomposer community structure and function, since plastic can directly affect edaphic factors while leaching novel compounds. To better characterize how plastic contamination influences the soil habitat, we sampled three farms characterized by agricultural plastic pollution in Monterey County, CA, United States. Using a randomized block design, we collected surface soil samples from the fields (“bulk PC soil”) to compare with soil directly in contact with the remaining polyethylene (PE) mulch and polyvinyl chloride (PVC) dripline fragments (“plastic-associated soil”). Soil directly associated with plastic fragments was hypothesized to have reduced microbial biomass and decomposer activities relative to the bulk soil, due to a greater likelihood of toxicity. In contrast to our expectations, we found that both PE and PVC macrofragments support a distinct microbial habitat that hosts a larger, more efficient microbial biomass with greater labile nutrient pools than the surrounding bulk soil. Because of the scope of macroplastic pollution likely occurring in agricultural soils, our findings suggest that this novel plastisphere habitat may significantly alter ecological functions critical to agricultural soils over time by encouraging microbial colonization within plastic debris.

Penicillium oxalicum SL2 as a sustainable option to mitigate the accumulation of Pb in rice (Oryza sativa L.)

Heavy metal contamination in agricultural soil and its associated risk of food safety are of great concern globally. It is therefore an urgent need to develop sustainable option to mitigate the accumulation of metals in crop plants. Here we investigated the potential of phosphorus-solubilizing fungus, Penicillium oxalicum SL2, on regulating the bioavailability of Pb in a lead (Pb) polluted soil-rice system. Our results showed that the content of Pb in rice grain was significantly decreased by ~80% with the application of P. oxalicum SL2. The competition between oxalate and phosphate for the complexation of Pb showed to be effective in mediating the bioavailability of Pb, and such impact varied with water fluctuation in paddy soil. The solubilization of phosphorus also played an important role in alleviating the dissolution of iron plaque caused by oxalic acid, which helped maintaining the biomass of iron plaque as a barrier to the uptake of Pb by root. The predominant indigenous microbial community was not affected by the inoculation with P. oxalicum SL2, suggesting it as an eco-friendly strain. Therefore, we suggest P. oxalicum SL2 as a promising fungus in enhancing the safe use of moderately Pb polluted paddy soil for safe rice.

Comparative study of organic contaminants in agricultural soils at the archipelagos of the Macaronesia

The occurrence of organic pollutants in soil is a major environmental concern. These compounds can reach the soil in different ways. Point sources, related to pesticides that are used intentionally, can be applied directly to the soil, or reach the soil indirectly due to application to the aerial parts of crops. On the other hand, non-point sources, which reach soils collaterally during irrigation and/or fertilization, or due to the proximity of plots to industrialized urban centers. Long-range transport of global organic pollutants must also be taken into account. In this study, 218 pesticides, 49 persistent organic pollutants, 37 pharmaceutical active compounds and 6 anticoagulant rodenticides were analyzed in 139 agricultural soil samples collected between 2018 and 2020 in the Macaronesia. This region comprised four inhabited archipelagos (Azores, Canary Islands, Cape Verde, and Madeira) for which agriculture is an important and traditional economic activity. To our knowledge, this is the first study on the levels of organic compound contamination of agricultural soils of the Macaronesia. As expected, the most frequently detected compounds were pesticides, mainly fungicides and insecticides. The Canary Islands presented the highest number of residues, with particularly high concentrations of DDT metabolites (p,p’ DDE: 149.5 ± 473.4 ng g−1; p,p’ DDD: 16.6 ± 35.6 ng g−1) and of the recently used pesticide fenbutatin oxide (302.1 ± 589.7 ng g−1). Cape Verde was the archipelago with the least contaminated soils. Very few pharmaceutical active compounds have been detected in all archipelagos (eprinomectin, fenbendazole, oxfendazole and sulfadiazine). These results highlight the need to promote soil monitoring programs and to establish maximum residue limits in soils, which currently do not exist at either continental or local level.

English

Contamination of agricultural soils with textile wastewaters loaded with synthetic dyes is one of the emerging issues because the presence of dyes in the soils not only affects the biological characteristics of the soils but also the germination and productivity of agricultural crops. The present study reports the characterization of two multifunctional bacterial strains Bacillus sp. SG36 and Bacillus sp. SG42, which have the potential not to promote the growth of plants in soil under stress due to reactive yellow 2 (RY2) dye but also the capability to cope with this dye through its decolorization. The strains were isolated from a rhizospheric soil repeatedly contaminated with colored textile wastewaters. Both the strains had optimal RY2 decolorization potential at slightly alkaline pH (7.5) and even in the presence of significant amount of NaCl (50 g L-1) in the medium. The strains harbor the phosphorus solubilization and indole acetic acid production potentials in concurrence with decolorization of RY2. In a pot experiment, the strains SG36 and SG42 were found to significantly promote the growth (Shoot/root length, shoot/root fresh weight) of mung bean (Vigna radiate) in non-contaminated and RY2 contaminated soils in parallel with RY2 decolorization in the soil. © 2022 Friends Science Publishers

Evaluation of statistical data on soil contamination of the Krasnodar Territory with pesticides

Agricultural activity is highly developed in the Krasnodar Territory, agricultural lands occupy more than 60% of its area. There is a risk of human health effects when eating agricultural products grown on soils contaminated with pesticides. Environmental problems caused by the contamination of agricultural soils of the region with pesticides determine its environmental safety and are very relevant. In the Russian Federation, many years of research are being conducted on soil contamination with pesticides in various regions. The annual reports contain data on the surveyed territories and survey areas, on the average and maximum concentrations of various pesticides, and on the types of pesticides. This study is devoted to the analysis of officially published data on soil pollution of the Krasnodar Territory in order to evaluate statistical data, identify trends in pollution changes in the field of observation and the possibility of forecasting. As a result of the conducted research, certain shortcomings were identified in the presentation of information on soil contamination with pesticides in the Krasnodar Territory, the trend of changes in soil contamination with pesticides was revealed and a forecast was made for some substances.

Macronutrients, trace metals and health risk assessment in agricultural soil and edible plants of Mahshahr City, Iran.

In this study, we evaluate the geochemistry of macro- (Fe, P, Ca, S, K, Na, Mg) and micronutrients (Mo, Cu, Pb, Zn, Co, Mn, Cd, Sr, Cr, Hg, Se), along with possible health risks of heavy metals contamination in agricultural soils and vegetables of the Mahshahr industrial port in Iran. Calculation of geochemical coefficients revealed the low pollution load of Mahshahr agricultural soils. Most of the investigated elements exhibited lower concentrations in soil than international standards. Element concentrations in plant samples were far below the permissible values set by environmental agencies. Based on permissible values, there was deficiency of several soil elements, including Cu, in vegetables because they are mostly present in the soil residual phase. An exception was Mn, which is the most mobile element in soil. The transfer factor (TF) of elements showed the following trend: K > Na > P > S > Mo > Hg > Se > Zn > Cd > Cu > Mg > Mn > Ca > Cr > Co ≈ Fe = Pb. There was high transfer of major elements from soil to plants, and lower values for micronutrients and heavy metals. The calculated daily intake (DIM) and health risk index (HRI) for ten plant species for adults were < 1, while the HRI was larger than 1 for Mn via radish consumption. According to geochemical investigations and statistical tests such as principal component analysis, Kruskal-Wallis, and correlation coefficient calculations, plant species play the most important role in elemental uptake by plants.