Ecological risk assessment and heavy metals accumulation in agriculture soils irrigated with treated wastewater effluent, river water, and well water combined with chemical fertilizers

Structure of O-polysaccharide from the Azospirillum himalayense ptl-3T lipopolysaccharide

Lipopolysaccharide was extracted with hot aqueous phenol from cells of Azospirillum himalayense ptl-3T, a diazotrophic Gram-negative bacterium isolated from Himalayan valley soil, India. The O-polysaccharide (OPS) was released by mild acid hydrolysis of the lipopolysaccharide and was structurally characterized by chemical analyses and by 1D and 2D NMR spectroscopy. The following structure of the OPS trisaccharide repeating unit was established. →3)-α-l-Fucp-(1→3)-α-l-Fucp-(1→3)-α-d-Rhap4NAc-(1→.

The negative aspects of using medicinal plants: human health risks assessment of mycotoxins and toxic metal contamination

Medicinal plants (MPs) have been valued for their therapeutic properties and are crucial in traditional and modern medicine. However, contamination with hazardous substances such as mycotoxins and toxic THMs (THMs) poses significant safety concerns. This study quantified the levels of mycotoxins and THMs in ten commonly used MPs in Tehran markets, Iran, and assessed their carcinogenic and non-carcinogenic risks to ensure consumer safety. A total of 210 samples were analyzed. THMs, including arsenic (As), mercury (Hg), cadmium (Cd), and lead (Pb), were detected using atomic absorption spectrometry, while mycotoxins such as aflatoxins (B1, B2, G1, G2) and ochratoxin A (OTA) were measured using high-performance liquid chromatography. Risk assessments used Target Hazard Quotient (THQ), Hazard Index (HI), Incremental Lifetime Cancer Risk (ILCR), and Total Carcinogenic Risk (TCR) methodologies. Results revealed variability in contaminant levels (p < 0.05). While heavy metal concentrations were within safe limits, mycotoxin exposure posed non-carcinogenic risks for children, with a THQ exceeding the acceptable limit. Mycotoxin levels remained below carcinogenic thresholds. To mitigate risks, storing MPs in dry, low-humidity environments is recommended to prevent fungal growth and reduce mycotoxin contamination, emphasizing the need for stricter safety measures.

Uncovering soil heavy metal pollution hotspots and influencing mechanisms through machine learning and spatial analysis

Soil heavy metal (HM) pollution is a significant and widespread environmental issue in China, highlighting the need to quantify influencing factors and identify priority concern areas for effective prevention and management. Based on published literature data of soil HM concentrations from 2000 to 2022, this study investigated the pollution characteristics and spatial distribution of eight soil HMs in China, and identified the hotspot areas of HM pollution and related influencing factors. The main findings were as follows: (1) The average concentrations of all eight HMs all exceeded their respective background values, with Cd (Igeo = 1.41) and Hg (Igeo = 0.85) showing the most serious pollution. (2) The Random forest-SHapley Additive exPlanations (RF-SHAP) model revealed that transportation and agriculture activities dominantly contribute to soil HM accumulation in China. (3) Bivariate local indicators of spatial association (LISA) based on Moran's I identified industry and transportation activities as primary drivers of HM pollution in the Yangtze River Delta and Pearl River Delta, whereas a combination of agriculture and industry activities was the main cause of pollution in Central China. This study offers valuable insights for the control and management of soil HM pollution and provides a critical reference for shaping comprehensive policies aimed at addressing HM pollution on a regional or national scale.

Evaluation of physiological responses of olive trees (Olea europaea L.) below dust stress from limestone quarry with ecological risks of trace elements in garden soils

This study was conducted to explain the stress caused by dust particles released from the limestone quarry with TEs pollution and ecological risk indices, to investigate how olive trees tolerate stress. As the distance decreased PM10, settled dust particle (SDP) and TEs concentration increased, and SDP was above the limit value in L1. Cd, Zn, Cu, and Ni contents were higher than the UCC and WSA. EF, Igeo, and Cf indices showed high-significant Cd pollution due to natural and anthropogenic sources. The decrease of Chla and Chlb affected the physiological and biochemical processes. Increased free radical H2O2 caused oxidative stress; this stimulated the production of more stomata. The assimilation and transpiration rates decreased. The decrease in leaf area (LA) and the increase in leaf water loss (LWL) showed that the plant began to tolerate stress by balancing the tissue water content. As the distance increased, membrane stability was achieved, and leaf tissue membrane permeability (LTMP) and leaf tissue density (LTD) increased. High water content at saturation (WCS), water saturation deficit (WSD), and low relative water content (RWC) indicated high water loss. The low RWC achieved that the physiological balance was disturbed and the plant's tolerance to pollution decreased. It has been observed that the dust originating from the limestone quarry affects the physiology of the Gemlik variety, and the plant tries to tolerate stress by balancing the tissue water content. However, anymore research is needed to investigate the genetic principle of the adaptation mechanism against dust stress in this genotype.

Assessment of ecological risks and spatiotemporal monitoring of heavy metal contamination in cultivated soils of the Liaohe River Basin, Jilin Province, China

Ensuring the quality and safety of soil is crucial for achieving ecological sustainability. This study systematically analyzed and evaluated the ecological risks, early warning mechanisms, and mitigation strategies for heavy metals in the Liaohe River Basin of Jilin Province, employing methods such as multiple index models, environmental capacity prediction models, and spatiotemporal cube models. The results indicate that local soil heavy metals range from non-polluted to moderately polluted (0.5-1), with Cr, Cd, and Ni exhibiting relatively high risks. Early warning results reveal that Cr is in a state of low capacity (capacity index = 0.67), and the environmental capacity of soil heavy metals is projected to decline over the next 15 years. Notably, after 15 years, the environmental capacities of As and Cd are expected to decrease to 4.579 kg/hm2 and 0.198 kg/hm2, respectively. Based on the findings, systematic mitigation recommendations, including graded management and land-use optimization, were proposed. This not only provides insights into heavy metal research but also establishes a theoretical foundation for soil pollution management.

Green triiron tetraoxide@Algae (Fe3O4@Algae) nanoparticles for highly efficient removal of lead (Pb2+), cadmium (Cd2+), and aluminum (Al3+) from contaminated water: an isothermal, kinetic, and thermodynamic study

Developing and producing a versatile adsorbent for effective wastewater treatment remains a significant obstacle to wastewater processing. As the objective is to eliminate various metal ions (lead, cadmium, and aluminum) from wastewater, we therefore strategically designed and synthesized new iron oxide nanoparticles (Fe3O4 NPs) based on the green algae called triiron tetraoxide@algae nanoparticles (Fe3O4@Algae NPs) that grow in the same contaminated water using a facile one-pot green synthetic method. Investigations were conducted into the adsorption circumstances, including pH, starting concentration, adsorbent dosage, and adsorption time. More importantly, great absorption of lead, cadmium, and aluminum was achieved, with 97.5%, 81.3%, and 75.13%, respectively. The best conditions were 60 min, 0.1 g of nanoparticles, at 25 °C, and 150 mL of water containing 30 mg/L of Pb, Cd, and Al, with pH 6 for Cd and Pb and pH 5 for Al. To analyze the kinetics and equilibrium adsorption data and to evaluate the interaction between the metal ions and the adsorbent, a variety of kinetic and isotherm models were employed. The Langmuir isotherm and a pseudo-second-order were the best ways to look at the adsorption isotherm and kinetics data for how the Fe3O4@algae removes metal ions. Furthermore, thermodynamic studies showed that the adsorption process was an exothermic, favorable, and spontaneous reaction. For the elimination of Al(III), Pb(II), and Cd(II), the Fe3O4@algae experimental adsorption capacity was 33.8 mg/g, 56.70 mg/g, and 36.58 mg/g, respectively. The composite of Fe3O4@algae nanoparticles was characterized using several analytical techniques including scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), and UV-vis spectroscopy. In addition, the material exhibited notable durability and recyclability, with the metal removal effectiveness remaining at a high level even after undergoing five successive adsorption cycles. This study paves the way to the use of green nanotechnology for eco-friendly, cheap, and rapid techniques that can be used in the purification of wastewater.

Metal contaminants in rice imported to Iran: A comprehensive assessment of carcinogenic and non-carcinogenic health risks

BACKGROUND

Rice is a staple food in Iran, where significant imports from India and Pakistan are necessary to meet demand. However, imported rice has been found to contain harmful levels of heavy metals, posing health risks.

OBJECTIVES

This study aimed to assess the levels of 34 metals in imported rice and evaluated the associated health risks for the Iranian population.

METHODS

Sixty samples of rice imported into the Iranian market from India, Pakistan, and Thailand were analyzed for 34 metals using inductively coupled plasma optical emission spectrometry (ICP-OES). The metals included carcinogenic elements-Arsenic (As), Lead (Pb), Nickel (Ni), and Cadmium (Cd)-and non-carcinogenic: Sodium (Na), Iron (Fe), Potassium (K), Calcium (Ca), Copper (Cu), Zinc (Zn), Magnesium (Mg), Platinum (Pt), Silicon (Si), Gold (Au), Boron (B), Bismuth (Bi), Tungsten (W), Tin (Sn), Molybdenum (Mo), Chromium (Cr), Barium (Ba), Strontium (Sr), Aluminum (Al), Selenium (Se), Manganese (Mn), Cobalt (Co), Antimony (Sb), Titanium (Ti), Lanthanum (La), Lithium (Li), Vanadium (V), Beryllium (Be), Palladium (Pd), and Mercury (Hg). The health risks associated with the consumption of rice were assessed through the Target Hazard Quotient (THQ), Hazard Index (HI), Incremental Lifetime Cancer Risk (ILCR), cumulative cancer risk (∑ILCR), and Margin of Exposure (MOE) approaches.

RESULTS

The analysis revealed that the Cd level in 1 sample and Pb levels in 5 samples exceeded the maximum concentrations established by the Institute of Standards and Industrial Research of Iran. The risk of cancer in adults exposed to As and Cd at mean concentrations was found to be higher than 1 in 100,000, while for Pb and Ni, the risk was greater than 1 in 10,000. In children, the ILCR for As and Cd at mean concentrations exceeded 10⁻⁴, indicating a moderate risk level, and for Pb and Ni, it reached 1 in 1000, emphasizing the need for enhanced public health safety measures. Additionally, ∑ILCR from all metals in both adults and children exceeded the 10⁻⁴ threshold. The MOE values for mean, median, and 90th percentile exposure to As, Pb, and Ni were below 10,000 in adults and children, indicating a significant health concern from rice consumption.

CONCLUSION

These findings highlight the potential health risks of consuming rice contaminated with heavy metals, particularly arsenic. Therefore, special attention should be directed towards monitoring and reducing toxic metal levels in imported rice, with interventions aimed at mitigating these risks.

Presence of Heavy Metals in Vegetables Irrigated with Wastewater-Impacted Rivers and Its Health Risks in Ethiopia: Systematic Review

Background

Vegetables play critical role in human nutrition and overall health. However, consumption of vegetables cultivated through wastewater-impacted river can be source of potentially toxic heavy metals, which can cause detrimental health effects when their concentration exceeds the recommended maximum levels. Despite growing body of evidence highlighting the dangers associated with heavy metal accumulation in vegetables, there remains critical gap in systematic assessments within Ethiopian context. Therefore, objective of this review is to reveal heavy metals concentrations in vegetables grown with wastewater-impacted river and assess associated public health risks.

Methodology

Research articles published in English were identified through systematic searching using electronic databases including PubMed, Google Scholar, WHO/FAO library, and searching from Google manually. The outcomes of interest were mean concentration of heavy metals in vegetables and associated health risks. Cross-sectional studies that met inclusion criteria were considered. Data were extracted by independent reviewers. Methodological quality of included studies was assessed using critical appraisal tools. Moreover, health risks of consumers were assessed through evaluating estimated daily intakes (EDI), Health Risk Index (HRI), and Hazard Index (HI).

Results

Nineteen articles were included in this systematic review. The findings revealed that the mean concentration of Pb, Cr, Cd, As, Hg, Cu, Ni, Zn, Mn, and Fe in tested vegetables ranged from: 0.28-7.68, 0.75-33.01, 0.14-3.93, 0.05-3.13, ND-4.25, 0.92-15.33, 2.13-13.1, 18.27-62.83, 8.83-331.8, and 177.8-1034.3 mg/kg (dry weight), respectively. The EDI of Pb, Cr, Cd, As, Hg, Cu, Ni, Zn, Mn, and Fe in vegetables was range from: 0.00104-0.0286, 0.00279-0.123, 0.00052-0.0146, 0.0000372-0.0116, 0.0124-0.0158, 0.00342-0.0439, 0.0079-0.0487, 0.068-0.23, 0.03-1.23, and 0.53-3.84 mg/kg/day, respectively. The HRI of toxic heavy metals for all vegetable types ranged as; Pb (0.26-7.15), Cr (0.00186-0.0820), Cd (0.52-14.6), As (0.12-38.7), and Hg (1.24-1.58). The HRI due to consumption of all vegetables was 35, 0.168, 46.6, 70, and 2.82 for Pb, Cr, Cd, As, and Hg, respectively indicating severe health impact except for Cr.

Conclusion

This review underscores health implications linked to consumption of vegetables cultivated using wastewater in Ethiopia. It revealed that the concentration of toxic heavy metals in vegetables grown with wastewater-affected water was higher than the maximum allowable safe limit set for edible vegetables by WHO that would be a public health risk.

Rhizophora mangle L. bioindicator of environmental exposure to heavy metals in the Navachiste lagoon complex, Sinaloa, Mexico

Rhizophora mangle's potential as a bioindicator of pollution trace metals (TM). TM in sediments, and leaves, stembark, and roots were evaluated. Absorbance was measured by an Atomic Absorption Spectrophotometer (AAS). TM content was obtained by acid nitric digestion. TM seasonal change, bioavailable fractions (BioF), enrichment factor (EF), and correlation to tissues were evaluated. TMs in sediments were Fe > Mn > Zn > Cr > Ni > Cu > Cd. In tissues was Mn > Fe > Zn > Cu > Cr > Ni > Cd. TM was correlated with silt, clay, and organic materials. In the sediment, the BioF of Cu showed a strong significant correlation in summer with Cu in leaves in leaf and stembark. A significant correlation was shown between the BioF of Mn in the sediment and Mn in leaves during the spring, summer, and winter. The BioF in sediments is correlated with organic matter, sandy and silty, temperature, salinity, and pH. R. mangle could be a potential pollutant bioindicator of Cu and Mn.

Capacity of an aquatic macrophyte, Pistia stratiotes L., for removing heavy metals from water in the Oued Fez River and their accumulation in its tissues

Water resources, particularly rivers, are increasingly exposed to pollutants, especially heavy metals of chemical origin, which are difficult to monitor and can pose risks to both ecosystems and human health. This study assesses heavy metal contamination in the Oued Fez River, focusing on the bioaccumulation by the invasive plant Pistia stratiotes. The methodology involves measuring and comparing metal concentrations in water and plant tissues. Results revealed that while aluminium (Al) slightly exceeded recommended levels at 0.2978 mg L-1, other metals like zinc (Zn), iron (Fe), copper (Cu), lead (Pb) and cadmium (Cd) remained within acceptable limits. The study demonstrates P. stratiotes' effectiveness in heavy metal phytoremediation, with its roots showing high bioaccumulation up to 19,726 mg kg-1 for Fe and 15,128 mg kg-1 for Al, indicating its potential for water decontamination. Eco-toxicological assessments, including bioconcentration and translocation factors, confirm the plant's capacity to mobilize toxic metals. Statistical analysis also points to possible industrial, urban, or agricultural contamination sources based on correlations between Al, Fe and Zn. The study underscores P. stratiotes' role in phytoremediation while emphasizing the need for monitoring and controlling contamination sources and managing the spread of this invasive species to ensure sustainable water resources.

Human health risk assessment of potentially toxic and essential elements in medicinal plants consumed in Zabol, Iran, using the Monte Carlo simulation method

Medicinal plants (MPs) have long been used for their therapeutic properties in traditional forms of medicine. However, the presence of potentially toxic elements (PTEs) in MPs raises concerns about their safety, efficacy, and potential adverse effects on human health. The current study aimed to determine the level of potentially toxic and essential elements (PTEEs) in commonly consumed MPs in Zabol, Iran, along with their health risk assessments. To conduct the present study, 10 types of MPs widely used in Zabol, Iran, were selected, and 15 samples of each type (150 samples in total) were taken. Each sample was analyzed for the presence of various PTEEs using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) for Lead (Pb), cadmium (Cd), chrome (Cr), nickel (Ni), copper (Cu), zinc (Zn), iron (Fe), aluminum (Al) and manganese (Mn); and Atomic Absorption Spectrometry (AAS) for arsenic (As) and mercury (Hg). Finally, to better comprehend the scope of exposure and its possible effects, the Monte Carlo simulation method is successfully applied to assess human health risks related to PTEs in MPs. Statistical analysis revealed statistically significant (P < 0.001) variations in PTE averages among MP types. Furthermore, all samples' overall PTE mean concentration (range: 0.18 to 215.5 µg/kg) was below the World Health Organization's (WHO) regulatory standards. Probabilistic health risks, including non-carcinogenic-target hazard quotient (THQ) for each element, total target hazard quotient (TTHQ) for all elements, and carcinogenic-incremental lifetime cancer risk (ILCR) for each element, and total carcinogenic risk (TCR) for all elements, were significantly lower than the acceptable limit for children and adults. Accordingly, it can be said that consuming MPs sold in Zabol is safe for children and adults regarding carcinogenic (ILCR/TCR = 10- 4) and non-carcinogenic (THQ/TTHQ = 1) effects. In light of the findings presented here, and to our understanding, the primary factor contributing to lower levels of PTEs in MPs in Zabol City markets is the cultivation of plants in nonindustrialized areas, separate from urban and industrial zones. This practice keeps them from environmental contaminations, including soil quality and water sources. It is recommended that it is essential to regulate the sources that enhance the transfer of PTEs and other harmful pollutants from surroundings to the soil and, consequently, MPs. It is also suggested that, like chemical drugs, MPs should undergo rigorous testing by quality control agencies before being made available to the market.

Tapping into haloalkaliphilic bacteria for sustainable agriculture in treated wastewater: insights into genomic fitness and environmental adaptation

The increasing salinity and alkalinity of soils pose a global challenge, particularly in arid regions such as Tunisia, where about 50% of lands are sensitive to soil salinization. Anthropogenic activities, including the use of treated wastewater (TWW) for irrigation, exacerbate these issues. Haloalkaliphilic bacteria, adapted to TWW conditions and exhibiting plant-growth promotion (PGP) and biocontrol traits, could offer solutions. In this study, 24 haloalkaliphilic bacterial strains were isolated from rhizosphere sample of olive tree irrigated with TWW for more than 20 years. The bacterial identification using 16S rRNA gene sequencing showed that the haloalkaliphilic isolates, capable of thriving in high salinity and alkaline pH, were primarily affiliated to Bacillota (Oceanobacillus and Staphylococcus). Notably, these strains exhibited biofertilization and enzyme production under both normal and saline conditions. Traits such as phosphate solubilization, and the production of exopolysaccharide, siderophore, ammonia, and hydrogen cyanide were observed. The strains also demonstrated enzymatic activities, including protease, amylase, and esterase. Four selected haloalkaliphilic PGPR strains displayed antifungal activity against Alternaria terricola, with three showing tolerances to heavy metals and pesticides. The strain Oceanobacillus picturea M4W.A2 was selected for genome sequencing. Phylogenomic analyses indicated that the extreme environmental conditions probably influenced the development of specific adaptations in M4W.A2 strain, differentiating it from other Oceanobacillus picturae strains. The presence of the key genes associated with plant growth promotion, osmotic and oxidative stress tolerance, antibiotic and heavy metals resistance hinted the functional capabilities might help the strain M4W.A2 to thrive in TWW-irrigated soils. By demonstrating this connection, we aim to improve our understanding of genomic fitness to stressed environments. Moreover, the identification of gene duplication and horizontal gene transfer events through mobile genetic elements allow the comprehension of these adaptation dynamics. This study reveals that haloalkaliphilc bacteria from TWW-irrigated rhizosphere exhibit plant-growth promotion and biocontrol traits, with genomic adaptations enabling their survival in high salinity and alkaline conditions, offering potential solutions for soil salinization issues.

Evaluation of ecological and health risks of trace elements in soils of olive orchards and apportionment of their sources using the APCS-MLR receptor model

İzmir, Turkey's third most populous city, is in an important position in terms of both agriculture and industry. The province, which contributes 9.3% to the country's industrial production, also has an important potential in terms of olive cultivation. However, until now, no research has been undertaken to analyze the content of trace elements (TEs) in the soil of olive orchards in İzmir. This study was carried out to determine the pollution level and ecological risks of TEs in the olive orchards soils of İzmir province, to reveal their potential sources and to evaluate their health risks. Among the TEs, the average content of only Ni (37.9 mg/kg) exceeded the world soil average content (29 mg/kg), while the average content of only Cd (0.176 mg/kg) exceeded the upper continental crust content (0.09 mg/kg). Enrichment factor revealed that there was significant enrichment for Cd in 73.6%, Ni in 11.6% and Cr in 5.4% of olive orchards, respectively, due to polluted irrigation water and agrochemicals. Similarly, ecological risk factor indicated that there were moderate and considerable ecological risks for Cd in 48.8% and 23.3% of olive orchards, respectively. Absolute principal component scores-multiple linear regression (APCS-MLR) model showed that Ni and Cr in the study area are affected by agricultural sources, Al, Co, Cu, Fe, Mn, Pb and Zn originate from lithogenic sources, and Cd originates from mixed sources. Based on health risk evaluation methods, non-carcinogenic and carcinogenic effects would not be expected for residents. This study provides significant knowledge for evaluating soil TE pollution in olive orchards and serves a model for source apportionment and human health risk evaluation of TEs in other agricultural regions.

Unravelling the halophyte Suaeda maritima as an efficient candidate for phytostabilization of cadmium and lead: Implications from physiological, ionomic, and metabolomic responses

Cadmium (Cd) and lead (Pb) are among the most toxic heavy metals affecting human health and crop yield. Suaeda maritima (L.) Dumort is an obligate halophyte that is well adapted to saline soil. The inbuilt salinity tolerance mechanisms of halophytes help them to survive in heavy metal-contaminated rhizospheric soil. In the present study, growth and ionomic responses, reactive oxygen species (ROS) accumulation, modulations of phytochelatins, antioxidative defense, and metabolomic responses were studied in S. maritima imposed to Cd and Pb stresses with an aim to elucidate Cd and Pb tolerance mechanisms and phytoremediation potential of this halophyte. Our results showed a reduction of biomass in S. maritima, which may serve as an energy conservation strategy for survival under heavy metal stress. The increased accumulation of ROS with concomitant higher expression of various antioxidative enzymes suggests the efficient scavenging of ROS. The metabolite profiling revealed significant up-regulation of sugars, sugar alcohols, amino acids, polyphenols, and organic acids under Cd and Pb stresses suggesting their possible role in osmotic balance, ionic homeostasis, ROS scavenging, and signal transduction for stress tolerance. In S. maritima, the translocation factors (Tf) are <1 in both Cd and Pb treatments, which indicates that this halophyte has high phytostabilization potential for Cd and Pb in roots and through restricted translocation of heavy metal ions to the aboveground part. The findings of this study offer comprehensive information on Cd and Pb tolerance mechanisms in S. maritima and suggest that this halophyte can detoxify the HMs through physiological, ionic, antioxidative, and metabolic regulations.

Transfer of heavy metals from soil to vegetables: A comparative assessment of different irrigation water sources

This study aimed to assess the transfer factor (TF) of heavy metals (HMs) from soil to commonly consumed vegetables irrigated with different water sources. The field study covered 36 m2 of agricultural land in Kermanshah province, Iran, divided into nine equal-sized plots. Coriander, basil, and radish were the three types of vegetables cultivated and subjected to irrigation over two months, utilizing three different water sources: treated wastewater effluent (TWE), river water (RW), and well water + nitrogen fertilizer (WWF). After the irrigation and harvesting stages, soil samples from the cultivation area and harvested vegetables were collected. These samples underwent analysis using the ICP-OES method to assess HM levels and subsequent calculation of the TF of HMs from soil to plants. The results revealed that the TF levels indicated plants' relatively weak response (TF < 1) to the absorption of HMs. For non-toxic elements (Mn, Fe, Zn, Cu, Ni), TF values were generally higher than those for toxic elements (Cd, As, Pb) across all three vegetable types and irrigation treatments. The study's findings suggest that the TF of HMs in the studied vegetables varied based on the irrigation source and vegetable type. Various factors, including the type of irrigation source and vegetable, influenced the TF of HMs, each having different impacts on the transfer rate of each HM. The study highlights the importance of monitoring irrigation water and soil quality to prevent the accumulation of HMs in cultivated vegetables, thereby mitigating potential risks to human health.

Hues of risk: investigating genotoxicity and environmental impacts of azo textile dyes

The textile industry, with its extensive use of dyes and chemicals, stands out as a significant source of water pollution. Exposure to certain textile dyes, such as azo dyes and their breakdown products like aromatic amines, has been associated with health concerns like skin sensitization, allergic reactions, and even cancer in humans. Annually, the worldwide production of synthetic dyes approximates 7 × 107 tons, of which the textile industry accounts for over 10,000 tons. Inefficient dyeing procedures result in the discharge of 15-50% of azo dyes, which do not adequately bind to fibers, into wastewater. This review delves into the genotoxic impact of azo dyes, prevalent in the textile industry, on aquatic ecosystems and human health. Examining different families of textile dye which contain azo group in their structure such as Sudan I and Sudan III Sudan IV, Basic Red 51, Basic Violet 14, Disperse Yellow 7, Congo Red, Acid Red 26, and Acid Blue 113 reveals their carcinogenic potential, which may affect both industrial workers and aquatic life. Genotoxic and carcinogenic characteristics, chromosomal abnormalities, induced physiological and neurobehavioral changes, and disruptions to spermatogenesis are evident, underscoring the harmful effects of these dyes. The review calls for comprehensive investigations into the toxic profile of azo dyes, providing essential insights to safeguard the aquatic ecosystem and human well-being. The importance of effective effluent treatment systems is underscored to mitigate adverse impacts on agricultural lands, water resources, and the environment, particularly in regions heavily reliant on wastewater irrigation for food production.

Revealing the seed microbiome: Navigating sequencing tools, microbial assembly, and functions to amplify plant fitness

Microbial communities within seeds play a vital role in transmitting themselves to the next generation of plants. These microorganisms significantly impact seed vigor and early seedling growth, for successful crop establishment. Previous studies reported on seed-associated microbial communities and their influence on processes like dormancy release, germination, and disease protection. Modern sequencing and conventional methods reveal microbial community structures and environmental impacts, these information helps in microbial selection and manipulation. These studies form the foundation for using seed microbiomes to enhance crop resilience and productivity. While existing research has primarily focused on characterizing microbiota in dried mature seeds, a significant gap exists in understanding how these microbial communities assemble during seed development. The review also discusses applying seed-associated microorganisms to improve crops in the context of climate change. However, limited knowledge is available about the microbial assembly pattern on seeds, and their impact on plant growth. The review provides insight into microbial composition, functions, and significance for plant health, particularly regarding growth promotion and pest control.

Characterization of heavy metal content distribution and evaluation of soil pollution in Maqin County, Qinghai Province, China

The Qinghai-Tibet Plateau stands as the loftiest geographical area on our planet, frequently denoted as the "Crown of the Globe." To acquire an exhaustive comprehension of the heavy metal contamination situation in the topsoil of Maqin County, Qinghai Province, a total of 1616 surface soil specimens were gathered across a 6300 km2 area. An examination was carried out on 12 metallic elements to investigate the impact of diverse geological contexts, soil categorizations, and land utilization practices on the levels of heavy metals. Additionally, the fundamental factors contributing to these trends were probed. The findings unveiled that the mean levels of the 12 metallic elements in the topsoil of Maqin County surpassed or equaled the baseline values of soil heavy metal concentrations within the research region. The coefficients of variation (CV) values for Hg, Sb, Ni, and Pb exceeded 30%, with Hg showing strong variation. The overall pollution level in the study area was classified as mild, posing a moderate ecological risk. In this study, we performed a multi-factor analysis of the significant differences in heavy metal concentrations among different geological backgrounds, soil types, and land-use types. The results showed that geological background had extremely significant impacts on elements such as Ba, Be, Cd, Cr, Cu, Hg, Ni, Sb, Tl, and Zn (p < 0.01). Soil type had an extremely significant influence on Be, Cd, Cu, and Zn (p < 0.01), as well as a significant influence on Ba (p < 0.05). Land-use type had an extremely significant impact on Ba (p < 0.01) and a significant impact on Cd (p < 0.05). Building upon the amalgamation of the outcomes from the Pearson correlation analysis, it was inferred that the main source of heavy metals in Maqin County, Qinghai Province, was the geological background.

Fertilization of Microbial Composts: A Technology for Improving Stress Resilience in Plants

Microbial compost plays a crucial role in improving soil health, soil fertility, and plant biomass. These biofertilizers, based on microorganisms, offer numerous benefits such as enhanced nutrient acquisition (N, P, and K), production of hydrogen cyanide (HCN), and control of pathogens through induced systematic resistance. Additionally, they promote the production of phytohormones, siderophore, vitamins, protective enzymes, and antibiotics, further contributing to soil sustainability and optimal agricultural productivity. The escalating generation of organic waste from farm operations poses significant threats to the environment and soil fertility. Simultaneously, the excessive utilization of chemical fertilizers to achieve high crop yields results in detrimental impacts on soil structure and fertility. To address these challenges, a sustainable agriculture system that ensures enhanced soil fertility and minimal ecological impact is imperative. Microbial composts, developed by incorporating characterized plant-growth-promoting bacteria or fungal strains into compost derived from agricultural waste, offer a promising solution. These biofertilizers, with selected microbial strains capable of thriving in compost, offer an eco-friendly, cost-effective, and sustainable alternative for agricultural practices. In this review article, we explore the potential of microbial composts as a viable strategy for improving plant growth and environmental safety. By harnessing the benefits of microorganisms in compost, we can pave the way for sustainable agriculture and foster a healthier relationship between soil, plants, and the environment.

Comprehensive health risk analysis of heavy metal pollution using water quality indices and Monte Carlo simulation in R software

Rapid urbanization, population growth, agricultural practices, and industrial activities have led to widespread groundwater contamination. This study evaluated heavy metal contamination in residential drinking water in Shiraz, Iran (2021). The analysis involved 80 groundwater samples collected across wet and dry seasons. Water quality was comprehensively assessed using several indices, including the heavy metals evaluation index (HEI), heavy metal pollution index (HPI), contamination degree (CD), and metal index (MI). Carcinogenic and non-carcinogenic risk assessments were conducted using deterministic and probabilistic approaches for exposed populations. In the non-carcinogenic risk assessment, the chronic daily intake (CDI), hazard quotient (HQ), and hazard index (HI) are employed. The precision of risk assessment was bolstered through the utilization of Monte Carlo simulation, executed using the R software platform. Based on the results, in both wet and dry seasons, Zinc (Zn) consistently demonstrates the highest mean concentration, followed by Manganese (Mn) and Chromium (Cr). During the wet and dry seasons, 25% and 40% of the regions exhibited high CD, respectively. According to non-carcinogenic risk assessment, Cr presents the highest CDI and HQ in children and adults, followed by Mn, As and HI values, indicating elevated risk for children. The highest carcinogenic risk was for Cr in adults, while the lowest was for Cd in children. The sensitivity analysis found that heavy metal concentration and ingestion rate significantly impact both carcinogenic and non-carcinogenic risks. These findings provide critical insights for shaping policy and allocating resources towards effectively managing heavy metal contamination in residential drinking water.

Contents and health risk assessments of selected heavy metals in vegetables produced through irrigation with effluent-impacted river

The widely consumed vegetables, khat, lettuce, and Swiss chard, in Hirna town, West Hararghe, Ethiopia, are extensively cultivated through irrigation with an effluent-impacted river that flows through the town which denotes that monitoring the safety of the vegetables is crucial. Herein, the contents of Pb, Zn, Cu, Cr, and Cd in vegetables, water, and soils were determined by flame atomic absorption spectrometry after a wet digestion procedure based on a mixture of HNO3 and HClO4 at 200 °C. pH and electrical conductivity of the water and soil, and health risks associated with vegetable consumption were determined. The pH of the water (6.64) and soil (6.67) was slightly acidic, and electrical conductivity values were 0.416 and 0.024 mS/cm, respectively, indicating both are in good condition. The metal concentrations were in the range of ND-3.12, 3.43-9.22, and 0.15-10.6 mg/L in the water, soil, and vegetables, respectively, and the contents followed a trend of Cu > Zn > Cr > Pb > Cd. The irrigation water contained all metals above the guidelines except Cd, and the soil contained safe levels except Cd which is above the guideline. The obtained metal levels in the vegetables were below the safe limits. Estimated daily intakes and the total target cancer risks were below the guidelines, and the target hazard quotient and the hazard index were below 1 indicating that the vegetables are safe for consumption. In general, the obtained results suggest that the vegetables are safe for consumption. However, continuous monitoring and policy development are required to mitigate contamination of the river.