Contamination of agricultural soils with microplastics and cadmium as an important environmental issue is causing oxidative stress in plants. In this research, the physiological and biochemical reactions of Kochia (Bassia scoparia L.) seedlings under the above stresses. The factorial experiment was conducted in the form of a completely randomized design in three replications, in the Faculty of Agriculture, Bu Ali Sina University in 2022. Polyvinyl chloride (PVC) microplastics were used at three levels of 0, 0.1 and 1 percent by weight of soil and cadmium (CdCl2) at two levels of 0 and 10 mg/kg of soil. The results of this research showed that by increasing the amount of cadmium to 10 mg in the presence of 0, 0.1 and 1 percent of microplastics, the amount of total chlorophyll decreased, which caused a decrease in the rate of net photosynthesis and transpiration of Kochia seedlings and as a result decreased the total dry weight of the plant. Microplastic and cadmium stress increased ion leakage, malondialdehyde content and hydrogen peroxide activity. In plants exposed to the simultaneous stress of microplastics and cadmium, total phenol increased compared to the control (without cadmium), so that with the increase of cadmium concentration from zero to 10 mg, the amount of total phenol increased by 40.72 per cent. In general, soil contamination with polyvinyl chloride microplastics, especially in high amounts increases the availability of the heavy metal cadmium and causes an increase in the intensity of stress in Kochia seedlings.

There is an accumulation of toxic metal ions in an aquatic habitat that modifies the physical and chemical characteristics of water, posing a threat to aquatic organisms. The fish's body absorbs heavy metals through the gills, dorsal surface, and gastrointestinal system when they eat foodstuff that has high levels of these metals. Zinc, Lead, Mercury, Copper, Arsenic, Nickel, chromium and cadmium are the primary heavy metal contaminants responsible for inducing toxicity in fish. Oxidative stress, or oxidative damage, is the primary chemical process responsible for metal poisoning. Stress undermines a low immune system, leading to harm to organs and tissues, developmental irregularities, and reduced reproductive capacity. Due to the copious availability of vitamins, proteins, and fatty acids such as omega-3 found in fish, individuals are inclined to consume seafood as their primary nutritional source. Consequently, the aggregation of toxic metallic elements in fish tissues has a direct impact on people, causing detrimental effects that accelerate the onset of various diseases. To effectively enforce aquatic conservation regulations and protect human lives, it is imperative to investigate the origins of toxic metals and their detrimental effects on the health of fish.

The presence of heavy metals, specifically cadmium, in the environment poses significant threats to both ecological systems and human health. However, microalgae have shown potential in addressing this issue through their ability to absorb cadmium and produce valuable biomass, making them a promising solution for bioremediation. Among the various microalgae species, Chlorella vulgaris stands out as a suitable candidate due to its potential for biodiesel production and its capacity to effectively absorb cadmium. Therefore, the main objective of this study is to assess the toxicity of cadmium on Chlorella vulgaris cells using network meta-analysis as a methodology. A comprehensive search was conducted on Scopus, Scilit, Google Scholar, and Web of Science to identify relevant studies published from 1 January 1990 to 16 January 2024. Only studies that reported the cell number of Chlorella vulgaris as a result of cadmium exposure were considered for inclusion. The collected data were then subjected to Bayesian frequentist network meta-analysis, utilizing standardized mean difference and a 95 percent confidence interval as measures of effect size. Additionally, a linear regression analysis was performed to examine the dose-dependent impact of cadmium toxicity. Dose-dependent toxic effects of cadmium on Chlorella vulgaris were evident (R-square of more than 0.90), particularly at a concentration of 1 part per million, deemed as the maximum tolerable threshold. Prolonged exposure revealed a concentration-dependent reduction in cell viability, suggesting potential lifespan shortening. A comparison of growth stimulants, gibberellic acid and brassinolide (standard means differences of 1.7 and 3.8, respectively), in mitigating cadmium toxicity indicated the latter superior effectiveness in sustaining microalgal survivability. The presence of high nitrogen and low phosphorous levels was found to be significantly associated with a reduction in Chlorella vulgaris cells due to cadmium exposure. This research has provided conclusive proof of the harmful effects of cadmium on Chlorella vulgaris through the implementation of Bayesian frequentist network meta-analysis, offering valuable insights for environmental management practices. The findings reveal concentration-dependent effects of cadmium toxicity. The survivability of Chlorella vulgaris is determined by the compositions of macronutrients nitrogen and phosphorous. Comparative analyses highlight the superior protective effect of brassinolide over gibberellic acid in mitigating cadmium toxicity. Overall, the findings highlight the potential of Chlorella vulgaris in both bioremediation of heavy metals and biomass production.

In order to evaluate the inoculation of mycorrhizal and growth-promoting bacteria (Pseudomonas genus) on the tolerance of European borage to cadmium toxicity, a factorial experiment was performed in the form of a completely randomized design with 3 replications in the research greenhouse of the Agriculture Faculty of Yasouj University in 2019. The experimental factors include the application of biological fertilizer at 4 levels (control, application of mycorrhiza, application of growth-stimulating bacteria and combined application of mycorrhiza and bacteria) and 4 levels of cadmium concentration (0, 25, 50 and 75 mg cadmium per kg soil). The investigated traits were included root colonization percentage, plant cadmium content, some physiological characteristics and shoot dry weight of European borage. The results showed that with the increase in cadmium concentration, electrolyte leakage, proline content and cadmium content of aerial organs increased. The use of mycorrhiza and bacteria was evaluated positively compared to their non-use, so that in all four levels of cadmium, the highest proline, chlorophyll and relative water content, as well as the lowest electrolyte leakage and shoot cadmium concentration, were obtained from the combined two biofertilizers. Application of biofertilizer increased the dry weight of the aerial parts of inoculated plants compared to the control. The results showed that in the presence of 25 and 50 mg/kg of cadmium, the combined application of bio-fertilizers reduced 21% and 17% of cadmium transfer from roots to shoots of borage. Therefore, it is recommended to use biological fertilizers in areas contaminated with cadmium.

Heavy metals are part of the most important and dangerous environmental pollutants due to their long shelf life, non-degradability by soil microorganisms, and high potential for absorption by plants and entering the food chain. Cadmium is one of the toxic metals for organisms such as plants. The purpose of this research was to investigate the effect of cadmium on the ability of the common daisy plant. In this research, the effect of different amounts of cadmium (0, 10, 20 and 30 mgl-1) had done in a completely randomized design with three replicates. The results showed that the increase of the cadmium hadn’t any significant effect on common daisy plant fresh weight and length. Also, plant dry weight, shoot total chlorophyll, shoot and root carotenoids contents, total protein contents, plant translocation factor and bioaccumulation factor decreased with the increase of cadmium concentration, significantly. While shoot and root proline, and cadmium contents and catalase, peroxidase and ascorbate peroxidase activity increased, significantly. According to this research, the common daisy isn’t suitable for planting in studied cadmium concentrations.

This study aimed to explore the possibility of removing cadmium, a toxic heavy metal, from soilusing Dandelion greens. To accomplish this, a greenhouse experiment was conducted with sixtreatments including a control, and varying concentrations of cadmium in the soil. After the plantswere harvested, the concentration of cadmium was measured in the plant roots, the above-groundparts, and soil samples. The results indicated that Dandelion greens have a remarkable ability toabsorb cadmium from contaminated soils. The higher the concentration of cadmium in the soil, thegreater the amount of cadmium absorbed by the plant roots and the above-ground parts. Specifically,the concentration of cadmium in the above-ground parts increased by 20.4 times and in the roots by38 times with an increase in cadmium concentration. The average amount of cadmium absorbed inthe root and shoot was 69.17 and 59.14 mg/kg, respectively. Furthermore, the study found that thetime required for plant purification increased with the increase of cadmium concentration, and theminimum time required for purification was found to be 5 mg/kg concentration. Dandelion greenshave a relatively short growth period and high yield, making them a viable option for treatingcadmium-contaminated soils. Therefore, Dandelion greens can be utilized as an ornamental plantfor phytoremediation of cadmium-contaminated soils. Overall, this study highlights the potentialof Dandelion greens as a cost-effective and eco-friendly solution for heavy metal pollution in soil.

Soil contamination with heavy metals, paticularly cadmium, poses significant environmental risks, threatening food security and human health. This study investigated the effect of activated biochar and hydrochar derived from Chlorella vulgaris algae on various cadmium forms in contaminated soils. Biochar and hydrochar were produced at 450 and 200°C, respectively, and activated with potassium hydroxide. They were applied at concentrations of 0, 1, and 4% by weight to soils contaminated with cadmium at levels of 50 and 100 mg kg-1. Cadmium fractions in soil—exchangeable, carbonate-bound, organic matter-bound, and those associated with iron and manganese oxides—were analyzed using atomic absorption spectroscopy.  Additionally, the surface morphology, gross calorific value, carbon, nitrogen, hydrogen content, specific surface area and biomass of the activated hydrochar and biochar were determined. The results indicated that with a cadmium concentration of 50 mg kg-1, the addition of 4% biochar reduced the exchangeable cadmium by 2.9 mg kg-1, attributed to the high specific surface area of biochar and hydrochar, providing numerous adsorption sites for cadmium ions. Increasing biochar and hydrochar concentrations from 1% to 4% enhanced the cadmium fractions bound to organic matter and iron/manganese oxides. At cadmium concentrations of 50 and 100 mg kg-1, the highest amounts of cadmium in the form of iron and manganese oxides were 23 and 24.8 mg kg-1, respectively. This study highlights the potential of biochar and activated hydrochar from Chlorella vulgaris algae to promote sustainable agriculture by reducing the bioavailability of cadmium in contaminated soils.

Cadmium is a toxic metal that has significantly increased its entry into the soil and food chain with the rise of environmental pollution. In this study, 11 grapevine cultivars (Vitis vinifera L.) were exposed to three levels of cadmium (0, 50, and 100 milligrams per kilogram) in a factorial experimental design based on a completely randomized design in the research greenhouse of Malayer University. After applying the different cadmium treatments over a period of approximately 4 months, leaf and rhizosphere soil samples of different grapevine cultivars were collected, and the concentrations of cadmium and zinc were measured using an atomic absorption spectrometer. Significant differences were observed among grapevine cultivars in terms of cadmium and zinc content in leaves and rhizosphere soil. The cultivar "Bidaneh Sefid" had the lowest cadmium content in leaves, while the highest cadmium content in rhizosphere soil was observed in the cultivar "Rish Baba." Moreover, the cultivar "Turkmen 4" had the highest zinc content in leaves, and the cultivar "Rish Baba" had the highest zinc content in rhizosphere soil. Geochemical indices including Igeo, Ipoll, CF, and BAC were evaluated in the surface soil compared to the standard shell and earthworm. Based on the results of this study, in the examination of soil indices in different grapevine cultivars and the impact of different cultivars, according to the Ipoll and Igeo (Müller) indices in the shell, in non-stressed soil without cadmium, it was considered slightly contaminated, and according to the standard shell in the earthworm, it was considered quantitatively contaminated. According to the Igeo index in the shell, in soil under 50 milligrams per kilogram of cadmium stress, it was considered slightly contaminated, and according to the Ipoll index, it was considered slightly to moderately contaminated, and according to the standard shell in the earthworm, it was considered heavily contaminated. According to the Igeo and Ipoll indices in the shell, the results of soil under 100 milligrams per kilogram of cadmium stress, were considered heavily contaminated, and according to the standard shell in the earthworm, it was considered severely contaminated. The results of these indices indicated that zinc was in the non-contaminated category.

Heavy metals are one of the most important environmental problems and have caused many concerns due to their carcinogenic properties, non-renewability and biological accumulation. Considering the expansion of lands contaminated with heavy metals and the inevitable cultivation of strategic grains such as wheat in these lands and the fact that according to research wheat accumulates more cadmium than other grains, therefore the purpose of this research is to investigate the effect of plasma Atmospheric cold and cadmium were on the activity levels of antioxidant enzymes, proline and the amount of protein and soluble sugars on two cultivars Karim and Gonbad. This experiment was carried out in a factorial form in a completely randomized design with four replications in the greenhouse of Mohaghegh Ardabili University. Factors included wheat cultivars (susceptible cultivar Gombad and resistant cultivar Karim), atmospheric cold plasma at three levels (control, 60 and 120 seconds) and treatment with cadmium metal at four levels (control, 50, 100 and 150 µM). The results showed that the amount of soluble sugar, protein, methionine amino acid concentration, catalase and superoxide dismutase enzymes, and root length were affected by the cultivar × plasma × cadmium interaction. The results of the comparison of three-way effects showed that Gombad wheat cultivar had the highest amount of methionine amino acid in plasma 60 and cadmium 150 with an average of 0.22 (nanmol/g). In general, it can be concluded from the results that the stress caused by the increase of cadmium and plasma concentration on the physiological processes of wheat is different and both cultivars use different mechanisms to deal with cadmium stress. Kareem and Gonbad wheat cultivars spend all their energy in the synthesis of factors involved in the defense mechanism in order to adapt and bear more in order to deal with the development and accumulation of toxic concentrations of this heavy metal in stress conditions. The results of the evaluation of cultivars showed that with the increase in the concentration of cadmium chloride, the amount of catalase, polyphenol oxidase, superoxide dismutase and ascorbate peroxidase decreased and the amount of soluble sugar, total protein, lysine and methionine increased. Also, in Gonbad variety, with the increase in the concentration of cadmium chloride, the amount of total protein, polyphenol oxidase enzyme, superoxide dismutase enzyme and ascorbate-peroxidase decreased, which shows the effects of cadmium toxicity and the production of oxygen free radicals. As a result, it follows oxidative damage and growth reduction, and the amount of soluble sugar of catalase enzyme, the amount of lysine and methionine increased. Also, Karim cultivar is more tolerant to cadmium stress than Gonbad cultivar. Therefore, this research showed that cadmium treatment at 150 micromolar in the presence of cold plasma was able to stimulate the defense mechanisms of the plant and make the plant bear the stress.

This 14-day trial was conducted on 24 Persian sturgeons with a mean weight of 300 g. The treatments consisted of the control group (no cadmium), treatment 1: 200 µg/L of dissolved cadmium, treatment 2: 400 µg/L of dissolved cadmium, and treatment 3: 800 µg/L of dissolved cadmium in triplicates. Results showed that the expression level of metallothionein (MT) at 200 μg/L on the first day was 1.06±0.02, which increased to 2.51±0.13 in the control with prolonged exposure until the fourteenth day. The rate rose from 1.43±0.19 on the first day of exposure to 2.60±0.36 folds the control by the seventh day at a concentration of 400μg/L. Moreover, the expression level at the concentration of 800 μg/L rose from 1.1±0.13 on the first day to 2.15±0.09 folds in the control on the fourteenth day. The results also indicated that the highest level of MT expression (2.60±0.36) was observed in Treatment 2. Accordingly, all three concentrations of dissolved cadmium (200, 400, and 800 µg/L) significantly increased the MT expression on the last day of the trial (p<0.05 and p<0.01). Therefore, MT can be considered a biomarker of cadmium exposure in Persian sturgeons. This study also demonstrated that the MT expression was increased in the kidney tissue of the samples with longer times of exposure to cadmium, but it did not increase by increasing cadmium concentration. Hence, the length of cadmium exposure can affect the kidney MT expression level of Persian sturgeon.