The accumulation and translocation of harmful Sb, Se, and Tl in certain vegetables grown in contaminated areas

Sevik, H. (2026). "The accumulation and translocation of harmful Sb, Se, and Tl in certain vegetables grown in contaminated areas," BioResources 21(3), 6365–6384.

Abstract

Heavy metal accumulation in food produced in polluted areas can reach high levels, posing a health risk. In this study, the variation in Sb, Se, and Tl concentrations was determined on a species and organ basis in tomatoes, peppers, eggplants, cucumbers, and corn grown near an industrial area in Düzce, one of Europe’s most polluted cities. The concentrations of these elements in the soil were also determined, and the bioconcentration factor and translocation factor in the organs of the plants were calculated, thus attempting to determine the risks in terms of food safety. The study found that the concentrations of these elements in the soil were quite high, while their translocation and accumulation in the above-ground parts of plants, especially fruit organs, were at lower levels compared to other organs. Nevertheless, their concentrations in fruit organs were still quite high. In many countries, limit values for Sb, Se, and Tl in vegetables have not been established. This is considered a major deficiency. However, the values obtained in this study are well above the limit values permitted by countries such as China and Italy. This poses a significant risk to human health.

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The Accumulation and Translocation of Harmful Sb, Se, and Tl in Certain Vegetables Grown in Contaminated Areas

Hakan Sevik *

DOI: 10.15376/biores.21.3.6365-6384

Keywords: Vegetables; Selenium; Tin; Thallium; Bioaccumulation

Contact information: Department of Environmental Engineering Faculty of Engineering and Architecture, Kastamonu University, Türkiye; *Corresponding author: hsevik@kastamonu.edu.tr

INTRODUCTION

Food safety has become a major global issue in recent years. Factors such as soil salinization and degradation, the conversion of agricultural land to residential areas, and various biotic and abiotic pests, are reducing the amount of agricultural land and degrading its quality (Şen et al. 2018; Xing and Wang 2024; Velilla et al. 2025). These factors also cause significant product loss and resource waste. It is stated that food loss due to pests, such as insects, mites, rodents, and mycotoxins, consumes 1/4 of the world’s fresh water resources and 1/5 of the total arable land (Junaid and Af 2024).

One of the factors that most threatens food security is global climate change. Global climate change is defined as an irreversible problem and is stated to affect all living things on earth (Erturk et al. 2024; Canturk et al. 2025; Zeren Cetin et al. 2025). It is stated that global climate change will also significantly affect agricultural production, potentially reducing agricultural productivity by 10 to 25% (Junaid and Af 2024). These factors are said to significantly threaten food security. According to the United Nations’ 2022 World Food Security and Nutrition Report, approximately 828 million people worldwide suffer from hunger (Sharma et al. 2024). It is stated that approximately 3.14 billion people do not have a healthy diet (Melgar-Quiñonez 2025). This situation is predicted to worsen.

Another factor threatening food security is pollution. Many researchers consider pollution to be the most significant global threat after irreversible global climate change and urbanization (Mutlu and Aydın Uncumusaoğlu 2018; Ozturk Pulatoglu et al. 2025; Şimşek et al. 2025). It has even been stated that some pollution factors, such as nanoparticles, may soon affect even the most remote ecosystems (Özel et al. 2024). Similarly, it is stated that the release of heavy metals into nature and the threats they pose, which can be harmful and toxic to humans even at very low concentrations, is constantly increasing (Kuzmina et al. 2023; Key et al. 2023; Sevik et al. 2025).

Selenium (Se), antimony (Sb), and thallium (Tl), which are among the most dangerous heavy metals for human health, are heavy metals whose industrial use and release into the environment are increasing. Moreover, due to their potential hazards, these heavy metals have been included in the priority pollutant list by both the ATSDR and the EPA (Canturk et al. 2024; Şevik et al. 2024). When heavy metals are absorbed into the human body through respiration or food, they can be much more threatening, harmful, and deadly (Ghoma et al. 2023; Gültekin et al. 2025). However, in recent years, the intermingling of agricultural areas with residential and industrial areas has caused serious health concerns in food products grown in these areas. This is because heavy metals enter plant tissues from the air or soil and enter the food chain, which can cause potentially fatal health risks (Angon et al. 2024). Therefore, determining heavy metal accumulation in food products grown in areas with high levels of heavy metal pollution and identifying which heavy metals accumulate in which organs is of great importance for food safety. This study aimed to determine the accumulation and translocation of the heavy metals Sb, Se, and Tl, which can be toxic and harmful to humans even at low concentrations, in the plant organs of certain vegetables grown in areas with high levels of pollution.

EXPERIMENTAL

Materials

The study was conducted in Düzce province, one of Turkey’s most polluted cities and ranked among Europe’s five most polluted cities according to the 2021 World Air Pollution Report. Previous studies in the region have identified Cr (Koc et al. 2024; Ozturk Pulatoglu et al. 2025), Cd (Isinkaralar et al. 2025a), Pb, Al, Cu, and Ni (Koc et al. 2025a, 2025b; Isinkaralar et al. 2025a), Ba (Sevik et al. 2025), Tl (Şen 2025), Sb (Canturk et al. 2024), As (Yaşar Ismail et al. 2025), V (Cebi Kilicoglu and Zeren Cetin 2024), Pd (Sevik et al. 2024), Sr and Sn (Erdem 2023; Yigit 2024; Kulac et al. 2025) as being at high levels, which are quite dangerous for human health. In studies conducted in the region, Tl has been associated with agricultural activities (Canturk 2023), Se with pollution from traffic and urban settlements (Koç et al. 2026), and Sb with traffic-related pollution (Canturk et al. 2024).

Within the scope of the study, five vegetables (tomatoes, peppers, eggplants, corn, and cucumbers) were grown in Düzce in agricultural areas adjacent to industrial zones. The vegetables grown from seeds were planted in the Düzce industrial area in mid-May, and no fertilizers, hormones, or pesticides were used on the plants, which underwent routine watering and maintenance. At the end of August, the plants were uprooted along with their soil and brought to the laboratory. In the laboratory, the roots were first cleaned of soil. The soil was sifted to separate it from debris and placed in glass Petri dishes. For plant samples, the roots were separated from the soil and thoroughly washed with tap water to remove soil particles adhering to the roots, followed by three rinses with deionized water. The plants were separated into roots, stems, leaves, and fruits. After thorough washing, the plant parts were rinsed with deionized water. This washing procedure was performed to remove surface dust and airborne particulate matter, ensuring that the measured heavy metal concentrations accurately reflect root uptake rather than external contamination. After washing, the plant samples were chopped with stainless steel knives, placed in Petri dishes, and labeled.

Methods

The samples were kept for 15 days in Petri dishes with open lids in a well-ventilated laboratory away from direct sunlight. They were then pre-dried in an oven at 45 ± 2 °C for two weeks. After pre-drying, the samples were ground into powder using a steel blender, weighed to 0.5 g, and placed in special tubes designed for microwave use. A total of 10 mL of 65% HNO was added to the samples, which were then heated in a microwave oven at 280 PSI pressure and 180 °C for 20 min. After the process, deionized water was added to the cooled samples to make up 50 mL, and they were filtered through filter paper. Cr and Cd concentrations were determined using a GBC Integra XL –SDS-270 ICP-OES (inductively coupled plasma – optical emission spectroscopy) device (GBC Scientific Equipment Pty Ltd., Melbourne, Australia). This pretreatment and heavy metal analysis have been frequently used in the analysis of plant samples in recent years (Erdem et al. 2024; Isinkaralar et al. 2025b). The obtained data were analyzed using the SPSS software package. Variance analysis was applied to the data, and the Duncan test was performed for factors with an F value, error rate, and statistically significant differences at a confidence level of at least 95%.

The bioaccumulation factor (BCF) and translocation factor (TF) were also calculated in the study. Thus, it was attempted to determine in which species and in which organs the elements were more accumulated. The following formulas were used in the calculations (Ergül and Kravkaz Kuşçu 2025):

BCF = (Concentration in the organ) / (Concentration in the soil) (1)

TF = (BCF of the organ) / (BCF of the root soil) (2)

RESULTS AND DISCUSSION

Change in Sb Concentration

The results of the variance analysis and Duncan test regarding the changes in Sb concentration in vegetables based on species and organ are presented in Table 1.

Table 1. Change in Sb (ppb) Concentration

As shown in Table 1, Sb concentration varied significantly among all species in terms of organs and among all organs in terms of species (p < 0.001). The lowest values were obtained in fruits in all species. According to the average values, the lowest values were obtained in fruits and stems, while the highest values were obtained in roots. The highest values in organs were obtained in the stem and leaves of tomatoes, in the fruit of peppers, and in the roots of corn. The lowest values in soils were obtained in peppers and eggplants, and the highest values in corn and cucumbers. The variation in BCF values for Sb by species and organ is given in Table 2.

Table 2. BCF Values for Sb

When examining the BCF values for Sb, they were found to range from 0.080 (corn fruit) to 1.011 (corn root). It was determined that BCF values were quite low (maximum 0.411) except for peppers and corn roots. According to the average values, the lowest BCF values were calculated for fruit as an organ (0.152) and for cucumber as a species (0.132), while the highest values were calculated for root as an organ (0.479) and for pepper as a species (0.478). The TF values calculated for Sb are given in Table 3.

Table 3. BCF values for Sb

When TF values for Sb are examined, it is seen that the lowest values were obtained in fruit for all species. The TF values in fruit were calculated as 0.079 in corn. The TF values calculated in fruit for other species ranged from 0.375 (eggplant) to 0.556 (pepper). The highest TF values in species other than corn were calculated in leaves, with the highest TF values in leaves calculated in tomatoes (0.935) and cucumbers (0.793).

Change in Se (ppb) Concentration

The results of the variance analysis and Duncan test regarding the changes in Se concentration in vegetables based on species and organ are presented in Table 4.

Table 4. Change in Se (ppb) Concentration

As a result of the variance analysis, it was observed that the Se concentration changed significantly in all types of organs and in all organs in terms of type (p < 0.001). The lowest values were obtained in corn in organs other than the roots. The lowest value in the roots was obtained in peppers. The highest values were obtained in the stems and leaves of tomatoes, in the fruit of cucumbers, and in the roots of corn. In the soil, the lowest value was obtained in peppers, and the highest value was obtained in corn. The variation in BCF values for Se by species and organ is given in Table 5.

Table 5. BCF Values for Se

As shown in Table 5, BCF values for Se range from 0.082 (corn fruit) to 1.004 (corn root). The lowest values were obtained in the fruit, with the exception of the cucumber. The highest values were obtained in the roots of all species. The change in average BCF values among species is as follows: cucumber < eggplant < tomato < corn < pepper. The TF values calculated for Se are given in Table 6.

Table 6. BCF Values for Se

The lowest TF value for Se was obtained in corn fruits with 0.082, while the highest TF value was obtained in tomato leaves with 0.974. The lowest values were obtained in corn. The TF values in corn ranged from 0.082 to 0.594, with an average of 0.429. No organ had a TF value exceeding 1, with the highest values obtained in tomato leaves (0.974), cucumber leaves (0.827), and pepper leaves (0.728).

Change in Tl (ppb) Concentration

The average data regarding the variation in Tl concentration, along with the results of the variance analysis and Duncan test, are presented in Table 7.

Table 7. Change in Tl (ppb) Concentration

As with the other two elements, it was determined that the change in the Tl element was statistically significant in all types of organs and in all organs in terms of type (p < 0.001). The highest values were obtained in the stem of tomatoes (3050.60 ppb), in the fruit of cucumbers (2283.23 ppb), in the leaves of tomatoes (4178.10 ppb), and in the roots of corn (19789.83 ppb). The change in Tl concentration in fruits was corn < tomato < pepper < eggplant < cucumber. The change in Tl concentration in soils was pepper < eggplant < tomato < corn < cucumber. The change in BCF values for Tl based on species and organ is given in Table 8.

Table 8. BCF Values for Tl

It was determined that BCF values in TL ranged from 0.084 (corn fruit) to 1.023 (corn roots). According to the calculations, the lowest values were obtained in cucumber stems, while the highest values were obtained in the roots of all species. The TF values calculated for Tl are given in Table 9.

Table 9. BCF Values for Tl

When examining the table values, the highest values were calculated as 0.957 for tomato leaves, 0.838 for cucumber leaves, and 0.712 for pepper leaves. The highest values in fruits were obtained for cucumber (0.597) and pepper (0.587). The lowest values were calculated for corn fruits (0.082) and corn stalks (0.090).

Within the scope of the study, the concentrations of Sb, Se, and Tl in some of the most commonly consumed vegetables were evaluated. It is stated that Sb, one of these elements, alters hormone levels in the human body and increases the risk of cancer (Lai et al. 2022). It is also stated that it causes symptoms such as conjunctivitis, upper respiratory tract inflammation, chronic bronchitis, chronic emphysema, and pleural adhesions (Gad 2014). As a result of the study, it was determined that Sb concentrations ranged from 5598 ppb to 7056 ppb in fruit organs consumed as food. The US Food and Drug Administration (FDA) or other international organizations have not set specific regulatory limits for Sb in food. The WHO has set a guideline value of 20 μg L-¹ for Sb in drinking water. However, the FDA has set a guideline level of 0.1 ng L-¹ for Sb in bottled water (Elik et al. 2024). The Food Safety and Standards Authority of India (FSSAI) has set the limit for Sb concentration in vegetables at 1.00 mg/kg (1000 ppb) (Kashyap and Jain 2024). In Italy, the permitted Sb limit in foods is also 1.0 mg kg⁻¹dw (Wei et al. 2024). The values obtained in the study are approximately 5.5 to 7 times this limit.

Another element covered in the study, Se, can cause vomiting, pain, nausea, garlic breath, and heart symptoms. In severe toxicity cases, cardiac and pulmonary symptoms may occur and lead to death (Hadrup and Ravn-Haren 2020). It is stated that Se is found at an average level of 0.110 mg kg^-1dw in leafy vegetables and 0.054 mg kg-1dw in vegetable fruits (Fordyce 2013). China has set Se concentration limits for products, such as grains, vegetables, fruits, edible mushrooms, etc., at 20.0 to 200.0 μg/100 g (Ren et al. 2024). Within the scope of the study, Se concentrations in the fruit organs of plants were determined to be 2270 ppb to 3210 ppb. These values are well above the limits set by China. Because 1 µg/kg = 1 ppb, the Chinese standards can be evaluated as 200 to 2000 ppb.

The final element discussed in this study, Tl, is extremely hazardous to human health. Tl is an element that is not essential for humans and has no biological use in the human body. It is one of the most toxic metals and is more toxic to humans than Hg, Cd, Pb, Cu, and Zn (Blain 2022). Tl can cause fatigue, muscle and joint pain, visual impairment, gastrointestinal dysfunction, ascending paralysis, and mental disorders in humans, and polyneuritis may occur (Duri et al. 2020; Şevik et al. 2024). In Italy, the permitted Tl limit in food is set at 0.50 mg kg⁻¹dw (Wei et al. 2024). Within the scope of the study, Tl concentrations in fruit organs ranged from 1624 ppb to 2283 ppb. These values are approximately 3.2 to 4.4 times the permitted Tl concentrations.

Studies have determined that heavy metal contamination in the region’s soils is quite high, and consequently, heavy metal concentrations in plants are also high (Guney et al.; Dışbudak et al. 2026). In a study conducted on vegetables grown in the region, it was determined that Cd concentrations in fruit organs ranged from 0.22 mg/kg to 0.33 mg/kg, and that these values exceeded the limit values set by international standards by more than twofold. The same study highlighted that chromium (Cr) concentrations in fruit organs ranged from 178.5 to 579.8 mg/kg, with these values being hundreds of times higher than the limit set by international standards (Sevik et al. 2026). Similarly, it was determined that Al concentrations in the fruit organs of vegetables significantly exceeded the limit values set by the WHO and the EU, and that there is a potential non-carcinogenic health risk associated with the consumption of tomatoes, cucumbers, and peppers, primarily due to nickel (Demirci et al. 2026).

In many countries, legal limits for the elements studied have not been specified in detail for vegetables. According to the ATSDR, the acceptable daily intake (minimal risk level) is 1 μg/g/day for Sb and 0.005 μg/g/day for Se; the limit value for Se, as per the Turkish Food Codex Contaminants Regulation, is 250 μg/day (Şahin and Türksoy 2024). Daily Sb intake is reported to be 3,471 µg/day (IQR 2,801 to 4,395 µg/day), and daily Tl intake is reported to be 533.7 ng/day (414.6 to 676.0 ng/day) (Filippini et al. 2020). Using results from similar studies, limits for Se, Sb, and Tl in foods can be determined. However, compared to elements, such as Pb, Cu, Cd, and Zn, for which limit values have been established, it can be said that the elements studied can be much more harmful at lower concentrations. The WHO and EU have set limit values for Cd in leafy vegetables at 0.1 mg/kg. The WHO has set a limit value of 0.3 mg/kg for Pb, while the EU has set a limit value of 0.1 mg/kg (Ejaz et al. 2023). The values obtained in the study are well above these limits.

The study focused on the accumulation of heavy metals in the fruit organs of vegetables. According to the study results, the lowest concentrations were generally obtained in the fruit organs, while concentrations in other organs were generally higher. However, the leaves and stems of these plants are used as animal feed in some regions. Corn, in particular, is ensiled in many regions, and the above-ground parts of the plant are used as animal feed (Shuo et al. 2024). Within the scope of the study, the Se concentration in corn leaves and stems was approximately 2.5 ppm (mg/kg), while it was calculated to be above 5 ppm in tomatoes. However, while the minimum Se requirement in animal husbandry is 0.05 to 0.10 mg/kg dry feed, the toxic Se concentration in animal feed is 2 to 5 mg/kg dry feed (Gupta and Gupta 2017). The same applies to other heavy metals. The use of the above-ground parts of these plants as animal feed poses a risk of toxicity in animals and can also threaten human health through the food chain.

As seen, the concentrations of the elements studied in the fruit organs of vegetables were well above the permissible levels for health. Furthermore, the determined heavy metal concentrations in other organs were even higher. Heavy metals can enter the plant body from the soil, air, or stem sections (Cobanoglu et al. 2023; Kulac et al. 2025). However, the transport of heavy metals within plants is a complex process that varies with many factors, primarily plant species. Many studies have shown that heavy metal concentrations vary significantly across plant species (Lin et al. 2025; Isinkaralar et al. 2025a; Ismail et al. 2026). In this study as well, it was determined that there was a significant difference between maize, a monocot, and other dicot species regarding both heavy metal accumulation and translocation. Plants manage metals through uptake, transport, storage, and detoxification. Numerous studies have shown that monocotyledonous and dicotyledonous plants differ in anatomical and physiological characteristics, and that these differences can alter where and how much metal accumulates. For example, monocotyledonous plants generally accumulate less Pb in their roots compared to dicotyledonous plants. This may be attributed to the fact that dicotyledonous plants have more divalent cation-binding sites in their root tissues (Rahman et al. 2024). Many dicotyledonous plants strongly acidify the rhizosphere and secrete chelators under iron deficiency. In contrast, monocotyledonous grasses employ different iron strategies. This leads to distinct uptake pathways and the co-uptake of other metals via shared transporters (Wallace 2008; Andresen et al. 2018). Dicotyledonous plants typically secrete organic acids (citrate, malate), monocotyledonous plants secrete phytosiderophores, which alter metal chelation and availability at the root-soil interface (Balagopa et al. 2025). Due to these differences between monocotyledonous and dicotyledonous plants, it is natural that their potentials for heavy metal uptake and accumulation differ.

The primary route of entry of many heavy metals into the plant body is through the roots from the soil (Yuan et al. 2024). Therefore, heavy metal concentrations in soils are also important. Within the scope of the study, it was determined that the Sb concentration in soils ranged from 18700 ppb to 69700 ppb, the Se concentration ranged from 7770 ppb to 27,900 ppb, and Tl concentrations ranged from 5,650 ppb to 20,100 ppb. These values are well above the permitted limits. For example, in Italy, the permitted limit for Tl in soil is 2.0 mg kg⁻¹dw, and the limit for Sb is 10.0 mg kg⁻¹dw (Wei et al. 2024). The permitted Se concentration in soils is 10 mg/kg in countries such as Mongolia and France (Fordyce 2013; Bataa et al. 2022). Furthermore, when the results of this study were compared with similar studies, it was determined that the values obtained were higher than those obtained in similar studies. For example, a study conducted in China found average concentrations in soils to be 2.78 mg/kg for Sb and 0.84 mg/kg for Tl (Li et al. 2025). It has been reported that the Tl concentration in contaminated soils can reach up to 7 mg/kg (Karbowska 2016; Grösslová et al. 2018; Minnikova et al. 2023). In a study conducted in the Mediterranean region, the average Se concentration was found to be 0.43 mg.kg^-1in natural soils, 0.40 mg.kg^-1in agricultural soils, and 0.93 mg.kg^-1in industrial soils (Roca-Perez et al. 2010). A study conducted in mining areas in Peru reported that the average Se concentration was 1.1 mg/kg, exceeding the limit values set by both the Ministry of the Environment of Peru (MINAM) and the Canadian Council of Ministers of the Environment (CCME) (GómezOquendo et al. 2026).

One of the most important factors influencing heavy metal accumulation in plants is the concentration of these heavy metals in the soil (Wu et al. 2024; Sevik et al. 2026). Heavy metal contamination in soils, however, is shaped by the influence of numerous and interrelated factors. The most significant factor contributing to uncertainty in studies on this topic is the heterogeneity of the soil’s physicochemical properties. Consequently, inconsistent responses in soil adsorption capacity may be observed. Failure to account for these factors can lead to serious interpretation errors. The adsorption and desorption of heavy metals at the soil interface is a highly complex, nonlinear process influenced by the interactive effects of multiple physicochemical properties (e.g., initial concentration, ionic strength, and solid-liquid ratio). Understanding these nonlinear, interactive, and multifactorial effects is of great importance for accurately predicting the potential migration of heavy metals to plant roots. For example, clay particles can significantly alter the physicochemical environment (e.g., pore size distribution, moisture retention) that facilitates long-term metal retention (Wu et al. 2025a). Similarly, ion exchange capacity (IEC) has a significant effect in this process. IEC controls the amount of metal ions adsorbed onto biomaterials (Hubbe et al. 2011). For every mole of a divalent metal element adsorbed, one mole of Ca is displaced (Crist et al. 2003). In other words, depending on the valence of the metal species, it is expected that each adsorbed metal ion will displace other ions such as hydrogen or sodium (Hubbe 2013). Thus, the presence and concentration of other elements in the soil can significantly influence heavy metal uptake by plants (Hubbe et al. 2022; Ergül and Kravkaz Kuşçu 2024).

Studies have shown that contaminant behavior in the unsaturated zone is shaped not by individual chemical parameters but also by the combined effect of multiple environmental factors. Factors such as pH, oxidation-reduction potential (ORP), moisture content, and electrical conductivity jointly and simultaneously control contaminant distribution. Furthermore, it has been determined that these factors are spatially heterogeneous and interact with one another. In this context, the bioavailability of heavy metals in soil is similarly regulated not only by solubility parameters but also, and particularly, by the surface properties and distribution coefficients of reactive mineral phases such as iron (Fe), manganese (Mn), and aluminum (Al) oxides. These oxides can immobilize heavy metals by binding them through microscopic mechanisms such as adsorption, complexation, and surface precipitation, thanks to their high specific surface areas and variable surface charges. However, changes in environmental conditions (such as a decrease in pH or reduced redox conditions) can weaken these bonds and release metals back into the soluble phase. The combined variation in environmental factors causes contaminant concentrations to exhibit different responses across regions, and a single factor’s value can be associated with varying contaminant levels. This situation demonstrates that heavy metals retained on Fe-Mn-Al oxides do not exhibit static behavior; rather, they exist within a dynamic sorption–desorption equilibrium that depends on environmental conditions. Consequently, these microscopic processes directly influence metal concentrations in soil solution, thereby determining uptake by vegetables via the root system (Wu et al. 2026a).

Therefore, the accurate assessment of heavy metal bioavailability requires holistic approaches that consider mineral phases and environmental factors together and hierarchically. For example, soil pH plays a decisive role in the mobility of heavy metals and in associated risk assessments. However, studies have shown that the risk of heavy metal mobility, particularly in relation to pH, can be systematically overestimated, leading to significant deviations in soil quality assessments. This situation highlights the inadequacy of treating pH as a standalone control parameter. This is because interactions with pH, mineral phase equilibrium, complexation processes, and other environmental variables shape metal mobility. Consequently, risk assessments based on fixed threshold values or univariate approaches may overestimate or underestimate actual mobility, particularly under alkaline or variable pH conditions (Wu et al. 2025b). In this context, holistic assessment frameworks based on explainable modeling approaches that consider environmental factors collectively and interactively are critical for accurately and context-sensitively assessing heavy metal risk. However, current risk assessment approaches have significant limitations in explaining contaminant behavior, particularly in the unsaturated zone (vadose zone). This is because these methods primarily rely on generalized predictions based on individual parameters or limited hydrogeological variables, and they fail to represent the environment’s highly heterogeneous nature adequately (Chen et al. 2025; Liu et al. 2025). Indeed, studies have clearly demonstrated that contaminant concentrations cannot be reliably back-calculated from a single environmental factor, and that the same parameter values may correspond to different concentration scenarios. Furthermore, the extensive data requirements of traditional physical and mathematical models, along with their temporal and spatial limitations and their reductionist approach to complex processes, increase uncertainties in risk assessments. In this context, the joint and hierarchical evaluation of environmental factors (such as moisture content, pH, redox potential, and electrical conductivity) is of critical importance for capturing the multidimensional nature of contaminant transport (Wu et al. 2026b).

The study found high levels of Tl, Se, and Sb contamination in the soils of the study area. Studies conducted in the region have shown that heavy metals such as Cu, Ni, Cd, Zn, and Pb in the soil—originating from vehicle emissions, industrial processes, ferroalloy industries, and coal-fired power plants—are present at levels high enough to pose a risk to human health (Dışbudak et al. 2026). It has been determined that this situation leads to the accumulation of heavy metals, including Al, Cr, Cd, Ni, and Zn, at very high levels in vegetables grown in the region (Demirci et al. 2026; Sevik et al. 2026). It is recommended to use the latest soil remediation strategies to mitigate the risks posed by high levels of heavy metal contamination. For example, the use of new environmentally friendly solidification/stabilization materials could be recommended to reduce the bioavailability of heavy metals and prevent their entry into the food chain at the source. Studies have indicated that red mud, biochar, phosphate rock (Derakhshan Nejad et al. 2018), liming materials, phosphates, minerals, and various industrial byproducts (Lwin et al. 2018) have been identified as potential solutions for this purpose; however, recent studies have yielded promising results from innovative applications such as amino-modified gangue-derived zeolite (Zhu et al. 2026) and even fungal inoculation (Zhang et al. 2025). Such applications can immobilize heavy metals in the soil, thereby preventing their entry into the food chain.

The study found that TF values were generally higher in leaves than in other organs. The TF value did not exceed 1 in any vegetable fruit organ. The TF value is an important criterion indicating a species’ potential for heavy metal accumulation. The higher this value, the greater the species’ potential for heavy metal accumulation in that organ (Wang et al. 2019). Plants with TF values greater than 1 are considered strong accumulators of the relevant metals (Takarina and Pin 2017). Based on these results, it can be said that the plants studied accumulate Sb, Se, and Tl at lower levels in fruit organs compared to other organs. However, the values obtained in fruit are still well above the health threshold values.

CONCLUSIONS

The study determined that TF values in vegetables remained at low levels in above-ground organs and did not reach a value of 1 in fruit organs. At first glance, this situation may be considered as positive. This is because it is understood that Sb, Se, and Tl accumulate at lower levels in fruit organs compared to other organs. However, when the average values were examined, it became apparent that despite the low TF value, the concentrations of Sb, Se, and Tl in the fruit organs were very high relative to some regulatory limits. This situation poses a great risk to health.
The study found that the concentrations of Sb, Se, and Tl in plant organs were quite high. Although these elements are known to be extremely harmful to human health, limit values for Sb, Se, and Tl in vegetables have not yet been established in many countries. However, these elements are much more harmful than many other pollutants for which limit values are specified in relevant laws. The fact that limit values have not been legally determined limits the power of legal sanctions. For this reason, limit values for these elements in food products, including the vegetables studied, must be determined urgently.
It has been determined that the concentrations of Sb, Se, and Tl in the soils of the study area are much higher than those in plants. Although it is known that heavy metal pollution is high in the study area, intensive agriculture and animal husbandry are still practiced. This situation poses a major risk to food safety. Food safety must be ensured by taking the necessary measures urgently.
Among the vegetables studied, the highest values for all elements in the edible parts of the fruit were found in peppers and cucumbers, while the lowest were in corn. Based on these results, it is recommended to avoid growing peppers and cucumbers in the region or to cultivate them in clean soil, while prioritizing corn cultivation in open fields.

DATA AVAILABILITY

The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.

REFERENCES CITED

Andresen, E., Peiter E., and Küpper H. (2018). “Trace metal metabolism in plants” Journal of Experimental Botany 69(5), 909-954. https://doi.org/10.1093/jxb/erx465

Angon, P. B., Islam, M. S., Das, A., Anjum, N., Poudel, A., and Suchi, S. A. (2024). “Sources, effects and present perspectives of heavy metals contamination: Soil, plants and human food chain,” Heliyon 10(7), article e28357. https://doi.org/10.1016/j.heliyon.2024.e28357

Balagopal, A., Alva, A. K., Chandrasekhar, H., Thorat, S. A., Kaniyassery, A., Koley, A., Balachandranb, S., Govender, N., and Muthusamy, A. (2025). “The fate of heavy metals and metalloids in plant systems–a comprehensive review,” Toxicological & Environmental Chemistry, 107(6), 1114-1170. https://doi.org/10.1080/02772248.2025.2515403

Bataa, B., Motohira, K., Dugar, D., Sainnokhoi, T. A., Gendenpil, L., Sainnokhoi, T., Pelden, B., Beyene, Y., Ganzorig, Y. S., and Ikenaka, Y. (2022). “Accumulation of metals in the environment and grazing livestock near a Mongolian mining area,” Toxics 10(12), article 773. https://doi.org/10.3390/toxics10120773

Blain, R. (2022). “Thallium,” in: Handbook on the Toxicology of Metals (Fifth Edition), Academic Press, Cambridge, MA, USA, pp. 795-806. https://doi.org/10.1016/B978-0-12-822946-0.00028-3

Canturk, U., Koç, İ., Erdem, R., Ozturk Pulatoglu, A., Donmez, S., Ozkazanc, N. K., Sevik, H., and Ozel, H. B. (2025). “Climate-driven shifts in wild cherry (Prunus avium L.) habitats in Türkiye: A multi-model projection for conservation planning,” Forests 16(9), article 1484. https://doi.org/10.3390/f16091484

Canturk, U., Koç, İ., Ozel, H. B., and Sevik, H. (2024). “Identification of proper species that can be used to monitor and decrease airborne Sb pollution,” Environmental Science Pollution Research 31, 56056-56066. https://doi.org/10.1007/s11356-024-34939-7

Cebi Kilicoglu, M., and Zeren Cetin, I. (2024). “Determination of the suitable biomonitors to be used in monitoring the change for reducing the concentration of V in areas with high-level of air pollution,” Bulletin of Environmental Contamination and Toxicology 113(6), article 63. https://doi.org/10.1007/s00128-024-03966-y

Chen, X., Ren, Y., Li, C., Shang, Y., Ji, R., Yao, D., and He, Y. (2025). “Pollution characteristics and ecological risk assessment of typical heavy metals in the soil of the heavy industrial city Baotou” Processes 13(1), article 170. https://doi.org/10.3390/pr13010170

Cobanoglu, H., Sevik, H., and Koç, İ. (2023). “Do annual rings really reveal Cd, Ni, and Zn pollution in the air related to traffic density? An example of the cedar tree,” Water, Air and Soil Pollution 234(2), article 65. https://doi.org/10.1007/s11270-023-06086-1

Crist, D. R., Crist, R. H., and Martin, J. R. (2003). “A new process for toxic metal uptake by a kraft lignin,” Journal of Chemical Technology & Biotechnology: International Research in Process, Environmental & Clean Technology 78(23), 199-202. https://doi.org/10.1002/jctb.735

Demirci, H., Sevik, H., Koc, I., Ucun Ozel, H., Erdem, R., Adiguzel, F., Imren, E., and Ozel, H. B. (2026). “Organ-based accumulation, translocation, and associated health risk of Al, Ni, and Zn in tomatoes, peppers, eggplants, cucumbers, and corn from an industrial zone in Düzce, Türkiye,” Foods 15(2), article 196. https://doi.org/10.3390/foods15020196

Derakhshan Nejad, Z., Jung, M. C., and Kim, K. H. (2018). “Remediation of soils contaminated with heavy metals with an emphasis on immobilization technology,” Environmental Geochemistry and Health 40(3), 927-953. https://doi.org/10.1007/s10653-017-9964-z

Dışbudak, H., Şevik, H., Isinkaralar, K., Isinkaralar, O., Lakestani, S., Baghani, A. N., and Bayraktar, E. P. (2026). “Heavy metal contamination in industrial surface dust: sources, levels, and health risks in Düzce City, Türkiye,” Water, Air, & Soil Pollution 237(11), article 677. https://doi.org/10.1007/s11270-026-09358-8

Duri, L. G., Visconti, D., Fiorentino, N., Adamo, P., Fagnano, M., and Caporale, A. G. (2020). “Health risk assessment in agricultural soil potentially contaminated by geogenic thallium: Influence of plant species on metal mobility in soil-plant system,” Agronomy 10(6), article 890. https://doi.org/10.3390/agronomy10060890

Ejaz, U., Khan, S. M., Khalid, N., Ahmad, Z., Jehangir, S., Fatima Rizvi, Z., Lho, L. H., Han, H., and Raposo, A. (2023). “Detoxifying the heavy metals: A multipronged study of tolerance strategies against heavy metals toxicity in plants,” Frontiers in Plant Science 14, article 1154571. https://doi.org/10.3389/fpls.2023.1154571

Elik, A., Doğan, B., Demirbaş, A., Haq, H. U., and Altunay, N. (2024). “Investigation of use of hydrophilic/hydrophobic NADESs for selective extraction of As (III) and Sb (III) ions in vegetable samples: Air assisted liquid phase microextraction and chemometric optimization,” Food Chemistry 451, article 139538. https://doi.org/10.1016/j.foodchem.2024.139538

Erdem, R. (2023). “Changes in strontium levels in bark and over the past 40 years in the wood of trees exposed to high levels of air pollution,” BioResources 18(4). 8020-8036. https://doi.org/10.15376/biores.18.4.8020-8036

Erdem, R., Koç, İ., Çobanoğlu, H., and Şevik, H. (2024). “Variation of magnesium, one of the macronutrients, in some trees based on organs and species,” Forestist 74(1), 84-93. https://doi.org/10.5152/forestist.2024.23025

Ergül, H. A., and Kravkaz Kuşçu, İ. S. (2024). “Variations in Sr, Tl, and V concentrations at copper mining sites based on soil depth, plant species, and plant organ,” BioResources 19(4), 7931-7945. https://doi.org/10.15376/biores.19.4.7931-7945

Ergül, H. A., and Kravkaz Kuşçu, İ. S. (2025). “Variations in Cu, Co, Cr, Cd, and Pb concentrations based on soil depth, plant species, and plant organs at copper mining sites,” BioResources 20(3), 6116-6134. https://doi.org/10.15376/biores.20.3.6116-6134

Ertürk, N., Arıcak, B., Yiğit, N., and Sevik, H. (2024). “Potential changes in the suitable distribution areas of Fagus orientalis Lipsky in Kastamonu due to global climate change,” Forestist 74(2), 159-165. https://doi.org/10.5152/forestist.2024.23024

Filippini, T., Tancredi, S., Malagoli, C., Malavolti, M., Bargellini, A., Vescovi, L., Nicolini, F., and Vinceti, M. (2020). “Dietary estimated intake of trace elements: risk assessment in an Italian population,” Exposure and Health 12(4), 641-655. https://doi.org/10.1007/s12403-019-00324-w

Fordyce, F. M. (2013). “Selenium deficiency and toxicity in the environment,” in: Essentials of Medical Geology, Springer Dordrecht Heidelberg, New York, London, pp. 375-416. https://doi.org/10.1007/978-94-007-4375-5

Gad, S. (2014). “Antimony trioxide,” in: Encyclopedia of Toxicology (Third Edition), Elsevier, Amsterdam, Netherlands, pp. 277-279. https://doi.org/10.1016/B978-0-12-386454-3.00816-2

Ghoma, W. E. O., Sevik, H., and Isinkaralar, K. (2023). “Comparison of the rate of certain trace metals accumulation in indoor plants for smoking and non-smoking areas,” Environmental Science and Pollution Research 30(30), 75768-75776. https://doi.org/10.1007/s11356-023-27790-9

Gómez-Oquendo, G., Fernandez-Curi, M., Carrión-Carrera, G., Garcia, S., Velarde-Guillén, J., and Gómez-Bravo, C. (2026). “Heavy metals and selenium in pastures of a high Andean mining area and its relationship with their content in water and soil,” Journal of Ecological Engineering 27(1), 280-291. https://doi.org/10.12911/22998993/209671

Grösslová, Z., Vaněk, A., Oborná, V., Mihaljevič, M., Ettler, V., Trubač, J., Drahota, B., Penížek, V., Pavlů, L., Sracek, O., et al. (2018). “Thallium contamination of desert soil in Namibia: Chemical, mineralogical and isotopic insights,” Environmental Pollution 239, 272-280. https://doi.org/10.1016/j.envpol.2018.04.006

Gültekin, Y., Bayraktar, M. K., Sevik, H., Cetin, M., and Bayraktar, T. (2025). “Optimal vegetable selection in urban and rural areas using artificial bee colony algorithm: Heavy metal assessment and health risk,” Journal of Food Composition and Analysis 139, article 107169. https://doi.org/10.1016/j.jfca.2024.107169

Guney, D., Koc, I., Isinkaralar, K., and Erdem, R. (2023). “Variation in Pb and Zn concentrations in different species of trees and shrubs and their organs depending on traffic density,” Baltic Forestry 29(2), article id661. https://doi.org/10.46490/BF661

Gupta, M. and Gupta, S. (2017). “An overview of selenium uptake, metabolism, and toxicity in plants,” Frontiers in Plant Science 7, article 2074. https://doi.org/10.3389/fpls.2016.02074

Hadrup, N., and Ravn-Haren, G. (2020). “Acute human toxicity and mortality after selenium ingestion: A review,” Journal of Trace Elements in Medicine and Biology 58, article 126435. https://doi.org/10.1016/j.jtemb.2019.126435

Hubbe, M. A. (2013). “New horizons for use of cellulose-based materials to adsorb pollutants from aqueous solutions,” Lignocellulose 2(2), 386-411.

Hubbe, M. A., Hasan, S. H., and Ducoste, J. J. (2011). “Cellulosic substrates for removal of pollutants from aqueous systems: A review. 1. Metals,” BioResources 6(2), 2161-2287.

Hubbe, M. A., Szlek, D. B., and Vera, R. E. (2022). “Detergency mechanisms and cellulosic surfaces: A review,” BioResources 17(4), 7167-7249. https://doi.org/10.15376/biores.17.4.Hubbe

Isinkaralar, K., Isinkaralar, O., Koç, İ., Şevik, H., and Özel, H. B. (2025a). “Atmospheric trace metal exposure in a 60-year-old wood: A sustainable methodological approach to measurement of dry deposition,” International Journal of Environmental Research 19, article 112. https://doi.org/10.1007/s41742-025-00783-x

Isinkaralar, O., Isinkaralar, K., and Sevik, H. (2025b). “Health for the future: Spatiotemporal CA-MC modeling and spatial pattern prediction via dendrochrono-logical approach for nickel and lead deposition,” Air Quality, Atmosphere & Health 18, 1087-1099. https://doi.org/10.1007/s11869-025-01702-x

Ismail, M. D., Koç, İ., Erdem, R., Çobanoğlu, H., and Sevik, H. (2026). “Variations in barium concentrations over time in regions with elevated air pollution,” Forestist, article 76, article 0010, https://doi.org/10.5152/forestist.2026.25010

Junaid, M. D., and Af, G. (2024). “Global agricultural losses and their causes,” Bulletin of Biological and Allied Sciences Research 9, Article Number 66. https://doi.org/10.54112/bbasr.v2024i1.66

Karbowska, B. (2016). “Presence of thallium in the environment: Sources of contaminations, distribution and monitoring methods,” Environmental Monitoring and Assessment 188(11), article 640.

Kashyap, P., and Jain, M. (2024). “Concentration and non-carcinogenic risk assessment of heavy metals in leafy vegetables among different farming practices,” International Journal of Environmental Analytical Chemistry 105(18), 6415-6437. https://doi.org/10.1080/03067319.2024.2420828

Key, K., Kulaç, Ş., Koç, İ., and Sevik, H. (2023). “Proof of concept to characterize historical heavy-metal concentrations in atmosphere in North Turkey: Determining the variations of Ni, Co, and Mn concentrations in 180-year-old Corylus colurna L. (Turkish hazelnut) annual rings,” Acta Physiologiae Plantarum 45(10), article 120. https://doi.org/10.1007/s11738-023-03608-6

Koc, İ., Canturk, U., Cobanoglu, H., Kulac, S., Key, K., and Sevik, H. (2025a). “Assessment of 40-year Al deposition in some exotic conifer species in the urban air of Düzce, Türkiye,” Water, Air and Soil Pollution 236, article 76. https://doi.org/10.1007/s11270-024-07723-z

Koc, I., Cobanoglu, H., Canturk, U., Key, K., Kulac, S., and Sevik, H. (2024). “Change of Cr concentration from past to present in areas with elevated air pollution,” International Journal of Environmental Science and Technology 21(2), 2059-2070. https://doi.org/10.1007/s13762-023-05239-3

Koc, I., Cobanoglu, H., Canturk, U., Key, K., Sevik, H., and Kulac, S. (2025b). “Variation of 40-year Pb deposition in some conifers grown in the air-polluted-urban area of Düzce, Türkiye,” Environmental Earth Sciences 84(7), article 186. https://doi.org/10.1007/s12665-025-12211-6

Koç, İ., Sevik, H., Nechita, C., Canturk, U., Iordache, A. M., and Camarero, J. J. (2026). “Selenium bioaccumulation in industrialized urban forests: case study of five tree species used for phytoremediation,” Urban Ecosystems 29(2), article 73. https://doi.org/10.1007/s11252-026-01935-3

Kulac, S., Pulatoglu, A. O., Koç, İ., Sevik, H., and Ozel, H. B. (2025). “Assessing tree species for monitoring and mitigating strontium pollution in urban environments,” Water, Air and Soil Pollution 236, article 605. https://doi.org/10.1007/s11270-025-08244-z

Kuzmina, N., Menshchikov, S., Mohnachev, P., Zavyalov, K., Petrova, I., Ozel, H. B., Aricak, B., Onat, S. M., and Sevik, H. (2023). “Change of aluminum concentrations in specific plants by species, organ, washing, and traffic density,” BioResources 18(1), 792-803. https://doi.org/10.15376/biores.18.1.792-803

Lai, Z., He, M., Lin, C., Ouyang, W., and Liu, X. (2022). “Interactions of antimony with biomolecules and its effects on human health,” Ecotoxicology and Environmental Safety 233, article 113317. https://doi.org/10.1016/j.ecoenv.2022.113317

Li, Z., Cai, X., Wang, G., and Wang, Q. (2025). “Heavy metal contamination of guizhou tea gardens: Soil enrichment, low bioavailability, and consumption risks,” Agriculture 15(10), article 1096. https://doi.org/10.3390/agriculture15101096

Lin, T., Manan, A., Yang, S., Zhu, G., Wang, Y., Dai, Z., Vrieling, K., and Li, B. (2025). “Heavy metal pollution enhances pathogen resistance of an invasive plant species over its native congener,” Functional Ecology 39(4), 1096-1111. https://doi.org/10.1111/1365-2435.70011

Liu, Z., Mo, L., Liang, J., Shi, H., Yao, J., and Lun, X. (2025). “Heavy metal pollution and health-ecological risk assessment in agricultural soils: A case study from the yellow river bend industrial parks,” Toxics 13(10), article 834. https://doi.org/10.3390/toxics13100834

Lwin, C. S., Seo, B. H., Kim, H. U., Owens, G., and Kim, K. R. (2018). “Application of soil amendments to contaminated soils for heavy metal immobilization and improved soil quality – A critical review,” Soil Science and Plant Nutrition 64(2), 156-167. https://doi.org/10.1080/00380768.2018.1440938

Melgar-Quiñonez, H. (2025). “The multiple faces of food insecurity and hunger,” in: Food Security in the Era of the SDGs: So Close to the Deadline, So Far from the Targets?, Springer Nature, Cham, Switzerland, pp. 79-103.

Minnikova, T., Kolesnikov, S., Khoroshaev, D., Tsepina, N., Evstegneeva, N., and Timoshenko, A. (2023). “Assessment of the health of soils contaminated with Ag, Bi, Tl, and Te by the intensity of microbiological activity,” Life 13(7), article 1592. https://doi.org/10.3390/life13071592

Mutlu, E., and Aydın Uncumusaoğlu, A. (2018). “Analysis of spatial and temporal water pollution patterns in Terzi Pond (Kastamonu/Turkey) by using multivariate statistical methods,” Fresenius Environmental Bulletin 27(5), 2900-2912.

Özel, H. B., Şevik, H., Yıldız, Y., and Çobanoğlu, H. (2024). “Effects of silver nanoparticles on germination and seedling characteristics of Oriental beech (Fagus orientalis) seeds,” BioResources 19(2), 2135-2148. https://doi.org/10.15376/biores.19.2.2135-2148

Ozturk Pulatoglu, A., Koç, İ., Özel, H. B., Şevik, H., and Yıldız, Y. (2025). “Using trees to monitor airborne Cr pollution: Effects of compass direction and woody species on Cr uptake during phytoremediation,” BioResources 20(1), 121-139. https://doi.org/10.15376/biores.20.1.121-139

Rahman, S. U., Qin, A., Zain, M., Mushtaq, Z., Mehmood, F., Riaz, L., Naveed, S., Ansarih, M.J., Saeed, M., Ahmad, I. and Shehzad, M. (2024). “Pb uptake, accumulation, and translocation in plants: Plant physiological, biochemical, and molecular response: A review,” Heliyon 10(6). article e27724. https://doi.org/10.1016/j.heliyon.2024.e27724

Ren, X., Wang, Y., Sun, J., Liang, K., Zhu, H., Li, Y., Gao, J., Zhang, Y., Huang, S., and Zhu, D. (2024). “Legal standards for selenium enriched foods and agricultural products: Domestic and international perspectives,” Nutrients 16(21), article 3659. https://doi.org/10.3390/nu16213659

Roca-Perez, L., Gil, C., Cervera, M. L., Gonzálvez, A., Ramos-Miras, J., Pons, V., Bech., J., and Boluda, R. (2010). “Selenium and heavy metals content in some Mediterranean soils,” Journal of Geochemical Exploration 107(2), 110-116.

Şahin, S., and Türksoy, V. A. (2024). “The evaluation of potential toxic metal levels of various drugs used in children,” Journal of Health Sciences and Medicine 7(1), 39-46. https://doi.org/10.32322/jhsm.1356020

Şen, G., Güngör, E., and Şevik, H. (2018). “Defining the effects of urban expansion on land use/cover change: A case study in Kastamonu, Turkey,” Environmental Monitoring and Assessment 190(8), article 454. https://doi.org/10.1016/j.gexplo.2010.08.004

Şen, S. G. (2025). “Long-term monitoring of thallium uptake and phytoremediation potential of Robinia pseudoacacia,” Turkish Journal of Agriculture-Food Science and Technology 13(10), 3026-3031. https://doi.org/10.24925/turjaf.v13i10.3026-3031.8041

Sevik, H., Koç, İ., and Cobanoglu, H. (2024b). “Determination of some exotic landscape species as biomonitors that can be used for monitoring and reducing Pd pollution in the air,” Water, Air, and Soil Pollution 235(10), 1-12. https://doi.org/10.1007/s11270-024-07429-2

Sevik, H., Koç, İ., Cregg, B., and Nzokou, P. (2025). “Tissue-specific barium accumulation in five conifer species: A 40-year dendrochemical assessment from a polluted urban environment,” Environmental Geochemistry and Health 47(9), 1-13. https://doi.org/10.1007/s10653-025-02679-3

Sevik, H., Koc, I., Ucun Ozel, H., Adiguzel, F., Erdem, R., Imren, E., Ozturk Pulatoglu, A., and Ozel, H. B. (2026). “Changes in Cr and Cd concentrations in certain crops based on species and organ, and their translocation within plants,” Horticulturae, 12(4), article 400. https://doi.org/10.3390/horticulturae12040400

Şevik, H., Yildiz, Y., and Özel, H. B. (2024). “Phytoremediation and long-term metal uptake monitoring of silver, selenium, antimony, and thallium by black pine (Pinus nigra Arnold),” BioResources 19(3), 4824-4837. https://doi.org/10.15376/biores.19.3.4824-4837

Sharma, T., Mrabet, R., Singh, A., Kumar, N., Baghla, D., Kumar, S., Rana, B. B., and Chauhan, G. (2024). “Global hunger: The need for smart and sustainable agriculture,” in: Sustainable Green Nanotechnology, CRC Press, London, UK, pp. 129-151.

Shuo, W., Peishan, H., Chao, Z., Wei, Z., Xiaoyang, C., and Qing, Z. (2024). “Novel strategy to understand the aerobic deterioration of corn silage and the influence of Neolamarckia cadamba essential oil by multi-omics analysis,” Chemical Engineering Journal 482, article 148715. https://doi.org/10.1016/j.cej.2024.148715

Şimşek, A., Ustaoğlu, F., and Mutlu, E. (2025). “A comprehensive study of water quality in the Western Black Sea: Implementation of prospective human health risk assessment in Kastamonu, Turkey,” Environmental Monitoring and Assessment 197(6), article 699. https://doi.org/10.1007/s10661-025-14172-6

Takarina, N. D., and Pin, T. G. (2017). “Bioconcentration factor (BCF) and translocation factor (TF) of heavy metals in mangrove trees of Blanakan fish farm,” Makara Journal of Science 21(2), 77-81. https://doi.org/10.7454/mss.v21i2.7308

Velilla, E., Snethlage, J., Poelman, M., van Der Meer, I. M., van Der Werf, A., Deolu‐Ajayi, A. O., and van Belzen, J. (2025). “Too salty to farm: Rethinking coastal land use in response to soil salinization,” Restoration Ecology 33(4), article e70006. https://doi.org/10.1111/rec.70006

Wallace, A. (2008). “Some physiological aspects of iron deficiency in plants,” Journal of Plant Nutrition 3(1-4), 637-642. https://doi.org/10.1080/01904168109362866

Wang, Z., Liu, X., and Qin, H. (2019). “Bioconcentration and translocation of heavy metals in the soil-plants system in Machangqing copper mine, Yunnan Province, China,” Journal of Geochemical Exploration 200, 159-166. https://doi.org/10.1016/j.gexplo.2019.02.005

Wei, X., Nicoletto, C., Sambo, P., Liu, J., Wang, J., Petrini, R., and Renella, G. (2024). “Thallium uptake and risk in vegetables grown in pyrite past-mining contaminated soil amended with organic fertilizer (compost): A potential method for Tl contamination remediation,” Science of The Total Environment 908, article 168002. https://doi.org/10.1016/j.scitotenv.2023.168002

Wu, Y., Yu, J., Huang, Z., Jiang, Y., Zeng, Z., Han, L., Deng, S., and Yu, J. (2024). “Migration of total petroleum hydrocarbon and heavy metal contaminants in the soil–groundwater interface of a petrochemical site using machine learning: Impacts of convection and diffusion,” RSC Advances 14(44), 32304-32313. https://doi.org/10.1039/D4RA06060A

Wu, Y., Yu, J., Zeng, Z., Huang, Z., Jiang, H., Wang, P., Deng, S., Han, L., Huangpeng, X., Jiang, Y., and Zhu, W. (2025a). “Multi-factor interaction perspective: machine learning-based analysis of Ni²⁺ adsorption onto soil,” Environmental Geochemistry and Health 47(7), article 276. https://doi.org/10.1007/s10653-025-02592-9

Wu, Y., Zeng, Z., Teng, R., Yu, J., Guo, G., Huang, P., Huang, Z., and Deng, S. (2025b). “pH-dependent overestimation of heavy metals mobility risk in soils: Implications for soil quality assessment” Journal of Hazardous Materials 2025, article 140792. https://doi.org/10.1016/j.jhazmat.2025.140792

Wu, Y., Li, J., Teng, R., Zeng, Z., Yu, J., Zhao, X., Li, Y., Huang, P., and Deng, S. (2026a). “Effects of iron, manganese, and aluminum oxides on soil cadmium distribution coefficient: A multi-scale analysis based on explainable machine learning,” Journal of Hazardous Materials, article 141702. https://doi.org/10.1016/j.jhazmat.2026.141702

Wu, Y., Zeng, Z., Teng, R., Yang, J., Yu, J., Sun, H., . Deng, S., Huang, P., Luo, J., Wu, Y. and Zhao, X. (2026b). “Buffering failure of the ratio of secondary to primary phases: Risk overestimation of soil heavy metals under alkaline conditions,” Journal of Hazardous Materials 507, article 141844. https://doi.org/10.1016/j.jhazmat.2026.141844

Xing, Y., and Wang, X. (2024). “Precision agriculture and water conservation strategies for sustainable crop production in arid regions,” Plants 13(22), article 3184. https://doi.org/10.3390/plants13223184

Yaşar İsmail, T. S., İsmail, M. D., Çobanoğlu, H., Koç, İ., and Sevik, H. (2024). “Monitoring arsenic concentrations in airborne particulates of selected landscape plants and their potential for pollution mitigation,” Forestist 75, 1-6.

Yiğit, N. (2024). “Determination of sixteen woody species’ ability to sequester Sr, Mo, and Sn pollutants,” BioResources 19(4), 7842-7855. https://doi.org/10.15376/biores.19.4.7842-7855

Yuan, Z., Cai, S., Yan, C., Rao, S., Cheng, S., Xu, F., and Liu, X. (2024). “Research progress on the physiological mechanism by which selenium alleviates heavy metal stress in plants: A review” Agronomy 14(8), article 1787. https://doi.org/10.3390/agronomy14081787

Zeren Cetin, I., Ozel, H. B., Sevik, H., Canturk, U., Varol, T., Atesoglu, A., Kocan, N., and Zeren, D. B. (2025). “Potential altitude change of oriental spruce in Türkiye due to global climate change,” Acta Geophysica 73(6), 6305-6314. https://doi.org/10.1007/s11600-025-01699-y

Zhang, H., Xu, R., Quan, Y., Xue, D., Hu, L., Yang, Y., Dong, Y., Wang, W., Bo, H., Zhang, Q., Xu, M., and Jin, D. (2026). “Indigenous fungi inoculation drives organic carbon accumulation and phosphorus transformation in coal gangue-based artificial soil: role of mineral-bioactivation,” Frontiers in Microbiology 17, article 1758978. https://doi.org/10.3389/fmicb.2026.1758978

Zhu, W., Xiong, J., Huangfu, Z., Yu, J., Hang, P., Han, C., Chen, M., Li, B., Gao, T., Yang, J., Du, Y. (2026). “Amino-modified gangue-derived NaX zeolite for enhanced stabilization of lead and cadmium in contaminated soils: synthesis, performance, and leaching stability,” Environmental Geochemistry and Health 48(4), article 192. https://doi.org/10.1007/s10653-026-03090-2

Article submitted: December 31, 2025; Peer review completed: April 25, 2026; Revisions accepted: May 21, 2026; Published: May 26, 2026.

DOI: 10.15376/biores.21.3.6365-6384