Heavy metals in food crops: Health risks, fate, mechanisms, and management

Assessment of Heavy Metal Contamination and Health Risk Associated with Cultivated Vegetables along Dhaka-Mymensingh Highway, Bangladesh

The purpose of this research work is to evaluate the degree of eight heavy metals (Fe, Mn, Cu, Zn, Cd, Pb, Cr, and Ni) contamination and health risks of three regularly consumed vegetables (papaya, bottle gourd, and esculent) near one of Bangladesh's busiest roadways, the Dhaka-Mymensingh highway. The heavy metal concentrations in 45 vegetable samples were analyzed using an atomic absorption spectrometer (AAS). These samples were collected from five different sampling sites based on various land use patterns adjacent to the highway. The average concentrations (mg/kg) of Cu, Fe, Mn, Zn, Cr, and Ni were found to be 9.86, 246.8, 16.9, 28.0, 9.02, and 2.02, respectively, for papaya; 14.9, 281.2, 387.6, 49.0, 10.1, and 2.92, respectively, for bottle gourd; and 17.6, 183.4, 107.2, 80.7, 7.98, and 2.34, respectively, for esculent. The mean concentrations of Cr, Zn, and Mn in papaya, bottle gourd, and esculent were higher than the acceptable limit. Correlation analysis revealed a significant positive correlation between Fe-Cu, Zn-Fe, Cu-Fe, and Fe-Zn in papaya; Cu-Zn, Fe-Cr, Zn-Ni, and Cr-Fe in bottle gourd; and Mn-Cr, Mn-Ni, Mn-Fe, and Cr-Ni in esculent, thereby indicating their common anthropogenic sources like agricultural activities, waste from the commercial area, filling station, and vehicular emissions. Health risk assessment through target hazard quotient (THQ) revealed the highest THQ of 9.52 for Cr in bottle gourd, which poses a high non-carcinogenic health risk to the localities upon the intake of these contaminated vegetables. Target cancer risk (TCR) was found to be highest for Cr in papaya (0.013) and bottle gourd (0.014). TCR trends were found for Cr in the following order: bottle gourd > esculent > papaya. This study contributed the greatest concern for both carcinogenic and non-carcinogenic health impacts through ingesting contaminated vegetables.

Concentration of Potentially Toxic Elements (PTEs) in Rapid Coffee Products in Bandar Abbas, Iran: Probabilistic Non-Carcinogenic and Carcinogenic Risk Assessment

Coffee is one of the most widely consumed beverages in the world. However, coffee plants are often exposed to potentially toxic elements (PTEs) pollution. The main aims of current study were to detect the PTEs in instant coffee and health risk assessment of consumers in Bandar Abbas city. To achieve this, 40 samples of instant coffee were randomly collected from various points in the city in 2023 and PTEs concentrations were measured using flame atomic absorption spectrometry (FAAS). The non-carcinogenic and carcinogenic risks were calculated using Monte Carlo simulation (MCS) method. The concentrations of Fe and Cu were higher than other PTEs, equaling 404.41 mg/kg and 0.0046 mg/kg, respectively. The non-carcinogenic risk assessment revealed that THQ (Fe > Pb > As > Cd > Ni > Cu) and TTHQ levels were less than 1 based on the 95% percentile in adults and children, indicating there is no possibility of a non-carcinogenic risk associated with instant coffee. The carcinogenic risk due to inorganic As in instant coffee was acceptable (2.63E-5 and 1.27E-5 based on the 95% percentile for adults and children, respectively), therefore PTEs in instant coffee do not endanger the health of consumers.

Mitigative effects of didymin against cadmium-induced renal injury via regulating Nrf-2/Keap-1, apoptosis, inflammation and oxidative stress

BACKGROUND

Cadmium (Cd) is a toxic heavy metal present in environment that has potential to instigate renal toxicity. Didymin (DDM) is a natural flavone, which shows anti-oxidant, anti-inflammatory and antiapoptotic nature. Therefore, the current study was formulated to appraise attenuative potential of DDM against Cd instigated nephrotoxicity.

METHODS

Forty-eight albino rats were divided into four equal groups, including control, Cd (5 mg/kg) inebriated group, Cd + DDM (5 mg/kg + 1 mg/kg) concurrent-treated group, as well as DDM (1 mg/kg) alone treated group. The trial was conducted for 30 days and then the rats were anesthetized, decapitated and further analyses were performed.

RESULTS

The results demonstrated that Cd treatment lowered the expressions of Nrf-2 and its anti-oxidant genes while escalating Keap-1 expression. Cd exposure downregulated the activities of antioxidant enzymes, SOD, GSR, CAT, HO-1, GPx, GST & GSH contents, while the levels of MDA and ROS were escalated. Furthermore, Cd exposure lowered the levels of creatinine clearance and albumin, while increasing the levels of urobilinogen, urinary proteins, urea, creatinine, NGAL and KIM-1. Moreover, Cd intoxication also augmented the levels of inflammatory indices including, IL-1β, NF-κB, TNF-α, IL-6 and COX-2. Additionally, Cd exposure reduced the expressions of Bcl-2, while increasing Bax and caspase-3 expressions. In addition to this, Cd also provoked multiple histological injuries in the renal tissues of the rats. However, DDM supplementation markedly recovered the renal tissues from the Cd induced damages.

CONCLUSION

In conclusion, DDM protected the renal tissues from Cd-provoked damages due to its antiapoptotic, anti-oxidant and anti-inflammatory efficacy.

Influence of irrigation with oxygen plasma treated metal contaminated water on plant growth

This study aimed to evaluate the effects of plasma treated metal contaminated water, used for irrigation, on plant growth. Zinc (Zn) is a commonly used metal that can enter the environment through industrial processes. It may be released as particles into the atmosphere or discharged as wastewater into waterways or the ground. Exposure to large amounts of zinc, even for a short duration, can seriously impact human health. In this experiment, three different DBD (dielectric barrier discharge) O2 plasma treated zinc contaminated water and a control (tap water) were used, with Arabidopsis thaliana as the model plant. The treatments were: (i) Control, (ii) Zn water, (iii) Zn + O3(30 min), and (iv) Zn + O3(60 min). Arabidopsis plant exhibited maximum growth in the Zn + O3(30 min) treatment. All growth parameters, except leaf area, followed this trend: Zn + O3(30 min) > Control > Zn water > Zn + O3(60 min). Gene expression analysis revealed that reduced metal ion stress and controlled oxidation due to active oxygen species contributed to favorable/improved growth of Arabidopsis in the Zn + O3(30 min) treatment. Therefore, 30 min of DBD O2 plasma treated zinc contaminated water [Zn + O3(30 min)] can mitigate the adverse effects of excess zinc ions and promote the growth of Arabidopsis plants.

Visualization of Hg2+ Stress on Plant Health at the Subcellular Level Revealed by a Highly Sensitive Fluorescent Sensor

The presence of Hg2+ causes substantial stress to plants, adversely affecting growth and health by disrupting cell cycle divisions, photosynthesis, and ionic homeostasis. Accurate visualization of the spatiotemporal distribution of Hg2+ in plant tissues is crucial for the management of Hg pollution; however, the related research is still at its early stage. Herein, a small-molecule amphiphilic fluorescent probe (termed LJTP2) was developed for the specific detection of Hg2+ with a high sensitivity (~16 nM). Fluorescent imaging applications with LJTP2 not only detected the dynamic distribution of Hg2+ within plant cells at the subcellular level but also enabled the understanding of cell membrane health under Hg2+ stress. This study introduces a valuable imaging tool for elucidating the molecular mechanism of Hg2+ stress in plants, demonstrating the potential of the application of small-molecule fluorescent probes in plant science.

A rapid, multiplexed and naked-eye readable paper assay for detecting heavy metal pollution in food using a catalytic colorimetric reaction

Heavy metal contamination is a serious food safety issue. Herein, we report a rapid, multiplexed and naked-eye readable method for detecting heavy metal pollution in food samples using a cheap colorimetric paper, including milk. We leverage the urease catalysis reaction to amplify the presence of heavy metal ions, Hg2+ and Pb2+, by exploiting their strong inhibitory effect on urease. Integrating with a paper-folding strategy, the visual assay realizes rapid detection of over 10 samples within 5 min. It allowed to detection of Hg2+ as low as 0.1 nM and Pb2+ as low as 2 μM, and the results can be read out either by naked eyes or smartphones. Results can be visually interpreted with the naked eye or a smartphone, making it practical for on-site testing and ensuring the safety of dairy products against metal contamination.

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.

Dirty Environment, Dark Mood: Exploring the Link Between Perceived Environmental Pollution and Depression Risk

To explore the impact of perceived environmental pollution on individual depression risk and the mechanisms involved, particularly the mediating roles of health level and life confidence. Ordinary least squares, Ologit, and Oprobit models were employed to analyze data from the 2020 China Family Panel Studies to test the hypothesized relations outlined above. The findings indicate that perceived environmental pollution significantly increases depression risk (β = 0.052, p < 0.01). Both health level and life confidence serve as mediators in this relationship, forming a serial mediation mechanism. This study reveals the negative impact of perceived environmental pollution on mental health. It emphasizes the importance of improving public health levels and life confidence and provides an evidence base for related policies.

Quantitative analysis and risk assessment of heavy metal pollution in an intensive industrial and agricultural region

In recent decades, the study of heavy metal pollution has garnered significant attention owing to the advancement of industrialization. To explore the contamination of heavy metals in an intensive industrial and agricultural region in Shandong province, China, 101 surface soil samples and 80 samples of edible crop parts were collected from the vicinity of an industrial park. A positive matrix factorization-multilayer perceptron model (PMF-MLP) was established to identify the sources of heavy metals and quantify the complex relationships between pollution sources, crop types, and pollution status. Index and human health-risk methods were used to assess the heavy metal pollution. The results show that (1) lead (Pb) and cadmium (Cd) in the soil may originate from industrial-traffic mixed pollution sources in the surrounding industrial park, whereas copper (Cu) is derived from agricultural pollution sources in the southern farmland. (2) Pollution is primarily concentrated in the central and northern regions of the study area. The analysis of the PMF-MLP model indicates that human activities account for the majority (79.6 %) of the risk of associated with heavy metal pollution. Among them, industrial, traffic, and agricultural mixed pollution sources, agricultural pollution sources associated with northern livestock farms, and crop types contribute to 49.3, 24.5, and 5.80 % of the total risk, respectively. (3) The oral intake of heavy metals represents the primary route of entry into the human body. Cd and Cu are the most significant elements associated with adverse human health, with Cd and Cu contributing the most to carcinogenic and non-carcinogenic risks in both adults and children, respectively. The results will provide references for the formulation of control strategies to curb heavy metal pollution.

Heavy metal contamination of vegetables in China: status, causes, and impacts

Exposure to heavy metals from vegetable consumption poses a serious health risk to the Chinese population. The lack of knowledge on the overall status of vegetable contamination at the national level hinders the development of national regulations on preventing heavy metal exposure. To address this issue, the study presents an overview of heavy metal contamination in vegetables across China based on 96 peer-reviewed studies published over the past 20 years. The average concentrations of As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn in the edible parts of vegetables are 3.7 ± 12.9, 1.6 ± 4.0, 4.3 ± 10.3, 18.6 ± 27.6, 164 ± 281, 4.5 ± 5.5, 7.7 ± 23.7, and 105 ± 283 mg kg-1 (dry weight), respectively. The associated daily exposures are 0.1-5.7, 0.1-1.7, 0.6-4.2, 4.1-20.5, 26-107, 0.7-3.0, 0.4-16.0, and 13-93 μg kg-1 d-1, respectively. General linear models explained 80%, 44%, 83%, 79%, 64%, 81%, 65%, and 55% of the total variance in As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn concentrations in vegetables, respectively, based on vegetable type and selected geological, meteorological, economic, and environmental factors. Agroforestry is the main source of heavy metal contamination, accounting for 3%-30% of the total variance in heavy metal concentrations in vegetables. Mining, smelting, refining, metalworking, and electrical equipment manufacturing are important source of As, Cr, Cu, Mn, Ni, and Pb, accounting for 7%-17% of the total variance.

A Systematic Review on Heavy Metals Contamination in Bangladeshi Fruits and Their Associated Health Risks

In Bangladesh, ensuring food safety from various hazardous contaminants, including heavy metals in different food items, has become a significant policy concern. This systematic review aimed to summarize the heavy metal contamination of locally produced fruits in Bangladesh and estimate the subsequent health risks of heavy metals upon consumption of reported fruits. A total of 1458 articles were retrieved from PubMed, Google Scholar, and manual Google searching, of which 10 were included in the current review. Health risks associated with the intake of these metals were evaluated in terms of estimated daily intake and carcinogenic and noncarcinogenic risks by target cancer risk, target hazard quotient, and hazard index. The heavy metal concentrations (mg/kg of fresh edible weight) in the fruits were As (ND-1.3), Cd (ND-0.64), Pb (ND-2.4), Cr (ND-2.5), Mn (ND-570), Ni (ND-9.0), Cu (0.5-32), Zn (0.24-134), and Hg (ND-0.006). The concentration of different heavy metals in various fruits particularly in the banana, mango, jackfruit, guava, litchi, blackberry, lemon, and tamarind fruit, were higher than the maximum acceptable concentration. All of the metals were consumed daily in amounts below the maximum tolerated daily intake for all fruits. The results showed that, except for As, all metals' target hazard quotients were below the safety level. The target hazard quotient for strawberry, guava, mango, pineapple, banana, and papaya surpassed the safety level. On the other hand, the target cancer risk levels of As, Cd, Cr, and Ni were higher than the acceptable levels for most fruit items, suggesting that long-term exposure to these toxic metals may raise the risk of developing various malignancies, including stomach and lung cancer. A more integrated strategy to reduce the contamination burden of heavy metals in fruits is important to conserve the health of the population.

Rice and heavy metals: A review of cadmium impact and potential remediation techniques

In recent decades, the menace of heavy metals to food security and human health has become a serious concern. Given its status as the primary provider of food globally, significant research has been done to ensure the safe cultivation of rice, particularly concerning the mitigation of heavy metal contamination. Therefore, this article focuses on the effects and poisoning mechanism of heavy metals, primarily cadmium, on rice. Here, we have discussed the absorption, translocation, and toxicity mechanism of cadmium in rice and the external factors, such as soil pH, organic matter, microorganisms, and climate change, associated with this pollution. It also discusses in detail the sources of heavy metal pollution and the countermeasures against their effects on rice, such as the use of nanoparticles, biochar, plant growth regulators, nutrient management, molecular approaches, tolerant genotypes, and associated genes/proteins. Lastly, a number of significant research prospects concerning heavy metals in rice fields were suggested for future investigation. This review serves as a crucial reference for addressing the issue of heavy metal contamination in paddy fields, ensuring the safe cultivation of rice, promoting environmentally friendly fish farming practices, and safeguarding future food security and human health.

Molecular characterization of a phytomelatonin receptor and its overexpression as a 'one-stop' solution to nullify the toxic effects of hazardous inorganic agro-pollutants

Inorganic toxicants like arsenic, copper, lead, nickel and fluoride are notorious agro-pollutants, impeding plant-productivity due to high bioaccumulation. Consumption of such contaminated plant-parts causes irreversible health hazards. We identified a G-protein coupled receptor, serving as melatonin receptor (MelR) in Nicotiana tabacum (NtMelR), that relayed downstream-signaling after binding melatonin, a potent growth regulator and antioxidant. Using inhibitors against G-protein-α and NADPH oxidase (NOX), and by supplementing epidermal strips with exogenous melatonin and H2O2, we established that NtMelR acted upstream of reactive oxygen species (ROS) production in guard cells. Transgenic lines of N. benthamiana overexpressing NtMelR maintained constitutive melatonin-signaling via MelR, leading to efficient stomatal closure for preventing desiccation during oxidative stress. Melatonin biosynthesis was stimulated in the transgenic lines, exposed to different agro-pollutant stress, providing a steady-abundance of ligand for NtMelR binding and activating the defence machinery, comprising of enzymatic-antioxidants like superoxide dismutase, catalase, peroxidases and glyoxalases. Due to increased antioxidant capacity, the transgenics exhibited less molecular injuries (electrolyte leakage, methylglyoxal accumulation and NOX activity), generated less ROS and bioaccumulated significantly lower levels of toxicants. Unlike the wild-type counterparts, the transgenics maintained high relative water content, photosynthetic efficiency, could flower abundantly and even produce seeds. Overall, we established that overexpression of NtMelR is a single-window strategy to generate multiple-stress tolerant genotypes.

Bioinspired metal-organic frameworks for aqueous environment decontamination: from laboratory scale to real-world technologies

Concerns regarding water contamination are escalating due to the increasing presence of all types of pollutants in water sources, which pose serious health risks to humans and wildlife, disrupt ecosystems, and compromise the safety of drinking water. Addressing water contamination requires stringent regulations and increased public awareness, but especially, it requires the development of highly effective new technologies to decontaminate those aquatic environments that have been already polluted over the past few decades. Since the emergence of metal-organic frameworks (MOFs), their use has been proposed in a multitude of fields, given their unique physicochemical properties, and one of the fields where a realistic application can be expected in the near future is water remediation. In particular, oxamidato-based biological MOFs (bioMOFs) have demonstrated, in recent years, unique properties such as extraordinary robustness, crystallinity and water- and pH-stability as well as very easy functionalisation, which situates them among the best adsorbents for this environmental purpose. In this review, we have summarised the most remarkable results of oxamidato-based bioMOFs in the field of water remediation. Moreover, on the basis of the reported results, we dare to suggest the real possibilities of application, in relevant real-world environments, for these and other MOFs, as well as the main obstacles that will need to be overcome, aiming to widening the range of applicability of MOFs and making solid headway towards sustainable development.

Unveiling the threat of lead, cadmium, and nickel toxicity in salient commercially grown vegetables in Kolkata, India

Heavy metal (HM) contamination in agricultural crops, particularly vegetables, is a matter of global concern due to its potential health risks to humans. Commercially growing vegetable samples were analyzed for heavy metals using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) for leafy greens and fruit vegetables collected during winter from highly susceptible zones, in the vicinity of Kolkata. ICP-MS is advantageous over Atomic Absorption Spectrometry (AAS) for unparalleled accuracy, efficiency, faster turnaround time, cost-effectiveness, etc. The results revealed that Saturia (Pb, 0.1-0.3 mg/Kg; Cd, 0.1 mg//kg; Ni, 0.1-0.2 mg/Kg) and Dhapa (Pb, 0.2-1.3 mg/Kg; Cd, 0.07-0.2 mg/Kg; Ni, 0.1-0.3 mg/Kg) have shown significantly higher heavy metal accumulation in the edible part of the vegetables. Leafy vegetables such as red spinach, bathua, and coriander have shown much higher accumulation (Pb, 0.1-1.3 mg/Kg; Cd, 0.07-0.2 mg/Kg; Ni, 0.1-0.2) than fruit vegetables in the edible parts, except capsicum from Chelegualia (Pb, 0.11 mg/Kg; Cd, 0.135 mg/Kg; 0.18 mg/Kg). Translocation factor (< 1.5) and bioaccumulation factor (< 1.2) are observed to have lower values for Dhapa, Saturia, Jirangachi, Raghunathpur, and Kulti compared to Chelegualia, Gabtala, and Vogalirampur. The health-risk effect Hazard Index is greatest in Dhapa, Saturia, and Chelegualia regions. Pb in red spinach and mustard in Dhapa had a higher hazard quotient. The study highlights the need for monitoring the regulation of HM contamination in commercially growing belts near Kolkata to ensure food safety and protection of human health. Putative remedial strategies like phytoremediation involving hyperaccumulators, soil amendments like biochar, and microbial mechanisms for diminishing the translocation of HMs to edible commodities are being explored presently.

Risk assessment and source tracing of heavy metals in major rice-producing provinces of Yangtze River Basin

Heavy metal contamination in rice constitutes a global concern, its migration is influenced by environmental factors as well as socioeconomic activities. However, tracing its origins within complex context remains a significant challenge. The concentrations of five heavy metals (HMs) in 1754 samples from major rice-producing provinces were analyzed, and their pollution characteristics, associated health risks and temporal-spatial variations were discussed. Potential sources were classified by positive matrix factorization (PMF) models, considering correlations with human activities, climatic conditions, and interaction within ecosystems. The results showed that cadmium (Cd) and arsenic (As) were the primary contributors to pollution risk, with the borders between Hunan and central Jiangxi, as well as northeast Jiangxi and northwest Anhui, identified as critical areas for risk management. PMF serves as an effective methodology for identifying the sources of HMs in rice. Industrial activities, particularly mining and transportation, represent the predominant sources of Cd and lead (Pb), accounting for 75.6 % of the total pollution. Conversely, agricultural practices and natural factors constitute the primary sources of As, contributing to the remaining 24.4 %. It is noteworthy that the rapid industrial development has facilitated the expansion of the freight industry, consequently increasing the risk associated with Pb. Furthermore, effective governmental policy management can mitigate the risks related to HMs. Our research highlights the influence of industrial development on HMs risk in various regions and the moderating role of policy formulation. SYNOPSIS: Minimal research exists on the impact of regional economic development on heavy metals in rice. This study reports mining and transportation activities increase carcinogenic risks caused by Cd and Pb in rice during industrialization.

Evaluating heavy metals-related risk in staple crops and making financing strategy for corresponding soil remediation across China

China's staple crops face heavy metal (HMs) contamination, a widespread issue lacking a national assessment. We used machine learning (ML) to assess risks of 8 HMs in rice, wheat, and maize, and estimated a financing strategy for soil remediation via linear optimization and computable general equilibrium (CGE). The accumulation of HMs in crops depends on Soil-HMs, climate, soil properties, and crop types. Cd and Hg pose major soil pollution risks, while Cr, Pb, and Cd are the most threatening in crops. High-risk zones are located at the warm temperature and subtropical zones, with wheat most vulnerable. Over a quarter (26.77 %) of the nation's croplands are classified as high-risk, with a significant 60.89 % falling into the medium-risk category, leaving merely 12.34 % of the agricultural land in a safe condition. The estimated remediation cost is 58596.73 billion RMB and the crop loss is 808.03 billion RMB in a ten-year remediation period at the context of secure crop supply. The reallocation of social investment rather than raising new taxation for the remediation is beneficial to the GDP increase and social welfare despite some loss in the household income and enterprise income. This study provides a comprehensive evaluation for Crop-HMs risk and remediation policy, crucial for national crop security.

Toxic metals in rice among Asian countries: A review of occurrence and potential human health risks

Heavy metals such as cadmium (Cd), arsenic (As), and lead (Pb) pose significant health risks, particularly in Asia, where rice is a staple for nearly three billion people. Despite their known dangers and environmental prevalence, studies addressing their concentrations in rice across different regions and the associated health implications remain insufficient. This review systematically examines the occurrence and impact of these toxic elements, filling a critical gap in the literature. Data from seven countries indicate mean concentrations in the order of Pb > As>Cd, with values of 0.255 ± 0.013, 0.236 ± 0.317, and 0.136 ± 0.150 mg/kg, respectively. Uncertainty analysis shows extensive variability, especially for Cd, with a 95% confidence interval range from 0.220 to 0.992 mg/kg. The typical daily intake of heavy metals through rice consumption, in the order of As>Cd > Pb, frequently exceeds safe limits. Generally, data obtained from various studies showed that children were more prone to heavy metal contamination through rice consumption than adults. This review is fundamental for ongoing monitoring, future research, and management strategies to reduce heavy metal contamination in rice.

Evaluation of selected minerals and health risk and proximate analysis of wasawasa (a street food)

This study was carried out to determine the proximate composition and the potential heavy metal health risk that may be associated with the consumption of wasawasa, a dish made from locally milled yam peels, by examining the presence of six metals (iron, nickel, chromium, sodium, and magnesium and potassium) in samples procured. Sixteen (16) samples of ready-to-eat wasawasa were collected from Aboabo, Manhyia, Sawaba, Asawase, Adenyase, and Ayigya in Kumasi, since these are the communities where wasawasa is mainly produced, sold, and consumed. The samples were digested with a nitric, perchloric, and sulfuric acid mixture and analyzed using a microwave plasma atomic emission spectrometer (Agilent 4210 MP-AES). The average concentrations of metals were Na (8506.88 mg/kg), Mg (222.63 mg/kg), Fe (84.45 mg/kg), Cr (2.31 mg/kg), K (1702.08 mg/kg, and Ni (1.12 mg/kg). Proximate analysis was used to determine Protein, fat, ash, moisture, and fiber content of the local wasawasa, which were found to be 15.667 %, 0.45 %, 1.00 %, 27.54 %, and 0.41 %, respectively. The hazard index of the heavy metals (Fe, Ni and Cr) for both adults and children were each greater than one, indicating the population is likely to experience non-carcinogenic effects from the consumption of wasawasa.

Do Crops Grown at Urban Dumpsites Contain Metals at Levels that Pose Unacceptable Health Risks to Consumers?

Excessive dietary metal intake from crops grown on contaminated urban dumpsites poses a global health risk to consumers. We evaluated the health risk to adult and child consumers from dietary exposure to metals and metalloids in crops cultivated at the Mbale (Uganda) dumpsite centre. Thirteen crop types grown on the dumpsite soil were sampled and analyzed for concentrations of 11 metals: Fe, Al, Zn, Mn, Cu, Pb, Cr, Hg, Co, Ni, Cd, and two metalloids: Se and As. Different proportions of the crops were combined into 12 meal classes to simulate the diets of residents and estimate noncancer and cancer risks. The findings indicated that most individual crop types and simulated diets lacked sufficient selenium for bodily functions. Furthermore, their metal accumulations exceeded the Food and Agriculture Organization (FAO) and the World Health Organization (WHO) permissible limits (mg/kg) for Al (20), Fe (100), Ni (10), Cu (20), Mn (10), Pb (0.3), Se (0.05), and Zn (99.4). The four most abundant metals in the various crop types and diets were Al, Fe, Mn, and Zn. A positive correlation between the metals in the crops indicated a common origin, which could possibly be the dumpsite soil. The chronic dietary intake (CDI) of metals was higher in children, and thus children faced higher noncancer and cancer risks compared with adults. The overall CDI values for each metal ranged from 0.000718 to 2.171 in adults, and 0.00125 to 3.781662 in children, which is approximately 1.74 times higher in children than in adult consumers. The noncancer and cancer risks ranged from moderate to high with Co, Cr, Fe, Mn, and Zn being mostly responsible for the high noncancer risks, and Al being the predominant contributor to cancer risks. The total noncancer risk levels equally ranged from moderate (1.4-3.3) for adults, and moderate to high (2.4-5.7) for children; the cancer risks were moderate to high in adults, with Al contributing to between 68% and 92% of the total risks across the 12 meal classes. Overall, CDI values and noncancer and cancer risks were all higher in children than in adults. The vegetables Amaranthus hybridus, Vigna unguiculate, Amaranthus dubius, and Cucurbita maxima significantly contributed to the high noncancer risk to both adults and children, particularly when they constituted 40% or more of the meal. Four additional vegetables (Cocorhrous olitorous, Brassica oleracea, Amaranthus cruentus, and Gynandropsis gynandra) also posed a high risk to children when consumed in large quantities. Our results highlight the urgent need to develop regulatory frameworks and/or rigorously enforce existing land and food governance policies to protect consumers' health from unsafe metal concentrations in crops grown on dumpsites. Environ Toxicol Chem 2024;43:2628-2644. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

A comprehensive toxicological analysis of panel of unregulated e-cigarettes to human health

Electronic cigarettes, commonly referred to as e-cigarettes have gained popularity over recent years especially among young individuals. In the light of the escalating prevalence of the use of these products and their potential for long-term health effects, in this study as the first of its kind a comprehensive toxicological profiling of the liquid from a panel of unregulated e-cigarettes seized in the UK was undertaken using an in vitro co-culture model of the upper airways. The data showed that e-cigarettes caused a dose dependent increase in cell death and inflammation manifested by enhanced release of IL1ß and IL6. Furthermore, the e-cigarettes induced oxidative stress as demonstrated by a reduction of intracellular glutathione and an increase in generation of reactive oxygen species. Moreover, the assessment of genotoxicity showed significant DNA strand breaks (following exposure to Tigerblood flavoured e-cigarette). Moreover, relevant to the toxicological observations, was the detection of varying and frequently high levels of hazardous metals including cadmium, copper, nickel and lead. This study highlights the importance of active and ongoing collaborations between academia, governmental organisations and policy makers (Trading standards, Public Health) and national health service in tackling vape addiction and better informing the general public regarding the risks associated with e-cigarette usage.

Impact of Metabolites from Foodborne Pathogens on Cancer

Foodborne pathogens are microorganisms that cause illness through contamination, presenting significant risks to public health and food safety. This review explores the metabolites produced by these pathogens, including toxins and secondary metabolites, and their implications for human health, particularly concerning cancer risk. We examine various pathogens such as Salmonella sp., Campylobacter sp., Escherichia coli, and Listeria monocytogenes, detailing the specific metabolites of concern and their carcinogenic mechanisms. This study discusses analytical techniques for detecting these metabolites, such as chromatography, spectrometry, and immunoassays, along with the challenges associated with their detection. This study covers effective control strategies, including food processing techniques, sanitation practices, regulatory measures, and emerging technologies in pathogen control. This manuscript considers the broader public health implications of pathogen metabolites, highlighting the importance of robust health policies, public awareness, and education. This review identifies research gaps and innovative approaches, recommending advancements in detection methods, preventive strategies, and policy improvements to better manage the risks associated with foodborne pathogens and their metabolites.

Major and Trace Airborne Elements and Ecological Risk Assessment: Georgia Moss Survey 2019-2023

The study, carried out as part of the International Cooperative Program on Effects of Air Pollution on Natural Vegetation and Crops, involved collecting 95 moss samples across the territory of Georgia during the period from 2019 to 2023. Primarily samples of Hypnum cupressiforme were selected, with supplementary samples of Abietinella abietina, Pleurozium schreberi, and Hylocomium splendens in cases of the former's absence. The content of 14 elements (Al, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, S, Sr, V, and Zn) was detected using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES), while the Hg content was determined using a Direct Mercury Analyzer. To identify any relationships between chemical elements and to depict their sources, multivariate statistics was applied. Principal component analysis identified three main components: PC1 (geogenic, 43.4%), PC2 (anthropogenic, 13.3%), and PC3 (local anomalies, 8.5%). The results were compared with the first moss survey conducted in Georgia in the period from 2014 to 2017, offering insights into temporal trends of air quality. Utilizing GIS, a spatial map illustrating pollution levels across Georgia, based on the Pollution Load Index, was generated. The Potential Environmental Risk Index emphasized significant risks associated with mercury and cadmium at several locations. The study highlights the utility of moss biomonitoring in assessing air pollution and identifying hotspots of contamination. The findings from this study could be beneficial for future biomonitoring research in areas with varying physical and geographical conditions.

Heavy metals in commonly consumed rice grains in Bangladesh and associated probabilistic human health risks

Food contamination by heavy metals is a concerning issue worldwide. The presence of elevated levels of heavy metals in commonly consumed rice has emerged as a critical issue in ensuring food safety. This research encompassed the collection of 44 rice samples, representing seven distinct varieties, through a randomized sampling approach across various retail markets within Dhaka city. The investigation of heavy metal content (including Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Hg, and Pb) within the rice samples was carried out employing Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The findings disclosed substantial disparities in heavy metal concentrations among the different rice varieties. Notably, the concentrations of Cr (0.99 mg/kg), Fe (8.35 mg/kg), Pb (0.49 mg/kg), and Co (0.02 mg/kg) were observed to exceed the established maximum permissible limits. This contamination of the rice varieties may stem from either natural processes or human activities. Utilizing these metal concentrations, this study employed Monte-Carlo simulation to calculate health risk and probabilistic health risk. The Target Hazard Quotients (THQs) for Cr, Fe, and As exceeded the threshold of 1 in each rice variety, particularly in Amon and Lal Biroi in Mymensingh, Najirshail in Bogra, 28 in Sherpur and Kushtia, Miniket in Bogra and Rajshahi, and lastly, paijam in Rangpur and Tangail. Furthermore, the Hazard Index (HI) exceeded 1 in all rice varieties, implying that the consumption of these selected rice grains may have a substantial impact on overall food quality and its potential health consequences. Both carcinogenic risk and probabilistic risk for As, Ni, Cd, Cr, and Pb were found to surpass the threshold levels and safe limits, respectively. This suggests that individuals who have regularly consumed these rice varieties may face a heightened probability of developing cancer in the future, as predicted. According to sensitivity analysis, metal concentration and food ingestion rate (FIR) are the most relevant components that contribute to the significant impact of carcinogenic health hazards. Finally, the study concluded that heavy metal intake from food poses a risk to human health, necessitating the effective monitoring based on each geographic location and identify the source of this heavy metal to limit its exposure.

Biochar and nanoscale silicon synergistically alleviate arsenic toxicity and enhance productivity in chili peppers (Capsicum annuum L.)

Arsenic (As) contamination in agricultural soils threatens crop productivity and food safety. In this study, we examined the efficacy of biochar (BC) and silicon nanoparticles (SiNPs) as environmentally sustainable soil amendments to alleviate As toxicity in chili (Capsicum annuum L.) plants. Our findings revealed that As stress severely inhibited the growth parameters of Capsicum annuum L., and subsequently reduced yield. However, the application of BC and SiNPs into the contaminated soil significantly reversed these negative effects, promoting plant length and biomass, particularly when applied together in a synergistic manner. Arsenic stress led to increased oxidative damage, as evidenced by a 29% increase in leaf malondialdehyde content as compared to the healthy plants. Nevertheless, the synergistic (BC + SiNPs) application effectively modulated antioxidant enzyme activity, resulting in a remarkable 55% and 66% enhancement in the superoxide dismutase and catalase levels, respectively, boosting chili's resistance against oxidative stress. Similarly, BC + SiNPs amendments improved photosynthesis by 52%, stomatal conductance by 39%, soluble sugars by 42%, and proteins by 30% as compared with those of control treatment. Additionally, the combined BC + SiNPs application significantly reduced root As content by 61% and straw As by 37% as compared with the control one. Transmission electron microscopy confirmed that the synergistic use of BC and SiNPs preserved chili leaf ultrastructure, shielding against As-induced damage. Overall, the supplementation of contaminated soil with BC and SiNPs was proved to be a sustainable strategy for mitigating As toxicity in chili peppers, enhancing plant growth, physiology, and yield, and thereby food safety.

Determination of Some Element’s Migrants in Aqueous Simulant from Plastic Food Contact Products by Inductively Coupled Plasma Mass Spectrometer

Various chemicals present at different stages in the food supply chain can lead to the leaching of heavy metals. These metals can accumulate in the human body through the consumption of contaminated food. Consequently, it is necessary to validate an analytical technique for the quantification chemical that could contaminate food. This study presents a rapid, straightforward, and efficient analytical method for the direct quantification of some potentially toxic elements in aqueous simulants from plastic food contact products using an inductively coupled mass spectrometer (ICP-MS). The method’s validation encompassed the study of the estimated detection limits, practical quantification limits, linearity, accuracy, and measurement uncertainty of aluminium (Al), antimony (Sb), arsenic (As), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), nickel (Ni), and zinc (Zn) under optimized ICP-MS conditions. The estimated detection limits ranged from 7.5 × 10−4 to 0.074 mg/kg, while practical quantification limits spanned from 0.02 to 0.8 mg/kg. The average recoveries ± standard deviations at different spiking levels were varied between 85.7 ± 1.51 and 115.6 ± 0.88% with coefficients of variation between 0.42 and 5.85%. The method trueness was verified by using references materials (test material in aqueous acetic acid) purchased from Food Chemistry Proficiency Testing and Analysis (FAPAS) yielding satisfactory results within acceptable recovery and Z-score values. The method precision, in terms of relative standard deviation (RSD), was being below 4.22%. The method uncertainty expressed as expanded uncertainty of all validated elements was found to be ≤ 21.9%. Validated method was employed to determine specific elements in aqueous simulants of thirty commercial plastic food packaging samples, representing three distinct types of plastic polymers. The results showed that the mean concentrations, in mg/kg, were as follows: 2.04 (Al), 0.02 (As), 0.02 (Cd), 0.02 (Co), 0.06 (Cr), 0.41 (Cu), 1.55 (Fe), 0.09 (Mn), 0.15 (Ni), 0.07 (Pb), 0.05 (Sb), and 0.81 (Zn). Furthermore, 30% of analyzed samples exceeding the maximum permissible limits of Al for plastic materials and articles intended to come into contact with food.

Microplastics from face masks: Unraveling combined toxicity with environmental hazards and their impacts on food safety

Microplastics (MPs) refer to tiny plastic particles, typically smaller than 5 mm in size. Due to increased mask usage during COVID-19, improper disposal has led to masks entering the environment and releasing MPs into the surroundings. MPs can absorb environmental hazards and transfer them to humans and animals via the food chain, yet their impacts on food safety and human health are largely neglected. This review summarizes the release process of MPs from face masks, influencing factors, and impacts on food safety. Highlights are given to the prevalence of MPs and their combined toxicities with other environmental hazards. Control strategies are also explored. The release of MPs from face masks is affected by environmental factors like pH, UV light, temperature, ionic strength, and weathering. Due to the chemical active surface and large surface area, MPs can act as vectors for heavy metals, toxins, pesticides, antibiotics and antibiotic resistance genes, and foodborne pathogens through different mechanisms, such as electrostatic interaction, precipitation, and bioaccumulation. After being adsorbed by MPs, the toxicity of these environmental hazards, such as oxidative stress, cell apoptosis, and disruption of metabolic energy levels, can be magnified. However, there is a lack of comprehensive research on both the combined toxicities of MPs and environmental hazards, as well as their corresponding control strategies. Future research should prioritize understanding the interaction of MPs with other hazards in the food chain, their combined toxicity, and integrating MPs detection and degradation methods with other hazards.

Unraveling the Role of Contaminants Reshaping the Microflora in Zea mays Seeds from Heavy Metal-Contaminated and Pristine Environment

Heavy metal (HM) contaminants are the emerging driving force for reshaping the microflora of plants by eradicating the non-tolerance and non-resistant microbes via their lethal effects. Seeds served as a prime source of ancestral microbial diversity hereditary transfer from generation to generation. However, the problem arises when they got exposed to metal contamination, does metal pollutant disrupt the delicate balance of microbial communities within seeds and lead to shifts in their microflora across generations. In this study, the endophytic community within Zea mays seeds was compared across three distinct regions in Yunnan province, China: a HM-contaminated site Ayika (AK), less-contaminated site Sanduoduo (SD), and a non-contaminated Site Dali (DL). High-throughput sequencing techniques were employed to analyze the microbial communities. A total of 492,177 high-quality reads for bacterial communities and 1,001,229 optimized sequences for fungal communities were obtained. These sequences were assigned to 502 and 239 operational taxonomic units (OTUs) for bacteria and fungi, respectively. A higher diversity was recorded in AK samples than in SD and DL. Microbial community structure analysis showed higher diversity and significant fluctuation in specific taxa abundance in the metal-polluted samples exhibiting higher response of microbial flora to HM. In AK samples, bacterial genera such as Gordonia and Burkholderia-Caballeronia-Paraburkholderia were dominant, while in SD Pseudomonas and Streptomyces were dominant. Among the fungal taxa, Fusarium, Saccharomycopsis, and Lecanicillium were prevalent in HM-contaminated sites. Our finding revealed the influential effect of HM contaminants on reshaping the seed microbiome of the Zea mays, showing both the resilience of certain important microbial taxa as well the shifts in the diversity in the contaminated and pristine conditions. The knowledge will benefit to develop effective soil remediation, reclamation, and crop management techniques, and eventually assisting in the extenuation of metal pollution's adverse effects on plant health and agricultural productivity.

Monitoring of urinary nickel and chromium in metal industries workers in Alborz, Iran

Heavy metal contamination from occupational sources is a cause for concern due to its potential accumulation in the environment and the body of living organisms, which leads to long-term toxic effects. There is limited evidence on the concentration of heavy metals in the body fluids of welding workers. This study aimed to measure the concentration of nickel (Ni) and chromium (Cr) as two main toxic heavy metals in the urine samples of welders and determine the potential relationship of various environmental factors on their concentration levels. This study was conducted in Iran in 2022-2023. Eighty-five urine samples were collected from the studied welding workers. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used to measure the concentration of Ni and Cr. Data related to socio-demographic characteristics (education level, income, work experience, age, and body mass index (BMI)), lifestyle profile (consumption of seafood and canned food, smoking, physical activity), type of ventilation and preventive devices at work, and suffering from underlying diseases (cardiovascular and high blood pressure) were collected using valid questionnaires. Ni and Cr were present in 100% of urine samples with mean concentrations of (1.09 ± 0.294) and (11.45 ± 16.751) µg/g creatinine, respectively. A significant correlation was observed between the mean concentration of Ni and Cr with the level of education, income, work experience, age, consumption of seafood and canned food, smoking, type of ventilation and preventive devices, and underlying diseases (p-value < 0.05). Also, there was no significant difference between Ni concentration and physical activity and Cr concentration with BMI. Lifestyle determinants and not using preventive devices are important predictors of urinary heavy metals in welding workers. Therefore, more research is required to determine the adverse effects of long-term exposure to these heavy metals.

Leveraging multi-omics tools to comprehend responses and tolerance mechanisms of heavy metals in crop plants

Extreme anthropogenic activities and current farming techniques exacerbate the effects of water and soil impurity by hazardous heavy metals (HMs), severely reducing agricultural output and threatening food safety. In the upcoming years, plants that undergo exposure to HM might cause a considerable decline in the development as well as production. Hence, plants have developed sophisticated defensive systems to evade or withstand the harmful consequences of HM. These mechanisms comprise the uptake as well as storage of HMs in organelles, their immobilization via chemical formation by organic chelates, and their removal using many ion channels, transporters, signaling networks, and TFs, amid other approaches. Among various cutting-edge methodologies, omics, most notably genomics, transcriptomics, proteomics, metabolomics, miRNAomics, phenomics, and epigenomics have become game-changing approaches, revealing information about the genes, proteins, critical metabolites as well as microRNAs that govern HM responses and resistance systems. With the help of integrated omics approaches, we will be able to fully understand the molecular processes behind plant defense, enabling the development of more effective crop protection techniques in the face of climate change. Therefore, this review comprehensively presented omics advancements that will allow resilient and sustainable crop plants to flourish in areas contaminated with HMs.

Assessment of microplastic and heavy metal pollution in agricultural soils of Ernakulam District, Kerala, India

Microplastics (MPs) and heavy metal pollution pose significant environmental threat, potentially leading to agroecosystem toxicity and jeopardizing food security. Therefore, this study aims to evaluate the abundance and risk assessment of these pollutants in five different farmlands of Ernakulam district, India. Results showed that MPs content in agricultural fields near commercialized areas such as Kakkanad Nedungapuzha, Nedumbassery, and Kadamakuddy was dominant compared to Nechoor, a rural area. The average microplastic abundance was found to be 45.6 ± 26.4 items kg⁻1 dw. Polypropylene (PP) and polyethylene (PE) were the dominant polymers found in the soil samples, constituting 45% and 25% of the microplastic content, respectively. The pollution load index of MPs indicates that the sampling sites are considered to be polluted as PLI > 1 with hazard level I. The heavy metal pollution status follows the order: Cu (80.3 to 724 mg/kg) > Zn (77 to 543.5 mg/kg) > Cr (171.65 to 334.65 mg/kg) > As (10.25 to 79.5 mg/kg) > Pb (2.05 to 30.3 mg/kg) > Cd (0.3 to 14.35 mg/kg). Calculated pollution load index (PLI) geo-accumulation index (Igeo), ecological risk assessment values indicate that commercialized regions exhibit high levels of trace metals, namely Cu, Zn, As, Cd, and Cr, posing a significant concern for the agricultural ecosystem. Our results indicate heightened microplastics and heavy metals prevalence in farmlands adjacent to commercial zones, necessitating immediate preventive action to mitigate increasing concentrations.

Interaction Between Heavy Metals Posed Chemical Stress and Essential Oil Production of Medicinal Plants

Plants exposed to abiotic stressors show diverse physiological, biochemical, and molecular responses. Biosynthesis of plant secondary metabolites-including essential oils-is a vital plant defense mechanism. As these bioactive compounds are widely used in the pharmaceutical, cosmetic and food industries, it is essential to understand how their production is affected in various environments. While interaction between specific abiotic stressors such as salt stress has been widely studied, relatively less information is available on how essential oil production is affected by toxic contaminants. Present review intends to give an insight into the possible interaction between chemical stress and essential oil production, with special regard to soil and air pollution. Available studies clearly demonstrate that heavy metal induced stress does affect quantity and quality of EOs produced, however, pattern seems ambiguous as nature of effect depends on the plant taxon and on the EO. Considering mechanisms, genetic studies clearly prove that exposure to heavy metals influences the expression of genes being responsible for EO synthesis.

Assessment of Ecological and Health Risks of Potentially Toxic Elements in Soil and Plant Under Long-Term Sewage Wastewater Irrigation

This paper aimed to evaluate the ecological and health risks for some potentially toxic trace elements (PTEs) in agricultural soils irrigated with sewage wastewater for more than 50 years. Therefore, soil and plant samples were collected from 21 sites at sewage wastewater irrigated area and these samples were analyzed for their contents of PTEs i.e. Cd, Cr, Cu, Ni, and Pb. The risks of PTEs pollution in the study area were analyzed using indices such as the individual and comprehensive potential ecological risk indices (Eri and RI, respectively), hazard quotient (HQ), hazard index (HI), and carcinogenic risk (CR) model. The results showed that the PTEs in soil samples ranged from 1.70 to 9.90 mg/kg for Cd, from 39.9 to 183.4 mg/kg for Cr, from 31.5 to 655.1 mg/kg for Cu, from 18.8 to 113.1 mg/kg for Ni and from 5.4 to 65.4 mg/kg for Pb. The results also demonstrated that the soil samples were characterized by high to very high ecological risk for Cd. According to the health risk assessment, the mean HQ and HI of the PTEs in soil for adults and children were below the risk threshold of 1, indicating no risk for non-carcinogenic health effects. However, the HI of PTEs via plant consumption was > 1, suggesting a non-carcinogenic health risk. The CR for most plant samples was above the acceptable range. These findings may offer helpful information regarding the ecological and human risks related to PTEs exposure in soil and plants irrigated with wastewater under arid conditions.

The molecular insights of cyanobacterial bioremediations of heavy metals: the current and the future challenges

In recent years, overexplorations of ore and the growth of industries are the prime factors in the release of heavy metals in environments. As a result, the food crops and water bodies are contaminated with metals which may have several adverse effects on the health of humans and other living species. These metals and metalloids, such as Zn, Cu, Mn, Ni, Cr, Pb, Cd, and As, upset the biochemical pathways of metabolite synthesis in living organisms and contribute to the etiology of different diseases. Microorganisms include bacteria, archaea, viruses, and many unicellular eukaryotes, which can span three domains of life-Archaea, Bacteria, and Eukarya-and some microorganisms, such as cyanobacteria, have shown high efficiency in the biosorption rate of heavy metals. Cyanobacteria are suitable for bioremediation as they can grow in adverse environments, have a less negative impact on the surrounding environment, and are relatively cheaper to manage. The structure of cyanobacteria has shown no extensive internal-bound membranes, so it can directly employ the physiological mechanisms to uptake heavy metals from contamination sites. Such biochemical makeups are suitable for managing and bioremediating heavy metal concentrations in polluted environments. This review aims to explore the potential of cyanobacteria in the bioremediation of heavy metals and metalloids in water bodies. Additionally, we have identified the prospects for enhancing bioremediation effectiveness.

Soil application of FeCl3 and Fe2(SO4)3 reduced grain cadmium concentration in Polish wheat (Triticum polonicum L.)

BACKGROUND

Wheat is one of major sources of human cadmium (Cd) intake. Reducing the grain Cd concentrations in wheat is urgently required to ensure food security and human health. In this study, we performed a field experiment at Wenjiang experimental field of Sichuan Agricultural University (Chengdu, China) to reveal the effects of FeCl3 and Fe2(SO4)3 on reducing grain Cd concentrations in dwarf Polish wheat (Triticum polonicum L., 2n = 4x = 28, AABB).

RESULTS

Soil application of FeCl3 and Fe2(SO4)3 (0.04 M Fe3+/m2) significantly reduced grain Cd concentration in DPW at maturity by 19.04% and 33.33%, respectively. They did not reduce Cd uptake or root-to-shoot Cd translocation, but increased Cd distribution in lower leaves, lower internodes, and glumes. Meanwhile, application of FeCl3 and Fe2(SO4)3 up-regulated the expression of TpNRAMP5, TpNRAMP2 and TpYSL15 in roots, and TpYSL15 and TpZIP3 in shoots; they also downregulated the expression of TpZIP1 and TpZIP3 in roots, and TpIRT1 and TpNRAMP5 in shoots.

CONCLUSIONS

The reduction in grain Cd concentration caused by application of FeCl3 and Fe2(SO4)3 was resulted from changes in shoot Cd distribution via regulating the expression of some metal transporter genes. Overall, this study reports the physiological pathways of soil applied Fe fertilizer on grain Cd concentration in wheat, suggests a strategy for reducing grain Cd concentration by altering shoot Cd distribution.

Self-standing membranes for separation: Achievements and opportunities

Supported membranes and mixed matrix membranes have a limitation of harming the mass transfer due to the incompatibility between the support layer or the matrix and the active components of the membrane. Self-standing membranes, which could structurally abandon the support layer, altogether avoid the adverse effect, thus greatly facilitating the transmembrane mass transfer process. However, the abandonment of the support layer also reduces the membrane's mechanical properties and formability. In this review, our emphasis will be on self-standing membranes within the realm of materials and separation engineering. We will explore the materials employed in the fabrication of self-standing membranes, highlighting their ability to simultaneously enhance membrane performance and promote self-standing characteristics. Additionally, we will delve into the diverse techniques utilized for crafting self-standing membranes, encompassing interfacial polymerization, filtration, solvent casting, Langmuir-Blodgett & layer-by-layer assembly, electrospinning, compression, etc. Throughout the discussion, the merits and drawbacks associated with each of these preparation methods were elucidated. We also provide a brief overview of the applications of self-standing membranes, including water purification, gas separation, organic solvent nanofiltration, electrochemistry, and membrane reactor, as well as a brief description of the general strategies for performance enhancement of self-standing membranes. Finally, the current status of self-standing membranes and the challenges they may encounter were discussed.

Enhanced Rock Weathering for Carbon Removal-Monitoring and Mitigating Potential Environmental Impacts on Agricultural Land

Terrestrial enhanced rock weathering (ERW) is the application of pulverized silicate rock to soils for the purposes of carbon removal and improved soil health. Although a geochemical modeling framework for ERW in soils is emerging, there is a scarcity of experimental and field trial data exploring potential environmental impacts, risks, and monitoring strategies associated with this practice. This paper identifies potential negative consequences and positive cobenefits of ERW scale-up and suggests mitigation and monitoring strategies. To do so, we examined literature on not only ERW but also industry, agriculture, ecosystem science, water chemistry, and human health. From this work, we develop recommendations for future research, infrastructure, and policy needs. We also recommend target metrics, risk mitigation strategies, and best practices for monitoring that will permit early detection and prevention of negative environmental impacts.

A nationwide study of heavy metal(loid)s in agricultural soils and the soil-grown black morel Morchella sextelata in China

The accumulation of heavy metal(loid)s (HMs) in soil-grown mushrooms poses potential health risks. Morchella sextelata (black morel) is a typical soil-grown mushroom with a rapidly expanding cultivation area. This study investigated the distribution of arsenic, cadmium, chromium, copper, mercury, nickel, lead, and zinc in 213 pairs of soil and morel samples collected from 29 provincial administrative regions in China, together with the nutritional contents in the morel samples. The HM contents in the arable soils used to cultivate morels were 2.4-33.1 times higher than those in desert soils, while the HM contents in arable-soil morels were 2.9-155.9 times higher than desert morels. The HM contents of morels and their cultivation soils were significantly correlated (0.465 ≤ R ≤ 0.778, P < 0.001). Furthermore, the enrichment factors of most HMs were higher in arable soils than in desert soils (P < 0.05), except Hg. A considerable proportion of the arable soils produced morels with HMs exceeding the risk control standards (RCSs) for food and the health-risk thresholds of dietary intake. In comparison, HMs in morels from desert soils were far below the RCSs and health-risk thresholds. In addition, desert morels contained higher contents of crude proteins, total polysaccharides, and free amino acids (P < 0.001). These findings indicate that growing morels in desert soils is a way of green production that provides mushroom products with improved safety and nutrition.

Risk assessment and soil heavy metal contamination near marble processing plants (MPPs) in district Malakand, Pakistan

Soil heavy metals (HMs) pollution is a growing global concern, mainly in regions with rapid industrial growth. This study assessed the concentrations, potential sources, and health risks of HMs in agricultural soils near marble processing plants in Malakand, Pakistan. A total of 21 soil samples were analyzed for essential and toxic HMs via inductively coupled plasma‒optical emission spectrometry (ICP‒OES), and probabilistic health risks were evaluated via Monte Carlo simulation. The concentrations (mg/kg) of Ca (29,250), P (805.5) and Cd (4.5) exceeded the average shale limits of 22,100, 700, and 3.0 mg/kg, respectively, and indices such as Nemerow's synthetic contamination index (NSCI) and the geoaccumulation index (Igeo) categorized the soil sites as moderately polluted. The potential ecological risk index (PERI) indicated considerable to high ecological risk for As and Cd. The deterministic analysis indicated non-carcinogenic risks for children (HI > 1), whereas the probabilistic analysis suggested no significant risk (HI < 1) for both adults and children. Both methods indicated that the total cancer risk for Cr, Ni, Cd, and As exceeded the USEPA safety limits of 1.0E-06 and 1.0E-04. Sensitivity analysis identified heavy metal concentration, exposure duration, and frequency as key risk factors. The study suggested that HM contamination is mainly anthropogenic, poses a threat to soil and human health, and highlights the need for management strategies and surveillance programs to mitigate these risks.

Trade-offs of reproductive growth and Cd remobilization regulated Cd accumulation in wheat grains (Triticum aestivum L.)

Minimization of cadmium (Cd) accumulation in wheat grain (Triticum aestivum L.) is an important way to prevent Cd hazards to humans. However, little is known about the mechanisms of varietal variation of Cd accumulation in wheat grain. This study explores the physiological mechanisms of Cd bioaccumulation through field and hydroponic experiments on two wheat varieties of low-Cd-accumulating variety (L-6331) and high-Cd-accumulating variety (H-6049). Field study showed that average Cd accumulative rates in spikes of H-6049 were 1.57-fold of L-6331 after flowering, ultimately grain-Cd of H-6049 was 1.70-fold of L-6331 in Cd-contaminated farmland. The hydroponic experiment further confirmed that more vegetative tissues of L-6331 were involved in the remobilization of Cd, which jointly mitigated the process of Cd loaded to grains when leaf-cutting conducted after Cd stress. Additionally, the L1 and N1 of L-6331 play an especially important role in regulating Cd remobilization, and the larger EVB areas in N1 have the morphological feature that facilitates the transfer of Cd to L1. Overall results implied that low-Cd-accumulating variety initiated more trade-offs of reproductive growth and Cd remobilizatoin under Cd-stress after flowering compared with high-Cd-accumulating variety, and provided new insights into the processes of Cd loaded into wheat grains among different varieties.

Distribution characteristics, sources and risk assessment of heavy metals in the surface sediments from the largest tributary of the Lancang River in the Tibet Plateau, China

Angqu, positioned in the eastern expanse of the Tibet Plateau, claims the title of the largest tributary to the Lancang River. In October and December of 2018, in the sediment of Angqu, a comprehensive investigation was conducted on nine heavy metals-arsenic (As), manganese (Mn), chromium (Cr), cadmium (Cd), lead (Pb), mercury (Hg), copper (Cu), zinc (Zn), and nickel (Ni). This investigation aimed to scrutinize the spatial and temporal distribution patterns of these metals, assess the pollution status and ecological risks associated with the sediments, and delve into the sources contributing to their presence. The research results indicate that the average concentrations of As, Hg, and Cd in Angqu sediments exceed the soil background values of Tibet, while the concentrations of other heavy metals are below the soil background values of Tibet. Notably, arsenic poses potential ecological risks. In Angqu sediments, the concentrations of Mn, Cu, Ni, and Pb are generally higher in the wet season, but the seasonal variations of heavy metals in Angqu sediments are not significant. The sediments in the Angqu Basin are predominantly affected by mercury Hg, Cd, and As, with varying degrees of pollution at different sampling points. In the main stream of Angqu (City section), Hg pollution has reached above a moderate level, whereas As pollution near the tributary is only slightly polluted. The analysis of heavy metal sources reveals that there are five primary contributors to heavy metals in surface sediments of Angqu: parent material, agricultural activities, groundwater, atmospheric deposition, and other unidentified sources. Mn, Cr, Pb, and Ni are mainly derived from soil parent material, accounting for more than 50%. About 60.82% of As comes primarily from groundwater. Zn and Cd are mainly sourced from agricultural activities, accounting for 41.25% and 34.33%, respectively. Additionally, 20.6% of Hg originates from atmospheric deposition.

Phosphorus-induced restructuring of the ascorbate-glutathione cycle and lignin biosynthesis alleviates manganese toxicity in peach roots

Manganese (Mn) is indispensable for plant growth, but its excessive uptake in acidic soils leads to toxicity, hampering food safety. Phosphorus (P) application is known to mitigate Mn toxicity, yet the underlying molecular mechanism remains elusive. Here, we conducted physiological and transcriptomic analyses of peach roots response to P supply under Mn toxicity. Manganese treatment disrupted root architecture and caused ultrastructural damage due to oxidative injury. Notably, P application ameliorated the detrimental effects and improved the damaged roots by preventing the shrinkage of cortical cells, epidermis and endodermis, as well as reducing the accumulation of reactive oxygen species (ROS). Transcriptomic analysis revealed the differentially expressed genes enriched in phenylpropanoid biosynthesis, cysteine, methionine and glutathione metabolism under Mn and P treatments. Phosphorus application upregulated the transcripts and activities of core enzymes crucial for lignin biosynthesis, enhancing cell wall integrity. Furthermore, P treatment activated ascorbate-glutathione cycle, augmenting ROS detoxification. Additionally, under Mn toxicity, P application downregulated Mn uptake transporter while enhancing vacuolar sequestration transporter transcripts, reducing Mn uptake and facilitating vacuolar storage. Collectively, P application prevents Mn accumulation in roots by modulating Mn transporters, bolstering lignin biosynthesis and attenuating oxidative stress, thereby improving root growth under Mn toxicity. Our findings provide novel insights into the mechanism of P-mediated alleviation of Mn stress and strategies for managing metal toxicity in peach orchards.

Influence of agro-wastes derived biochar and their composite on reducing the mobility of toxic heavy metals and their bioavailability in industrial contaminated soils

The agro-waste derived valuable products are prime interest for effective management of toxic heavy metals (THMs). The present study investigated the efficacy of biochars (BCs) on immobilization of THMs (Cr, Zn, Pb, Cu, Ni and Cd), bioaccumulation and health risk. Agro-wastes derived BCs including wheat straw biochar (WSB), orange peel biochar (OPB), rice husk biochar (RHB) and their composite biochar (CB) were applied in industrial contaminated soil (ICS) at 1% and 3% amendments rates. All the BCs significantly decreased the bioavailable THMs and significantly (p < 0.001) reduced bioaccumulation at 3% application with highest efficiency for CB followed by OPB, WSB and RHB as compared to control treatment. The bioaccumulation factor (BAF), concentration index (CI) and ecological risk were decreased with all BCs. The hazard quotient (HQ) and hazard index (HI) of all THMs were <1, except Cd, while carcer risk (CR) and total cancer risk index (TCRI) were decreased through all BCs. The overall results depicted that CB at 3% application rate showed higher efficacy to reduce significantly (p < 0.001) the THMs uptake and reduced health risk. Hence, the present study suggests that the composite of BCs prepared from agro-wastes is eco-friendly amendment to reduce THMs in ICS and minimize its subsequent uptake in vegetables.

Contaminant and residue profiles in Lebanese food: a comparative analysis with global standards

Lebanon's agricultural sector, known for its diverse crop and livestock production, faces challenges in the international market due to the presence of chemical residues and contaminants in its food exports. Recent rejections of these exports have raised global concerns about food safety, increasingly seen as vital for public health and economic prosperity. This review focuses on examining scientific studies about the levels of various chemical residues including pesticides, and veterinary drugs and contaminants like mycotoxins, and polycyclic aromatic hydrocarbons, and heavy metals in Lebanese food products. Findings indicate that these residues and contaminants often exceed both the maximum residue limits (MRLs) and maximum limits (MLs) set by the Codex Alimentarius and the European Union. The review concludes with recommendations for reducing these contaminants and residues to enhance Lebanon's food safety and quality, aligning with international standards, and mitigating the risk of export rejections.

Plant growth-promoting rhizobacterial secondary metabolites in augmenting heavy metal(loid) phytoremediation: An integrated green in situ ecorestorative technology

In recent times, increased geogenic and human-centric activities have caused significant heavy metal(loid) (HM) contamination of soil, adversely impacting environmental, plant, and human health. Phytoremediation is an evolving, cost-effective, environment-friendly, in situ technology that employs indigenous/exotic plant species as natural purifiers to remove toxic HM(s) from deteriorated ambient soil. Interestingly, the plant's rhizomicrobiome is pivotal in promoting overall plant nutrition, health, and phytoremediation. Certain secondary metabolites produced by plant growth-promoting rhizobacteria (PGPR) directly participate in HM bioremediation through chelation/mobilization/sequestration/bioadsorption/bioaccumulation, thus altering metal(loid) bioavailability for their uptake, accumulation, and translocation by plants. Moreover, the metallotolerance of the PGPR and the host plant is another critical factor for the successful phytoremediation of metal(loid)-polluted soil. Among the phytotechniques available for HM remediation, phytoextraction/phytoaccumulation (HM mobilization, uptake, and accumulation within the different plant tissues) and phytosequestration/phytostabilization (HM immobilization within the soil) have gained momentum in recent years. Natural metal(loid)-hyperaccumulating plants have the potential to assimilate increased levels of metal(loid)s, and several such species have already been identified as potential candidates for HM phytoremediation. Furthermore, the development of transgenic rhizobacterial and/or plant strains with enhanced environmental adaptability and metal(loid) uptake ability using genetic engineering might open new avenues in PGPR-assisted phytoremediation technologies. With the use of the Geographic Information System (GIS) for identifying metal(loid)-impacted lands and an appropriate combination of normal/transgenic (hyper)accumulator plant(s) and rhizobacterial inoculant(s), it is possible to develop efficient integrated phytobial remediation strategies in boosting the clean-up process over vast regions of HM-contaminated sites and eventually restore ecosystem health.

Assessment of seasonal variations in soil heavy metal concentrations and potential health risks in Gujarat, India

This study investigates the prevalence, distribution, and ecological consequences of 21 heavy metals (Ag, Al, As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Na, Ni, Pb, Sr, and Zn) in the soils between the Mahi and Dhadhar rivers in Gujarat, India. It aims to assess the seasonal variations in soil contamination and the potential human health risk associated with the heavy metal exposure through ingestion, inhalation, and dermal contact pathways. Soil samples were collected from 57 sites across three distinct seasons and analyzed using indices such as the geo-accumulation index, contamination factor, pollution load index, ecological risk factor, and global potential ecological risk. Human health risks were also evaluated for carcinogenic and non-carcinogenic effects. The findings reveal significant soil contamination, especially during the Monsoon and Post-Monsoon seasons, with heavy metals like Ag, Cd, Cr, Cu, Co, Ni, and Pb posing considerable ecological threats. Cr and Ni were identified as presenting the highest carcinogenic risks, while Fe and Cr posed major non-carcinogenic challenges. Seasonal variations significantly influenced heavy metal concentrations and distribution patterns. The study highlights the urgent need for comprehensive policies and sustainable practices to mitigate soil contamination and protect environmental health. It emphasizes the critical role of human activities, such as industrial, agricultural, and mining operations, in soil degradation and calls for increased community awareness and action to address these challenges.

Gamma-aminobutyric acid interactions with phytohormones and its role in modulating abiotic and biotic stress in plants

Gamma-aminobutyric acid (GABA), a ubiquitous non-protein 4-carbon amino acid present in both prokaryotic and eukaryotic organisms. It is conventionally recognized as a neurotransmitter in mammals and plays a crucial role in plants. The context of this review centers on the impact of GABA in mitigating abiotic stresses induced by climate change, such as drought, salinity, heat, and heavy metal exposure. Beyond its neurotransmitter role, GABA emerges as a key player in diverse metabolic processes, safeguarding plants against multifaceted abiotic as well as biotic challenges. This comprehensive exploration delves into the GABA biosynthetic pathway, its transport mechanisms, and its intricate interplay with various abiotic stresses. The discussion extends to the nuanced relationship between GABA and phytohormones during abiotic stress acclimation, offering insights into the strategic development of mitigation strategies against these stresses. The delineation of GABA's crosstalk with phytohormones underscores its pivotal role in formulating crucial strategies for abiotic stress alleviation in plants.

Effects of nitrogen regulation on heavy metal phytoextraction efficiency (Leucaena leucocephala): Application of a nitrogen fertilizer and a fungal agent

Lead (Pb) and cadmium (Cd) have been identified as the primary contaminants in soil, posing potential health threats. This study aimed to examine the effects of applying a nitrogen fertilizer and a fungal agent Trichoderma harzianum J2 (nitrogen alone, fungi alone, and combined use) on the phytoremediation of soils co-contaminated with Pb and Cd. The growth of Leucaena leucocephala was monitored in the seedling, differentiation, and maturity stages to fully comprehend the remediation mechanisms. In the maturity stage, the biomass of L. leucocephala significantly increased by 18% and 29% under nitrogen-alone (NCK+) and fungal agent-alone treatments (J2), respectively, compared with the control in contaminated soil (CK+). The remediation factors of Pb and Cd with NCK+ treatment significantly increased by 50% and 125%, respectively, while those with J2 treatment increased by 73% and 145%, respectively. The partial least squares path model suggested that the nitrogen-related soil properties were prominent factors affecting phytoextraction compared with biotic factors (microbial diversity and plant growth). This model explained 2.56 of the variation in Cd concentration under J2 treatment, and 2.97 and 2.82 of the variation in Pb concentration under NCK+ and J2 treatments, respectively. The redundancy analysis showed that the samples under NCK+ and J2 treatments were clustered similarly in all growth stages. Also, Chytridiomycota, Mucoromucota, and Ciliophora were the key bioindicators for coping with heavy metals. Overall, a similar remediation mechanism allowed T. harzianum J2 to replace the nitrogen fertilizer to avoid secondary pollution. In addition, their combined use further increased the remediation efficiency.