Environmental cadmium exposure and pancreatic cancer: Evidence from case control, animal and in vitro studies

The synthesis strategies of covalent organic frameworks and advances in their application for adsorption of heavy metal and radionuclide

Covalent organic frameworks (COFs) are a novel type of porous materials, with unique properties, such as large specific surface areas, high porosity, pronounced crystallinity, tunable pore sizes, and easy functionalization, and thus have received considerable attention in recent years. COFs play an essential role in the catalytic degradation, adsorption, and separation of heavy metals, radionuclides. In recent years, considering several outstanding characteristics of COFs, including their good thermal/chemical stability, high crystallinity, and remarkable adsorption capacity, they have been widely used in the removal of various environment pollutants. This review primarily discusses the synthesis strategies of COFs along with their diverse synthesis methods, and provides a comprehensive summary and analysis of recent research advances in the use of COFs for removing heavy metal ions and radionuclides from water bodies. Additionally, the adsorption mechanism of COFs with regard to metal ions was determined by analyzing the structural characteristics of COFs. Finally, the future research directions on COFs adsorb rare earth element was discussed.

Spatial - temporal mapping of urine cadmium levels in China during 1980 - 2040: Dietary improvements lower exposure amid rising pollution

Persistent cadmium exposure poses significant health risks to the Chinese population, underscored by its prevalence as an environmental contaminant. This study leverages a machine-learning model, fed with a comprehensive dataset of environmental and socio-economic factors, to delineate trends in cadmium exposure from 1980 to 2040. We uncovered that urinary cadmium levels peaked at 1.09 μg/g Cr in the mid-2000 s. Encouragingly, a decline is projected to 0.92 μg/g Cr by 2025, tapering further to 0.87 μg/g Cr by 2040. Despite this trend, regions heavily influenced by industrialization, such as Hunan and Guizhou, as well as industrial counties in Jilin, report stubbornly high levels of exposure. Our demographic analysis reveals a higher vulnerability among adults & adolescents over 14, with males displaying elevated cadmium concentrations. Alarmingly, the projected data suggests that by 2040, an estimated 41% of the population will endure exposure beyond the safety threshold set by the European Food Safety Authority. Our research indicates disproportionate cadmium exposure impacts, necessitating targeted interventions and policy reforms to protect vulnerable groups and public health in China.

Factors moderating cadmium bioavailability: Key considerations for comparing blood cadmium levels between groups

Cadmium (Cd) is recognized as a significant hazard to human health, with exposure linked to a variety of adverse outcomes including various cancers, cardiovascular diseases, chronic kidney disease, and osteoporosis. Residing in areas contaminated with Cd is undoubtedly a risk factor for developing the aforementioned conditions. However, the risk of developing Cd-related disorders is not uniform among individuals. Deficiencies in iron, zinc, and calcium, along with iron deficiency anemia, decreased lung function often seen in chronic obstructive pulmonary disease (COPD), and low circulating levels of parathyroid hormone (PTH), may enhance Cd intestinal absorption. Conversely, chronic liver disorders can lead to the progressive loss of hepatocytes and the release of free Cd into the circulation, resulting in elevated Cd blood levels. Moreover, studies comparing Cd blood levels between different regions within a country or between two groups of individuals, for example, those with and without osteoporosis, should consider all variables that may impact Cd levels. These include age, sex, alcohol consumption, blood levels of iron, calcium, and zinc, the presence of anemia, COPD, PTH levels, and the presence of liver or kidney disease. In this review, we delve into all factors that could influence Cd blood levels, providing a comprehensive analysis.

Trace elements in pancreatic cancer

BACKGROUND

Pancreatic cancer (PCA) is an extremely aggressive malignant cancer with an increasing incidence and a low five-year survival rate. The main reason for this high mortality is that most patients are diagnosed with PCA at an advanced stage, missing early treatment options and opportunities. As important nutrients of the human body, trace elements play an important role in maintaining normal physiological functions. Moreover, trace elements are closely related to many diseases, including PCA.

REVIEW

This review systematically summarizes the latest research progress on selenium, copper, arsenic, and manganese in PCA, elucidates their application in PCA, and provides a new reference for the prevention, diagnosis and treatment of PCA.

CONCLUSION

Trace elements such as selenium, copper, arsenic and manganese are playing an important role in the risk, pathogenesis, diagnosis and treatment of PCA. Meanwhile, they have a certain inhibitory effect on PCA, the mechanism mainly includes: promoting ferroptosis, inducing apoptosis, inhibiting metastasis, and inhibiting excessive proliferation.

Navigating Intraductal Papillary Mucinous Neoplasm Management through Fukuoka Consensus vs. European Evidence-Based Guidelines on Pancreatic Cystic Neoplasms-A Study on Two European Centers

This study addresses the critical need for the accurate diagnosis and management of intraductal papillary mucinous neoplasms (IPMNs), which are pancreatic cystic neoplasm types holding a substantial potential for malignancy. It evaluates the diagnostic effectiveness of the Fukuoka consensus guidelines and the European evidence-based guidelines in detecting high-grade dysplasia/invasive carcinoma in IPMNs, utilizing a retrospective analysis of 113 patients from two European medical centers. The methods include a comparative analysis of clinical, radiological, and endoscopic ultrasonography data, alongside an assessment of guideline-driven diagnostic performance. The results demonstrate that both guidelines offer similar accuracy in identifying severe disease stages in IPMNs, with certain clinical markers-such as jaundice, solid mass presence, and an increase in CA 19-9 levels-being pivotal in predicting the need for surgical intervention. This study concludes that while both guidelines provide valuable frameworks for IPMN management, there is an inherent need for further research to refine these protocols and improve patient-specific treatment strategies. This research contributes to the ongoing discourse on optimizing diagnostic and treatment paradigms for pancreatic cystic neoplasms, aiming to enhance clinical outcomes and patient care in this challenging medical field.

Mechanisms of Heavy Metal Cadmium (Cd)-Induced Malignancy

The environmental pollution of cadmium is worsening, and its significant carcinogenic effects on humans have been confirmed. Cadmium can induce cancer through various signaling pathways, including the ERK/JNK/p38MAPK, PI3K/AKT/mTOR, NF-κB, and Wnt. It can also cause cancer by directly damaging DNA and inhibiting DNA repair systems, or through epigenetic mechanisms such as abnormal DNA methylation, LncRNA, and microRNA. However, the detailed mechanisms of Cd-induced cancer are still not fully understood and require further investigation.

The Role of Endocrine Disruption Chemical-Regulated Aryl Hydrocarbon Receptor Activity in the Pathogenesis of Pancreatic Diseases and Cancer

The aryl hydrocarbon receptor (AHR) serves as a ligand-activated transcription factor crucial for regulating fundamental cellular and molecular processes, such as xenobiotic metabolism, immune responses, and cancer development. Notably, a spectrum of endocrine-disrupting chemicals (EDCs) act as agonists or antagonists of AHR, leading to the dysregulation of pivotal cellular and molecular processes and endocrine system disruption. Accumulating evidence suggests a correlation between EDC exposure and the onset of diverse pancreatic diseases, including diabetes, pancreatitis, and pancreatic cancer. Despite this association, the mechanistic role of AHR as a linchpin molecule in EDC exposure-related pathogenesis of pancreatic diseases and cancer remains unexplored. This review comprehensively examines the involvement of AHR in EDC exposure-mediated regulation of pancreatic pathogenesis, emphasizing AHR as a potential therapeutic target for the pathogenesis of pancreatic diseases and cancer.

Catalytic oxidation of lignite by Pt/TiO2 can enhance cadmium adsorption capacity

Addressing global warming necessitates innovative strategies in fossil fuel management. This study evaluates lignite, a low-rank coal with limited calorific value, exploring applications beyond its use as fuel. Utilizing Pt/TiO2 catalytic oxidation, the research aims to enhance the cadmium adsorption capacity of lignite in wastewater. Lignite, treated with 0.5% Pt/TiO2 at 125 °C for 2 h, demonstrated a threefold increase in cadmium adsorption capacity. Characterization using TGA-DSC confirmed the modification process as exothermic and self-sustainable. Spectroscopic analysis and Boehm titration revealed significant alterations in pore structure, surface area, and oxygen-containing functional groups, emphasizing the effectiveness of catalytic oxidation. Adsorption mechanisms such as complexation, cation exchange, and cation-π interactions were identified, enhancing Cd adsorption. Techniques, including the d-band model, H2-TPR, and O2-TPD, indicated that dissociative adsorption of molecular O2 and the subsequent generation of reactive oxygen species introduced additional oxygen-containing functional groups on the lignite surface. These findings provide essential strategies for the alternative use of lignite in environmental remediation, promoting sustainable resource utilization and enhancing cost-effectiveness in remediation processes. ENVIRONMENTAL IMPLICATION: This study innovates in using lignite to reduce cadmium (Cd) contamination in wastewater. Employing Pt/TiO2 catalytic oxidation, lignite is transformed, enhancing its cadmium adsorption capacity. This process, being exothermic, contributes to decreased energy consumption. The approach not only mitigates the hazardous impacts of cadmium but also aligns with sustainability by reducing greenhouse gas emissions and energy use, showcasing a multifaceted environmental advancement.

Addressing the challenges of combined sewer overflows

Europe's ageing wastewater system often combines domestic sewage with surface runoff and industrial wastewaters. To reduce the associated risk of overloading wastewater treatment works during storms, and to prevent wastewater backing-up into properties, Combined Sewer Overflows (CSOs) are designed into wastewater networks to release excess discharge into rivers or coastal waters without treatment. In view of growing regulatory scrutiny and increasing public concern about their excessive discharge frequencies and potential impacts on environments and people, there is a need to better understand these impacts to allow prioritisation of cost-effective solutions.We review: i) the chemical, physical and biological composition of CSOs discharges; ii) spatio-temporal variations in the quantity, quality and load of overflows spilling into receiving waters; iii) the potential impacts on people, ecosystems and economies. Despite investigations illustrating the discharge frequency of CSOs, data on spill composition and loading of pollutants are too few to reach representative conclusions, particularly for emerging contaminants. Studies appraising impacts are also scarce, especially in contexts where there are multiple stressors affecting receiving waters. Given the costs of addressing CSOs problems, but also the likely long-term gains (e.g. economic stimulation as well as improvements to biodiversity, ecosystem services, public health and wellbeing), we highlight here the need to bolster these evidence gaps. We also advocate no-regrets options to alleviate CSO problems taking into consideration economic costs, carbon neutrality, ecosystem benefit and community well-being. Besides pragmatic, risk-based investment by utilities and local authorities to modernise wastewater systems, these include i) more systemic thinking, linking policy makers, consumers, utilities and regulators, to shift from local CSO issues to integrated catchment solutions with the aim of reducing contributions to wastewater from surface drainage and water consumption; ii) broader societal responsibilities for CSOs, for example through improved regulation, behavioural changes in water consumption and disposal of waste into wastewater networks, and iii) greater cost-sharing of wastewater use.

Spatial-temporal distribution and source analysis of atmospheric particulate-bound cadmium from 1998 to 2021 in China

Cadmium (Cd) is one of the most serious atmospheric heavy metal pollutants in China. PM2.5, PM10, and total suspended particle (TSP) are all important media for population Cd exposure. However, no studies so far have systematically explored the spatial and temporal distribution of atmospheric Cd bound to all these media in China, and the specific industrial sectors that contribute to the airborne Cd level are still unclear at present. In this study, we constructed the spatial and temporal distribution of PM (PM2.5, PM10, and TSP) binding Cd concentrations in China. Quantitative source apportionment of atmospheric Cd was carried out by analyzing the association of 23 industrial or energy-consuming sectors with Cd concentrations. Our results showed PM2.5, PM10, and TSP binding Cd concentrations decreased by 5.8%, 5.9%, and 6.1% per year at the national level, respectively. High PM-Cd concentrations were concentrated and distributed mainly in central and northwestern China. In addition, the medians of atmospheric PM2.5, PM10, and TSP binding Cd concentrations at the national level were 0.0026 μg/m3, 0.0036 μg/m3, and 0.0042 μg/m3, respectively. The main sources of PM-Cd include nonferrous metal smelting (Zn, Pb, Al) (47%), glass production (13%), pesticide production (12%), cement production (10%), and coal consumption (9%). This study analyzes comprehensively the atmospheric PM-bound Cd pollution, identifies the major industrial sectors that affect atmospheric Cd concentrations at the macroscale for the first time, and provides a basis for further reduction in the atmospheric Cd pollution.

Effect of trace element mixtures on the outcome of patients with esophageal squamous cell carcinoma: a prospective cohort study in Fujian, China

BACKGROUND

The evidence about the effects of trace elements on overall survival(OS) of patients with esophageal squamous cell carcinoma(ESCC) is limited. This study aims to evaluate mixed effects of plasma trace elements on OS of ESCC.

METHODS

This prospective cohort analysis included 497 ESCC patients with a median follow-up of 52.3 months. The concentrations of 17 trace elements were measured. We fitted Cox's proportional hazards regression, factor analysis and Bayesian kernel machine regression (BKMR) models to estimate the association between trace elements and OS.

RESULTS

Our analysis found that in the single-element model, Co, Ni, and Cd were associated with an increased risk of death, while Ga, Rb, and Ba were associated with a decreased risk. Cd had the strongest risk effect among all elements. As many elements were found to be mutually correlated, we conducted a factor analysis to identify common factors and investigate their associations with survival time. The factor analysis indicated that the factor with high factor loadings in Ga, Ba and B was linked to a decreased risk of death, while the factor with high factor loadings in Co, Ti, Cd and Pb was associated with a borderline significantly increased risk. Using BKMR analysis to disentangle the interaction between elements in significant factors, we discovered that Ga interacted with Ba and both elements had U-shaped effects with OS. Cd, on the other hand, had no interaction with other elements and independently increased the risk of death.

CONCLUSIONS

Our analysis revealed that Ga, Ba and Cd were associated with ESCC outcome, with Ga and Ba demonstrating an interaction. These findings provide new insights into the impact of trace elements on the survival of patients with ESCC.

Toxic Metal and Essential Element Concentrations in the Blood and Tissues of Pancreatic Ductal Adenocarcinoma Patients

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive lethal neoplasm, and it has an average 5-year survival rate of less than 10%. Although the factors that influence PDAC development remain unclear, exposure to toxic metals or the imbalance in essential elements may have a role in PDAC-associated metabolic pathways.

METHODS

This study determined the concentrations of Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se and Zn in whole blood, cancer and non-cancer tissues of patients affected by PDAC, and compared them with levels in healthy controls using inductively coupled plasma mass spectrometry.

RESULTS

Results of the whole blood showed significantly higher levels of Cr, Cu and Cu/Zn ratio in PDAC patients compared to the controls. In addition, the concentrations of Cu, Se, Fe and Zn significantly increased in cancer tissue compared to the healthy counterparts.

CONCLUSIONS

This study revealed evidence of altered metal levels in the blood and pancreatic tissues of PDAC patients with respect to healthy controls. These changes may contribute to multiple mechanisms involved in metal-induced carcinogenesis, including oxidative stress, DNA damage, genetic alteration, decreased antioxidant barriers and inflammatory responses. Thus, the analysis of metals can be used in the diagnosis and monitoring of PDAC neoplasms.

Association between environmental cadmium exposure and increased mortality in the U.S. National Health and Nutrition Examination Survey (1999-2018)

BACKGROUND

Cadmium (Cd) is toxic to human health and increases overall mortality. In this study, we investigated the association between Cd exposure and all-cause, cardiovascular (CVD), and cancer mortality in the general population and the mediating effect of smoking on these association.

METHODS

We used data from U.S. National Health and Nutrition Examination Survey for 1999-2018. To evaluate the hazard ratio (HR) for mortality, a multiple Cox regression analysis was conducted by adjusting for age, sex, race/ethnicity, body mass index, smoking, alcohol, hypertension, diabetes, hyperlipidemia, and history of CVD and cancer. A causal mediation analysis was performed to estimate the effects of smoking.

RESULTS

Among the 31,637 subjects, 5452 (12.3%) died. Blood Cd concentrations were significantly associated with all-cause (HR 1.473, 95% confidence interval [CI] 1.403-1.546, p < 0.001), CVD (HR 1.445, 95% CI 1.344-1.554, p < 0.001), and cancer (HR 1.496, 95% CI 1.406-1.592, p < 0.001) mortality. Urinary Cd concentrations were also significantly associated with them. Using feature selection via machine learning, the importance of Cd in all-cause and cancer mortality was second only to age. The association between Cd concentrations and all-cause mortality was significant in both ever-smokers and never-smokers. The mediating effect of smoking was estimated at 32%, whereas a large proportion (68%) remained a direct effect of Cd. In a subgroup analysis of subjects with cancer history, blood Cd concentrations were significantly associated with cancer-related deaths in those with a history of breast, gastrointestinal, and skin cancers.

CONCLUSION

High Cd exposure is an important risk factor for all-cause, CVD, and cancer mortality among the general population. Cd exposure increased the risk of death even in never-smokers, and its effects unrelated to smoking were substantial, suggesting the importance of regulating other sources of Cd exposure such as food and water.

IMPACT STATEMENT

Using national large-scale data, we found that low-level environmental exposure to cadmium significantly increased the risk of all-cause, cardiovascular, and cancer mortality in the general population even after adjusting for several risk factors. Although smoking is a major source of cadmium exposure, cadmium was nevertheless significantly associated with all-cause mortality in never-smokers, and the mediating effect of smoking on this association was only 32%. Hence, other sources of cadmium exposure such as food and water may be important.

Exposure status, spatial variation, and health risk assessment of selected heavy metal(loid)s in common commercial fish species of the Beibu Gulf

Fishes are considered as biological indicators of heavy metal(loid)s pollution. In this study, contents of seven heavy metal(loid)s, including Cu, Cr, Cd, Pb, Zn, As, and Hg, in the muscles of ten common fish species in the Beibu Gulf were analyzed to figure out the pollutants status and their health risk. Results showed all species were largely contaminated by arsenic. Under conservative estimation scenario, target hazard quotient and health index revealed no health risk of species except Alepes kleinii. Under pessimistic estimation scenario, target cancer risk and estimated daily intake showed that, except Saurida undosquamis, Saurida tumbil, and Trachinotus ovatus, the remaining species were at risk of causing cancer for their consumers. Daily intake of arsenic and mercury in most species by residents in the Beibu Gulf exceeded provisional maximum tolerable amount recommended by FAO, suggesting the need of moderate consumption of these species.

The role of cadmium in the pathogenesis of myeloid leukemia in individuals with anemia, deficiencies in vitamin D, zinc, and low calcium dietary intake

Iron deficiency, vitamin D deficiency and low calcium diet are frequent health problems with severe long- term consequences. Upon absorption from the duodenum, cadmium binds to transferrin, and cells with the highest density of transferrin receptor 1 (TfR1) take up the majority of the circulating cadmium. Nowadays, it is clear that individuals with iron deficiency anemia have increased blood levels of cadmium because of higher absorption rate, mediated by divalent metal transporter 1 (DMT1). However, the transient receptor potential vanilloid receptor 6 (TRPV6), known as a calcium carrier, is able to bind and transport cadmium as well. In the case of low calcium diet or vitamin D deficiency, TRPV6 may be overexpressed in the intestine and kidney tubules and absorbs (re-uptake in the case of renal tubules) cadmium in larger quantities, resulting in an increased cadmium blood levels. We speculate that the final event in the case of low calcium dietary diet and/or vitamin D deficiency is similar to what is observed in the case of iron deficiency, that cells with the highest levels of TfR1 (for example, megakaryocyte/erythrocyte progenitors and pro-erythroblasts) take up most of the circulating cadmium, which is powerful malignancy inductor, leading to appearance of acute myeloid leukemia (AML).

Cadmium and lead implication in testis cancer; is there a connection?

Testis cancer (TC) is the most common malignancy of young men. Current evidence from studies, alongside genetics and hormonal status, suggests a significant role of toxic metals, cadmium (Cd) and lead (Pb), in the origin and development of TC. Besides oxidative stress and endocrine disruption, interaction with bioelements is one of the critical mechanisms of Cd and Pb toxicity and malign transformation. This study aimed to investigate metal levels in blood, healthy, and tumor testis tissue and to reveal hormone, oxidative status, and bioelements levels in patients with TC. The study enrolled 52 patients with TC and 61 healthy volunteers. Toxic metals and bioelements levels were analyzed by atomic absorption spectrophotometry (AAS) while electrochemiluminescence immunoassay (ECLIA) and spectrophotometry methods were used for hormone and oxidative parameters evaluation. Significantly higher blood Cd levels were depicted in TC cohort. Furthermore, blood Cd elevation was associated with a 1.98 higher probability of TC developing. However, a metal concentration between healthy and tumor testis tissue did not differ significantly. Lower levels of estradiol and testosterone, established in a cohort of TC patients, followed the significant role of hormones in TC development. At the same time, ischemia-modified albumin (IMA) has been recognized as a parameter with very good accuracy as a potential diagnostic marker for TC. The study revealed different distribution patterns of copper (Cu) and zinc (Zn) in the three compartments of the patients, as well significant correlation between essential metals Cu/Zn and toxic metals Cd/Pb indicating metal-metal interactions as pivotal mechanisms of metals toxicity.

Meta-analysis and health risk assessment of toxic heavy metals in muscles of commercial fishes in Caspian Sea

Heavy metals from contaminated seafood can have serious consequences for human health. Several studies on the amount of heavy metals in Caspian Sea fish have been conducted to ensure their food safety. This meta-analysis aimed to investigate the levels of five toxic heavy metals; Lead (Pb), Cadmium (Cd), Mercury (Hg), Chromium (Cr), and Arsenic (As) in muscles of commercial fishes of the Caspian Sea with assessing their health risk of developing oral cancer in terms of fish collection place and fish type. A systematic search was performed, and the random effect model was applied for meta-analysis. Finally, 14 studies with 30 different sets of results were included. Our results showed that the pooled estimates for Pb, Cd, Hg, Cr, and As were 0.65 mg/kg (0.52, 0.79), 0.08 mg/kg (0.07, 0.10), 0.11 mg/kg (0.07, 0.15), 1.77 mg/kg (1.26, 2.27), and 0.10 mg/kg (- 0.06, 0.26) respectively. The levels of Pb and Cd were higher than their (FAO/WHO) maximum limits. The Estimated Daily Intake (EDI) of Pb and Cd in Mazandaran, and Hg in Gilan were more than Total Daily Intake (TDI) limits. The consumers' non-carcinogenic risk (THQ) for Hg in Mazandaran and Gilan, and As in Gilan, was unsafe. Carcinogenic risk (CR) for Cr and Cd in all three provinces, and for As in Mazandaran and Gilan, was greater than 1*10 - 4 and was unsafe. The lowest and highest risk levels of oral cancer were for Rutilus kutum and Cyprinus carpio respectively.

Recovering the Soybean Hulls after Peroxidase Extraction and Their Application as Adsorbent for Metal Ions and Dyes

This study is aimed at extending the soybean hulls’ lifetime by their utilization as an adsorbent for metal ions (Cd2+ and Cu2+) and dyes (Reactive Yellow 39 (RY 39) and Acid Blue 225 (AB 225)). ATR-FTIR spectroscopy, FE-SEM microscopy, and zeta potential measurements were used for adsorbent characterization. The effect of the solution’s pH, peroxidase extraction, adsorbent particle size, contact time, the pollutant’s initial concentration, and temperature on the soybean hulls’ adsorption potential was studied. Before peroxidase extraction, soybean hulls were capable of removing 72% Cd2+, 71% Cu2+ (at a pH of 5.00) or 81% RY 39, and 73% AB 225 (at a pH of 3.00). For further experiments, soybean hulls without peroxidase were used for several reasons: (1) due to their observed higher metal ion removal, (2) in order to reduce the waste disposal cost after the peroxidase (usually used for wastewater decolorization) extraction, and (3) since the soybean hulls without peroxidase possessed significantly lower secondary pollution than those with peroxidase. Cd2+ and Cu2+ removal was slightly increased when the smaller adsorbent fraction (710-1000 μm) was used, while the adsorbent particle size did not have an impact on dye removal. After 30 min of contact time, 92% and 88% of RY 39 and AB 225 were removed, respectively, while after the same contact time, 80% and 69% of Cd2+ and Cu2+ were removed, respectively. Adsorption of all tested pollutants follows a pseudo-second-order reaction through the fast adsorption, intraparticle diffusion, and final equilibrium stage. The maximal adsorption capacities determined by the Langmuir model were 21.10, 20.54, 16.54, and 17.23 mg/g for Cd2+, Cu2+, RY 39, and AB 225, respectively. Calculated thermodynamic parameters suggested that the adsorption of all pollutants is spontaneous and of endothermic character. Moreover, different binary mixtures were prepared, and the competitive adsorptions revealed that the soybean hulls are the most efficient adsorbent for the mixture of AB 225 and Cu2+. The findings of this study contribute to the soybean hulls’ recovery after the peroxidase extraction and bring them into the circular economy concept.

Probiotic cultures as a potential protective strategy against the toxicity of environmentally relevant chemicals: State-of-the-art knowledge

Environmentally relevant toxic substances may affect human health, provoking numerous harmful effects on central nervous, respiratory, cardiovascular, endocrine and reproductive system, and even cause various types of carcinoma. These substances, to which general population is constantly and simultaneously exposed, enter human body via food and water, but also by inhalation and dermal contact, while accumulating evidence suggests that probiotic cultures are able to efficiently adsorb and/or degrade them. Cell wall of probiotic bacteria/fungi, which contains structures such as exopolysaccharide, teichoic acid, protein and peptidoglycan components, is considered the main place of toxic substances adsorption. Moreover, probiotics are able to induce metabolism and degradation of various toxic substances, making them less toxic and more suitable for elimination. Other probable in vivo protective effects have also been suggested, including decreased intestinal absorption and increased excretion of toxic substances, prevented gut microbial dysbiosis, increase in the intestinal mucus secretion, decreased production of reactive oxygen species, reduction of inflammation, etc. Having all of this in mind, this review aims to summarize the state-of-the-art knowledge regarding the potential protective effects of different probiotic strains against environmentally relevant toxic substances (mycotoxins, polycyclic aromatic hydrocarbons, pesticides, perfluoroalkyl and polyfluoroalkyl substances, phthalates, bisphenol A and toxic metals).

Toxic mechanisms of cadmium and exposure as a risk factor for oral and gastrointestinal carcinomas

Incidence and mortality rates of gastrointestinal (GI) and oral cancers are among the highest in the world, compared to other cancers. GI cancers include esophageal, gastric, colon, rectal, liver, and pancreatic cancers, with colorectal cancer being the most common. Oral cancer, which is included in the head and neck cancers category, is one of the most important causes of death in India. Cadmium (Cd) is a toxic element affecting humans and the environment, which has both natural and anthropogenic sources. Generally, water, soil, air, and food supplies are reported as some sources of Cd. It accumulates in organs, particularly in the kidneys and liver. Exposure to cadmium is associated with different types of health risks such as kidney dysfunction, cardiovascular disease, reproductive dysfunction, diabetes, cerebral infarction, and neurotoxic effects (Parkinson's disease (PD) and Alzheimer's disease (AD)). Exposure to Cd is also associated with various cancers, including lung, kidney, liver, stomach, hematopoietic system, gynecologic and breast cancer. In the present study, we have provided and summarized the association of Cd exposure with oral and GI cancers.

Urine metabolomic characteristics of female patients with occupational chronic cadmium poisoning after 15 years of treatment

Occupational chronic cadmium poisoning (OCCP) can cause irreversible organ damage. Currently, no effective treatment is available for OCCP, and effective and sensitive biomarkers for treatment evaluation are still lacking. In this study, metabolomics techniques were used to analyze changes in endogenous metabolites in the urine of patients with OCCP after 15 years of treatment. Thirty urine samples from female patients with OCCP and healthy female controls (n = 15 per group) were assessed using gas chromatography-time-of-flight mass spectrometry and ultra-high-performance liquid chromatography-Q-Exactive mass spectrometry. The OCCP group had higher concentrations of blood urea nitrogen and urinary cadmium but near-normal urinary concentrations of β₂ -microglobulin and retinol-binding protein. Compared with the control group, the OCCP group had 66 significantly different metabolites with a variable importance in projection score >1 and p < 0.05. These differential metabolites were involved in various metabolic pathways, such as creatine metabolism, nicotinate and nicotinamide metabolism, the pentose phosphate pathway, d-glutamine and d-glutamate metabolism, and amino acid metabolism. Compared with the control group, the OCCP group had significantly higher urinary concentrations of creatine, glutamic acid, quinolinic acid and nicotinic acid. In a receiver operator characteristic analysis, the area under the curve of creatine was higher than those for glutamic acid, quinolinic acid and nicotinic acid, indicating that urinary concentrations of creatine could be used as a sensitive biomarker for the diagnosis and prognosis of OCCP and for monitoring its treatment.

Exploring the relationship between blood toxic metal(oid)s and serum insulin levels through benchmark modelling of human data: Possible role of arsenic as a metabolic disruptor

The major goal of this study was to estimate the correlations and dose-response pattern between the measured blood toxic metals (cadmium (Cd), mercury (Hg), chromium (Cr), nickel (Ni))/metalloid (arsenic (As)) and serum insulin level by conducting Benchmark dose (BMD) analysis of human data. The study involved 435 non-occupationally exposed individuals (217 men and 218 women). The samples were collected at health care institutions in Belgrade, Serbia, from January 2019 to May 2021. Blood sample preparation was conducted by microwave digestion. Cd was measured by graphite furnace atomic absorption spectrophotometry (GF-AAS), while inductively coupled plasma-mass spectrometry (ICP-MS) was used to measure Hg, Ni, Cr and As. BMD analysis of insulin levels represented as quantal data was done using the PROAST software version 70.1 (model averaging methodology, BMD response: 10%). In the male population, there was no correlation between toxic metal/metalloid concentrations and insulin level. However, in the female population/whole population, a high positive correlation for As and Hg, and a strong negative correlation for Ni and measured serum insulin level was established. BMD modelling revealed quantitative associations between blood toxic metal/metalloid concentrations and serum insulin levels. All the estimated BMD intervals were wide except the one for As, reflecting a high degree of confidence in the estimations and possible role of As as a metabolic disruptor. These results indicate that, in the case of As blood concentrations, even values higher than BMD (BMDL): 3.27 (1.26) (male population), 2.79 (0.771) (female population), or 1.18 (2.96) μg/L (whole population) might contribute to a 10% higher risk of insulin level alterations, meaning 10% higher risk of blood insulin increasing from within reference range to above reference range. The obtained results contribute to the current body of knowledge on the use of BMD modelling for analysing human data.

Exposure to multiple toxic metals and polycystic ovary syndrome risk: Endocrine disrupting effect from As, Pb and Ba

BACKGROUND

Polycystic ovarian syndrome (PCOS) affects 5 % ~ 20 % of women of reproductive age and is a serious health problem. Whether exposure to lead (Pb), mercury (Hg), arsenic (As), barium (Ba) or (cadmium) Cd is associated with an increased risk of PCOS, particularly their joint effect as well as their association with the clinical phenotype of PCOS is limited and unclear.

OBJECTIVES

We aimed to explore the associations of the blood Pb, Hg, As, Ba and Cd levels and risk of PCOS in Chinese women of reproductive age.

METHODS

A case-control study was used and included 369 women with PCOS and 441 controls. The levels of Pb, Hg, As, Ba and Cd were measured in fasting blood samples collected on the 2nd or 3rd day of menstruation or vaginal bleeding after drug withdrawal; basal sex hormone levels, fasting glucose and fasting insulin were measured simultaneously. Unconditional logistic regression models were used to assess the relationship of the blood Pb, Hg, As, Ba or Cd levels with PCOS risk. Bayesian kernel machine regression (BKMR) was used to assess the joint effect of Pb, Hg, As, Ba and Cd on PCOS risk and estimate which metal or metals contributed most to the association. Multiple linear regression models were used to investigate the relationships between the levels of selected metals and parameters of the clinical PCOS phenotype.

RESULTS

The mean ± SD ages of women in the case and control groups were 28.80 ± 3.39 and 28.97 ± 2.39 years, respectively; their mean ± SD BMIs were 23.86 ± 3.51 kg/m² and 22.08 ± 3.14 kg/m², respectively. The blood levels of three metals (Pb, As and Ba) were statistically associated with PCOS risk based on single-metal models. With each natural logarithm transformed (ln) unit increase in blood concentrations of Pb, higher likelihood of PCOS can be found, the adjusted odd ratio (aOR) and 95 % confidence interval (CI) was 1.83 (1.35-2.48), and these for As and Ba were 2.49 (1.86-3.33) and 1.20 (1.04-1.39), respectively. Compared with women at the first tertile group, higher likelihoods of PCOS among women in the second and third tertiles of the Pb group were observed, aORs and 95 % CIs were 1.81 (1.22-2.68) and 2.08 (1.42-3.04), respectively; and higher likelihoods of PCOS among women in the third tertiles of As and Ba group were also observed, the aORs and 95%CIs were 2.83 (1.93-4.15) and 1.89 (1.32-2.72), respectively. BKMR analysis also showed a statistically significant and positive joint effect of five metals on PCOS risk when the blood levels of five metals were all above the 55th percentile compared with their median levels, and As (100 %) and Pb (67.44 %) were the major contributors to the association. The blood As levels were positively associated with the luteinizing hormone (LH) levels and LH/FSH (follicle-stimulating hormone) ratio values, the blood Ba levels were negatively associated with the FSH levels, and the blood Pb levels were positively associated with the fasting insulin levels and homeostasis model assessment of insulin resistance (HOMA-IR) values.

CONCLUSIONS

Our results suggest a positive association between exposure to multiple toxic metals (Pb, Hg, As, Ba and Cd) and PCOS risk. As and Pb were the major contributors, evaluated either as a single agent or metal mixture; and Pb, As, and Ba were associated with different parameters of the clinical PCOS phenotype. Additional studies are warranted to confirm these associations, particularly regarding the synergistic effect of toxic metals.

The Beneficial Impact of Zinc Supplementation on the Vascular Tissue of the Abdominal Aorta under Repeated Intoxication with Cadmium: A Study in an In Vivo Experimental Model

In an in vivo rat model of human exposure to cadmium (Cd; 5 and 50 mg/L, 6 months), whether the supplementation with zinc (Zn; 30 and 60 mg/L, increasing its daily intake by 79% and 151%, respectively) protects against the unfavourable impact of this xenobiotic on the vascular tissue of the abdominal aorta was investigated. The treatment with Cd led to oxidative stress and increased the concentrations of pro-inflammatory interleukin 1β (IL-1β), total cholesterol (TC), triglycerides (TG), and endothelial nitric oxide synthase (eNOS) and decreased the concentration of anti-inflammatory interleukin 10 (IL-10) in the vascular tissue. Cd decreased the expression of intercellular adhesion molecule-1 (ICAM-1), platelet endothelial cell adhesion molecule-1 (PECAM-1), and L-selectin on the endothelial cells. The administration of Zn prevented most of the Cd-induced alterations or at least weakened them (except for the expression of adhesive molecules). In conclusion, Zn supplementation may protect from the toxic impact of Cd on the blood vessels and thus exert a beneficial influence on the cardiovascular system. The increase in the intake of Zn by 79% may be sufficient to provide this protection and the effect is related to the antioxidative, anti-inflammatory, and antiatherogenic properties of this essential element.

The function of omega-3 polyunsaturated fatty acids in response to cadmium exposure

Throughout history, pollution has become a part of our daily life with the improvement of life quality and the advancement of industry and heavy industry. In recent years, the adverse effects of heavy metals, such as cadmium (Cd), on human health have been widely discussed, particularly on the immune system. Here, this review summarizes the available evidence on how Cd exposure may affect health. By analyzing the general manifestations of inflammation caused by Cd exposure, we find that the role of omega-3 (n-3) polyunsaturated fatty acids (PUFAs) in vivo can counteract Cd-induced harm. Additionally, we elucidate the effects of n-3 PUFAs on the immune system, and analyze their prophylactic and therapeutic effects on Cd exposure. Overall, this review highlights the role of n-3 PUFAs in the pathological changes induced by Cd exposure. Although n-3 PUFAs remain to be verified whether they can be used as therapeutic agents, as rehabilitation therapy, supplementation with n-3 PUFAs is reliable and effective.

Environmental thallium exposure and the risk of early embryonic arrest among women undergoing in vitro fertilization: thallium exposure and polymorphisms of mtDNA gene interaction and potential cause exploring

Early embryonic arrest (EEA) leads to cancelation of fresh cycles among infertile women undergoing in vitro fertilization (IVF), bringing a great challenge for IVF. Whether exposure to thallium (Tl) is associated with an increased risk of EEA, especially its interaction with polymorphisms of mitochondria DNA (mtDNA) gene, is worthy of study. A case-control design was performed, including 74 EEA cases with 123 IVF cycles and 157 age and BMI-matched controls with 180 IVF cycles. Levels of Tl and other toxic metals (lead (Pb), (mercury) Hg, and (arsenci) As) were assessed by measuring them in blood samples collected on the day of oocyte retrieval; PCR amplification and sequencing were performed to screen the polymorphic sites of mtDNA gene in D-loop region. Bayesian kernel machine regression (BKMR) was used to confirm that Tl played a leading role in the situation of combined exposure; generalized estimating equation (GEE) models were used to evaluate the associations of Tl concentrations, polymorphisms of mtDNA gene, and their interactions with the risk of EEA. The impact of Tl exposure or polymorphisms of mtDNA gene on the oogenesis and embryonic development was also evaluated. BKMR analysis revealed that PIP (posterior inclusion probability) value of T1 was 0.9096, indicating that it played a leading role in the situation of combined exposure. Compared to the first quartile of Tl, the adjusted ORs (95% CIs) of EEA risk were 0.66 (0.26, 1.70), 1.18 (0.52, 2.64), and 4.53 (2.11, 9.69) for the second, third, and fourth quartile, respectively (p trend < 0.001). Compared to the wild type of mtDNA 16,519 gene (T 16,519 T), the adjusted OR (95% CI) of EEA risk for the variant type (T 16,519 C) was 3.11 (1.70, 5.72), and the variant types of the other sites with a minor allele frequency > 10% were not significantly related with the risk of EEA after FDR (False Discovery Rate) correction. With respect to interaction, compared to women at low Tl exposure level & wild type of mtDNA 16,519 gene group, the adjusted OR (95% CI) of EEA risk for women at high Tl exposure level & variant type of mtDNA 16,519 gene group was 9.28 (3.33, 25.81). Additionally, Tl exposure and polymorphisms of mtDNA 16,519 gene are inversely associated with the outcomes of oogenesis and embryonic development significantly. Our study indicated that high Tl exposure level was associated with the increased risk of EEA and Tl played a leading role in the situation of combined exposure; the strength of association was much higher when Tl exposure interacted with polymorphism of 16,519 mtDNA gene. These relationships might originate from the impact of Tl exposure or polymorphism of 16,519 mtDNA gene on the oogenesis and early embryonic development in vitro. Infertile women should keep high vigilant against Tl exposure especially those with variant type of mtDNA 16,519 gene.

Benchmark dose approach in investigating the relationship between blood metal levels and reproductive hormones: Data set from human study

The main objective of this research was to conduct a dose-response modeling between the internal dose of measured blood Cd, As, Hg, Ni, and Cr and hormonal response of serum testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH). The study included 207 male participants from subjects of 5 different cohorts (patients with prostate, testicular, and pancreatic cancer, patients suffering from various thyroid and metabolic disorders, as well as healthy volunteers), enrolled from January 2019 to May 2021 at the Clinical Centre of Serbia in Belgrade, Serbia. Benchmark dose-response modeling analysis was performed with the PROAST software version 70.1, showing the hormone levels as quantal data. The averaging technique was applied to compute the Benchmark dose (BMD) interval (BMDI), with benchmark response set at 10%. Dose-response relationships between metal/metalloid blood concentration and serum hormone levels were confirmed for all the investigated metals/metalloid and hormones. The narrowest BMDI was found for Cd-testosterone and Hg-LH pairs, indicative of high confidence in these estimates. Although further research is needed, the observed findings demonstrate that the BMD approach may prove to be significant in the dose-response modeling of human data.

Plasma concentrations of persistent organic pollutants and pancreatic cancer risk

BACKGROUND

Findings and limitations of previous studies on persistent organic pollutants (POPs) and pancreatic cancer risk support conducting further research in prospective cohorts.

METHODS

We conducted a prospective case-control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Participants were 513 pancreatic cancer cases and 1020 matched controls. Concentrations of 22 POPs were measured in plasma collected at baseline.

RESULTS

Some associations were observed at higher concentrations of p, p'-DDT, trans-nonachlor, β-hexachlorocyclohexane and the sum of six organochlorine pesticides and of 16 POPs. The odds ratio (OR) for the upper quartile of trans-nonachlor was 1.55 (95% confidence interval 1.06-2.26; P for trend = 0.025). Associations were stronger in the groups predefined as most valid (participants having fasted >6 h, with microscopic diagnostic confirmation, normal weight, and never smokers), and as most relevant (follow-up ≥10 years). Among participants having fasted >6 h, the ORs were relevant for 10 of 11 exposures. Higher ORs were also observed among cases with microscopic confirmation than in cases with a clinical diagnosis, and among normal-weight participants than in the rest of participants. Among participants with a follow-up ≥10 years, estimates were higher than in participants with a shorter follow-up (for trans-nonachlor: OR = 2.14, 1.01 to 4.53, P for trend = 0.035). Overall, trans-nonachlor, three PCBs and the two sums of POPs were the exposures most clearly associated with pancreatic cancer risk.

CONCLUSIONS

Individually or in combination, most of the 22 POPs analysed did not or only moderately increased the risk of pancreatic cancer.

The association between environmental cadmium exposure, blood pressure, and hypertension: a systematic review and meta-analysis

We performed a systematic and meta-analysis study to find the association between cadmium (Cd) exposure and blood pressure (BP)/hypertension (HTN) in exposed general populations. We searched main databases for literature published between year 2000 and April 15, 2021. Quality assessment was performed with the Joanna Briggs Institute (JBI) critical appraisal tools. Heterogeneity between studies was determined by I-squared (I²) statistic. The random effects model was used to determine the association between blood and urine Cd levels with hypertension. The overall standard differences in mean for Cd level in hypertensive and control groups were 3.34, 1.79, and 8.09 based on samples from blood, urine, and hair, respectively. The overall standard differences in mean for Cd level in the low and high exposure groups were - 0.795 and - 1.036 based on blood and urinary samples, respectively. Our findings indicate a positive relationship between blood and hair Cd levels and hypertension. We also found that hair is the optimal biological sample to find the relationship between Cd exposure and hypertension for both genders. However, more studies are needed to confirm these findings.

Novel QTL for Low Seed Cadmium Accumulation in Soybean

Soybean is a valuable crop, used in animal feed and for human consumption. Selecting soybean cultivars with low seed cadmium (Cd) concentration is important for the purpose of minimizing the transfer of Cd into the human body. To ensure international trade, farmers need to produce soybean that meets the European Union (EU) Cd limit of 0.2 mg kg-1. In this study, we evaluated two populations of recombinant inbred lines (RILs), X5154 and X4050, for seed Cd accumulation. Linkage maps were constructed with 325 and 280 polymorphic simple sequence repeat (SSR) markers, respectively, and used to identify a novel minor quantitative trait locus (QTL) on chromosome 13 in the X4050 population between SSR markers Satt522 and Satt218. Based on a gene ontology search within the QTL region, seven genes were identified as candidates responsible for low seed Cd accumulation, including Glyma.13G308700 and Glyma.13G309100. In addition, we confirmed the known major gene, Cda1, in the X5154 population and developed KASP and CAPS/dCAPS allele-specific markers for efficient marker-assisted breeding for Cda1.

Epigenetic mechanisms in metal carcinogenesis

Many metals exhibit genotoxic and/or carcinogenic effects. These toxic metals can be found ubiquitously - in drinking water, food, air, general use products, in everyday and occupational settings. Exposure to such carcinogenic metals can result in serious health disorders, including cancer. Arsenic, cadmium, chromium, nickel, and their compounds have already been recognized as carcinogens by the International Agency for Research on Cancer. This review summarizes a wide range of epigenetic mechanisms contributing to carcinogenesis induced by these metals, primarily including, but not limited to, DNA methylation, miRNA regulation, and histone posttranslational modifications. The mechanisms are described and discussed both from a metal-centric and a mechanism-centric standpoint. The review takes a broad perspective, putting the mechanisms in the context of real-life exposure, and aims to assist in guiding future research, particularly with respect to the assessment and control of exposure to carcinogenic metals and novel therapy development.

Nickel's Role in Pancreatic Ductal Adenocarcinoma: Potential Involvement of microRNAs

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancer types with a limited overall survival rate due to the asymptomatic progression of symptoms in metastatic stages of the malignancy and the lack of an early reliable diagnostic biomarker. MicroRNAs (miRs/miRNAs) are small (~18–24 nucleotides), endogenous, non-coding RNAs, which are closely linked to the development of numerous malignancies comprising PDAC. Recent studies have described the role of environmental pollutants such as nickel (Ni) in PDAC, but the mechanisms of Ni-mediated toxicity in cancer are still not completely understood. Specifically, Ni has been found to alter the expression and function of miRs in several malignancies, leading to changes in target gene expression. In this study, we found that levels of Ni were significantly higher in cancerous tissue, thus implicating Ni in pancreatic carcinogenesis. Hence, in vitro studies followed by using both normal and pancreatic tumor cell lines and increasing Ni concentration increased lethality. Comparing LC50 values, Ni-acetate groups demonstrated lower values needed than in NiCl₂ groups, suggesting greater Ni-acetate. Panc-10.05 cell line appeared the most sensitive to Ni compounds. Exposure to Ni-acetate resulted in an increased phospho-AKT, and decreased FOXO1 expression in Panc-10.05 cells, while NiCl₂ also increased PTEN expression in Panc-10.05 cells. Specifically, following NiCl₂ exposure to PDAC cells, the expression levels of miR-221 and miR-155 were significantly upregulated, while the expression levels of miR-126 were significantly decreased. Hence, our study has suggested pilot insights to indicate that the environmental pollutant Ni plays an important role in the progression of PDAC by promoting an association between miRs and Ni exposure during PDAC pathogenesis.

The relationship between oral cancer and cadmium: a review

Cadmium (Cd) has been classified as a type I carcinogen. Since it is ingested orally through food and tobacco use, Cd is likely to be closely related to oral cancers. The relationship between cadmium and oral cancer was investigated using papers on Pubmed and Web of Science. Thus a total of 11 studies from these databases were included in the review. Cd concentrations were significantly higher in both the blood and hair of oral cancer patients than in controls. Additionally, it has been reported that Cd increases the activity of reactive oxygen species. Tobacco plants contain varying levels of Cd. The presence of high Cd concentrations in patients who use tobacco products and develop oral cancer is strong evidence that Cd is directly related to oral cancer. While planning a study to determine the Cd concentrations in biological samples, it is advisable to examine the methodologies of previous studies and to avoid technical deficiencies. New cell line studies are required to explain the relationship between Cd and autophagy-apoptosis.

Agricultural waste materials for adsorptive removal of phenols, chromium (VI) and cadmium (II) from wastewater: A review

Management of basic natural resources and the spent industrial and domestic streams to provide a sustainable safe environment for healthy living is a magnum challenge to scientists and environmentalists. The present remedial approach to the wastewater focuses on recovering pure water for reuse and converting the contaminants into a solid matrix for permanent land disposal. However, the ground water aquifers, over a long period slowly leach the contaminants consequently polluting the ground water. Synthetic adsorbents, mainly consisting of polymeric resins, chelating agents, etc. are efficient and have high specificity, but ultimate disposal is a challenge as most of these materials are non-biodegradable. In this context, it is felt appropriate to review the utility of adsorbents based on natural green materials such as agricultural waste and restricted to few model contaminants: phenols, and heavy metals chromium(VI), and cadmium(II) in view of the vast amount of literature available. The article discusses the features of the agricultural waste material-based adsorbents including the mechanism. It is inferred that agricultural waste materials are some of the common renewable sources available across the globe and can be used as sustainable adsorbents. A discussion on challenges for industrial scale implementation and integration with advanced technologies like magnetic-based approaches and nanotechnology to improve the removal efficiency is included for future prospects.

Carcinogenic Risk of Pb, Cd, Ni, and Cr and Critical Ecological Risk of Cd and Cu in Soil and Groundwater around the Municipal Solid Waste Open Dump in Central Thailand

Several consequences of health effects from municipal solid waste caused by carcinogenic and noncarcinogenic metals have been recognized. The water quality index ( $\text{WQI}$ ) in the groundwater around this landfill is 2945.58, which is unacceptable for consumption. The contaminated groundwater mainly appears within a 1 km radius around the landfill. The metal pollution levels in the soil in descending order were Cu > Cd > Zn=Cr > Pb > Ni. The pollution degree (ER) of Cd was 2898.88, and the potential ecological risk index (RI) was 2945.58, indicating that the risk level was very high. Surprisingly, the hazard index (HI) of Pb (2.05) and Fe (1.59) in children was higher than 1. This indicated that the chronic risk and cancer risk caused by Pb and Fe for children were at a medium level. Carcinogenic risk by oral (CR oral) consumption of Ni, Cd, and Cr in children was 1.4E − 04, 2.5E − 04, and 1.8E − 04, respectively, while the lifetime carcinogenic risk (LCR) of Ni, Cd, and Cr in children was 1.5E − 04, 2.8E − 04, and 2.0E − 04, respectively. In adults, CR oral of Ni and Cr were 1.6E − 03 and 3.0E − 04, respectively, while LCR of Ni and Cr were 1.6E − 03 and 3.4E − 04, respectively, which exceeded the carcinogenic risks limits. Our study indicated a lifetime carcinogenic risk to humans. Environmental surveillance should focus on reducing health risks such as continuous monitoring of the groundwater, soil, and leachate treatment process.

N6-methyladenosine-mediated downregulation of miR-374c-5p promotes cadmium-induced cell proliferation and metastasis by targeting GRM3 in breast cancer cells

Cadmium (Cd) is a toxic heavy metal that can facilitate the development and progression of breast cancer (BC). Emerging evidence has indicated that the progression of Cd-exposed BC is related to the dysregulation of microRNAs (miRNAs). The purpose of our study was to investigate the expression pattern and underlying mechanisms of miR-374c-5p in Cd-mediated BC progression. In this study, T-47D cells and MCF-7 cells were treated with different concentrations of Cd (0.1, 1 and 10 μM) for 72 h. MiR-374c-5p expression was downregulated, and transfection of miR-374c-5p mimics significantly decreased BC cell proliferation, migration and invasion induced by 10 μM Cd. Importantly, we used the Cytoscape software plugin cytoHubba to analyse the intersected genes between our RNA-Seq results and the mirDIP database, and six hub genes (CNR1, CXCR4, GRM3, RTN1, SLC1A6 and ZEB1) were identified as potential direct targets of miR-374c-5p in our model; however, luciferase reporter assays indicated that miR-374c-5p only repressed GRM3 by directly binding to its 3'-untranslated region (UTR). Of note, we verified that suppression of N6-methyladenosine (m6A) modification led to miR-374c-5p downregulation by decreasing its RNA transcript stability. Together, these findings demonstrated that m6A modification of pri-miRNA-374c blocks miRNA-374c-5p maturation and then activates GRM3 expression, which drives BC cell metastasis after Cd exposure.

Biochemical composite material using corncob powder as a carrier material for ureolytic bacteria in soil cadmium immobilization

Corncob powder possessing its superiority in environmental sustainability and cost, was approved with strong capability of being a replacement of biochar in facilitating the microbial carbonate precipitation process. In this study, the ureolytic bacterial strain Bacillus sp. WA isolated from a pre-acquired metal contaminated soil in Guiyu, China, was showed to be well attached on the surfaces of corncob powder, indicating the carrier's role as a durable shelter for bacterial cells. The efficient immobilization helped develop biochemical composite material (BCM) and proven to function better the calcite precipitation. Afterwards, the mechanism and multi-directional benefits of BCM in edaphic cadmium remediation were examined through pot experiment and compared with corncob powder/bacterial strain/nutrient media as control groups. Integrated lab-scale analyses emphasized the advantages of BCM by the maximum soil urease activity (up to 3.440 U/mg and increased by 214% in 28 days), maximal bacterial propagation (most abundant population in fluorescence microscopy), richest surface functional group (most remarkable OC bond and CO bond in FTIR result), notable calcite precipitation (clear calcite crystals on the surface of BCM compared to control group under SEM-EDS), and highest Cd immobilization rate (exchangeable Cd decreased by 68.54%), among all treatments. The pH and electroconductivity measurements additionally led to the mechanism of corncob powder and NBU promoting pre-existed ureolytic bacteria in soil, which demonstrated the added value of corncob to be fine carbon source and residence shelter for soil microorganism, revealing its potential in developing agricultural materials.

Human health risk assessment of lead, cadmium, and mercury co-exposure from agricultural soils in the Tuzla Canton (Bosnia and Herzegovina)

The aim of this study was to assess the risk of human exposure to lead (Pb), cadmium (Cd), and mercury (Hg) through agricultural soil by considering both uncertainty and variability in key exposure parameters. For this reason we collected soil samples from 29 locations in the Tuzla Canton (Bosnia and Herzegovina) and measured their metal levels with inductively coupled plasma atomic emission or absorption spectrometry (ICP-AES and ICP-AAS, respectively). The levels of Pb ranged from 13.33 to 1692.33 mg/kg, of Cd from 0.05 to 3.67 mg/kg, and of Hg from 0.02 to 2.73 mg/kg. To estimate cancer and non-cancer risks we used deterministic and semi-probabilistic methods. Lead was found to involve higher health risk than the other two heavy metals. Its hazard index (HI) decreased between population groups (children>women>men) and exposure routes (ingestion>skin contact>inhalation). Our Monte Carlo simulations indicated that Pb HIs for both adult populations had a 0.6 % probability to exceed the threshold value of 1, while in children this probability was 14.2 %. Cd and Hg showed no probability to exceed the threshold in any scenario. Our simulation results raise concern about possible adverse health effects of heavy metals from soil, especially in children. It is very important to continue monitoring environmental pollution and assess human health risk, not only with respect to soil, but also with other important environmental compartments, such as air and water.

Role of microRNAs in response to cadmium chloride in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal and aggressive malignancies with a 5-year survival rate less than 9%. Early detection is particularly difficult due to the lack of symptoms even in advanced stages. microRNAs (miRs/miRNAs) are small (~ 18–24 nucleotides), endogenous, non-coding RNAs, which are involved in the pathogenesis of several malignancies including PDAC. Alterations of miR expressions can lead to apoptosis, angiogenesis, and metastasis. The role of environmental pollutants such as cadmium (Cd) in PDAC has been suggested but not fully understood. This study underlines the role of miRs (miR-221, miR-155, miR-126) in response to cadmium chloride (CdCl₂) in vitro. Lethal concentration (LC50) values for CdCl₂ resulted in a toxicity series of AsPC-1 > HPNE > BxPC-3 > Panc-1 = Panc-10.5. Following the treatment with CdCl₂, miR-221 and miR-155 were significantly overexpressed, whereas miR-126 was downregulated. An increase in epithelial–mesenchymal transition (EMT) via the dysregulation of mesenchymal markers such as Wnt-11, E-cadherin, Snail, and Zeb1 was also observed. Hence, this study has provided evidence to suggest that the environmental pollutant Cd can have a significant role in the development of PDAC, suggesting a significant correlation between miRs and Cd exposure during PDAC progression. Further studies are needed to investigate the precise role of miRs in PDAC progression as well as the role of Cd and other environmental pollutants.

Different Routes of Administration Lead to Different Oxidative Damage and Tissue Disorganization Levels on the Subacute Cadmium Toxicity in the Liver

The toxic effects of cadmium (Cd) on hepatic parameters are widely described in the literature. Experimental models often make use of the intraperitoneal route (i.p.) because it is easier to apply, while in the oral route, Cd poisoning in humans is best represented by allowing the metal to pass through the digestive system and be absorbed into the bloodstream. Thus, this study investigated the Cd exposure impact on the liver, by comparing both i.p. and oral routes, both in single dose, in addition to the oral route in fractional doses. Swiss adult male mice received CdCl₂ 1.5 mg/kg i.p., 30 mg/kg oral single dose, and 4.28 mg/kg oral route in fractional doses for 7 consecutive days. Cd bioaccumulation was observed in all animals exposed to Cd. Hepatic concentrations of Ca and Fe increased only in the fractionated oral route. Liver activities of SOD and CAT increased only by oral single dose. GST decreased in all forms of oral administration, while MDA decreased only in i.p. route. Liver weight and HSI increased in the i.p. route, while organ volume increased in all forms of oral administration, and liver density increased in all animals exposed to Cd. In hepatic histomorphometry, the changes were more evident in oral administration, mainly in exposure to metal in a single dose. Thus, the subacute administration of Cd in different routes of administration leads to different changes in liver poisoning.

Cadmium promotes apoptosis and inflammation via the circ08409/miR-133a/TGFB2 axis in bovine mammary epithelial cells and mouse mammary gland

Cadmium is a common environmental heavy metal pollutant that can accumulate over long periods of time and cause disease. Thus, analysis of the molecular mechanisms affected by cadmium in the body could be of great significance for the prevention and treatment of cadmium-related diseases. In this study, flow cytometry, immunofluorescence, transmission electron microscopy, H&E (Hematoxylin Eosin) staining and TUNEL (TdT-mediated dUTP Nick-End Labeling) assays were used to verify that cadmium induced apoptosis and immune responses in bovine mammary epithelial cells (BMECs) and in mouse mammary gland. Isolated BMECs cultured with or without cadmium were collected to screen miRNA (microRNA) using high-throughput sequencing. There were 42 differentially-expressed miRNAs among which 27 were upregulated and 15 downregulated including bta-miR-133a, bta-miR-23b-5p, bta-miR-29e, bta-miR-365-5p, bta-miR-615, bta-miR-7, bta-miR-11975, bta-miR-127, and bta-miR-411a. Among those, miR-133a (which can specifically target TGFB2 (Recombinant Transforming Growth Factor Beta 2) was the most significantly downregulated with a fold-change of 5.27 in BMECs cultured with cadmium. Application of the double luciferase reporter system, western blotting, and qRT-PCR (Quantitative Real-time PCR) revealed that circ08409 can directly bind to miR-133a. Experiments demonstrated that circRNA-08409 could adsorb bta-miR-133a. Both circ08409 and TGFB2 significantly increased apoptosis and altered expression level of a series of inflammatory factors in BMECs. In contrast, miR-133a decreased significantly apoptosis and inflammation in the cells. Compared with cultures receiving only cadmium, the miR-133a+cadmium cultures exhibited significant reductions in the occurrence of late apoptosis. Overall, results indicated that circ08409 could relieve the inhibitory effect of miR-133a on TGFB2 expression by combining with miR-133a and subsequently modulating cell proliferation, apoptosis and inflammation. Overall, the data suggested that the circ08409/miR-133a/TGFB2 axis might play a role in mediating the effect of cadmium on BMECs. As such, data provide novel insights into controlling hazards that cadmium could induce in the mammary gland.

A Strategy to Revalue a Wood Waste for Simultaneous Cadmium Removal and Wastewater Disinfection

In this investigation, the possibility of wood waste (hardwoods such as oaks’ and alternatives’ staves from Balkan cooperage) revalorization for simultaneous cadmium removal and wastewater disinfection was examined. All samples were characterized in terms of their crystallinity index and crystallite size, amount of functional groups, and surface chemistry (determined by ATR-FTIR) as well as antibacterial activity. Mulberry is characterized by the lowest crystallinity index which can be ascribed to the highest crystallite size disabling crystallite denser packaging, while myrobalan plum has about 23% lower crystallite size that enables crystallite better packaging, thus resulting in a 42.4% higher crystallinity index compared to the mulberry. All oaks have a significantly higher amount of carboxyl groups compared to the alternatives (0.23-0.28 vs. 0.12-0.19 mmol/g). The adsorption experiments revealed that with increasing the initial cadmium concentration from 15 up to 55 mg/g, samples’ adsorption capacity increases by 89-220%. The equilibrium data fit well with the Langmuir isotherm model implying monolayer coverage of cadmium ions over a homogeneous wood surface. The relationship between the samples’ maximum adsorption capacities (ranged from 5.726 to 12.618 mg/g), their crystallinity index, and crystallite size was established. According to ATR-FTIR spectra, aldehyde, carboxyl, hydroxyl, and phenyl groups present on the wood waste surface are involved in Cd2+ adsorption which proceeds via the interplay of the complexation, cation-π interactions, and ion-exchange mechanisms. Mulberry and myrobalan plum showed about 89% and 80% of the total uptake capacity of cadmium within 60 min, while the equilibrium was attained after 240 min of contact time. Good compliance with pseudo-second kinetic order indicated that cadmium adsorption was mediated by chemical forces. Thermodynamic parameters revealed the spontaneous and exothermic character of cadmium ion adsorption onto mulberry and myrobalan plum. All studied samples provide maximum bacterial reduction (>99%) for E. coli and S. aureus. Wood waste from Balkan cooperage can be successfully used for simultaneous cadmium removal and wastewater disinfection.

Cadmium tissue level in women diagnosed with breast cancer - A case control study

Breast cancer is at the forefront of female malignancy and the leading cause of cancer death among women. Gender, age, hormone therapy, smoking, exposure to endocrine disruptors and family history are significant breast cancer risk factors according to epidemiological data. Considering metalloestrogenic Cd property and a plethora of research work on hormone involvement in breast cancer the study aimed to determine Cd concentration in three compartments of breast cancer patients in relation to their blood hormone status. Further, as oxidative stress is a critical mechanism of Cd toxicity, the objective of this study was to determine potential changes in oxidative status homeostasis. The study enrolled 55 patients with breast cancer diagnosis and 41 healthy women with benign breast changes. Concentration of Cd was determined using graphite furnace atomic absorption spectrometry. Cadmium concentration in tumor tissue was significantly higher than control and almost four times higher than Cd concentration in the healthy surrounding tissue. Strong positive correlation was observed between Cd concentrations in changed breast tissue and FSH and LH levels, while the correlation was negative with estradiol level. Cancer patients had significantly increased blood total antioxidative status while total oxidative status did not significantly differ between study groups. The study revealed Cd implication in breast cancer onset following a significant odd ratio for Cd levels in changed tissue samples. Moreover, presented data confirmed sex hormone and oxidative status imbalance caused by Cd presence, closely related to cancer development.

Associations between concentrations of selected perfluoroalkyl acids and concentrations of blood cadmium, lead, and total mercury

Data (N = 2552) from National Health and Nutrition Examination Survey for US adults aged ≥ 20 years for 2011-2016 were analyzed to estimate the associations between the concentrations of blood cadmium, lead, and total mercury and the concentrations of seven perfluoroalkyl acids (PFAA), namely, 2-(N-Methyl-perfluorooctane sulfonamido) acetic acid (MPAH), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonic acid (PFOS). Concentrations of blood cadmium were negatively associated with the concentrations of PFHxS (β = - 0.05428, p < 0.01) and PFOS (β = - 0.0212, p = 0.02). Concentrations of blood lead were positively associated with the concentrations of MPAH (β = 0.03301, p < 0.01), PFOA (β = 0.04783, p = 0.01), PFNA (β = 0.11761, p < 0.01), PFDA (β = 0.08007, p < 0.01), PFUA (β = 0.11382, p < 0.01), and PFOS (β = 0.04996, p = 0.02). Percent increases in the concentration of blood lead were 0.32%, 0.46%, 1.13%, 0.77%, 1.09%, and 0.48% for 10% increases in the concentrations of MPAH, PFOA, PFNA, PFDA, PFUA, and PFOS, respectively. Concentrations of blood total mercury were positively associated with the concentrations of PFNA (β = 0.37105, p < 0.01), PFDA (β = 0.46875, p < 0.01), PFUA (β = 0.56934, p < 0.01), and PFOS (β = 0.17557, p < 0.01). Percent increases in the concentration of blood total mercury were 3.6%, 4.57%, 5.58%, and 1.69% for 10% increases in the concentrations of PFNA, PFDA, PFUA, and PFOS, respectively. Associations between the concentrations of PFAAs with blood total mercury were substantially stronger than the concentrations with blood lead. Higher the carbon chain length for PFAAs, stronger were the associations between PFAAs with lead and mercury.

The Role of Toxic Metals and Metalloids in Nrf2 Signaling

Nuclear factor erythroid 2-related factor 2 (Nrf2), an emerging regulator of cellular resistance to oxidants, serves as one of the key defensive factors against a range of pathological processes such as oxidative damage, carcinogenesis, as well as various harmful chemicals, including metals. An increase in human exposure to toxic metals via air, food, and water has been recently observed, which is mainly due to anthropogenic activities. The relationship between environmental exposure to heavy metals, particularly cadmium (Cd), lead (Pb), mercury (Hg), and nickel (Ni), as well as metaloid arsenic (As), and transition metal chromium (Cr), and the development of various human diseases has been extensively investigated. Their ability to induce reactive oxygen species (ROS) production through direct and indirect actions and cause oxidative stress has been documented in various organs. Taking into account that Nrf2 signaling represents an important pathway in maintaining antioxidant balance, recent research indicates that it can play a dual role depending on the specific biological context. On one side, Nrf2 represents a potential crucial protective mechanism in metal-induced toxicity, but on the other hand, it can also be a trigger of metal-induced carcinogenesis under conditions of prolonged exposure and continuous activation. Thus, this review aims to summarize the state-of-the-art knowledge regarding the functional interrelation between the toxic metals and Nrf2 signaling.

MicroRNA-363-3p promotes apoptosis in response to cadmium-induced renal injury by down-regulating phosphoinositide 3-kinase expression

We previously determined that specific microRNAs (miRNAs) are involved in renal pathophysiological occurrences induced by cadmium (Cd) in rats. This study expands our studies on miRNAs, determining their role in Cd-induced nephrotoxicity in occupational workers. We performed miRNA microarray analyses of blood and urine samples from patients diagnosed as occupational chronic Cd poisoning (OCCP) with abnormally elevated concentrations of urinary beta-2-microglobulin (U-β₂-MG), an indicator of tubular proteinuria. We also performed in vitro bioinformatics-based investigations of apoptosis-related genes targeted by miRNAs involved in the biological response to Cd exposure. We tested five differentially expressed miRNAs and determined a significant increase of sera miR-363-3p. Also, we determined that miR-363-3p increase is associated with phosphoinositide 3-kinase (PI3K) down-regulation and the suppressed proliferation and enhanced apoptosis of renal tubule epithelial cells. The obtained results suggest miR-363-3p involvement in the pathophysiology of Cd-induced renal injury in humans and maybe considered for possible interventional therapeutic strategies for Cd-associated kidney damage.