Blood Cd Levels Research Articles

Detrimental effects of cadmium on male infertility: A review.

Infertility has become a serious health and socio-economic-psychological problem globally. The harmful role of trace metals in male infertility is recognized but still not sufficiently explained. Herein, a comprehensive review was conducted to elucidate the detrimental role of cadmium (Cd) on male infertility, particularly on infertility with unknown (idiopathic) causes. Peer-reviewed studies from 2000 to 2024 dealing with seminal plasma and blood Cd levels of fertile and infertile men were retrieved were interrogated with regard to strict inclusion/exclusion criteria, and then were thoroughly reviewed and analyzed. Another aim of this review was to indicate the potential effects of Cd on changes in seminogram findings. A median range of seminal plasma Cd levels from 0.2 to 1.5 µg/L can be considered safe for men's fertility. This review strongly implies that Cd levels were notably higher in seminal plasma of infertile cases than controls. The review's data also indicate that exposure to tobacco smoke is a major source of elevated seminal and blood Cd levels in infertile men. Newer research points to the importance of Cd in lower levels from the environment on changes in seminogram findings, primarily count, motility of spermatozoa, and their morphology. Overall, this review implies that seminal plasma Cd levels could be a good indicator of semen quality. However, new, in-depth studies are needed to confirm or reject the causal relationship of Cd with male infertility.

Pb-Cd in Maternal Blood and Affecting Factors

The exposure to Pb-Cd during pregnancy has negative effects on both the mother and the baby. Karabuk province, which is the center of the iron and steel industry, is a region with a high risk of Pb-Cd exposure. This study was designed to determine the levels of lead and cadmium in maternal blood samples and the factors influencing them. After the ethical committee approval from Karabük Training and Research Hospital Ethical Committee, descriptive and analytical analyses were started on the blood samples collected from 100 pregnant women in their third trimester with the childbirth between 01.09.2018-01.09.2019 in Karabük Training and Research Hospital Obstetrics and Gynecology Clinic. The study, conducted in a descriptive and analytical manner, utilized a 32-question survey form prepared by the researchers and venous blood samples collected simultaneously. For the Pb-Cd analysis, a 3 ml venous blood sample was obtained from pregnant women using a sterile syringe into hemogram tubes with purple caps containing Ethylenediaminetetraacetic acid (EDTA). The collected samples were preserved in a -20°C refrigerator immediately after labeling and were kept until they were taken for analysis. Maternal blood samples were analyzed using the Atomic Absorption Spectroscopy (AAS) Graphite System method. According to the analysis results, the mean maternal blood Pb levels of pregnant women with an average age of 28.3±5.37 were found to be 0.89±0.22 μg/dl, and Cd levels were 0.26±0.07 μg/dl. Maternal blood Pb-Cd levels were compared each other according to five parameters which are socio-demographic aspect, obstetrical variables, location characteristics, dietary history, and cosmetic use. Based on these parameters any statistically significant results were obtained. However, blood lead levels were significantly different in pregnant women who smoked (p=0.001) and were exposed to secondhand smoke (p<0.05) compared to non-smokers and those not exposed to secondhand smoke. On the other hand, there was no significant difference in blood Cd levels with respect to exposure to secondhand smoke (p>0.05). Since exposure to Pb-Cd is not a short-term exposure, but rather long-term exposure to low concentrations in daily life, and because their half-lives are long-term. These results obtained from this study can shed light on future studies which aimed to determine the effect of long- term exposure of heavy metals on pregnant women and infants.

Heavy Metal and Trace Element Status and Dietary Determinants in Children with Phenylketonuria

Background/Objectives: Heavy metals are a group of metals and metalloids that have a relatively high density. They can cause toxicity even at very low levels. Trace elements are required by all living organisms to maintain their normal growth, metabolism, and development. Oral intake is the main route of exposure to both heavy metals and trace elements. Phenylketonuria (PKU) is the most common amino acid metabolic disorder, and the best known treatment for patients requiring treatment is a phenylalanine (Phe)-restricted diet. The objective of the present study was to evaluate the plasma heavy metal levels, sources of exposure, changes in these levels according to dietary regimen, and trace element levels and their correlations with heavy metals in PKU patients. Methods: The study was conducted between July 2022 and January 2024 on 105 patients aged 2–6 years diagnosed with PKU. Results: The percentage of Pb levels in individuals in the upper quartile increased by 3.47 times (95% CI = 1.07–11.29) in those who consumed canned foods and 7.29 times (95% CI = 1.21–44.03) in those who consumed spring water. The percentage of As levels in the upper tertile increased by a factor of 7.26 (95% CI = 2.09–25.28) in individuals under four years of age and 8.17 times (95% CI = 2.13–31.27) in canned food users. The odds of having blood Cd levels in the upper tertile were 0.09 (95% CI = 0.01–0.96) for those being breastfed for 6–11 months compared to 0–5 months. Zn levels were lower (93.0 vs. 83.6 µg/dL, p = 0.008) in patients on a Phe-restricted diet. Conclusions: The present study did not find a relationship between heavy metal exposure and the dietary treatment status of patients with PKU. Our findings indicate that canned food consumption is a significant contributing factor to heavy metal exposure in PKU patients. Furthermore, our findings revealed a relationship between age, perception of economic level, breastfeeding, kitchen equipment, and water usage and the levels of certain heavy metals.

Physical activity modified the association of blood cadmium and lead with Helicobacter pylori infection: A cross-sectional analysis with NHANES data.

Cadmium (Cd) and lead (Pb) exposure have been identified as risk factors for Helicobacter pylori seropositivity, possibly due to the immune suppression by Cd and Pb. Physical activity (PA) can induce an immune response. However, whether PA can reduce the effect of Cd and Pb on H pylori infection remains elusive. This study aims to investigate the association of blood Cd and Pb levels with H pylori infection and explore the intermediary effects of PA. This cross-sectional survey was conducted using the National Health and Nutrition Examination Survey (NHANES) of the 1999 to 2000 cycle (n = 9965). Participants without clear serological testing data, or absent in PA, blood Cd, and Pb information were excluded. Collinearity analysis was performed to remove the variables with high collinearity. Restricted cubic spline curve analysis was adopted to assess the nonlinear association of Cd and Pb with H pylori infection. The logistic regression analysis, generalized linear models, sensitivity analysis, and P for trend test were used to further analyze their relationship. Then, we analyzed the association of Cd and Pb with H pylori infection in 2 PA groups. Totally 3638 participants were divided into H pylori-negative (n = 2545) and H pylori-positive group (n = 1093). Pb exhibited a linear relationship but Cd had a nonlinear relationship with H pylori infection. Besides, the elevation of Cd and Pb both independently predicted H pylori infection after adjusting various variables (P < .05). The robust relationship was confirmed by the P for trend test (P for trend < .05). Under Cd exposure, the risk of H pylori infection was lower in the active PA group than in the inactive group (P < .05). A reverse result was found under the Pb exposure (P < .05). Exposure to Cd and Pb are positively linked to H pylori infection. PA may alleviate the effect of Cd on H pylori infection but may enhance H pylori infection under Pb exposure. Therefore, PA should be recommended in the appropriate season or region.

Health risk assessment of lead and cadmium exposure from food and snuff in Pakistani population

BackgroundSmokeless tobacco (SLT) is a tobacco-based product consumed without burning or smoking. Snuff, commonly known as naswar, is a widely used SLT product in Pakistan. This study is designed to investigate the concentrations of lead (Pb) and cadmium (Cd) in snuff and their associated health risks to consumers. MethodsBlood samples from snuff consumers and non-consumers were analyzed for Pb and Cd concentrations. Additionally, samples of drinking water and wheat flour were also analyzed for Pb and Cd. Health risk assessments were calculated using hazard quotient (HQ) and incremental lifetime cancer risk (ILCR) for Pb and Cd. ResultsSnuff consumers had significantly higher blood-Pb and blood-Cd levels compared to non-consumers. Approximately 38.5 % of snuff consumers were found to exceed blood-Pb levels from the safe limits (10 µg dL⁻¹) of the World Health Organization (WHO), while 48.9 % of snuff consumers were found to exceed blood-Cd levels from the WHO safe range of 0.03–0.12 µg dL⁻¹. Snuff samples contained Pb and Cd concentrations ranging from 5.3 to 22.4 µg g⁻¹ and 0.5–2.2 µg g⁻¹, respectively. Drinking water and wheat flour samples were found within the safe limits for Pb and Cd concentration, suggesting snuff as the primary source of exposure. Health risk assessments indicated elevated HQ values, for Pb (38.9 %) and Cd (14.3 %) detected in snuff, surpassing the safe HQ threshold of 1. Concerning ILCR from snuff, values for Pb were within the acceptable range, but alarmingly 100 % of samples for Cd exceeded the safe limits of USEPA (1.0×10⁻⁴), indicating a significant cancer risk in snuff users. ConclusionThis study highlights the exceeded Pb and Cd concentrations in snuff as well as also reporting significant carcinogenic and non-carcinogenic health risks to consumers. These findings emphasized the urgent need for regulatory bodies to ensure the safety of snuff before selling in the market. Public Health Professionals should also initiate educational campaigns to raise awareness among consumers and manufacturers about various health risks associated with the snuff.

A cross-sectional study of the association between blood cadmium and mortality among adults with myocardial infarction.

Cadmium (Cd) plays a key role in the occurrence of myocardial infarction (MI). We aimed to explore the association between blood Cd levels and all-cause mortality of MI on the basis of the National Health and Nutrition Examination Survey databases. This study included 800 adults with MI to obtain blood Cd concentrations and their follow-up information. The association between Cd concentrations and mortality was analyzed using Cox regression, restricted cubic spline (RCS) models, mediation analysis, receiver operating characteristic curve, and Kaplan-Meier curves. All the patients were divided into 4 groups according to the quartiles of blood Cd levels (Q1, Q2, Q3, and Q4). Cox regression analysis with adjustment for covariates indicated that Cd was the promoting factor of mortality, and patients with higher Cd had a higher death risk. The RCS model indicated an "inverted checkmark" shaped correlation between Cd levels and mortality, and a turning point of 1.06 μg/L was found. A significant positive correlation was observed on the left of the turning point. Grouped patients by turning point into 2 groups, Kaplan-Meier analysis showed that the low-concentration group had a lower death risk than the high-concentration group. Subgroup analysis revealed that the prognostic effect of Cd was more pronounced in patients with former smoking history, and receiver operating characteristic curve showed that blood Cd had a better-predicting function in patients with MI. Blood Cd levels were significantly related to all-cause mortality in patients with MI, especially in patients with Cd < 1.06 μg/L.

Blood cadmium concentration and pulmonary function injury: potential mediating role of oxidative stress in chronic obstructive pulmonary disease patients

BackgroundExposure to cadmium (Cd) is associated with a reduction in lung function among patients with chronic obstructive pulmonary disease (COPD). The longitudinal relationship and mechanism underlying the link between Cd exposure and lung function changes among COPD patients are yet unknown.MethodsThe cohort study included 259 eligible patients who underwent regular professional follow-ups. Blood Cd levels and serum 8-iso-prostaglandin F2 alpha (8-iso-PGF2α) levels were assessed. Lung function was determined at baseline and follow-up research. The associations between changes in lung function and blood Cd concentration were analysed using multivariate linear and logistic regression models.ResultsEach 1-ppb elevation in blood Cd content resulted in a 0.420 L decrease in forced vital capacity (FVC), a 0.424 L decrease in forced expiratory volume in 1 s (FEV1), a 4.341% decrease in FEV1/FVC%, and a 8.418% decrease in FEV1% predicted in patients with COPD. Blood Cd concentration showed a positive correlation with serum 8-iso-PGF2α levels in a specific range. The relative contribution of increased serum levels of 8-iso-PGF2α to Cd-induced declines in FEV1, predicted FEV1%, and FEV1/FVC% were 2.08%, 8.08%, and 13.19%, respectively.ConclusionBlood Cd levels are associated with lung function changes in COPD patients. Oxidative stress is thought to be an important mediator in Cd-induced reduction of pulmonary function.

Cadmium Exposure and Noncommunicable Diseases in Environmentally Exposed Brazilian Population: Cross-Sectional Study without Association of GSTP1 Polymorphism.

Cadmium (Cd) is a toxic metal which is harmful to humans and the environment. Cd levels and adverse effects may be associated with genetic polymorphisms in genes involved in its toxicokinetics. This study investigated Cd levels in 198 residents of a condominium in Rio de Janeiro, Brazil, built on industrial steel slag waste and the influence of glutathione S-transferase pi isoform 1 (GSTP1) rs1695 A>G polymorphism. Polymorphism was genotyped using a validated TaqMan assay; Cd levels were measured in blood (BCd) and urine (UCd) by graphite furnace atomic absorption spectrometry. Associations were evaluated by multiple logistic regression, odds ratios (ORs), and 95% confidence intervals (CIs). The mean Cd levels were 0.70 ± 0.20 µg L-1 (BCd), 0.58 ± 0.57 µg L-1 (UCd), and 0.61 ± 0.65 µg g-1 in urine corrected by creatinine (UcCd), and the Cd results were above tolerable levels (BCd > 0.5 µg L-1) in 87.4% of subjects. Higher blood Cd levels (>0.69 µg L-1) were associated with respiratory disease (OR = 2.4; 95%CI = 1.2-5.0), as almost 30% of people with respiratory diseases had higher Cd levels. The GSTP1 rs1695AA genotype frequency was 38.1%, and there were no significant differences between the SNP and Cd levels. High Cd levels and a high prevalence of diseases highlight the importance of implementing public policies and the continuous monitoring of this at-risk population.

Association between blood lead, cadmium, selenium levels and hyperlipidemia: A population-based study.

There are limited epidemiological investigations of blood metal levels related to hyperlipidemia, and results indicating the association between blood lead (Pb), cadmium (Cd) and selenium (Se), and lipid biomarkers have been conflicting. We included populations for which NHANES collected complete data. Multivariate logistic regression and subgroup analyses were conducted to ascertain the relationship between blood Pb, Cd, and Se levels and hyperlipidemia. Nonlinear relationships were characterized by smoothed curve fitting and threshold effect analysis. 5429 participants in all, with a mean age of 53.70 ± 16.63 years, were included; 47.1% of the subjects were male, and 3683 (67.8%) of them had hyperlipidemia. After modifying for variables with confounders in a multivariate logistic regression model, we discovered a positive correlation between blood Pb and Se levels and hyperlipidemia (Pb: OR:2.12, 95% CI:1.56-2.88; Se: OR:1.84, 95% CI:1.38-2.45). Gender, age, smoking status, alcohol use status, hypertension, diabetes, and body mass index were not significantly linked with this positive correlation, according to subgroup analysis and interaction test (P for interaction>0.05). Positive correlations between blood Pb, Cd, and Se levels and the risk of hyperlipidemia have been found using smooth curve fitting. This study demonstrates that higher blood levels of Pb, Cd, and selenium are linked to an increased risk of hyperlipidemia.

Cadmium exposure and its association with oxidative stress, MT1A methylation, and idiopathic male infertility in Egypt: A case-control study

Idiopathic male infertility, a significant health concern, lacks a clear etiology. Cadmium (Cd), a widespread environmental pollutant known to impact male reproductive health negatively, can accumulate in mussels, a common food source in Egypt. This study investigated the link between ecological Cd exposure, oxidative stress, MT1A methylation, and idiopathic male infertility in two regions of Alexandria. Thirty-three infertile men and 33 fertile controls were included. Cd levels were measured in mussels from the study sites and in participants' blood and semen. Biomarkers reflecting Cd exposure and its effects were assessed. Mussel Cd levels exceeded regulatory limits. Infertile men revealed significantly higher blood and semen Cd levels, reduced semen quality, increased oxidative stress, and elevated MT1A methylation compared to controls. MT1A methylation was inversely correlated with sperm count and is the strongest predictor of idiopathic male infertility, demonstrating the lowest p-value and considerable effect size. This study suggests that environmental Cd exposure, potentially through mussel consumption, may contribute to idiopathic male infertility in Egypt by increasing oxidative stress, inducing epigenetic modifications, and impairing semen quality. These findings underscore the need for further research into the mechanisms underlying Cd-induced male infertility and the development of preventative strategies.

Investigation of the Relationship Between Heavy Metals (Cadmium, Arsenic, and Lead) and Metallothionein in Multiple Sclerosis.

Multiple sclerosis (MS) is one of the most common neurological disorders. Metals are important for the maintenance and preservation of homeostasis and dysregulated metal homeostasis has an impact on neurodegeneration. Environmental factors are considered to contribute to MS risk and progression. Heavy metals such as arsenic (As), cadmium (Cd), and lead (Pb) are widely found in the environment and because of their toxic nature, they pose a great danger to human health. Metallothioneins (MTs) play important roles in metal homeostasis and detoxification of heavy metals. The aim of this study was to investigate the relationship between levels of heavy metals (As, Cd, and Pb) andMT levels in MS patients and also to assess the oxidative stress status of patients. Fifty subjects (20 healthy subjects and 30 MS patients) were included. Demographic characteristics of the patients, plasma MT levels, blood Cd, As, and Pb levels, as well as iron (Fe), copper (Cu), and zinc (Zn) levels, were determined. Malondialdehyde (MDA) levels were investigated as a marker of oxidative stress. MT levels were slightly higher in the MS group (p > 0.05). As Cd and Pb levels were significantly higher in the control subjects. MDA levels were significantly higher in MS patients. Our results support the relevance of MT and MDA levels in MS. Further clinical studies with larger cohorts will provide more insights into these factors.

Resource partitioning influences levels of toxic trace elements in sympatric tropical seabirds

Morphologically similar species that occupy resource-limited environments tend to differ in their ecological traits in order to coexist, which may result in differential exposure to environmental threats. For instance, partitioning of feeding resources may influence contaminant exposure and bioaccumulation in marine predators through different diets or foraging habitats. Here, we sampled three tropical seabird species breeding in sympatry in the southwestern Atlantic Ocean for blood and feather trace element concentrations (As, Hg, Cd, Pb), and assessed their foraging ecology with bio-logging (GPS tracks and time-depth recorders), analysis of regurgitated prey, and carbon and nitrogen stable isotope mixing models. Red-billed tropicbirds (Phaethon aethereus), brown (Sula leucogaster) and masked (S. dactylatra) boobies differed in their preferred foraging locations, the range of foraging trips, diving parameters and diets. In addition, interspecific differences were detected in blood or feathers for all trace elements analyzed, suggesting influence of the differences observed in diet and space use. Red-billed tropicbirds had the largest foraging range over the continental shelf and over the slope, suggesting lower exposure to continental sources of metals. Brown and masked boobies had higher Hg concentrations than tropicbirds, higher δ15N values (a proxy for trophic level), and δ15N correlated with Hg levels, suggesting biomagnification of Hg along the food chain. Nonetheless, red-billed tropicbirds showed comparable levels of As and Cd in blood or feathers, and higher levels of Pb in both tissues in comparison to boobies, which may suggest overall exposure of seabirds in the region, through their diets and foraging areas. Resource partitioning is critical for allowing coexistence of different seabird species in shared breeding sites where they act as central-place foragers. Nonetheless, in scenarios of environmental pollution, these species-specific strategies lead to differential bioaccumulation, and thus distinct effects of pollution on populations are expected.

The Association between Cadmium Exposure and Thyroid Function in Animals: A Systematic Review.

Several studies have indicated an association between cadmium (Cd) exposure and the induction of thyroid dysfunction in animal models. Objective and Aims: There are inconsistent findings on the effect of Cd on the thyroid gland. Therefore, this systematic study was designed to determine the association between changes in thyroid function markers and Cd exposure in animals. The search was performed on Scopus, PubMed, Web of Science and databases, and Google Scholar until May 2023. Studies on the relationship between Cd exposure and fish's thyroid function were conducted on rodents and fish. In total, 171 articles were obtained from the main databases using the search strategy mentioned in this study. Finally, 24 articles were selected according to our inclusion criteria for systematic studies. The findings indicated an increase/decrease or no change in triiodothyronine (T3), thyroxine (T4), and thyroid stimulating hormone (TSH) levels in rodents, fish, and animals exposed to Cd. Our findings indicated an association between Cd exposure and thyroid dysfunction in rodents, fish, and other animals. However, the association between urinary and blood Cd levels and thyroid function remains unclear in humans because of controversial findings and a lack of strong mechanistic evidence. We perform large cohort human studies to the answer to this question.

Environmental Cadmium Exposure Induces an Increase in Systolic Blood Pressure by Its Effect on GFR

Chronic exposure to the nephrotoxic metal pollutant, cadmium (Cd), has been associated with hypertension, but the mechanism by which it raises blood pressure is not understood. We hypothesize that exposure to Cd reduces the glomerular filtration rate (GFR), which in turn causes a rise in blood pressure. Data were collected from 447 Thai subjects with a mean age of 51.1 years, of which 48.8% had hypertension, 15.4% had diabetes, and 6.9% had an estimated GFR (eGFR) below 60 mL/min/1.73 m2 (low eGFR). More than half (58.8%) and 23.9% had moderate and severe tubular proteinuria, respectively. The mean blood and urinary Cd concentrations were 2.75 and 4.23 µg/L, respectively. Doubling of body burden of Cd increased the prevalence odds ratios (POR) for low eGFR and severe tubular proteinuria 41% and 48%, respectively. The POR for hypertension rose twofold in those with blood Cd levels of 0.61–1.69 µg/L or urinary Cd excretion levels ≥ 0.98 µg/g creatinine. In the hypertensive group, the eGFR was inversely associated with age (β = −0.517), the Cd excretion rate (β = −0.177), and diabetes (β = −0.175). By mediation analysis, an increase in SBP was attributable totally to the effect of Cd on GFR. Thus, blood pressure appeared to rise as GFR fell. This finding is consistent with the well-known role of the kidney in long-term blood pressure regulation, and explains a universally high prevalence of hypertension among patients with low eGFR.

Blood Cadmium Level Is a Marker of Cancer Risk in Men.

Cadmium (Cd) is a known carcinogen, but its impact on cancer risk at lower concentrations is poorly understood. Previous studies on Cd and cancer risk in men show inconsistent results, prompting further investigation. A prospective cohort study involving 2956 men was conducted. Blood Cd levels were measured, and participants were followed for 78 months to assess cancer incidence. Men with high blood Cd levels (>0.71 µg/L) had a significantly increased risk of cancer compared to those with low levels (<0.19 µg/L) (HR 3.42, p < 0.001), particularly among non-smokers (HR 3.74, p = 0.003), individuals aged < 60 years (HR 2.79, p = 0.017), and ≥60 (HR 4.63, p = 0.004). The influence of smoking on cancer risk based on Cd levels was not significant in this study. Blood Cd levels may influence cancer risk in men, emphasizing the importance of minimizing Cd exposure to reduce risk. Confirmation of these results in other populations is essential for effective preventive measures against Cd-related cancers.

Cadmium inhibits calcium activity in hippocampal CA1 neurons of freely moving mice.

Cadmium (Cd) is a ubiquitous toxic heavy metal and a potential neurotoxicant due to its wide use in industrial manufacturing processes and commercial products, including fertilizers. The general population is exposed to Cd through food and smoking due to high transfer rates of Cd from contaminated soil. Cd has been shown to mimic calcium ions (Ca2+) and interfere with intracellular Ca2+ levels and Ca2+ signaling in in vitro studies. However, nothing is known about Cd's effects on Ca2+ activity in neurons in live animals. This study aimed to determine if Cd disrupts Ca2+ transients of neurons in CA1 region of the hippocampus during an associative learning paradigm. We utilized in vivo Ca2+ imaging in awake, freely moving C57BL/6 mice to measure Ca2+ activity in CA1 excitatory neurons expressing genetically encoded Ca2+ sensor GCaMP6 during an associative learning paradigm. We found that a smaller proportion of neurons are activated in Cd-treated groups compared with control during fear conditioning, suggesting that Cd may contribute to learning and memory deficit by reducing the activity of neurons. We observed these effects at Cd exposure levels that result in blood Cd levels comparable with the general U.S. population levels. This provides a possible molecular mechanism for Cd interference of learning and memory at exposure levels relevant to U.S. adults. To our knowledge, our study is the first to describe Cd effects on brain Ca2+ activity in vivo in freely behaving mice. This study provides evidence for impairment of neuronal calcium activity in hippocampal CA1 excitatory neurons in freely moving mice following cadmium exposure.

Effects of Selenium and Cadmium on Human Liver and Kidney Functions in Exposed Black Shale Areas.

Animal experiments suggest that selenium (Se) may alleviate cadmium (Cd) toxicity in animal liver and kidneys, but its effect on human liver and kidneys remains uncertain. In China, areas with black shale have shown elevated levels of Se and Cd. According to the USEPA (U.S. Environmental Protection Agency) evaluation method, the soil and rice in these areas pose significant risks. In black shale regions such as Enshi and Zhuxi County, residents who long-term consume local rice may surpass safe Se and Cd intake levels. Significantly high median blood Se (B-Se) and urine selenium (U-Se) levels were detected in these areas, measuring 416.977μg/L and 352.690μg/L and 104.527μg/L and 51.820μg/L, respectively. Additionally, the median blood Cd (B-Cd) and urine Cd (U-Cd) levels were markedly elevated at 4.821μg/L and 3.848μg/L and at 7.750μg/L and 7.050μg/L, respectively, indicating substantial Cd exposure. Nevertheless, sensitive liver and kidney biomarkers in these groups fall within healthy reference ranges, suggesting a potential antagonistic effect of Se on Cd in the human body. Therefore, the USEPA method may not accurately assess Cd risk in exposed black shale areas. However, within the healthy ranges, residents in the Enshi study area had significantly greater median levels of serum creatinine and cystatin C, measuring 67.3μmol/L and 0.92mg/L, respectively, than those in Zhuxi did (53.6μmol/L and 0.86mg/L). In cases of excessive Se and Cd exposure, high Se and Cd levels impact the filtration function of the human kidney to some extent.

Exogenous Melatonin Supplement Contributes as Antioxidant to Attenuate the Oxidative Stress Induced by Cadmium Toxicity in Male Wistar Rats

Abstract Background: Melatonin is a peptide neurohormone naturally synthesized in the brain by the pineal gland. The basic function of melatonin is related to the causation and regulation of the sleep–wake cycle (circadian cycle). Cadmium (Cd) is a hazardous heavy metal and its toxic effects induce extensive tissue damage. The present study was undertaken to elucidate the efficiency of exogenous melatonin in attenuating Cd-induced oxidative stress. Methods: The experimental rats were allotted into four groups (n = 20), designated as untreated control, melatonin accessed, Cd exposed, and Cd exposed with access. Results: The hematological and biochemical parameters (serum and tissues) of Cd-exposed rats were significantly altered. Cd-exposed rats that received melatonin demonstrated increased erythrocytic indices; showed significantly increased levels of total proteins, catalase, total thiols, and glutathione; and exhibited decreased levels of blood Cd, urea, creatinine, bilirubin, malondialdehyde, and hydrogen peroxide. Conclusions: It was concluded that melatonin has an efficient antioxidant activity in attenuating oxidative stress induced by Cd.

Is Chronic Kidney Disease Due to Cadmium Exposure Inevitable and Can It Be Reversed?

Cadmium (Cd) is a metal with no nutritional value or physiological role. However, it is found in the body of most people because it is a contaminant of nearly all food types and is readily absorbed. The body burden of Cd is determined principally by its intestinal absorption rate as there is no mechanism for its elimination. Most acquired Cd accumulates within the kidney tubular cells, where its levels increase through to the age of 50 years but decline thereafter due to its release into the urine as the injured tubular cells die. This is associated with progressive kidney disease, which is signified by a sustained decline in the estimated glomerular filtration rate (eGFR) and albuminuria. Generally, reductions in eGFR after Cd exposure are irreversible, and are likely to decline further towards kidney failure if exposure persists. There is no evidence that the elimination of current environmental exposure can reverse these effects and no theoretical reason to believe that such a reversal is possible. This review aims to provide an update on urinary and blood Cd levels that were found to be associated with GFR loss and albuminuria in the general populations. A special emphasis is placed on the mechanisms underlying albumin excretion in Cd-exposed persons, and for an accurate measure of the doses-response relationships between Cd exposure and eGFR, its excretion rate must be normalised to creatinine clearance. The difficult challenge of establishing realistic Cd exposure guidelines such that human health is protected, is discussed.

Assessment Of Occupational Exposure To Lead, Cadmium And Arsenic In A Lead-Acid Battery Manufacturing And Recycling Plant In Algeria

Introduction: Plants manufacturing and recycling lead-acid batteries emit this metal and other metal and metalloid particles into the air, which can be transported and deposited on various surfaces, exposing workers and even nearby populations. Occupational metal contamination is a cause for concern because of their potential accumulation in the environment and in living organisms, leading to long-term toxic effects.The aim of this study was to assess Cd, As and Pb levels in the whole blood of 170 people working in a lead battery manufacturing and recycling plant in eastern Algeria, and in that of 50 non-occupationally exposed controls. Metal compound levels were determined using ICP-MS. Lead was the most prominent element in the workers' blood (521.24 µg/L) compared to the controls (23.08 µg/L), confirming that lead exposure is significantly higher compared to other elements. The average and median concentrations of Cd and As in the blood did not exceed the biological exposure indices for both populations. Cadmium levels were significantly higher in the blood of exposed workers compared to the controls. However, there was no significant correlation between blood lead levels and cadmium levels in exposed subjects. For arsenic, although the mean and median values ​​were within the normal range, the maximum and 95th percentile exceeded the normal value. There was also no significant correlation between lead and arsenic concentrations in the blood of workers. The results of this study highlight the alarming working conditions that the employees of this factory face.These conditions lead to significant lead exposure and potentially to other elements such as Cd and As.