Urinary cadmium in relation to bone damage: Cadmium exposure threshold dose and health-based guidance value estimation

The association between blood cadmium levels and bone mineral density in U.S. adolescents aged 12-19 years

According to the multivariable adjusted models, there was an inverse association between B-Cd levels and BMD, which was particularly evident in the subgroup analyses of other Hispanic and female individuals in the adolescent population. Clinicians and policy-makers should thoroughly consider the genetic implications of B-Cd levels in relation to BMD during the prevention and treatment of osteoporosis.

OBJECTIVE

To investigate the associations between blood cadmium (B-Cd) levels and bone mineral density (BMD) in adolescents.

METHODS

On the basis of the National Health and Nutrition Examination Survey (NHANES) database spanning from 2011 to 2018, we used weighted multiple regression, a generalized weighted model and smoothed curve methods to investigate the associations between B-Cd levels and BMD in adolescents. Subgroup analyses were also conducted to examine potential differences across age, sex, race, tobacco exposure status and other relevant variables.

RESULTS

Among the 2427 participants, 52% were males, and 48% were females. In this study, multistage sampling data from the NHANES database were analysed, and the positive association between B-Cd levels and BMD shifted to a negative association after adjustment for age, sex and race. Subgroup analyses revealed a more pronounced association among females (β =  - 0.07, 95% CI: - 0.09, - 0.04, P < 0.001), other Hispanic individuals (β =  - 0.08, 95% CI: - 0.14, - 0.02, P = 0.012) and individuals exposed to tobacco (β =  - 0.04, 95% CI: - 0.06, - 0.01, P = 0.016).

CONCLUSION

The findings revealed a negative association between B-Cd levels and BMD in multivariable adjusted models.

Effect of Luteolin on cadmium-inhibited bone growth via suppressing osteoclastogenesis in laying chickens

Luteolin (Lut) is a flavonoid derived from several plant sources. Cadmium (Cd) is a widespread environmental contaminant and potential toxin with detrimental effects on animal health. However, the effect of Lut on Cd-induced inhibition of bone growth in laying chickens remains unclear. This study investigates the effects of Lut on Cd-induced inhibition of bone growth in the femur and tibia of laying chickens. A total of sixty 1-d-old green-eggshell yellow feather laying chickens were randomly assigned to 4 groups after a 5-d acclimation period: basal diet (Con), cadmium chloride (CdCl2, Cd), Lut, and Lut + Cd. Bone microstructure, serum biomarkers of bone remodeling, the levels of Cd, calcium (Ca), phosphorus (P), and trace metal elements were assessed using the micro-computed tomography (Micro-CT), enzyme-linked immunosorbent assay (ELISA), and microwave digestion, respectively. Bone remodeling biomarkers, late endosomal/lysosomal adaptor and MAPK and mTOR activator 1 (LAMTOR1), as well as the phosphorylation of AMP-activated protein kinase α (AMPKα) and protein kinase B (Akt), were quantified using the qRT-PCR and western blot. The results indicated that Lut effectively mitigated Cd-induced bone mass loss compared to the Cd group, resulting in increased bone volume (BV), bone surface/BV (BS/BV), connectivity density (Conn.Dn), and the length and weight of the femur and tibia in laying chickens. Mechanistically, compared to the Cd group, Lut restored the ratio of osteoprotegerin (OPG)/receptor activator of NF-κB ligand (RANKL) in serum and bone tissue, enhanced the expression of bone morphogenetic protein-2 (BMP-2), runt-related transcription factor 2 (Runx2), osteocalcin (OCN), and Osterix (OSX), while reducing the levels of Ca, Cd, and alkaline phosphatase (ALP) activity, as well as the expression of osteopontin (OPN), c-Fos, osteoclast stimulatory-transmembrane protein (OC-STAMP), tartrate-resistant acid phosphatase, cathepsin K (CTSK), matrix metalloprotein-9 (MMP-9), LAMTOR1, and the phosphorylation of AMPKα and Akt. Therefore, Lut alleviates Cd-induced damage to the femur and tibia of chickens by promoting osteogenesis and inhibiting osteoclastogenesis, positioning Lut as a potential therapeutic plant extract for enhancing bone growth in laying chickens.

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.

The association of cadmium heavy metal with growth failure in children: A systematic review and meta-analysis

Introduction

Introduction: early exposure to cadmium toxic metal has been suggested to be associated with reduced infants/children growth; nevertheless, the available evidence is contradictory. Objective: this meta-analysis aimed to examine the association of cadmium exposure through biological samples to growth measurements of infants/children, including body weight, height, body mass index (BMI), BMI-for-age (BMI Z-score), weight-for-age (WAZ), height-for-age (HAZ), and weight-for-height (WHZ) z-scores. Methods: a systematic search in PubMed and Scopus was implemented to obtain the related studies. The standardized beta coefficients (β) and 95 % confidence intervals (95 % CI) were used as effect sizes to test the associations using the random effects analysis. Results: a total of 15 studies with 6,181 participants were included in the meta-analysis. In the overall analysis, pooled analysis of available data revealed that cadmium exposure was inversely linked to height (β = -0.06, 95 % CI = -0.12 to -0.01) and WAZ (β = -0.01, 95 % CI = -0.02 to -0.003). These relationships were also supported by prospective cohort studies and urinary cadmium exposure. In the stratified analysis, cadmium exposure was negatively linked to the weight of children in prospective cohort studies, in studies that assessed urinary cadmium exposure. No significant association was detected between cadmium exposure and BMI, BMI Z-score, WHZ, and HAZ in the overall and subgroup analyses. Conclusions: this meta-analysis emphasized the importance of cadmium exposure as a risk factor for growth failure in infants/children.

Relationship between blood cadmium levels and bone mineral density in adults: a cross-sectional study

Introduction

Osteoporosis, a disease of reduced bone mass and microstructural deterioration leading to fragility fractures, is becoming more prevalent as aging progresses, significantly increasing the socioeconomic burden. In past studies, there has been a growing awareness of the harmful effects of heavy metals on bone, with cadmium being a significant exposure factor. The purpose of this study was to look into the association between adult bone mineral density(BMD) and blood cadmium levels.

Methods

Based on information from the 2013-2014, 2017-2018 NHANES, weighted multiple regression, generalized weighted modeling, and smoothed curve fitting were utilized to investigate the association between blood cadmium and femur BMD. Furthermore, subgroup analyses were conducted to investigate any differences in the associations between age, sex, race, chronic kidney disease, and diabetes.

Results

In 2,146 participants, blood cadmium levels and total femur [-0.02 (-0.03, -0.01), 0.0027], femoral neck [-0.01 (-0.02, -0.00), 0.0240], femoral trochanter [-0.01 (-0.02, -0.00), 0.0042], and intertrochanteric femoral trochanter [-0.02 (-0.03, -0.00), 0.0101] BMD were negatively correlated. Subgroup analyses showed that this association was more pronounced in women, non-Hispanic white people and other Hispanics, and those with chronic kidney disease and diabetes. Our results pointed to a negative relationship between femoral BMD and blood cadmium. This negative association varied by age, sex, race, diabetes, and chronic kidney disease. In particular, bone mineral density was more significantly negatively affected by blood cadmium levels in groups with diabetes and chronic kidney disease.

Conclusion

Our findings demonstrated a significant negative association between blood cadmium levels and bone mineral density in a population of U.S. adults.

The Protective Potential of Aronia melanocarpa L. Berry Extract against Cadmium-Induced Kidney Damage: A Study in an Animal Model of Human Environmental Exposure to This Toxic Element

The impact of cadmium (Cd) on the function and structure of the kidney and the potential protective effect of an extract from Aronia melanocarpa L. berries were investigated in a rat model of low- and moderate-level environmental exposure to this heavy metal (1 and 5 mg Cd/kg feed for up to 24 months). The sensitive biomarkers of Cd-induced damage to the kidney tubules (N-acetyl-β-D-glucosaminidase (NAG), alkaline phosphatase (ALP), β2-microglobulin (β2-MG), and kidney injury molecule-1 (KIM-1) in the urine), clinically relevant early markers of glomerular damage (albumin in the urine and creatinine clearance), and other markers of the general functional status of this organ (urea, uric acid, and total protein in the serum and/or urine) and Cd concentration in the urine, were evaluated. The morphological structure of the kidney and inflammatory markers (chemerin, macrophage inflammatory protein 1 alpha (MIP1a), and Bcl2-associated X protein (Bax)) were also estimated. Low-level and moderate exposure to Cd led to damage to the function and structure of the kidney tubules and glomeruli. The co-administration of A. melanocarpa berry extract significantly protected against the injurious impact of this toxic element. In conclusion, even low-level, long-term exposure to Cd poses a risk of kidney damage, whereas an intake of Aronia berry products may effectively protect from this outcome.

Nutraceuticals as Alternative Approach against Cadmium-Induced Kidney Damage: A Narrative Review

Cadmium (Cd) represents a public health risk due to its non-biodegradability and long biological half-life. The main target of Cd is the kidney, where it accumulates. In the present narrative review, we assessed experimental and clinical data dealing with the mechanisms of kidney morphological and functional damage caused by Cd and the state of the art about possible therapeutic managements. Intriguingly, skeleton fragility related to Cd exposure has been demonstrated to be induced both by a direct Cd toxic effect on bone mineralization and by renal failure. Our team and other research groups studied the possible pathophysiological molecular pathways induced by Cd, such as lipid peroxidation, inflammation, programmed cell death, and hormonal kidney discrepancy, that, through further molecular crosstalk, trigger serious glomerular and tubular injury, leading to chronic kidney disease (CKD). Moreover, CKD is associated with the presence of dysbiosis, and the results of recent studies have confirmed the altered composition and functions of the gut microbial communities in CKD. Therefore, as recent knowledge demonstrates a strong connection between diet, food components, and CKD management, and also taking into account that gut microbiota are very sensitive to these biological factors and environmental pollutants, nutraceuticals, mainly present in foods typical of the Mediterranean diet, can be considered a safe therapeutic strategy in Cd-induced kidney damage and, accordingly, could help in the prevention and treatment of CKD.

Cadmium dietary exposure assessment in the adult population and pre-school children in the Republic of Serbia

Cadmium (Cd) is a toxic metal, present in all matrices of the environment and a common food contaminant. Human exposure to it may elicit many diverse health impairments. The aim of this study was to assess the dietary exposure to Cd for the adult population and preschool children in Serbia using probabilistic methodology. We measured Cd in 11,227 food samples belonging to 50 food items on the Serbian market. Cd was detected in 90% of the tested food items, and in 30.8% of the overall tested samples. The food item that contributed the most to total dietary Cd intake was potatoes (median Cd concentration of 7 ng/g) in adults, and fruit and vegetable juices in children (median Cd concentration of 19 ng/g). Weekly Cd intake shown as 50th and 95th percentiles were 2.54 and 4.74 µg/kg bw in the adult population, and 3.29 and 4.93 µg/kg bw in children. The results of this study are rather preliminary and should be considered as an indication of the need for further, more refined research, which would contribute to a more realistic risk assessment as a high-priority approach, especially in the case of vulnerable subpopulations such as children. Abbreviations: AT SDR: Agency for Toxic Substances and Disease Registry; EEA: European Environment Agency; EFSA: European Food Safety Authority; FAO/WHO: Food and Agriculture Organization/World Health Organization; HI: hazard index; IARC: International Agency for Research on Cancer; JECFA: Joint FAO/WHO Expert Committee on Food Additives; LOD: limit of detection; Cd: cadmium; TWI: tolerable weekly intake; UNEP: United Nations Environment Program; WI: weekly intake.

Race and Gender Differences in the Associations Between Cadmium Exposure and Bone Mineral Density in US Adults

Several previous studies have found the deleterious effects of cadmium exposure on bone. However, studies on the effects of cadmium exposure on bone mineral density (BMD) in gender- and race-specific groups are still lacking. The aim of this study was to investigate the relationship between cadmium exposure and BMD in adults and the gender and racial differences therein. Weighted multivariate regression, generalized weighted model, and smoothed curve fitting were used to explore the relationship between lumbar BMD with blood cadmium (B-Cd) and urine cadmium (U-Cd) based on data from the National Health and Nutrition Examination Survey (NHANES). In addition, subgroup analyses were further used to investigate the differential associations across gender and race. Of the 4335 adult participants. After adjusting for primary demographic variables, B-Cd [- 0.018 (- 0.028, - 0.008)] and U-Cd [- 0.010 (- 0.020, - 0.001)] were shown to be negatively related to lumbar BMD. In the fully adjusted model, the negative association between B-Cd and lumbar BMD was maintained [- 0.010 (- 0.018, - 0.002)]. In the subgroup analysis stratified by gender and race, this relationship was retained in females and non-Hispanic blacks. Furthermore, these negative associations were most pronounced among non-Hispanic black women [B-Cd and lumbar BMD, - 0.046 (- 0.076, - 0.017); U-Cd and lumbar BMD, -0.034 (- 0.063, - 0.006)]. Our findings suggest that there are significant sex and race differences in the negative association between cadmium exposure and BMD. This negative association was most prominent in non-Hispanic black females.

Assessment of Children's Metal Exposure via Hand Wipe, Outdoor Soil and Indoor Dust and Their Associations with Blood Biomarkers

The soil environment contributes considerably to human exposure to metals. This study aimed to comprehensively compare children's exposure to soil metals using different sampling approaches (i.e., hand wipe, indoor dust and outdoor soil) and assessment strategies, combing the method of external exposure evaluation and the correlation with internal biomarkers. Environmental exposure samples (hand wipe, outdoor soil and indoor dust), blood samples and child-specific exposure factors were simultaneously collected for 60 children aged 3 to 12 years from an area of northwestern China. Eight typical toxic metals were analyzed. Results showed that metal levels in hand wipes were associated with children's age, years of residency and the ground types of the play areas. Hand-to-mouth contact was an important pathway for children's metal exposure, with the corresponding oral exposure cancer risk to Cr already exceeding the maximum acceptable level. In comparison, metal concentrations in hand wipes were one to seven times higher than those in outdoor soil and indoor dust. Even greater discrepancies were found for the estimated exposure dose, which could lead to differences of several to dozens of times. In addition, Pb, Mn and Cr in hand wipes were significantly correlated with those in blood, whereas no relationships were found with soil and dust. This study indicates that the selection of different sampling and assessing strategies could lead to great differences in children metal exposure outcomes. It also suggests that hand wipe, which could reflect the true and integrated exposure level and the individual difference, serves as a better matrix to assess children's metal exposure compared to soil and dust. Further studies should standardize the sampling method for hand wipes and verify its applicability for other age groups.

Toxicity of cadmium salts on indicators of embryogenesis of rats

Cadmium is a toxic heavy metal which is considered a dangerous environmental pollutant and has a detrimental effect on the organs of the reproductive system, the period of implantation and the development of embryos. The experiment presented in this article established the effect of cadmium salts (chloride and citrate) on the general progress of embryogenesis. For this purpose, 60 rats were randomly divided into three groups: control, experimental group with cadmium chloride exposure and experimental group with cadmium citrate exposure. Cadmium chloride solvent, cadmium citrate solvent at a dose of 1.0 mg/kg and distilled intragastric water were injected from the first to the thirteenth (first subgroup) and from the first to the twentieth days of embryogenesis (second subgroup). When cadmium chloride was injected, total embryonic (by 4.24 and 3.67 times), pre-implantation (by 6.50 and 14.03 times) and post-implantation mortality (by 3.07 and 2.49 times) increased with a reduction of the number of surviving fetuses by 24.0% and 25.9% compared with the control group on the 13th and 20th days of embryogenesis respectively. At the same time, during exposure to cadmium citrate, indicators of total embryonic mortality increased by 4.02 and 3.52 times, pre-implantation mortality by 6.04 and 13.03 times, and post-implantation mortality by 3.09 and 2.26 times, and indicators of the number of live fetuses decreased by 18.3% and 22.2% in relation to the control group. When determining the accumulation of cadmium in embryos on the 20th day of gestation, polyelement analysis of biological materials using the atomic emission method with electric arc atomization revealed a 15.83-fold increase in cadmium chloride and 9.00 times in cadmium citrate relative to the control group. Embryolethality rates increased in animals of both experimental groups while the number of live fetuses per female decreased, which indicated an obvious embryotoxic effect of cadmium compounds. It is would be useful to conduct histological studies, which will help detect changes at the tissue level and possibly explain the level of embryonic mortality.

Maternal exposure to cadmium from puberty through lactation induces abnormal reproductive development in female offspring

Four-week-old female ICR mice were exposed to Cd through drinking water from puberty through lactation to investigate the effects of reproductive development in female offspring. Our results showed that maternal Cd exposure from puberty to lactation induced vaginal opening delay, and disturbed estrous cycle in the offspring on postnatal day (PND) 21, without affecting the body weight at vaginal opening. The histopathology results showed the increased primordial follicles and the decreased secondary follicles, and the mRNA level of Amh increased in the offspring's ovaries upon Cd exposure, suggesting the inhibition of ovarian follicular development on PND21. Moreover, the level of serum estradiol reduced and genes associated with steroidogenesis (3β-Hsd, P450scc and P450arom) were downregulated upon Cd exposure on PND 21. Thus, Cd may inhibit the follicular development via disturbing the mRNA level of genes associated with steroidogenesis and then the synthesis of estradiol in prepuberty. Taken together, despite the lack of attention to estrous cycle at termination, maternal Cd exposure from puberty to lactation induced the adverse effects on reproductive development of female offspring, including the delay of vaginal opening, irregular estrous cycle and inhibition of follicular development, via disturbing the mRNA level of genes associated with follicular development and steroidogenesis.

Paternal cadmium exposure affects testosterone synthesis by reducing the testicular cholesterol pool in offspring mice

Cadmium（Cd） is a heavy metal that is harmful to human health. Early studies have shown that cadmium can damage testicular structure, affecting testosterone synthesis and spermatogenesis. However, the effect of paternal Cd exposure on the reproductive system of offspring remains unclear. In this study, male 8-week C57BL/6 J mice were used as research objects, and Cd was injected intraperitoneally every other day at a dose of 1 mg/kg for 5 weeks, after which the effect on the reproductive system of offspring male mice was studied. Our results showed that the body weight of the offspring male mice increased faster, with increases of the testicular and epididymis indices under Cd exposure. At the same time, the serum testosterone and free cholesterol decreased, total cholesterol increased, and the sperm concentration decreased. Further qRT-PCR and western blot analyses showed that the expressions of StAR, P450scc, 3β-HSD and 17β-HSD, which are related to testosterone synthesis, was significantly downregulated. Additionally, ATGL, LDLR and SR-BI, which are related to the intracellular cholesterol pool were downregulated, leading to the reduction of the cholesterol pool and the accumulation of lipid droplets. Oil red O and BODIPY staining revealed an increase in the abundance of lipid droplets in testicular tissue of newborn and adult mice. Prediction of tsRNA target genes in the sperm of parents and testicular transcriptome of newborn mice showed that the differentially expressed genes were associated with catabolism of fatty acids, cholesterol and ion channels, while the mitochondrial and lysosome functions of testicular tissue of adult offspring mice were decreased. Overall, our results suggest that paternal Cd exposure reduced the intracellular cholesterol pool of testicular of offspring, affected testosterone synthesis and reproductive system development.

Recognition of Heavy Metals by Using Resorcin[4]arenes Soluble in Water

The complexing properties of two water-soluble resorcin[4]arenes (tetrasodium 5,11,17,23-tetrakissulfonatemethylen 2,8,14,20-tetra(butyl)resorcin[4]arene, Na₄BRA, and tetrasodium 5,11,17,23-tetrakissulfonatemethylen-2,8,14,20-tetra(2-(methylthio)ethyl)resorcin[4]arene, Na₄SRA) with polluting heavy metals such as Cu²⁺, Pb²⁺, Cd²⁺ and Hg²⁺ were studied by conductivity, and the findings were confirmed by using other techniques to try to apply this knowledge to removing them. The results indicate that Na₄BRA is able to complex Cu²⁺ in a 1:1 ratio and Pb²⁺ in a 1:2 ratio, while Na₄SRA complexes Hg²⁺ in a 1:1 ratio. On the contrary, no indications have been observed that either of the resorcin[4]arenes studied complexes the Cd²⁺ ions. The results suggest that the bonds established between the sulfur atoms located at the lower edge of the SRA^4- and the solvent hydrogens could prevent the entry of the guest into the host cavity. However, in the case of Hg²⁺ ions, the entry is favoured by the interactions between the sulfur donor atoms present on the lower edge of Na₄SRA and the Hg²⁺ ions. Therefore, it can be said that Na₄BRA is selective for Cu²⁺ and Pb²⁺ ions and Na₄SRA is selective for Hg²⁺ ions.

Health Safety Assessment of Ready-to-Eat Products Consumed by Children Aged 0.5-3 Years on the Polish Market

Toxic elements have a negative impact on health, especially among infants and young children. Even low levels of exposure can impair the normal growth and development of children. In young children, all organs and metabolic processes are insufficiently developed, making them particularly vulnerable to the effects of toxic elements. The aim of this study is to estimate the concentration of toxic elements in products consumed by infants and young children. The health risk of young children due to consumption of ready-made products potentially contaminated with As (arsenic), Cd (cadmium), Hg (mercury), and Pb (lead) was also assessed. A total of 397 samples (dinners, porridges, mousses, snacks "for the handle", baby drinks, dairy) were analyzed for the content of toxic elements. Inductively coupled plasma mass spectrometry (ICP-MS) was used to assess As, Cd, and Pb concentration. The determination of Hg was performed by atomic absorption spectrometry (AAS). In order to estimate children's exposure to toxic elements, the content of indicators was also assessed: estimated daily intake (EDI), estimated weekly intake (EWI), provisional tolerable weekly intake (PTWI), provisional tolerable monthly intake (PTMI), the benchmark dose lower confidence limit (BMDL), target hazard quotient (THQ), hazard index (HI), and cancer risk (CR). The average content of As, Cd, Hg, and Pb for all ready-made products for children is: 1.411 ± 0.248 µg/kg, 2.077 ± 0.154 µg/kg, 3.161 ± 0.159 µg/kg, and 9.265 ± 0.443 µg/kg, respectively. The highest content As was found in wafer/crisps (84.71 µg/kg); in the case of Cd, dinners with fish (20.15 µg/kg); for Hg, dinners with poultry (37.25 µg/kg); and for Pb, fruit mousse (138.99 µg/kg). The results showed that 4.53% of the samples attempted to exceed Pb, and 1.5% exceeded levels of Hg. The highest value of THQ was made in the case of drinks, for Cd and Pb in mousses for children, and Hg for dairy products. The THQ, BMDL, and PTWI ratios were not exceeded. The analyzed ready-to-eat products for children aged 0.5-3 years may contain toxic elements, but most of them appear to be harmless to health.