Dietary Cadmium Research Articles

The cadmium content in commercially key species of seafood from Shandong, China: Potential human health risk estimation

Seafood serves as a vital protein source for human nutrition, yet it also significantly contributes to the intake of dietary cadmium. In this study, we measured the cadmium content in 274 samples from 20 species, including fish, shrimp, and bivalves collected across five cities in Shandong province and assessed the associated health risks for local residents with varying consumption habits. The findings revealed a distinct increasing trend in cadmium concentrations from pelagic fish to benthic bivalve species; however, no evidence of biomagnification was observed among the studied species. Health risk assessments indicated that while there were no non-carcinogenic health risks posed by seafood consumption for local residents exposed to cadmium, carcinogen risks exceeded acceptable levels for lifetime cancer risk. Furthermore, children exhibited approximately twice as high risk indices compared to adults. Bivalve consumption emerged as the primary contributor to these health risks.

The metal tolerance protein OsMTP11 facilitates cadmium sequestration in the vacuoles of leaf vascular cells for restricting its translocation into rice grains

Rice (Oryza sativa) provides >20% of the consumed calories in the human diet. However, rice is also a leading source of dietary cadmium (Cd) that poses a serious threat to human health. Deciphering the genetic network that underlies the grain-Cd accumulation will benefit the development of low-Cd rice to mitigate the effects of Cd accumulation in the rice grain. In this study, we identified a QTL-gene, OsCS1, that is allelic to OsMTP11 and encodes a protein sequestering Cd in the leaf during vegetative growth and preventing Cd from being translocated to the grain after heading in rice. OsCS1 is predominantly expressed in leaf vascular parenchyma cells, where it binds to a vacuole sorting receptor protein OsVSR2 and is translocated intracellularly from the trans-Golgi network (TGN) to pre-vacuolar compartments (PVCs) and then to the vacuole. In this trafficking process, OsCS1 actively transports Cd into the endomembrane system and eventually sequesters it in vacuoles. There are natural variations in the promoter of OsCS1 between the indica and japonica rice subspecies. Duplication of a G-box-like motif in the promoter region of the superior allele of OsCS1 from indica rice enhances the binding of the transcription factor OsIRO2 to the OsCS1 promoter, thereby promoting OsCS1 expression. Introgression of this allele into commercial rice varieties could significantly lower grain-Cd levels compared to the inferior allele present in japonica rice. Our findings fill a gap in the genetic control of leaf-to-grain Cd translocation and provide a novel gene and its superior allele for the genetic improvement of low-Cd variety in rice.

Health Hazards Associated with Dietary Exposure of Female Rat to Cadmium-Contaminated Cooked Rice: Biochemical, Hormonal, and Histopathological Analysis.

The actual exposure, bioavailability, and body burden of dietary cadmium (Cd) vary with the food matrix. Here, we evaluated the health hazards of 45-day long-term exposure of growing Sprague-Dawley (SD) female rats to a natural and endogenous Cd-contaminated brown and white cooked rice dietary model. Cd was found mainly in the duodenum, kidney, and liver; the cecum and colon also contained substantial amounts of Cd in rats fed Cd-contaminated cooked white rice (cWR-test) but not Cd-contaminated cooked brown rice (cBR-test). Damage due to Cd exposure was reflected in liver dysfunction, altered estradiol levels, and distinctive pathologies in organ systems, although urinary Cd (U-Cd) excretion and blood Cd (B-Cd) were not detectable, suggesting that these are not the most accurate or appropriate biomarkers for evaluating dietary Cd exposure. Brown rice, despite being higher in Cd, can reduce Cd absorption and distribution in organs and increase the volume of Cd-containing feces, even achieving slightly higher excretion and lower apparent absorption rates of Cd than white rice, thereby reducing Cd damage to the body. The beneficial components of brown rice such as more dietary fiber, rice bran oil and polyphenol were speculated therefore to confer a degree of protection or repair. Nevertheless, the high apparent absorption levels observed here (> 5%) and signs of significant physical damage indicate that more stringent Cd intake guidelines and measures are needed to minimize Cd levels in rice.

Cadmium (Third Edition) (Chemicals and Contaminants).

Exposure to cadmium tends to be higher in Japan than in other countries due to the wide spreading of ore deposits and many mines throughout Japan. The proximal tubule of the kidney is recognized as the most susceptible site to be affected by cadmium exposure. Food Safety Commission of Japan (FSCJ) considered it appropriate to investigate studies of the effects of cadmium intake on renal proximal tubular function using urinary β2-microglobulin concentration of 1,000 μg/g creatinine as a criterion for the dysfunction. Based on these epidemiological studies, FSCJ established a tolerable weekly intake (TWI) of 7 µg/kg bw per week for cadmium. This value is derived from the results of actual dietary surveys and urinary β2-microglobulin concentrations in Japan, and not from the results of application of blood or urinary cadmium levels to theoretical models. Therefore, no uncertainty factor is required. The estimated dietary intake of cadmium in 2022 was 2.03 µg/kg bw per week, approximately 30% of the TWI of 7 µg/kg bw per week. Therefore, it is unlikely that dietary cadmium intake in the general Japanese population would cause adverse health effects.

Potassium Ion Channel Modulation as a Potential Remedy for Cadmium-induced Hypertension

Objective: Hypertension remains a chief non-communicable lifestyle disease that is negatively associated with dietary cadmium (Cd). The exact mechanism of Cd toxicity and the mitigating role of potassium supplementation are not fully known, hence, this study aimed to investigate their effects on the aorta. Hypothesis: We hypothesized that potassium supplementation can modulate Cd-induced vascular dysfunction. Method: Six cohorts of control, Cd-exposed, and potassium supplemented male Sprague-Dawley rats were selected. Hypertension was induced using cadmium chloride (2.5 or 5 mg/kg b.w.). Blood pressure was measured twice weekly. Reactivity to pharmacological agents with and without potassium ion channel modulation was assessed in thoracic aortic rings after eight weeks, using an organ bath set-up. Data: Statistical analysis was done using one-way analysis of variance and the results were reported as mean ± standard error of the mean. The Games-Howell or Bonferroni post hoc test was used for multiple comparisons. Summary of Results: Cadmium significantly (p<0.05) elevated systolic, diastolic, mean arterial, and pulse pressures, reduced (p<0.001) phenylephrine-induced contraction mostly via BKCa channels, and augmented (p<0.05) sodium nitroprusside-induced relaxation via K-ATP, KV, and KIR channels, without affecting acetylcholine-induced relaxation. Potassium supplementation ameliorated these effects via KIR and BKCa channels. Conclusions: The results indicate that modulation of potassium ion channels in the vasculature might provide therapeutic management for environmentally-induced hypertension and should be further explored. Funding source: The Mona Campus Committee for Research and Publications and Graduate Awards, School for Graduate Studies and Research, University of the West Indies. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Toxic Impact of Dietary Cadmium on Bioaccumulation, Growth, Hematological Parameters, Plasma Components, and Antioxidant Responses in Starry Flounder (Platichthys stellatus)

Starry flounders (Platichthys stellatus) (average weight—114.69 ± 13 g, length—19.0 ± 0.21 cm) underwent a 4-week exposure to varying dietary cadmium (Cd) concentrations: 0, 10, 20, 40, 60, and 80 mg/kg. Bioaccumulation patterns were revealed in the intestine, kidney, liver, and gills in descending order of accumulation. Significant declines in growth indicators—body weight gain (BWG), specific growth rate (SGR), and feed efficiency ratio percentage (FER)—were evident at 80 mg Cd/kg for 2 weeks and beyond 60 mg Cd/kg for 4 weeks. Hematological parameters, including red blood cell (RBC) count, hematocrit (Ht), and hemoglobin (Hb), remarkably reduced at 80 mg Cd/kg for both 2 and 4 weeks. The total plasma protein reduced significantly after exposure to Cd for 2 and 4 weeks, alongside increased glucose levels, glutamic oxaloacetic transaminase (GOT), and glutamic pyruvate transaminase (GPT). Considerable increases in antioxidant responses—superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and glutathione (GSH) levels—were observed after exposure to Cd for 2 and 4 weeks. P. stellatus exhibits a high accumulation of dietary Cd in specific tissues. Moreover, concentrations above 60 mg Cd/kg adversely affected the growth performance, hematological parameters, plasma components, and antioxidant responses.

Cadmium induces microcytosis and anisocytosis without anaemia in hypertensive rats.

Dietary cadmium (Cd2+) intake is implicated in the pathogenesis of hypertension and anaemia, but there is a paucity of information on the haematological changes in hypertensive conditions. This study, therefore, aims to evaluate the effects of Cd2+ on blood pressure (BP) and haematological indices in the Sprague-Dawley rat model. Three cohorts (n = 10 each) of control and Cd2+-fed male Sprague-Dawley rats were selected. Cd2+-exposed rats received 2.5 or 5mg/kg b.w. cadmium chloride via gavage thrice-weekly for eight weeks, while control animals received tap water. BP and flow were measured non-invasively from rat tails twice-weekly using a CODA machine, while weights were measured thrice-weekly. Haematological indices were assessed using the Cell-Dyn Emerald Haematology Analyzer. Data were reported as mean ± SEM, and statistically analyzed using One-Way Analysis of Variance. Bonferroni post hoc test was used for multiple comparisons. Cd2+-exposure induced hypertension by significantly (p < 0.05) elevating systolic, diastolic, and mean arterial BPs, pulse pressure, and heart rate (HR), and increased (p < 0.05) blood flow. Mean cell volume (MCV) and haemoglobin (MCH) were significantly (p < 0.05) reduced, and red cell distribution width (RDW) significantly (p < 0.01) increased by exposure to 5mg/kg b.w. Cd2+. Haemoglobin concentration (MCHC), haematocrit, haemoglobin, red blood cell, platelet, mean platelet volume, and white blood cell counts were unaffected by Cd2+-exposure. Cd2+ induced hypertension, microcytosis, hypochromicity, and anisocytosis without anaemia, which may be precursor to microcytic anaemia and coronary artery disease. This study is important in Cd2+-exposed environments and warrants further investigations.

The effects of dietary cadmium on growth, antioxidant defence system and feed evaluation performance of rainbow trout (Oncorhynchus mykiss)

The present study was carried out to determine the effect of dietary cadmium exposure on growth performance, changes in manganese, zinc, copper, calcium, magnesium, iron, selenium, and cadmium metals in liver and muscle tissue, liver antioxidant enzymes, and the histology of the fish. Rainbow trout (Oncorhynchus mykiss) with weights of 39.45 ±1.13 g was used in the experiment conducted in 2 groups and three replicates. The Control group was fed a cadmium-free diet, and the Cadmium group was fed a diet containing 5.03 µg/kg of cadmium twice a day until satiation. It was determined that cadmium intake through the diet affected growth rate and the feed evaluation performance negatively. In fish exposed to cadmium, manganese, zinc, copper, calcium, magnesium, iron, selenium, superoxide dismutase, catalase and glutathione peroxidase values in both muscle and liver tissues were significantly (p&lt;0.05) decreased, whereas cadmium levels in muscle and liver and malondialdehyde levels in liver were significantly (p&lt;0.05) increased. The histopathological examination of the liver revealed that cadmium caused liver damage. These results showed that rainbow trout exposed to dietary cadmium were highly sensitive to the metal, and the decreased levels of metals such as copper, zinc, manganese, and selenium in the liver tissue, which are involved in the antioxidant defence system, can be considered an indicator of the weakening of the antioxidant defence system.

Toxicity and detoxication assessment of juvenile black seabream (Acanthopagrus schlegelii) in response to dietary cadmium exposure: Based on growth performance and stress indicators

Cadmium (Cd) is a major pollutant in water, and long-term Cd exposure seriously threatens aquatic organisms. This study evaluated the effects of dietary Cd on growth performance, tissue Cd accumulation, oxidative stress, endoplasmic reticulum (ER) stress, inflammation, apoptosis, and anti-stress response in juvenile black seabream (Acanthopagrus schlegelii). Six experimental diets containing different concentration of Cd were formulated: 0.02 (Control, Cd0.02), 1.60 (Cd1.60), 24.29 (Cd24.29), 49.04 (Cd49.04), 117.26 (Cd 117.26), and 289.65 (Cd289.65) mg/kg. A feeding experiment was performed on 540 juvenile black seabreams (initial weight, 1.42 ± 0.01 g), which were conducted for ten weeks. The findings revealed that Cd in the diet lowered weight gain (WG) and specific growth rate (SGR), but had no effect on survival. Dramatically positive linear trends were found between increasing dietary Cd contents and tissue Cd accumulation, including liver, kidney, and muscle. Dietary Cd exposure increased malondialdehyde (MDA) production in both serum and liver, hence, caused oxidative stress. The endoplasmic reticulum (ER) stress-related genes, including grp78, atf6, and xbp1, were markedly increased with increased dietary Cd levels, showing ER stress was triggered. Likewise, transcriptional expression levels of genes related to anti-stress response mt2, hsp70, and hsp90 were linearly up-regulated with increased dietary Cd contents. Regarding apoptosis, the transcriptional expression levels of pro-apoptosis genes caspase7, caspase9, and bax and anti-apoptosis gene bcl-2 were all significantly promoted with the increasing dietary Cd levels. Similar patterns were found for gene expression levels linked to inflammatory response, as the dietary Cd contents increased, nuclear transcription factor nf-κb, pro-inflammatory cytokines tnfα and il-1β, and anti-inflammatory il-10 and tgfβ were dramatically elevated. In conclusion, dietary Cd supplementation suppressed growth performance, increased Cd deposition in tissues, induced oxidative stress, ER stress, apoptosis, and inflammation. In contrast, black seabream juveniles also showed substantial tolerance for dietary Cd exposure by promoting anti-stress ability.

Assessment of long-term dietary cadmium exposure in children in Germany: Does consideration of data from total diet studies reduce uncertainties from food monitoring programmes?

Total diet studies (TDS) and food monitoring programmes are different approaches for collecting occurrence data on substances in food. This case study evaluated the practical applicability of TDS data (BfR MEAL Study) and monitoring data for the assessment of long-term cadmium exposure in children in Germany. Cadmium data from both programmes were combined with food consumption data from the KiESEL study. Uncertainties associated with both assessments were systematically described. Using monitoring data resulted in cadmium intakes approximately 3 times higher than the use of BfR MEAL Study data. Incomplete data and neglect of market shares and consumption weights were considered by conservative data adjustments to the monitoring data and mainly explain the higher estimates. Fewer data adjustments were necessary for BfR MEAL Study data, which covered almost the entire diet and considered consumer behaviour during sample collection and sample preparation. In sum, the use of the BfR MEAL Study data resulted in less uncertainty and more reliable exposure estimates for chronic assessments over the entire diet. However, description of variability and upper tails of substance distributions in food remain essential features of monitoring data. The integration of both programmes into a complementary system further improves food safety.

Blood cadmium is associated with increased fracture risk in never-smokers - results from a case-control study using data from the Malmö Diet and Cancer cohort

BackgroundSeveral studies have shown associations between cadmium (Cd) exposure and an increased risk of fractures. However, the size of the risk is still unclear and proper adjustment for smoking is a challenge. The aim of this study was to quantify the association between dietary cadmium measured in blood and fracture risk in the general Swedish population through a large population-based case-control study in never-smokers. MethodsThe study included 2113 incident cases with osteoporosis-related fractures and the same number of age- and sex-matched controls in never-smokers from the Swedish population-based Malmö Diet and Cancer study cohort. Cd in blood (B-Cd) was analyzed at baseline (1991–1996). Incident osteoporosis-related fractures (of the hip, distal radius, and proximal humerus) up to the year 2014 were identified using the National Patient Register. Associations between B-Cd and fractures were analyzed using logistic regression. ResultsMedian B-Cd was 0.22 μg/L (P25 = 0.16, P75 = 0.31) among 2103 cases and 0.21 (P25 = 0.15, P75 = 0.30) among 2105 controls. The risk of fracture was significantly increased (OR 1.58; 95 % confidence interval 1.08–2.31, per μg/L of B-Cd), after adjustment for age, sex, BMI, physical activity, and fiber consumption. In analyses by cadmium quartiles, the OR increased monotonically and was significant in the highest quartile of B-Cd (for B-Cd > 0.31 versus B-Cd < 0.15 μg/L; OR 1.21; 95 % confidence interval 1.01–1.45). ConclusionEven modestly increased blood cadmium in never-smokers is associated with increased risk of incident osteoporosis-related fractures.

Assessing the Effects of Dietary Cadmium Exposure on the Gastrointestinal Tract of Beef Cattle via Microbiota and Transcriptome Profile.

Cadmium (Cd) is an environmental pollutant, widely existing in soil, and can be absorbed and accumulated by plants. Hunan Province exhibits the worst cadmium contamination of farmland in China. Ruminants possess an abundant microbial population in the rumen, which enables them to tolerate various poisonous plants. To investigate whether the rumen microbiota could respond to Cd and mitigate the toxicity of Cd-accumulated maize to ruminants, 6-month-old cattle were fed with 85.82% (fresh basis) normal whole-plant maize silage diet (CON, n = 10) or Cd-accumulated whole-plant maize silage diet (CAM, n = 10) for 107 days. When compared to the CON cattle, CAM cattle showed significantly higher gain-to-feed ratio and an increased total bacterial population in the rumen, but a decreased total bacterial population in the colon. CAM cattle had higher relative abundance of Prevotella and Lachnospiraceae ND3007 group in the rumen, and Lachnospiraceae NK4A136 group and Clostridia vadinBB60 group in the colon. Notably, microbial correlations were enhanced in all segments of CAM cattle, especially Peptostreptococcaceae in the jejunum. Transcriptome analysis revealed down-regulation of several immune-related genes in the rumen of CAM cattle, and differentially expressed genes in the rumen were mostly involved in immune regulation. These findings indicated that feeding Cd-accumulated maize diet with a Cd concentration of 6.74 mg/kg dry matter (DM) could stimulate SCFA-related bacteria in the rumen, induce hormesis to promote weight gain, and improve energy utilization of cattle.

Burden of diabetes attributable to dietary cadmium exposure in adolescents and adults in China

At present, the health risk assessment of cadmium exposure has become a major focus of environmental health research. However, there is still a lack of systematic research on the burden of diabetes (DM) attributable to dietary cadmium exposure in adolescents and adults in China. Using the top-down method, the blood cadmium level (B-Cd) of Chinese adolescents and adults from 2001 to 2023 was combined with the relative risk (RR) of cadmium-induced diabetes to calculate the population attribution score (PAF). Subsequently, PAF was used to assess the disease burden (DB) of diabetes caused by cadmium exposure, expressed in disability adjusted life years (DALYs), and attribution analysis was carried out for cadmium exposure from different sources. The average blood cadmium concentration in Chinese adolescents and adults was 1.54 ± 1.13 µg/L, and the burden of DM attributable to cadmium exposure was 56.52 (44.81, 70.33) × 105 DALYs. The contribution rate of dietary cadmium exposure was 59.78%, and the burden of DM attributable to dietary cadmium exposure was 337.86 (267.85, 420.42) × 108 DALYs. In addition, the highest blood cadmium concentrations were found in Henan, Shanxi, and Jiangxi provinces, while the highest burden of DM attributable to cadmium exposure was found in Jiangsu, Henan, and Guangdong provinces. Cadmium exposure is a risk factor for DM, and we need to take comprehensive action to reduce the burden of DM attributable to dietary cadmium from health, economic, and social perspectives.

In vitro characterization of cadmium transport across the gastro-intestinal membrane of the fathead minnow (Pimephales promelas) in the presence and absence of microplastics

There is concern that microplastics can act as a vector for cadmium through adsorption and desorption of free-ionic cadmium. Little is known about the uptake of cadmium following ingestion of cadmium-microplastic complexes. This study used an in vitro gut sac technique to investigate the translocation of cadmium across the gut barrier of fathead minnows following the simulated ingestion of cadmium, microplastics, or their complexed mixture. Microplastics did not cross the gut membrane, nor did microplastics alter the rate of cadmium translocation, which was estimated to be 1.2 ± 0.04 ng Cd / hour. Less cadmium translocated when cadmium-microplastic complexes were injected than the equivalent dose of only cadmium, indicating that the presence of microplastics was protective of dietary cadmium uptake. This work highlights the importance of considering dietary uptake and the role of microplastics acting as a vector for cadmium in aquatic environments and stresses the need to understand how environmental (digestive or ambient) characteristics govern cadmium-microplastic interactions.

Dietary cadmium health risk assessment for the Chinese population.

Cadmium (Cd) has high rates of soil-to-plant transference, coupled with its non-biodegradability and persistence; long-term management of Cd in agriculture is thus required to ensure better soil and food security and safety. Identifications of regions with high soil Cd concentration or high dietary Cd intakes are critical public health priorities. Human health risk assessment for dietary Cd intake was thus undertaken by employing three approaches: FCA (food chain approach), TDA (total diet approach), and FQA (food quality approach). The correlation between green/total vegetable consumption rates and dietary Cd intake from vegetables was statistically significant. For consumption, the hazard quotients (HQs) calculated by FCA and TDA were all less than 1 except for Hunan and Sichuan province. For rice consumption, the HQs derived by FCA or TDA approach for eight provinces exceeded 1. Residents in Hubei, Guangxi, Jilin, Zhejiang, Liaoning, Shanghai, Sichuan, and Guangxi were more vulnerable due to their notable higher consumption rates.Weighted rankings of the health risk levels were determined to derive the comparative risk management priority. For Cd intake from vegetables, four provinces/cities have high relative priority; for Cd intake from grains, three provinces have high relative priority. The comparative risk management priority for Hunan and Sichuan was high for dietary intake from vegetables or rice. Weighted average HQs were derived to determine the integrated dietary Cd intake health risk levels for dietary intake from vegetables or grains. The risk levels for Hunan, Guangxi, Sichuan, and Zhejiang are high, so effective measures should be taken to reduce Cd dietary intakes to ensure health protection.It is envisaged that the methodology employed in this study could provide useful insights into how various approaches can be integrated to determine human health risk levels for Cd intake, so more effective and targeted measures can be taken accordingly for the relevant regions.

Health risk assessment of dietary cadmium intake in children aged 2-17years in East China.

Food is the main way for people to be exposed to heavy metal cadmium (Cd), and Cd pollution will affect human health. In this paper, exposure and health risk assessment of dietary Cd intake were conducted in children aged 2, 3, 4, 5, 6-8, 9-11, 12-14 and 15-17years in East China. The results showed that the total exposure of dietary Cd intake in children exceeded the standard limits. The total exposure of all age groups were 1.11 × 10-3, 1.15 × 10-3, 9.67 × 10-4, 8.75 × 10-4, 9.18 × 10-4, 7.75 × 10-4, 8.24 × 10-4, 7.11 × 10-4mgkg-1d-1, respectively, and the highest was the children aged 3years. The hazard quotients of children aged 2 and 3years were 1.11 and 1.15, respectively, at an unacceptable health risk level. The hazard quotients of dietary Cd intake in children of other ages were less than 1, at an acceptable health risk level. Staple foods were the most significant contributor to the dietary Cd intake in children, and the contribution ratio of non-carcinogenic risk of dietary Cd intake in all age groups were more than 35%, the proportion of non-carcinogenic risk in children aged 6-8 and 9-11years were as high as 50%. This study provides scientific basis for the health of children in East China.

Multi-Element Assessment of Potentially Toxic and Essential Elements in New and Traditional Food Varieties in Sweden.

With the global movement toward the consumption of a more sustainable diet that includes a higher proportion of plant-based foods, it is important to determine how such a change could alter the intake of cadmium and other elements, both essential and toxic. In this study, we report on the levels of a wide range of elements in foodstuffs that are both traditional and "new" to the Swedish market. The data were obtained using analytical methods providing very low detection limits and include market basket data for different food groups to provide the general levels in foods consumed in Sweden and to facilitate comparisons among traditional and "new" food items. This dataset could be used to estimate changes in nutritional intake as well as exposure associated with a change in diet. The concentrations of known toxic and essential elements are provided for all the food matrices studied. Moreover, the concentrations of less routinely analyzed elements are available in some matrices. Depending on the food variety, the dataset includes the concentrations of inorganic arsenic and up to 74 elements (Ag, Al, As, Au, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, Ge, Hf, Hg, K, Li, Mg, Mn, Mo, Na, Nb, Ni, P, Pb, Rb, S, Sb, Sc, Se, Si, Sn, Sr, Ta, Te, Th, Ti, Tl, U, W, V, Y, Zn, Zr, rare Earth elements (REEs) (Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Sm, Tb, Tm, and Yb), platinum group elements (PGEs) (Ir, Os, Pd, Pr, Pt, Re, Rh, Ru, and Pr), and halogens (Br, Cl, and I)). The main focus (and thus the most detailed information on variation within a given food group) is on foods that are currently the largest contributors to dietary cadmium exposure in Sweden, such as pasta, rice, potato products, and different sorts of bread. Additionally, elemental concentrations in selected food varieties regarded as relatively new or "novel" to the Swedish market are provided, including teff flour, chia seeds, algae products, and gluten-free products.

Cadmium nitrate and DNA methylation in gastropods: comparison between ovotestis and hepatopancreas.

Dietary ingestion is the main route of exposure to hazardous contaminants in land animals. Cadmium, a high-profile toxic metal, affects living systems at different organismal levels, including major storage organs (liver, kidneys), key organs for species survival (gonads), and epigenetic networks regulating gene expression. 5-methylcytosine (5mC) is the most common and best-characterized epigenetic mark among different modified nucleosides in DNA. This important player in methylation-driven gene expression is impacted by cadmium in sentinel terrestrial vertebrates. However, limited information exists regarding its impact on macroinvertebrates, especially land snails commonly used as (eco)toxicological models. We first investigate the methylomic effects of dietary cadmium given as cadmium nitrate on terrestrial mollusks. Mature specimens of the common brown garden snail, Cornu aspersum, were continuously exposed for four weeks to environmentally-relevant cadmium levels. We determined global genomic DNA methylation in hepatopancreas and ovotestis, as well as changes in the methylation status of CG pairs at the 5' region close to the transcription site of gene encoding the Cd-selective metallothionein (Cd-MT). Weight gain/loss, hypometabolism tendency, and survival rates were also assessed. Although this exposure event did not adversely affect survival, gastropods exposed to the highest Cd dose revealed a significant reduction in body weight and a significant increase in hypometabolic behavior. The hepatopancreas, but not the ovotestis, displayed significant hypermethylation, but only for the aforementioned specimens. We also found that the 5' end of the Cd-MT gene was unmethylated in both organs and its methylation status was insensitive to cadmium exposure. Our results are important since they provide scientists, for the first time, with quantitative data on DNA methylation in gastropod ovotestis and refine our understanding of Cd epigenetic effects on terrestrial mollusks.

The contribution of cacao consumption to the bioaccessible dietary cadmium exposure in the Belgian population.

Since 2019, EU limits apply to cadmium (Cd) concentrations in cacao-derived food products. The dietary risk assessment leading to that regulation used consumption surveys aggregated to a limited number of chocolate product categories and did not consider differences in Cd bioaccessibility. Here, the cacao-related dietary Cd exposure in the Belgian population was estimated with higher resolution and accounting for bioaccessibility. A food frequency questionnaire and a 24-h recall (N = 2055) were set up for the Belgian population, in combination with ICP-MS analysis of a large subset of cacao-containing products (N = 349). Both the average chocolate consumption (28 g day-1) and the relative contribution of chocolate to the total dietary Cd exposure (7-9%) were higher than previously estimated for the Belgian population, probably because of some selection bias towards chocolate consumers in the cohort. The Cd bioaccessibility in chocolate products was a factor 5 (cacao powder) and 2 (dark chocolate) lower compared to wheat flour, suggesting lower bioavailability in chocolate than in wheat, which is a main contributor to dietary Cd. This study suggests that Cd intake from cacao consumption has been underestimated because of hidden cacao in non-chocolate food categories but, in contrast, may have overestimated the true exposure because of lower bioavailability compared to the main foodstuffs contributing to Cd exposure.

Estimation of health risks associated with dietary cadmium exposure.

In much of the world, currently employed upper limits of tolerable intake and acceptable excretion of cadmium (Cd) (ECd/Ecr) are 0.83µg/kg body weight/day and 5.24µg/g creatinine, respectively. These figures were derived from a risk assessment model that interpreted β2-microglobulin (β2MG) excretion > 300μg/g creatinine as a "critical" endpoint. However, current evidence suggests that Cd accumulation reduces glomerular filtration rate at values of ECd/Ecr much lower than 5.24µg/g creatinine. Low ECd/Ecr has also been associated with increased risks of kidney disease, type 2 diabetes, osteoporosis, cancer, and other disorders. These associations have cast considerable doubt on conventional guidelines. The goals of this paper are to evaluate whether these guidelines are low enough to minimize associated health risks reliably, and indeed whether permissible intake of a cumulative toxin like Cd is a valid concept. We highlight sources and levels of Cd in the human diet and review absorption, distribution, kidney accumulation, and excretion of the metal. We present evidence for the following propositions: excreted Cd emanates from injured tubular epithelial cells of the kidney; Cd excretion is a manifestation of current tissue injury; reduction of present and future exposure to environmental Cd cannot mitigate injury in progress; and Cd excretion is optimally expressed as a function of creatinine clearance rather than creatinine excretion. We comprehensively review the adverse health effects of Cd and urine and blood Cd levels at which adverse effects have been observed. The cumulative nature of Cd toxicity and the susceptibility of multiple organs to toxicity at low body burdens raise serious doubt that guidelines concerning permissible intake of Cd can be meaningful.