Associations of urinary and dietary cadmium with urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine and blood biochemical parameters

Association Between Urinary Metals and Polycyclic Aromatic Hydrocarbon Levels and Cardiovascular Disease Among Adult Americans: Data from NHANES 2011 to 2016

Previous studies have inconclusively examined the associations of metals or polycyclic aromatic hydrocarbons (PAHs) with cardiovascular disease (CVD) separately, highlighting the need to explore their combined association with CVD. Based on the 2011-2016 National Health and Nutrition Examination Survey, the association of 12 metals and six PAHs in urine with CVD was analyzed using weighted logistic regression, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR). Crucial metals and PAHs were screened, and dose-response, subgroup, interactions, and mediation analyses were conducted. 4306 participants were included, of whom 406 had CVD. Weighted logistic regression showed that cadmium (OR = 1.41, 95% CI 1.11-1.78), tin (OR = 1.63, 95% CI 1.03-2.60), and 1-hydroxypyrene (1-PYR) (OR = 1.40, 95% CI 1.15-1.69) were positively correlated with CVD. These factors also showed a linear relation with CVD. The WQS and BKMR models indicated that the combined association of 12 metals and six PAHs was positively associated with CVD. Cadmium, cesium, tin, uranium, and 1-PYR played critical roles (all weights > 0.050). Subgroup analysis revealed that these substances were mostly positively associated with CVD in young and middle-aged people, smokers, drinkers, and those who were overweight. There was an interaction between tin and smoking status (P for interaction < 0.05). Cadmium and tin mediated 18.40% and 6.90% of the association of 1-PYR with CVD, respectively, whereas the proportions of the mediating effects of 1-PYR in the association of cadmium and tin with CVD were 8.10% and 7.90%, respectively. Overall, higher levels of urinary metals and PAHs mixtures may be associated with higher CVD prevalence. Cadmium, cesium, tin, uranium, and 1-PYR played crucial roles in this association. Cadmium and tin played mediating roles in the association between 1-PYR and CVD. Meanwhile, 1-PYR also played a mediating role in the association between cadmium and tin and CVD.

Oxidative stress and inflammation mediate the adverse effects of cadmium exposure on all-cause and cause-specific mortality in patients with diabetes and prediabetes

BACKGROUND

The effect of cadmium exposure on mortality risk among individuals with diabetes and prediabetes remains unclear, particularly regarding potential mediation by oxidative stress and inflammation. This study aimed to investigate the associations of blood cadmium levels with all-cause, cardiovascular disease (CVD), and cancer mortality and the mediating effects of oxidative stress and inflammation biomarkers in patients with diabetes and prediabetes.

METHODS

In this prospective cohort study, we analyzed 17,687 adults with diabetes and prediabetes from the National Health and Nutrition Examination Survey (NHANES, 1999-2018). Nine biomarkers related to oxidative stress (gamma-glutamyl transferase [GGT], uric acid [UA], high-density lipoprotein [HDL], UA to HDL ratio [UHR]) and inflammation (neutrophil-lymphocyte ratio [NLR], monocyte-lymphocyte ratio [MLR], neutrophil-monocyte-lymphocyte ratio [NMLR], systemic inflammation response index [SIRI], systemic immune-inflammation index [SII]) were systematically assessed. Kaplan-Meier survival analysis, Cox proportional hazards models, and restricted cubic splines (RCS) were applied to evaluate the association of cadmium with mortality risk. Generalized linear models were used to assess the association of cadmium with oxidative stress and inflammation biomarkers, while Cox regression and RCS evaluated their effects on mortality. Causal mediation analysis identified biological pathways mediated by oxidative stress and inflammation. Stratified and sensitivity analyses were further employed to confirm the robustness of the results.

RESULTS

During 161,047.75 person-years of follow-up, 3562 deaths occurred, including 1214 from CVD and 680 from cancer. Higher blood cadmium levels were associated with increased risks of all-cause mortality (fully adjusted hazard ratio [HR]: 2.17; 95% confidence interval [CI] 1.69-2.79, comparing highest vs. lowest quartile), CVD mortality (HR 2.06; 95% CI 1.41-3.02), and cancer mortality (HR 2.38; 95% CI 1.47-3.85), without evidence of nonlinear relationship. Mediation analyses indicated that UA, NLR, MLR, NMLR, and SIRI partially mediated the associations of cadmium with all-cause and CVD mortality, although the mediated proportions were relatively modest (ranging from 1.4 to 4.8%). Additionally, GGT mediated a small fraction of the associations with all-cause and cancer mortality.

CONCLUSION

Cadmium exposure increases the risk of all-cause, CVD, and cancer mortality in patients with diabetes and prediabetes. Oxidative stress and inflammation appear to partially mediate this adverse effect. These findings emphasize the urgent need for targeted interventions to reduce cadmium-related mortality risks.

RESEARCH INSIGHTS

What is currently known about this topic? Cadmium exposure is linked to increased mortality. Oxidative stress and inflammation are critical in diabetes development and complications. What is the key research question? Does cadmium exposure increase mortality risk in patients with diabetes and prediabetes? Are oxidative stress and inflammation involved in mediating these effects? What is new? Cadmium exposure increases all-cause and cause-specific mortality in diabetes and prediabetes. Oxidative stress and inflammation mediate these associations. How might this study influence clinical practice? Monitor cadmium, oxidative stress, and inflammation to reduce mortality in diabetes and prediabetes.

Cadmium exposure and thyroid hormone disruption: a systematic review and meta-analysis

INTRODUCTION

This meta-analysis aimed to analyze the effect of cadmium (Cd) exposure on thyroid hormone disruption.

CONTENT

Databases including PubMed, Embase, Cochrane Library, and Scopus were searched for studies published up to December 14, 2022. Studies evaluating the association between Cd exposure (blood Cd [BCd] or urine Cd [UCd]) and thyroid function (thyroid-stimulating hormone [TSH], free thyroxine [FT4], total triiodothyronine [TT3]) or thyroid autoimmunity (thyroglobulin antibody [TgAb] or thyroperoxidase Ab [TPOAb]) were included.

SUMMARY AND OUTLOOK

This systematic review included 12 cross-sectional studies. Cd exposure showed a neutral association with TSH (pooled correlation=0.016, 95 % confidence interval [CI]=-0.013 to 0.045, p=0.277), FT4 (pooled correlation=0.028, 95 % CI=-0.005 to 0.061, p=0.098), and thyroid autoimmunity (pooled odds ratio=1.143, 95 % CI=0.820-1.591, p=0.430). However, Cd exposure showed a positive association with TT3 (pooled correlation=0.065, 95 % CI=0.050-0.080, p<0.001), which was consistent with the BCd and UCd subgroup analyses (pooled correlation=0.053 and 0.081, respectively, both p<0.001). Cd exposure was not associated with TSH, FT4, or thyroid autoimmunity but tended to increase with TT3.

Exposure to Cadmium and Other Trace Elements Among Individuals with Mild Cognitive Impairment

BACKGROUND

A limited number of studies have investigated the role of environmental chemicals in the etiology of mild cognitive impairment (MCI). We performed a cross-sectional study of the association between exposure to selected trace elements and the biomarkers of cognitive decline.

METHODS

During 2019-2021, we recruited 128 newly diagnosed patients with MCI from two Neurology Clinics in Northern Italy, i.e., Modena and Reggio Emilia. At baseline, we measured serum and cerebrospinal fluid (CSF) concentrations of cadmium, copper, iron, manganese, and zinc using inductively coupled plasma mass spectrometry. With immuno-enzymatic assays, we estimated concentrations of β-amyloid 1-40, β-amyloid 1-42, Total Tau and phosphorylated Tau181 proteins, neurofilament light chain (NfL), and the mini-mental state examination (MMSE) to assess cognitive status. We used spline regression to explore the shape of the association between exposure and each endpoint, adjusted for age at diagnosis, educational attainment, MMSE, and sex.

RESULTS

In analyses between the serum and CSF concentrations of trace metals, we found monotonic positive correlations between copper and zinc, while an inverse association was observed for cadmium. Serum cadmium concentrations were inversely associated with amyloid ratio and positively associated with Tau proteins. Serum iron concentrations showed the opposite trend, while copper, manganese, and zinc displayed heterogeneous non-linear associations with amyloid ratio and Tau biomarkers. Regarding CSF exposure biomarkers, only cadmium consistently showed an inverse association with amyloid ratio, while iron was positively associated with Tau. Cadmium concentrations in CSF were not appreciably associated with serum NfL levels, while we observed an inverted U-shaped association with CSF NfL, similar to that observed for copper. In CSF, zinc was the only trace element positively associated with NfL at high concentrations.

CONCLUSIONS

In this cross-sectional study, high serum cadmium concentrations were associated with selected biomarkers of cognitive impairment. Findings for the other trace elements were difficult to interpret, showing complex and inconsistent associations with the neurodegenerative endpoints examined.

Cadmium exposure and risk of hypertension: A systematic review and dose-response meta-analysis

BACKGROUND

Exposure to environmental toxic metals represents a significant global public health concern. Many studies have reported that cadmium (Cd) exposure increases the risk of hypertension. Since the shape of such relation has not been well characterized, we assessed it by performing a systematic review and dose-response meta-analysis of human studies.

METHODS

We searched the literature through September 5, 2024 to identify papers related to Cd, hypertension, and blood pressure. Inclusion criteria were: observational design, adult population, assessment of exposure using Cd biomarkers, and availability of exposure category-specific risk estimates for hypertension. We performed a dose-response meta-analysis of the results from included studies.

RESULTS

Of the 18 studies published between 2006 and 2024, most had a cross-sectional design. Cd was measured in whole blood and/or urine in almost all studies, whereas only two studies measured Cd in serum. The dose-response meta-analysis indicated an almost linear relation between urinary Cd concentrations and hypertension risk with RR = 1.18, 95% CI 1.02-1.37 at 2.0 μg/g creatinine compared with no exposure. In contrast, the association between blood Cd concentrations and hypertension risk was non-linear: there was a steep monotonic increase in risk for Cd concentrations below 2 μg/L, reaching a RR of 1.48 (95% CI 1.17-1.86) at 2.0 μg/L, after which a plateau seemed reached. We found similar trends when restricting to studies of Asian population, while when considering North American studies, hypertension risk increased above 1.0 μg/g creatinine.

CONCLUSIONS

In this dose-response meta-analysis, risk of hypertension showed a non-linear positive association with blood Cd concentrations and a linear positive association with urinary Cd concentrations. Inconsistency in the shape of associations could relate to the different timing of exposure assessed by the biomarkers or the alteration Cd excretion at increasing exposure levels. Mitigation of Cd exposure is confirmed as a public health priority for chronic disease prevention.

Cadmium exposure and cardiovascular disease risk: A systematic review and dose-response meta-analysis

Exposure to toxic metals is a global public health threat. Among other adverse effects, exposure to the heavy metal cadmium has been associated with greater risk of cardiovascular disease (CVD). Nonetheless, the shape of the association between cadmium exposure and CVD risk is not clear. This systematic review summarizes data on the association between cadmium exposure and risk of CVD using a dose-response approach. We carried out a literature search in PubMed, Web of Science, and Embase from inception to December 30, 2023. Inclusion criteria were: studies on adult populations, assessment of cadmium exposure, risk of overall CVD and main CVD subgroups as endpoints, and observational study design (cohort, cross-sectional, or case-control). We retrieved 26 eligible studies published during 2005-2023, measuring cadmium exposure mainly in urine and whole blood. In a dose-response meta-analysis using the one-stage method within a random-effects model, we observed a positive association between cadmium exposure and risk of overall CVD. When using whole blood cadmium as a biomarker, the association with overall CVD risk was linear, yielding a risk ratio (RR) of 2.58 (95 % confidence interval-CI 1.78-3.74) at 1 μg/L. When using urinary cadmium as a biomarker, the association was linear until 0.5 μg/g creatinine (RR = 2.79, 95 % CI 1.26-6.16), after which risk plateaued. We found similar patterns of association of cadmium exposure with overall CVD mortality and risks of heart failure, coronary heart disease, and overall stroke, whereas for ischemic stroke there was a positive association with mortality only. Overall, our results suggest that cadmium exposure, whether measured in urine or whole blood, is associated with increased CVD risk, further highlighting the importance of reducing environmental pollution from this heavy metal.

Adherence to the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet and exposure to selenium species: A cross-sectional study

Selenium is a trace element found in many chemical forms. Selenium and its species have nutritional and toxicologic properties, some of which may play a role in the etiology of neurological disease. We hypothesized that adherence to the Mediterranean-Dietary Approach to Stop Hypertension Intervention for Neurodegenerative Delay (MIND) diet could influence intake and endogenous concentrations of selenium and selenium species, thus contributing to the beneficial effects of this dietary pattern. We carried out a cross-sectional study of 137 non-smoking blood donors (75 females and 62 males) from the Reggio Emilia province, Northern Italy. We assessed MIND diet adherence using a semiquantitative food frequency questionnaire. We assessed selenium exposure through dietary intake and measurement of urinary and serum concentrations, including speciation of selenium compound in serum. We fitted non-linear spline-based regression models to investigate the association between MIND diet adherence and selenium exposure concentrations. Adherence to the MIND diet was positively associated with dietary selenium intake and urinary selenium excretion, whereas it was inversely associated with serum concentrations of overall selenium and organic selenium, including serum selenoprotein P-bound selenium, the most abundant circulating chemical form of the metalloid. MIND diet adherence also showed an inverted U-shaped relation with inorganic selenium and particularly with its hexavalent form, selenate. Our results suggest that greater adherence to the MIND diet is non-linearly associated with lower circulating concentrations of selenium and of 2 potentially neurotoxic species of this element, selenoprotein P and selenate. This may explain why adherence to the MIND dietary pattern may reduce cognitive decline.

Does fluoride exposure affect thyroid function? A systematic review and dose-response meta-analysis

INTRODUCTION

Fluoride exposure may have various adverse health effects, including affecting thyroid function and disease risk, but the pattern of such relation is still uncertain.

METHODS

We systematically searched human studies assessing the relation between fluoride exposure and thyroid function and disease. We compared the highest versus the lowest fluoride category across these studies, and we performed a one-stage dose-response meta-analysis for aggregated data to explore the shape of the association.

RESULTS

Most retrieved studies (27 of which with a cross-sectional design) were conducted in Asia and in children, assessing fluoride exposure through its concentrations in drinking water, urine, serum, or dietary intake. Twenty-four studies reported data on thyroid function by measuring thyroid-related hormones in blood (mainly thyroid-stimulating-hormone - TSH), 9 reported data on thyroid disease, and 4 on thyroid volume. By comparing the highest versus the lowest fluoride categories, overall mean TSH difference was 1.05 μIU/mL. Dose-response curve showed no change in TSH concentrations in the lowest water fluoride exposure range, while the hormone levels started to linearly increase around 2.5 mg/L, also dependending on the risk of bias of the included studies. The association between biomarkers of fluoride exposure and TSH was also positive, with little evidence of a threshold. Evidence for an association between fluoride exposure and blood concentrations of thyroid hormones was less evident, though there was an indication of inverse association with triiodothyronine. For thyroid disease, the few available studies suggested a positive association with goiter and with hypothyroidism in both children and adults.

CONCLUSIONS

Overall, exposure to high-fluoride drinking water appears to non-linearly affect thyroid function and increase TSH release in children, starting above a threshold of exposure, and to increase the risk of some thyroid diseases.

Cadmium-induced reproductive toxicity combined with a correlation to the oogenesis process and competing endogenous RNA networks based on a Caenorhabditis elegans model

Accumulation of the heavy metal Cadmium (Cd) in the ovaries and placenta can affect the structure and function of these organs and induce female reproductive toxicity. This toxicity may be due to Cd's similarity to estrogen and its ability to disrupt endocrine systems. However, the exact molecular mechanism by which Cd causes reproductive toxicity at the transcriptome level remains poorly understood. Hence, this study aimed to observe Cd-induced reproductive damage at the gene level, scrutinize the repercussions of Cd exposure on oogenesis, and explicate the putative pathogenesis of Cd-induced oogenesis based on Caenorhabditis elegans (C. elegans) as an in vivo model. The results showed that Cd exposure significantly decreased the number of offspring and prolonged the reproductive span of C. elegans. Cd exposure also reduced the number of cells in mitosis and the pachytene and diakinesis stages of meiosis, thereby disrupting oogenesis. Combined with transcriptional sequencing and bioinformatics analysis, a total of 3167 DEmRNAs were identified. Regarding gene expression, cul-6, mum-2, and vang-1 were found to be related to Cd-induced reproductive toxicity, and their competing endogenous RNA networks were constructed. We observed that mutations of mom-2 and vang-1 in the Wnt pathway could induce susceptibility to Cd-caused meiosis injury. In conclusion, the results indicated that Cd could impair the oogenesis of C. elegans and the Wnt pathway might serve as a protective mechanism against Cd reproductive toxicity. These findings contribute to a better understanding of the damaging effects and molecular biological mechanisms of Cd on the human reproductive system.

Influence of dietary patterns on urinary excretion of cadmium in an Italian population: A cross-sectional study

INTRODUCTION

Cadmium is a toxic heavy metal with detrimental effects on human health. Apart from smoking and occupational factors, diet is the main source of cadmium. However, the relation between adherence to so-called "healthy" dietary patterns and cadmium exposure has not been investigated in detail. In this study, we aimed at assessing such association in a Northern Italian population.

METHODS

Using a cross-sectional study design, we investigated a population of non-smokers aged 30-60 years in the period 2017-2019. Each subject completed a validated food frequency questionnaire (FFQ) in order to estimate adherence to four dietary patterns, namely the Dietary Approach to Stopping Hypertension-DASH diet, Greek Mediterranean Index-GMI, the Italian Mediterranean Index-IMI, and the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet. We collected a fasting morning urinary sample to measure urinary levels of cadmium and cotinine. The association between increasing adherence to dietary patterns and cadmium exposure was evaluated using a cubic spline regression non-linear model and adjusting for relevant confounders (age, sex, body mass index, urinary cotinine levels, intake of fiber, and alcohol).

RESULTS

We recruited 137 participants (males/females: 62/75) with median (interquartile range-IQR) age of 47 (IQR: 43-53) years. Median scores for the investigated dietary patterns were 24 (IQR: 21-28), 4 (IQR: 3-6), 4 (IQR: 3-5), and 7.5 (IQR: 6.5-8.5) for DASH, GMI, IMI and MIND diets, respectively. The median urinary cadmium level was 0.21 μg/L (IQR: 0.11-0.34 μg/L). Spline regression analysis showed an inverse linear association between increasing adherence to the DASH and MIND diets and urinary cadmium levels, reaching a plateau at high adherence scores, approximately > 25 and > 9 for DASH and MIND diets, respectively. An increase of cadmium exposure with increasing MIND score also emerged. Conversely, the association was almost null for IMI, and slightly positive for GMI.

CONCLUSIONS

The present findings suggest that increasing adherence to the DASH and MIND diets are associated with decreased cadmium levels only at moderate level. Overall, these results indicate that public health strategies, including the decrease of cadmium contamination in healthy foods should be implemented.

Association between urinary concentrations of toxic metals/metalloids and oxidative stress in Brazilians living in areas affected by the Fundão dam failure

The Fundão Dam failure has been the most significant environmental disaster in Brazil. The catastrophe released large amounts of mining waste into the environment, including toxic metals/metalloids, which are recognized to induce carcinogenic effects. The urinary levels of 8-hydroxy-2'-deoxyguanosine (8OHdG), a widely accepted oxidative stress and carcinogenesis biomarker, provide a potential tool for assessing the disaster's health implications. This study investigated the association between urinary levels of some toxic metals/metalloids and 8OHdG in Brazilian individuals living in areas affected by the Fundão dam failure. Urinary concentrations of arsenic (As), cadmium (Cd), mercury (Hg), nickel (Ni), and lead (Pb) were determined using inductively coupled plasma mass spectrometry, while 8OHdG was analyzed by liquid chromatography-tandem mass spectrometry. Non-parametric bootstrap regression was used to estimate the associations between the urinary levels of toxic elements and 8OHdG. The results showed that except for Hg, urinary concentrations of all metals/metalloids analyzed here exceeded the reference ranges for the Brazilian population. The regression analysis revealed that As (0.337; CI 95%: 0.203; 0.474), Cd (0.268; CI 95%: 0.036; 0.520), and Ni (0.296; CI 950.108; 0.469) were positively associated with creatinine-adjusted urinary 8OHdG levels. Associations were not found for Hg (0.0122; CI 95%: -0.155; 0.183) and Pb (0.201; CI 95%: -0.040; 0.498). The current findings suggest that high exposure to toxic metals/metalloids might increase 8OHdG levels with potential adverse health effects. This study is the first one in which the relationship between toxic metals/metalloids and oxidative stress biomarkers is investigated in populations affected by environmental disasters. Further prospective studies are necessary to monitor exposure levels and explore additional health impacts.

Sex-Specific Associations of Urinary Metals with Renal Function: a Cross-sectional Study in China

BACKGROUND

Extensive studies have revealed the link between heavy metals and CKD. Compared to single meta-elements, mixture of metals reflect real-life metals exposure scenarios and are of interest. However, the mechanism of action of metal mixture on renal function is unclear.

METHODS

This study aimed to explore the potential relationship between urinary arsenic (As), cadmium (Cd), lead (Pb), manganese (Mn), and chromium (Cr) contents with estimated glomerular filtration rate (eGFR) levels in 2775 participants. The levels of metals in urine were determined by inductively coupled plasma-mass spectrometry. We used linear regression models and the Bayesian kernel machine regression (BKMR) to evaluate the association between metals and eGFR levels.

RESULTS

In linear regression analysis, urinary As (β = 2.723, 95%CI: 0.29, 5.157) and Pb (β = 3.081, 95%CI: 1.725, 4.438) were positively associated with eGFR in the total population. In the BKMR model, a mixture of the five metals had a positive joint effect on eGFR levels, while Pb (PIP = 0.996) contributed the most to eGFR levels. Pb was positively associated with eGFR levels in the total participants and women. As was positively correlated with eGFR levels in women. Pb and eGFR levels were positively correlated when the other metals were set at 25th, 50th, and 75th percentiles.

CONCLUSIONS

To the best of our knowledge, all five metals mixed exposure was positively associated with eGFR. Pb showed more important effects than the other four metals in the mixture, especially in women.

Selenium exposure and urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine: Major effects of chemical species and sex

Selenium is an element present in trace amounts and different chemical forms. It may exert both beneficial and adverse effects on cellular redox status and on the generation of reactive oxygen species. 8-oxo-7,8-dihydro-2'deoxyguanosine (8-oxodG) is an oxidized derivative of deoxyguanosine, and a sensitive biomarker of oxidative stress and genotoxicity. The present study assessed the extent to which selenium status was associated with urinary 8-oxodG concentrations in a Northern Italian population. We recruited healthy, non-smoking blood donors living in the Reggio Emilia province during 2017-2019. We measured urinary 8-oxodG concentrations and used restricted cubic spline regression analyses to investigate the association between selenium status (estimated using food frequency questionnaires, urinary concentrations, and serum concentrations of selenium and selenium species) and 8-oxodG/g creatinine. Among 137 participants aged 30-60 years, median urinary selenium and 8-oxodG concentrations were 22.02 μg/L and 3.21 μg/g creatinine, respectively. Serum samples and selenium speciation analyses were available for 104 participants. Median total serum selenium levels and dietary intake were 116.5 μg/L and 78.7 μg/day, respectively. In spline regression analysis, there was little association between dietary, serum, or urinary selenium with 8-oxodG concentrations. In sex-specific analyses, urinary selenium showed a positive association with the endpoint among males. For single selenium species, we observed positive associations with urinary 8-oxodG for serum organic selenium species, and negative associations for inorganic selenium forms. In the most adjusted analysis, urinary 8-oxodG concentrations showed a strong positive association with selenomethione-bound selenium (Se-Met) and a negative association with inorganic tetravalent selenium, selenite. In sex-specific analyses, these associations were considerably stronger in males than in females. Overall, study findings indicate that selenium species exhibited very different patterns of associations with the biomarker of oxidative stress, and that these associations also depended on sex. Background exposure to Se-Met appears to be strongly and positively associated with oxidative stress.

Effects of Endocrine-Disrupting Heavy Metals on Human Health

Heavy metals play an important endocrine-disrupting role in the health consequences. However, the endocrine-disrupting mechanism of heavy metals is unclear. There are long-term and low-level metal/element exposure scenes for the human body in real life. Therefore, animal models exposed to high doses of heavy metals may not provide key information to elucidate the underlying pathogeny of human diseases. This review collects current knowledge regarding the endocrine-disrupting roles of heavy metals such as lead (Pb), cadmium (Cd), arsenic (As), mercury (Hg), nickel (Ni), copper (Cu), zinc (Zn), and manganese (Mn), summarizes the possible molecular mechanisms of these endocrine-disrupting chemicals (EDCs), and briefly evaluates their endocrine toxicity on animals and humans.

Urinary cadmium concentrations and intake of nutrients, food groups and dietary patterns in women from Northern Mexico

Cadmium (Cd) is a toxic metal found in some foods. There is limited evidence about the relationship of Cd exposure with nutrient and food groups consumption, and almost no information regarding dietary patterns. The objective was to evaluate the association between diet and urinary Cd, and to explore whether metal concentrations vary according to the intake of some nutrients. Urinary Cd concentrations of 891 female residents of northern Mexico were determined by tandem mass spectrometry. We obtained food consumption through a food frequency questionnaire and we used previously defined food groups and estimated dietary patterns by factor analysis. We found positive associations between Cd and daily consumption of non-starchy vegetables (ß = 0.067, 95% CI 0.030, 0.1023), legumes (ß = 0.139, 95% CI 0.065, 0.213) and processed meats (ß = 0.163, 95% CI 0.035.0.291), as well as the Western (ß = 0.083, 95% CI: 0.027.0.139) and Prudent dietary patterns (ß = 0.035, 95% CI: -0.020, 0.091). In contrast, we observed a negative association with the vegetable oil group (ß = -0.070, 95% CI -0.125, -0.014). In addition, we found higher concentrations of Cd in women under 50 years of age with a lower iron intake than recommended. Food is a source of exposure to this metal and at the same time provides nutrients that modulate its metabolism. It is important to generate dietary guidelines to reduce the health effects of Cd exposure.

A probabilistic hazard and risk assessment of exposure to metals and organohalogens associated with a traditional diet in the Indigenous communities of Eeyou Istchee (northern Quebec, Canada)

Hunting, trapping, and fishing are part of an Indigenous lifestyle in subarctic Canada. However, this lifestyle may be a route of exposure to contaminants and may pose a risk for the people who rely on a subsistence diet. Monte Carlo simulations for the chemical concentration of eight game species and one fish species were carried out by randomly sampling 10,000 samples from the contaminant measures for each species. We then calculated a probabilistic non-carcinogenic hazard quotient or carcinogenic risk values to estimate the human health risk of exposure to contaminants. Of the species examined, ducks were of concern for potential carcinogenic risk. There was a modeled probabilistic 95th-percentile risk associated with the consumption of ducks and polybrominated biphenyl (PBB) congener 153 in boys, women, and men (1.09 × 10-6, 1.57 × 10-6, and 2.17 × 10-6, respectively) and, to a lesser extent, with geese and polychlorinated biphenyl (PCB) congener 153 in men (1.19 × 10-6). Contaminant concentration in the intake rate (food consumption) for PBB congener 153 exposure risk was more important than that for PCB congener 153, where intake rate had greater relevance. The consumption of waterfowl may increase the exposure to organohalogens; however, there are health and wellness benefits associated with the harvesting and consumption of subsistence foods that must also be considered. We recommend follow-up species-specific studies focused on ducks to clarify and elucidate the results in the present study.