Diabetes and Exposure to Environmental Lead (Pb)

An insight on the plausible biological and non-biological detoxification of heavy metals in tannery waste: A comprehensive review

A key challenge for the tannery industries is the volume of tannery waste water (TWW) generated during the processing of leather, releasing various forms of toxic heavy metals resulting in uncontrolled discharge of tannery waste (TW) into the environment leading to pollution. The pollutants in TW includes heavy metals such as chromium (Cr), cadmium (Cd), lead (Pb) etc, when discharged above the permissible limit causes ill effects on humans. Therefore, several researchers have reported the application of biological and non-biological methods for the removal of pollutants in TW. This review provides insights on the global scenario of tannery industries and the harmful effects of heavy metal generated by tannery industry on micro and macroorganisms of the various ecological niches. It also provides information on the process, advantages and disadvantages of non-biological methods such as electrochemical oxidation, advanced oxidation processes, photon assisted catalytic remediation, adsorption and membrane technology. The various biological methods emphasised includes strategies such as constructed wetland, vermitechnology, phytoremediation, bioaugmentation, quorum sensing and biofilm in the remediation of heavy metals from tannery wastewater (TWW) with special emphasize on chromium.

Combined exposure to lead and microplastics increased risk of glucose metabolism in mice via the Nrf2/NF-κB pathway

The purpose of this study was to explore the effects of combined lead (Pb) and two types of microplastic (MP) (polyvinyl chloride [PVC] and polyethylene [PE]) exposure on glucose metabolism and investigate the role of the nuclear factor erythroid 2-related factor 2 (Nrf2)/nuclear factor-kappa B (NF-κB) signaling pathway in mediating these effects in mice. Adult C57BL/6J mice were randomly divided into four groups: control, Pb (100 mg/L), MPs (containing 10 mg/L PE and PVC), and Pb + MPs, each of which was treated with drinking water. Treatments were conducted for 6 weeks. Co-exposure to Pb + MPs exhibited increase glycosylated serum protein levels, insulin resistance, and damaged glucose tolerance compared with the control mice. Additionally, treatment with Pb + MPs caused more severe damage to hepatocytes than when exposed to them alone concomitantly, exposed to Pb + MPs exhibited improved the levels of interleukin-6, tumor necrosis factor-alpha, and malondialdehyde, but reduced superoxide dismutase, glutathione peroxidase, and catalase assay in livers. Furthermore, they increase the Kelch-like ECH-associated protein 1 (Keap1) and phosphorylated p-NF-κB protein levels but reduced the protein levels of heme oxygenase-1 and Nrf2, as well as increased Keap1 mRNA and Nrf2 mRNA. Co-exposure to Pb + MP impacts glucose metabolism via the Nrf2 /NF-κB pathway.

Unveiling the lead exposure attributed burden in Iran from 1990 to 2019 through the lens of the Global Burden of Disease study 2019

This study aimed to investigate the estimated burden attributed to lead exposure (LE), at the national and subnational levels from 1990 to 2019 in Iran. The burden attributed to LE was determined through the estimation of deaths, disability-adjusted life years (DALYs), years of life lost (YLLs) and years lived with disability (YLDs) using the comparative risk assessment method of Global Burden of Disease (GBD) study presenting as age-standardized per 100,000 person year (PY) with 95% uncertainty intervals (95% UI). Furthermore, the burden of each disease were recorded independently. Eventually, the age-standardized YLLs, DALYs, deaths and YLDs rates attributed to LE demonstrated a decrease of 50.7%, 48.9%, 38.0%, and 36.4%, respectively, from 1990 to 2019. The most important causes of LE burden are divided into two acute and chronic categories: acute, mainly causes mental disorders (DALYs rate of 36.0 in 2019), and chronic, results in cardiovascular diseases (CVDs) (DALYs rate of 391.8) and chronic kidney diseases (CKDs) (DALYs rate of 26.6), with CVDs bearing the most significant burden. At the sub-national level, a decrease in burden was evident in most provinces; moreover, low and low-middle SDI provinces born the highest burden. The burden increased mainly by ageing and was higher in males than females. It was concluded that although the overall decrease in the burden; still it is high, especially in low and low-middle SDI provinces, in advanced ages and in males. Among IDID, CKDs and CVDs that are the most important causes of LE-attributed burden in Iran; CVDs bear the highest burden.

Associations between patterns of blood heavy metal exposure and health outcomes: insights from NHANES 2011-2016

BACKGROUND

Extensive research has explored the association between heavy metal exposure and various health outcomes, including malignant neoplasms, hypertension, diabetes, and heart diseases. This study aimed to investigate the relationship between patterns of exposure to a mixture of seven heavy metals and these health outcomes.

METHODS

Blood samples from 7,236 adults in the NHANES 2011-2016 studies were analyzed for levels of cadmium, manganese, lead, mercury, selenium, copper, and zinc. Cluster analysis and logistic regression identified three distinct patterns of mixed heavy metal exposure, and their associations with health outcomes were evaluated.

RESULTS

Pattern 1 exhibited higher odds ratios (ORs) for malignancy during NHANES 2011-2012 (OR = 1.33) and 2015-2016 (OR = 1.29) compared to pattern 2. Pattern 3 showed a lower OR for malignancy during NHANES 2013-2014 (OR = 0.62). For hypertension, pattern 1 displayed higher ORs than pattern 2 for NHANES 2011-2012 (OR = 1.26), 2013-2014 (OR = 1.31), and 2015-2016 (OR = 1.41). Pattern 3 had lower ORs for hypertension during NHANES 2013-2014 (OR = 0.72) and 2015-2016 (OR = 0.67). In terms of heart diseases, pattern 1 exhibited higher ORs than pattern 2 for NHANES 2011-2012 (OR = 1.34), 2013-2014 (OR = 1.76), and 2015-2016 (OR = 1.68). Pattern 3 had lower ORs for heart diseases during NHANES 2013-2014 (OR = 0.59) and 2015-2016 (OR = 0.52). However, no significant trend was observed for diabetes. All three patterns showed the strongest association with hypertension among the health outcomes studied.

CONCLUSIONS

The identified patterns of seven-metal mixtures in NHANES 2011-2016 were robust. Pattern 1 exhibited higher correlations with hypertension, heart disease, and malignancy compared to pattern 2, suggesting an interaction between these metals. Particularly, the identified patterns could offer valuable insights into the management of hypertension in healthy populations.

Associations Between Prenatal Blood Metals and Vitamins and Cord Blood Peptide Hormone Concentrations

Background

Nonessential metals have endocrine disrupting properties, interfere with cellular processes, generate reactive oxygen and deplete antioxidants, while essential metals and vitamins act as antioxidants. The extent to which prenatal metals and vitamins are associated with cord blood hormones involved in maternal and fetal metabolic and growth processes is unknown.

Methods

We measured six nonessential (arsenic, barium, cadmium, cesium, lead, mercury) and four essential (magnesium, manganese, selenium, zinc) metals and trace elements, and two vitamins (B12 and folate) in first trimester blood from participants in the longitudinal pre-birth Project Viva cohort, who were recruited between 1999-2002 in eastern Massachusetts. We measured adiponectin, C-peptide, IGF-1, IGF-2, IGFBP-3, insulin, and leptin concentrations in cord blood (~n=695). We used covariate-adjusted quantile g-computation for mixtures and linear regression for individual exposures to estimate associations with cord blood peptide hormones.

Results

The essential metal mixture (magnesium, manganese, selenium, zinc) was associated with higher IGF-1 (β=3.20 ng/ml per quartile, 95% CI: 0.39, 6.01), IGF-2 (β=10.93 ng/ml, 95% CI: 0.08, 21.79), and leptin (β=1.03 ng/ml, 95% CI: 0.25, 1.80). Magnesium was associated with higher leptin (β=2.90 ng/ml, 95% CI: 0.89, 4.91), while B12 was associated with lower adiponectin, IGF-2, and leptin, but higher C-peptide. Other individual nonessential metals were associated with cord blood hormones.

Conclusions

Our findings suggest that some prenatal metals and vitamins are associated with cord blood hormones, which may influence growth and development.

Effects of Gestational and Lactational Lead Exposure and High Fat Diet Feeding on Cerebellar Development of Postnatal Rat Offspring

Obesity and heavy metals, such as lead (Pb), are detrimental to the adult brain because they impair cognitive function and structural plasticity. However, the effects of co-administration of Pb and a high-fat diet (HFD) on the developing cerebellum is not clearly elucidated. We investigated the effects of Pb exposure (0.3% lead acetate) on developing cerebellum in the pups of an HFD-fed obese rat model. One week before mating, we fed a chow diet (CD) or HFD to the rats for one week and additionally administered Pb to HFD-fed female SD rats. Thereafter, treatment with Pb and a HFD was continued during the gestational and lactational periods. On postnatal day 21, the pups were euthanized to sample the brain tissue and blood for further analysis. Blood Pb levels were significantly higher in HFD-fed rats than in CD-fed rats. Histologically, the prominent degeneration of Purkinje cells was induced by the co-administration of Pb and HFD. The calbindin-28Kd-, GAD67-, NMDAR1-, and PSD95-immunopositive Purkinje cells and inhibitory synapse-forming pinceau structures were significantly decreased following Pb and HFD co-administration. MBP-immunoreactive myelinated axonal fibers were also impaired by HFD but were significantly damaged by the co-administration of HFD and Pb. Oxidative stress-related Nrf2-HO1 signaling was activated by HFD feeding, and Pb exposure further aggravated oxidative stress, as demonstrated by the consumption of endogenous anti-oxidant in HFD-Pb rats. The pro-inflammatory response was also increased by the co-administration of HFD and Pb in the cerebellum of the rat offspring. The present results suggest that HFD and Pb treatment during the gestational and lactational periods are harmful to cerebellar development.

The association between e-cigarette use or dual use of e-cigarette and combustible cigarette and prediabetes, diabetes, or insulin resistance: Findings from the National Health and Nutrition Examination Survey (NHANES)

BACKGROUND

Studies have established associations between combustible cigarette use and diabetes. However, there is limited evidence on the association between e-cigarette use or dual use of e-cigarettes and combustible cigarettes and diabetes.

METHOD

With cross-sectional data of 5101 U.S. adults from the National Health and Nutrition Examination Survey, this study examined how e-cigarette use or dual use was related to diabetes, prediabetes, or insulin resistance. The presence of diabetes or prediabetes was determined by fasting glucose level, hemoglobin A1C (HbA1c), or the use of prescribed medications. Insulin resistance was assessed by the homeostatic model (HOMA-IR). The independent association between e-cigarette use or dual use and outcomes was examined using weighted multivariable logistic regression models controlling for potential confounders.

RESULTS

Of all participants, 6.3% were current e-cigarette users and 17.1% were former e-cigarette users. In the fully adjusted model, e-cigarette use was not associated with prediabetes or diabetes (P>0.05). However, former e-cigarette users were 22% (95% CI: 1.00, 1.84) more likely to report higher HOMA-IR (Q3 vs Q1) than never e-cigarette users. Among ever combustible cigarette users, current e-cigarette users and former e-cigarette users were 63% (95% CI: 1.00, 2.91) and 64% (95% CI: 1.04, 2.59) more likely to report higher HOMA-IR than never e-cigarette users, respectively. There was no significant association between dual use and diabetes, prediabetes, or insulin resistance (P>0.05).

CONCLUSIONS

E-cigarette use may be associated with insulin resistance. Our findings may inform future tobacco control policies and longitudinal studies assessing insulin resistance associated with e-cigarette use.

An evaluation of the effects of mixed heavy metals on prediabetes and type 2 diabetes: epidemiological and toxicogenomic analysis

The link between mixed heavy metals (mercury, lead, and cadmium), prediabetes, and type 2 diabetes mellitus (T2DM), especially molecular mechanisms, is poorly understood. Thus, we aimed to identify the association between mixed heavy metals and T2DM and its components using a data set from the Korean National Health and Nutrition Examination Survey. We further analyzed the main molecular mechanisms implicated in T2DM development induced by mixed heavy metals using in-silico analysis. Our findings observed that serum mercury was associated with prediabetes, elevated glucose, and ln2-transformed glucose when using different statistical methods. "AGE-RAGE signaling pathway in diabetic complications", "non-alcoholic fatty liver disease", "metabolic Syndrome X", and three miRNAs (hsa-miR-98-5p, hsa-let-7a-5p, and hsa-miR-34a-5p) were listed as the most important molecular mechanisms related to T2DM development caused by mixed heavy metals. These miRNA sponge structures were created and examined, and they may be beneficial in the treatment of T2DM. The predicted cutoff values for three heavy metal levels linked to T2DM and its components were specifically identified. Our results imply that chronic exposure to heavy metals, particularly mercury, may contribute to the development of T2DM. To understand the changes in the pathophysiology of T2DM brought on by a combination of heavy metals, more research is required.

Blood Lead Level Is Associated with Visceral Adipose Dysfunction in Patients with Type 2 Diabetes

We aimed to explore whether an elevated blood lead level (BLL) is associated with visceral adipose dysfunction in patients with type 2 diabetes mellitus (T2DM). Four thousand one hundred and fourteen diabetic participants were enrolled from seven communities in Shanghai in 2018 in the cross-sectional METAL study. BLL was measured by graphite furnace atomic absorption spectrometry. Visceral adiposity index (VAI) and lipid accumulation product (LAP)were calculated by simple anthropometric and biochemical parameters. We found that medians (IQR) of BLL were 26.0 μg/L (18.0-37.0) for men and 25.0 μg/L (18.0-35.0) for women, respectively. In men, each doubling of BLL was associated with a 2.0% higher VAI (95% CI, 0.6 to 3.5%) and 1.8% higher LAP (95% CI, 0.2 to 3.3%) after full adjustment. Using the lowest BLL quartile as the referent group, significant positive trends were observed for BLL with VAI and LAP. In women, each doubling of BLL was associated with a 1.9% higher LAP (95% CI, 0.6 to 3.1%). Additionally, there was a marginally significant positive association between BLL and VAI, either using log2-transformed concentrations as continuous variables or categorized in quartiles. In conclusion, lead exposure is associated with visceral adipose dysfunction in patients with T2DM. Further prospective studies are warranted to confirm our findings.

Consequences of the exposome to gestational diabetes mellitus

The exposome is the cumulative measure of environmental influences and associated biological responses throughout the lifespan, including those from the environment, diet, behaviour, and endogenous processes. The exposome concept and the 2030 Agenda for the Sustainable Development Goals (SDGs) from the United Nations are the basis for understanding the aetiology and consequences of non-communicable diseases, including gestational diabetes mellitus (GDM). Pregnancy may be developed in an environment with adverse factors part of the immediate internal medium for fetus development and the external medium to which the pregnant woman is exposed. The placenta is the interface between maternal and fetal compartments and acts as a protective barrier or easing agent to transfer exposome from mother to fetus. Under and over-nutrition in utero, exposure to adverse environmental pollutants such as heavy metals, endocrine-disrupting chemicals, pesticides, drugs, pharmaceuticals, lifestyle, air pollutants, and tobacco smoke plays a determinant role in the development of GDM. This phenomenon is worsened by metabolic stress postnatally, such as obesity which increases the risk of GDM and other diseases. Clinical risk factors for GDM development include its aetiology. It is proposed that knowledge-based interventions to change the potential interdependent ecto-exposome and endo-exposome could avoid the occurrence and consequences of GDM.

Perinatal Lead Exposure Promotes Sex-Specific Epigenetic Programming of Disease-Relevant Pathways in Mouse Heart

Environmental contaminants such as the metal lead (Pb) are associated with cardiovascular disease, but the underlying molecular mechanisms are poorly understood. In particular, little is known about how exposure to Pb during early development impacts the cardiac epigenome at any point across the life course and potential differences between sexes. In a mouse model of human-relevant perinatal exposures, we utilized RNA-seq and Enhanced Reduced Representation Bisulfite Sequencing (ERRBS) to investigate the effects of Pb exposure during gestation and lactation on gene expression and DNA methylation, respectively, in the hearts of male and female mice at weaning. For ERRBS, we identified differentially methylated CpGs (DMCs) or differentially methylated 1000 bp regions (DMRs) based on a minimum absolute change in methylation of 10% and an FDR < 0.05. For gene expression data, an FDR < 0.05 was considered significant. No individual genes met the FDR cutoff for gene expression; however, we found that Pb exposure leads to significant changes in the expression of gene pathways relevant to cardiovascular development and disease. We further found that Pb promotes sex-specific changes in DNA methylation at hundreds of gene loci (280 DMCs and 99 DMRs in males, 189 DMCs and 121 DMRs in females), and pathway analysis revealed that these CpGs and regions collectively function in embryonic development. In males, differential methylation also occurred at genes related to immune function and metabolism. We then investigated whether genes exhibiting differential methylation at weaning were also differentially methylated in hearts from a cohort of Pb-exposed mice at adulthood. We found that a single gene, Galnt2, showed differential methylation in both sexes and time points. In a human cohort investigating the influence of prenatal Pb exposure on the epigenome, we also observed an inverse association between first trimester Pb concentrations and adolescent blood leukocyte DNA methylation at a locus in GALNT2, suggesting that this gene may represent a biomarker of Pb exposure across species. Together, these data, across two time points in mice and in a human birth cohort study, collectively demonstrate that Pb exposure promotes sex-specific programming of the cardiac epigenome, and provide potential mechanistic insight into how Pb causes cardiovascular disease.

The Association between Methionine Intake and Diabetes in Chinese Adults-Results from the China Health and Nutrition Survey

This study aimed to evaluate the association between methionine intake and diabetes prevalence in Chinese adults and explore whether the association was source-specific. Data from 12,849 adults aged ≥20 years old were used from the China Health and Nutrition Survey during 1997-2011. Diabetes was diagnosed as self-reported and/or when blood tests results met the diagnostic criteria. A 3-day, 24-h recall was used to assess different sources of methionine. Multivariable mixed linear regression was used to examine the associations. Across the quartiles of total methionine intake, the odds ratio (ORs, 95% CI) of diabetes were 1.00, 1.49 (1.21 to 1.82), 1.72 (1.37 to 2.15), and 2.53 (1.97 to 3.23). In the subgroup analysis, similar trends were observed in both animal and plant methionine. There was a significant interaction between urbanization and diabetes. The positive association was only significant in those who lived in low or medium urbanization areas. The ORs (95% CI) were 1.00, 1.27 (0.85 to 1.88), 1.56 (1.01 to 2.39), and 1.79 (1.09 to 2.95) for medium urbanization, respectively. No interaction was identified when stratified by different methionine sources. In conclusion, methionine intake was positively associated with diabetes independent of food source, and it was modified by urbanization levels.

The construction and validation of a lead exposure screening tool for pregnant women in Thailand (ThaiL8Is)

Objectives

To construct, validate, and implement a new screening tool for lead exposure in Thai pregnant women.

Methods

A cross-sectional study that included three processes: screening tool development, validation, and implementation. The participants were pregnant women who had received antenatal care at district health promotion hospitals. There were 100 pregnant women in Nakhon Si Thammarat province during the validation process, and 30 pregnant women in Phang Nga province during the implementation process. Blood lead levels (BLLs) were analysed by atomic absorption spectrophotometry. The sensitivity and specificity of the screening instrument, as well as the Area Under the Curve (AUC), demonstrate its validity.

Results

There were 80 BLL-related items found through the collection of primary and secondary data and examined for validity and inter-rater reliability by five experts. Six items were excluded because the values were less than the criteria set. Seventy-four items remained with the Item Content Validity Index (I-CVI) = 0.80-1.00, the Content Validity Index Average (S-CVI/Ave) = 0.91, and Kappa scores = 0.76-1.00. After using 74 items collected on pregnant women, only 31 items were included in the validation process. Following that, the pooled eight items with cut-off point scores of 1 had the highest validity, which included systolic blood pressure, diastolic blood pressure, urine sugar, haemoglobin level, occupation, drinking coffee, using chemical products, and education level (ThaiL8Is). The ThaiL8Is in the validation process yielded sensitivity = 80.9%, specificity = 69.8%, and an AUC (95%CI) = 0.78 (0.69-0.87). The implementation process has confirmed the validity of the screening tool; sensitivity = 78.9%, specificity = 81.8%, and the AUC (95%CI) = 0.80 (0.63-0.97).

Conclusions

The ThaiL8Is a valid screening tool for Thai pregnant women. ThaiL8Is' sensitivity in detecting the risk groups for lead exposure can be enhanced by a combination of biochemical markers used in routine prenatal screening. It can be used to screen pregnant women for early indicators of lead exposure prior to a blood lead test.

Associations of exposure to lead and cadmium with risk of all-cause and cardiovascular disease mortality among patients with type 2 diabetes

The aim of this paper is to investigate the associations of lead and cadmium exposure with all-cause and cardiovascular disease (CVD) mortality among adults with type 2 diabetes (T2D). The prospective cohort study included participants with T2D (n = 7420 for blood lead; n = 5113 for blood cadmium) from the National Health and Nutrition Examination Survey (NHANES) III and NHANES 1999-2014. Death outcomes were ascertained through linkage with the National Death Index records. The geometric mean (interquartile range) concentrations of blood lead and cadmium were 19.6 (11.8, 35.0) μg/L and 0.39 (0.21, 0.60) μg/L, respectively. During 72,279 and 37,017 person-years of followup, 2818 all-cause deaths (including 832 CVD deaths) for blood lead and 1237 all-cause deaths (including 319 CVD deaths) for blood cadmium were documented, respectively. Comparing extreme quartiles, the multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of all-cause mortality were 1.51 (1.25, 1.82) for blood lead (P_trend < 0.001) and 1.58 (1.22, 2.03) for blood cadmium (P_trend < 0.001); and the HRs (95% CIs) of CVD mortality were 2.27 (1.54, 3.34) for blood lead (P_trend < 0.001) and 1.78 (1.04, 3.03) for blood cadmium (P_trend = 0.07). In the joint analysis, compared with participants in the lowest tertiles of blood lead and cadmium, participants in the highest tertiles had a HR (95% CI) of 2.09 (1.35, 3.24) for all-cause mortality. Exposure to lead and cadmium alone or in combination was significantly associated with higher risk of mortality among patients with T2D. These findings imply that minimizing exposure to lead and cadmium may aid in the prevention of premature death among individuals with diabetes.

Lead exposure and impaired glucose homeostasis in Chinese adults: A repeated measures study with 5 years of follow-up

Experimental studies suggest the diabetogenic effects of lead, but relevant data in humans are limited and have been primarily based on cross-sectional study design. We aimed to prospectively examine the association between lead exposure and glucose homeostasis in general population using repeated measurements. This cohort study included 5505 Chinese adults free of glucose-lowering medication use at baseline in 2014 and followed up 5 years later. Blood lead and glucose metabolic traits including fasting plasma glucose (FPG), fasting serum insulin, the homeostasis model assessment of insulin resistance (HOMA-IR), and HOMA of beta-cell function (HOMA-B) were measured at baseline and follow-up. Linear mixed models and linear regression models were performed to evaluate the associations between blood lead and markers of glucose homeostasis. After full adjustment for confounders including BMI, an interquartile range (IQR) increase in blood lead levels was associated with a 2.26 % increase in FPG (95 % CI: 0.16 %, 4.39 %) and an 11.3 % decrease in HOMA-B (95 % CI: - 19.1 %, - 2.71 %) in women. The odds ratios of hyperglycemia and beta-cell dysfunction corresponding to an IQR increase in blood lead levels were 1.39 (95 % CI: 0.99, 1.95) and 1.74 (95 % CI: 1.00, 3.03), respectively. Similar results were found for 5-year changes of glucose metabolic markers. Compared with the first quartile of baseline lead levels, the highest lead quartile was associated with an additional 3.03 % increase in FPG (95 % CI: 0.84 %, 5.26 %) and an additional 13.3 % decrease in HOMA-B (95 % CI: - 20.4 %, - 5.53 %) in women during follow-up. We observed no overall associations between blood lead levels and glucose metabolic markers in men. Our findings provide suggestive evidence that environmental exposure to lead might contribute to sex-dependent disruption of glucose homeostasis in general adult population.

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

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

The Association of Thyroid Nodules With Blood Trace Elements Identified in a Cross-Section Study

Background

The association between occurrence of thyroid nodules (TNs) and trace elements detectable in blood are still inconclusive. The present study sought to determine the relationship between selected trace elements and TNs in the iodine-adequate area of Guangdong, China.

Methods

A total of 1,048 participants from four communities were enrolled. A number of medical checkups were conducted to collect relevant data on anthropometric parameters, blood pressure, glucose blood levels and lipid profiles, as well as data on thyroid function, presence of thyroid autoantibodies, and trace elements. Presence of TN was diagnosed by ultrasonography.

Results

Of the 1048 participants (49.5 ± 14.4 years old), 543 participants (51.8%) had TNs. Serum copper, magnesium and zinc levels are associated with the presence of TNs among healthy subjects. Subjects with higher levels of zinc, magnesium and copper had 1.23-fold, 1.04-fold, and 1.007-fold increased risks of the prevalence of TNs (P = 0.013, 0.017, and < 0.001, resp). Compared with the first quartile of copper content in serum, participants in the fourth quartile had the highest prevalence of TNs with an odds ratio of 8.90 (95% confidence interval (CI) 5.41, 14.94) among all participants. Women in the third quartile of magnesium level had a 1.86-fold (95%CI 1.05, 3.31) risk of the prevalence of TNs. Subjects in the highest quartile of zinc level had a 1.82-fold (95%CI 1.06, 3.16) risk of the prevalence of TNs in females.

Conclusion

TNs were found highly prevalent in females in the investigated population from an iodine-adequate area of Guangdong, China. The imbalance of selected trace elements (copper, magnesium and zinc) in the body is related to the presence of TNs among healthy subjects. The observed correlation of copper on TNs warrants further studies.

Effects of multi-metal exposure on the risk of diabetes mellitus among people aged 40-75 years in rural areas in southwest China

INTRODUCTION

Metals play an important role in diabetes mellitus (DM). This cross-sectional study aims to evaluate the overall, individual, and interactive effects of multi-metal exposure on the prevalence of DM, impaired fasting glucose (IFG) rate, and fasting blood glucose (FBG) levels.

MATERIALS AND METHODS

The FBG levels of a study population from a cadmium (Cd)-polluted area (n=250) and an unpolluted area (n=204) and the metal levels, including magnesium (Mg), calcium (Ca), iron (Fe), zinc (Zn), arsenic (As), Cd, copper (Cu), and lead (Pb), in blood and urine were detected. The study population was divided into a normal fasting glucose (NFG) group, an IFG group, and a DM group on the basis of FBG levels.

RESULTS

IFG rate and DM prevalence were negatively associated with blood Cd and urine Zn levels (IFG rate: OR=0.780, 95%CI: 0.655-0.928; OR=0.622, 95%CI: 0.465-0.831. DM prevalence: OR=0.506, 95%CI: 0.288-0.888; OR=0.609, 95%CI: 0.395-0.939), IFG rate was positively associated with urine Fe levels (OR=1.876, 95%CI: 1.290-2.778), and DM prevalence was positively associated with urine Pb and blood Fe levels (OR=1.185, 95%CI: 1.022-1.376; OR=1.008, 95%CI: 1.001-1.014). A linear negative correlation was observed between FBG levels and blood Cd, and nonlinear inverted U-shaped associations were found between FBG levels and Zn, Pb, and Cu in urine.

CONCLUSIONS

This research suggests that multi-metal exposure, especially Cd, Fe, Zn, Cu, and Pb, is linked to DM, and the interactive effects of multiple metals need further exploration.

Lead, mercury, and cadmium exposures are associated with obesity but not with diabetes mellitus: Korean National Environmental Health Survey (KoNEHS) 2015-2017

BACKGROUND

Associations of heavy metal exposures with obesity and obesity-related traits have been suggested, while those with nonalcoholic fatty liver disease (NAFLD) and diabetes mellitus (DM) are often inconsistent.

METHODS

This study included 3787 adults aged ≥19 years who participated in the Korean National Environmental Health Survey 2015-2017, and investigated the association of toxic heavy metals with metabolic diseases. Lead (Pb), mercury (Hg), and cadmium (Cd) were measured either in urine (uHg, uCd) or total blood (bPb, bHg). Body mass index (BMI) was calculated, and DM cases were identified through a self-answered medication history. Hepatic Steatosis Index (HSI) as a surrogating index of NAFLD, was calculated using hepatic enzyme measurements, including aspartate aminotransferase (AST) and alanine aminotransferase (ALT).

RESULTS

Adults in the highest quartile of bPb, bHg, and uHg showed significantly elevated odds of obesity (BMI ≥25 kg/m²), compared to the lowest quartile (OR 1.58 for bPb, 1.92 for bHg, and 1.81 for uHg). HSI was positively correlated with bHg, uHg, and uCd concentrations. The odds of NAFLD (HSI ≥36) were also increased with increasing quartile of bHg, uHg, and uCd concentrations. For DM, bPb showed a significant negative association, while bHg and uCd exhibited non-monotonic and inconclusive associations.

CONCLUSIONS

Among the general adult population of Korea, both Pb and Hg exposures were associated with an increased risk of obesity. In addition, both Hg and Cd exposures were associated with increased odds of NAFLD. These metals, however, were not associated with an increased risk of DM.

Modification Strategies of Kapok Fiber Composites and Its Application in the Adsorption of Heavy Metal Ions and Dyes from Aqueous Solutions: A Systematic Review

Kapok fiber (Ceiba pentandra) belongs to a group of natural fibers that are mainly composed of cellulose, lignin, pectin, and small traces of inorganic compounds. These fibers are lightweight with hollow tubular structure that is easy to process and abundant in nature. Currently, kapok fibers are used in industry as filling material for beddings, upholstery, soft toys, and nonwoven materials. However, kapok fiber has also a potential application in the adsorptive removal of heavy metal ions and dyes from aqueous systems. This study aims to provide a comprehensive review about the recent developments on kapok fiber composites including its chemical properties, wettability, and surface morphology. Effective and innovative kapok fiber composites are analyzed with the help of characterization tools such as scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and Brunauer-Emmett-Teller analysis. Different pre-treatment methods such as alkali and acid pre-treatment, oxidation pre-treatment, and Fenton reaction are discussed. These techniques are applied to enhance the hydrophilicity and to generate rougher fiber surfaces. Moreover, surface modification and synthesis of kapok fiber-based composites and its environmental applications are examined. There are various methods in the fabrication of kapok fiber composites that include chemical modification and polymerization. These procedures allow the kapok fiber composites to have higher adsorption capacities for selective heavy metal and dye removal.

Molecular pathways dysregulated by Pb2+ exposure prompts pancreatic beta-cell dysfunction

Type 2 diabetes mellitus (T2DM) is a metabolic disease characterized by reduced insulin sensitivity and dysfunction of β-cells. Although the increasing prevalence of diabetes worldwide is largely attributed to genetic predisposition or lifestyle factors (insufficient physical activity), and caloric intake. Environmental factors, exposure to xenobiotics and heavy metals have also been reported to be causative factors of T2DM. At this juncture, we, through our work unveil a plausible link between Pb²⁺ exposure and diabetes mellitus, and delineated a comprehensive understanding of the potential mechanisms of Pb²⁺-induced β-cells dysfunction. In our in vivo observations, we found that Pb²⁺ exposure strongly reduced glucose-stimulated insulin secretion and diminished functional pancreatic β-cell mass. Mechanistically, we found that Pb²⁺ downregulates intracellular cAMP level via hyper-activating Ca²⁺/calmodulin-dependent 3',5'-cyclic nucleotide phosphodiesterase 1C and thereby reduces glucose-stimulated insulin secretion. Further, we report that Pb²⁺ inhibited mitochondrial adenosine triphosphate production and also identified Pb²⁺ as a negative regulator of β-cell proliferation via Ca²⁺/calmodulin-dependent protein kinase kinases-pAMPK-pRaptor axis. Together, our findings strongly reinforce Pb²⁺ to hijack the physiological role of calcium ions, by mimicking Ca²⁺ within pancreatic β-cell and thereby stands as a diabetogenic xenobiotic.

Relationships Between Indicators of Metabolic Disorders and Selected Concentrations of Bioelements and Lead in Serum and Bone Tissue in Aging Men

BACKGROUND

The aim of this study was to investigate the relationships between serum and bone concentrations of selected bioelements, ie, zinc (Zn), copper (Cu), iron (Fe), chrome (Cr), magnesium (Mg), and selenium (Se), and a heavy metal, ie, lead (Pb), and the selected indicators of metabolic disorders - Visceral Adiposity Index (VAI), Lipid Accumulation Product (LAP) and Body Mass Index (BMI).

MATERIAL AND METHODS

The study comprised 151 men aged 60 to 75 years who were scheduled for hip replacement surgery due to osteoarthritis. The concentrations of elements in the serum and bone tissue were measured using inductively coupled plasma optical emission spectrometry (Mg, Zn, Cu, Cr, Fe, and Pb) and the spectrofluorometric method (Se). Fasting plasma glucose (FPG), high-density cholesterol (HDL-Ch), and triacylglycerols (TAG) were determined. Lipid accumulation product (LAP) and visceral adiposity index (VAI) were calculated.

RESULTS

There was no relationship between serum and bone concentrations of bioelements and lead and the BMI index. Bone Mg was significantly higher in men with higher VAI, but no such relation was observed in the serum. Similarly, bone Mg and Zn were higher in patients with higher LAP, which was not observed in the serum. Multivariate logistic regression analysis with adjustment for age was performed. There was a correlation between serum Zn concentration and the cut-off point for VAI. The cut-off point for LAP was related to the bone tissue concentrations of Mg, Zn, and Cu.

CONCLUSION

We found some relationships between the concentrations of selected bioelements and Pb and VAI, LAP, and BMI in bone but not in the serum. VAI positively correlated with bone Mg, while LAP positively correlated with bone Cu, Zn, and Mg.

Lead exposure as a causative factor for metabolic associated fatty liver disease (MAFLD) and a lead exposure related nomogram for MAFLD prevalence

The relationship between lead exposure and neurological disorders has been extensively studied, but the effects of lead exposure on hepatotoxicity are unknown. Metabolically related fatty liver disease (MAFLD) is an update of previous non-alcoholic fatty liver disease (NAFLD). It redefines the diagnostic conditions and emphasizes metabolic factors while considering non-alcoholic factors. Lead can affect the endocrine system and metabolism, so we believe that lead exposure may contribute to MAFLD. 41,723 individuals who had undergone blood lead testing from 2005 to 2018 in the National Health and Nutrition Examination Survey (NHANES) database were selected for this study. The characteristics of population lead exposure in the last decade or so, the effect of lead exposure on liver function and whether lead exposure can cause MAFLD were analyzed. Co-variates were adjusted according to age, ethnicity, body mass index (BMI), waist circumference, visceral adiposity index (VAI), poverty indices (PIR), diabetes, hypertension, and hyperlipidemia. The results showed that blood lead concentrations stabilized at a low level after a decreasing trend from year to year. The differences in blood lead concentrations were associated with differences in age, sex, race, education level, and PIR. Lead exposure was an independent risk factor for MAFLD, and lead and nine other factors were used as independent risk factors for MAFLD, so a nomogram was established to predict the prevalence probability of MAFLD.

Hospital admissions due to endocrine diseases in Korean male firefighters

Background

The aim of this study was to investigate the relationship between occupational exposure to various hazards and hospital admission due to endocrine diseases in Korean male firefighters.

Methods

From 2000 to 2008, former and current male firefighters registered in the Korean National Emergency Management Agency were investigated based on their hospitalized health insurance admission data for the same period. Admission data for endocrine, nutritional, and metabolic diseases were obtained from the Korean National Health Insurance Service database. Standardized admission ratio (SAR) with reference to the general population of Korean men was analyzed.

Results

SAR for firefighters with endocrine, nutritional, and metabolic diseases was 0.56 (95% confidence interval [CI]: 0.49–0.65), which was significantly less than that of the general population of Korean men. For those with endocrine, nutritional, and metabolic diseases, SARs for those with a history of fire suppression tasks and those without experience of fire suppression tasks were 0.58 (95% CI: 0.49–0.68) and 0.53 (95% CI: 0.40–0.70), respectively.

Conclusions

The admission rate of Korean male firefighters due to endocrine, nutritional and metabolic diseases was significantly lower than that of the general Korean men population, the hazardous potential of endocrine disruptors remains an open question. Further studies of firefighters with longer follow-up are needed.

Environmental Nickel Exposure and Diabetes in a Nationally Representative Sample of US Adults

Laboratory studies have shown that nickel exposure may adversely affect glucose metabolism. However, studies about the effects of environmental nickel exposure on diabetes pathogenesis in humans are sparse. We aimed to evaluate the association of urinary nickel concentrations, as a biomarker of environmental nickel exposure, and diabetes in a nationally representative sample of US adults. The data from a nationally representative population (n = 1585) in the National Health and Nutrition Examination Survey 2017-18 were used. Diabetes (n = 330) was defined as self-reported physician's diagnosis, HbA1c ≥ 6.5%, fasting plasma glucose ≥ 126 mg/dL, or 2-h plasma glucose ≥ 200 mg/dL. Urinary nickel concentrations were determined by inductively coupled plasma mass spectrometry. Logistic regression with sample weights was used to estimate the odds ratios (ORs) of diabetes and 95% confidence intervals (CIs). Urinary nickel concentrations were higher in individuals with diabetes (weighted median 1.23 μg/L) than those without diabetes (1.01 μg/L). After adjustment for urinary creatinine and other risk factors for diabetes, the OR of diabetes comparing the highest with lowest quartile of urinary nickel concentrations was 2.70 (95% CI 1.39-5.24; P_trend = 0.03). Environmental nickel exposure is positively and significantly associated with diabetes in U.S. adults.

Blood lead, nutrient intake, and renal function among type 2 diabetic patients

Lead (Pb) exposure has been reported to have nephrotoxicity. However, such an effect has not been well investigated in type 2 diabetes (T2D) patients, especially when taking into account the nutrition status of the patients. Therefore, we explore the association between blood lead levels (BLLs), dietary intake of nutrients, and impaired renal function among patients with T2D. We measured BLLs and biochemical parameters of renal injury in 780 patients. Dietary nutrients intake was assessed by a food frequency questionnaire in 420 of 780 participants. We found high BLLs were significantly associated with certain parameters of renal injury, and dietary intake of specific nutrients (mainly micronutrients) was associated with reduced BLLs at high percentile distribution of concentration. BLLs were also found to have moderation effects on the association between specific dietary nutrients and specific renal function parameters.

Recovery of Banana Waste-Loss from Production and Processing: A Contribution to a Circular Economy

Banana is a fruit grown mainly in tropical countries of the world. After harvest, almost 60% of banana biomass is left as waste. Worldwide, about 114.08 million metric tons of banana waste-loss are produced, leading to environmental problems such as the excessive emission of greenhouse gases. These wastes contain a high content of paramount industrial importance, such as cellulose, hemicellulose and natural fibers that various processes can modify, such as bacterial fermentation and anaerobic degradation, to obtain bioplastics, organic fertilizers and biofuels such as ethanol, biogas, hydrogen and biodiesel. In addition, they can be used in wastewater treatment methods by producing low-cost biofilters and obtaining activated carbon from rachis and banana peel. Furthermore, nanometric fibers commonly used in nanotechnology applications and silver nanoparticles useful in therapeutic cancer treatments, can be produced from banana pseudostems. The review aims to demonstrate the contribution of the recovery of banana production waste-loss towards a circular economy that would boost the economy of Latin America and many other countries of emerging economies.

Impacts of heavy metals and medicinal crops on ecological systems, environmental pollution, cultivation, and production processes in China

Heavy metals are widely distributed in the environment due to the natural processes and anthropogenic human activities. Their migration into no contaminated areas contributing towards pollution of the ecosystems e.g. soils, plants, water and air. It is recognized that heavy metals due to their toxicity, long persistence in nature can accumulate in the trophic chain and cause organism dysfunction. Although the popularity of herbal medicine is rapidly increasing all over the world heavy metal toxicity has a great impact and importance on herbal plants and consequently affects the quality of herbal raw materials, herbal extracts, the safety and marketability of drugs. Effective control of heavy metal content in herbal plants using in pharmaceutical and food industries has become indispensable. Therefore, this review describes various important factors such as ecological and environmental pollution, cultivation and harvest of herbal plants and manufacturing processes which effects on the quality of herbal plants and then on Chinese herbal medicines which influence human health. This review also proposes possible management strategies to recover environmental sustainability and medication safety. About 276 published studies (1988-2021) are reviewed in this paper.

Exposure to heavy metals from point pollution sources and risk of incident type 2 diabetes among women: a prospective cohort analysis

Heavy metal exposures may contribute to diabetes risk but prospective studies are uncommon. We analyzed the Australian Longitudinal Study on Women's Health (three cohorts aged 18-23, 45-50, or 70-75 at baseline in 1996, N = 34,191) merged with emissions data for 10 heavy metals (As, Be, Co, Cr, Cu, Hg, Mn, Ni, Pb, Zn) from the National Pollutant Inventory. Over 20-year follow-up, 2,584 women (7.6%) reported incident diabetes. Cox proportional hazards regression models showed that women aged 45-50 at baseline had higher diabetes risk in association with exposure to total air emissions, total water emissions, all individual metals air emissions, and six individual water emissions. After correction for false discovery rate, nine of 11 air emissions and five water emissions remained significant. Associations were not observed for land-based emissions, or for younger or older cohorts. Emissions were dominated by mining, electricity generation and other metals-related industrial processes.

High Blood Lead Levels: An Increased Risk for Development of Brain Hyperintensities among Type 2 Diabetes Mellitus Patients

The current study was aimed to ascertain the effect of blood lead level on brain tissues in patients with type 2 diabetes. A total of 300 human participants ages 27 to 60 years with type 2 diabetes (n = 150) and healthy individuals (n = 150) were included in this study. The serum samples were used for measuring HbA1c and fasting blood glucose. Blood lead level was measured using flame atomic absorption spectrophotometer. Magnetic resonance imaging sub-analysis was used to assess the brain hyperintensities. Brain hyperintensities were found in 55% of patients with diabetes and 6% of non-diabetic control group subjects. The deep white matter hyperintensities were observed in 45% of diabetic patients, while the subcortical hyperintensities were noted in 10% of cases. Entorhinal cortex changes (31%) and hippocampus changes (42%) were noted in diabetic patients with brain hyperintensities. Diabetic patients with brain hyperintensities showed higher blood lead levels, HbA1c, and fasting blood sugar (p < 0.0001) as compared with healthy volunteers. A higher correlation (R² = 0.8922) was found between deep white matter hyperintensities' size and blood lead levels. In nutshell, persistence of high blood lead level in diabetic patients may progress to brain hyperintensities which may consequently lead to cognitive, behavioral changes and Alzheimer's disease.

Lead (Pb) exposure is associated with changes in the expression levels of circulating miRNAS (miR-155, miR-126) in Mexican women

The environmental contamination with lead (Pb) is considered a critical issue worldwide. Therefore, this study aimed to evaluate the expression levels of circulating miRNAs (miR-155, miR-126, and miR-145) in Mexican women exposed to Pb. Blood lead levels (BLL) were assessed in enrolled women (n = 190) using an atomic absorption method. Also, serum miRNAs expression levels were quantified through a real-time PCR assay. A mean BLL of 10.5 ± 4.50 μg/dL was detected. Overexpression of miR-155 was detected in highly exposed women. Besides, a significant simple positive relationship (p < 0.05) was found between BLL and serum miR-155 expression levels. Additionally, a significant inverse correlation (p < 0.05) was determined between BLL and serum miR-126 expression levels, as downregulation of miR-126 expression levels was observed in highly exposed women. The findings in this study are the concern, as epigenetic changes detected may represent a connection between health illnesses and Pb exposure.

Plasma metals and cancer incidence in patients with type 2 diabetes

There is limited evidence on the relationships between plasma levels of multiple metals and risk of incident cancer in patients with type 2 diabetes mellitus (T2DM). We examined the associations between plasma levels of 12 metals (iron, copper, zinc, selenium, chromium, manganese, molybdenum, cobalt, nickel, arsenic, cadmium, and lead) and cancer risk in 4573 T2DM patients using Cox proportional hazards models. With a median follow-up of 10.2 years, 541 incident cancers were identified. The multiple-metals model revealed that each 1-SD increase in ln-transformed plasma copper (HR: 1.14; 95%CI: 1.02, 1.27) and lead (HR:1.20; 95%CI:1.03, 1.39) were significantly associated with increased cancer incidence while each 1-SD increase in ln-transformed plasma zinc (HR: 0.82; 95%CI: 0.71, 0.96) and chromium (HR: 0.88; 95%CI: 0.82, 0.94) were significantly associated with decreased cancer incidence. When all participants were further stratified into four subgroups by the quartile levels (Q1-4) of plasma metals, manganese showed significant positive associations with cancer incidence in the upper two quartiles (P trend = 0.003) while nickel showed significant negative associations with cancer incidence in Q2 and 4 groups (P trend = 0.033) compared with participants in Q1 group. Collectively, monitoring of metal levels in diabetic patients needs to be strengthened, which is of great significance for the prevention of incident cancer.

Significant association between blood lead (Pb) level and haemoglobin A1c in non-diabetic population

Although many heavy metals are necessary for normal biological function, a subset of heavy metals have no role in human physiology, such as lead (Pb) and arsenic (As). Such elements have deleterious effects on physiology and be associated with the incidence of diabetes and related metabolic syndromes. Haemoglobin A1c (HbA1c) is not only a useful diagnostic and prognostic parameter in patients with diabetes, but it is also helpful in prediction of future diabetic risk in non-diabetic patients. However, no studies have evaluated the relationship between heavy metal concentration and HbA1c in non-diabetic patients. Therefore, the present study was designed to address this issue. We performed surveys for general populations living in southern Taiwan from June 2016 to September 2018. All participants received face-to-face interviews, laboratory tests, and measurements of weight and height, waist circumference, heart rate, and systolic and diastolic blood pressures. HbA1c was positively associated with Log blood Pb, after adjustments for age, body mass index, fasting blood glucose, total cholesterol, and triglyceride. Additionally, a Log 1 μg/dL increase in Pb was associated with a small (0.819 mmol/mol, 95% confidence interval = 0.072-1.566) increase in HbA1c (P =  0.032). No association with HbA1c was observed for urine nickel, chromium, manganese, As, copper, and cadmium in the multivariable analysis. In conclusion, after adjusting for important clinical parameters, Log blood Pb was positively associated with HbA1c in our non-diabetic population. This finding implies that high blood Pb might have the potential to predict future diabetic risk in non-diabetic populations. Further prospective studies are necessary to validate this issue.

Exposure to heavy metals modifies optimal gestational weight gain: A large nationally representative cohort of the Japan Environment and Children's Study

Clinical guidelines including those set by the US Institute of Medicine, have based optimal gestational weight gain (GWG) on maternal pre-pregnancy body mass index (BMI), but have not considered the role of environmental toxicants such as heavy metals that can disrupt these processes. This study designed to determine optimal GWG ranges in women grouped according to BMI, and to assess whether blood concentrations of heavy metals alter the relationships between GWG and outcomes. A total of 103,060 participants in the Japan Environment and Children's Study recruited between 2011 and 2014 were followed until their children reached 3 years of age. Outcomes included 1 min Apgar score <7, caesarean delivery, childhood obesity, gestational diabetes, pregnancy-induced hypertension, low birth weight, large for gestational age, macrosomia, operative vaginal delivery, postpartum weight retention, preterm birth and small for gestational age. The optimal GWG ranges were determined using multivariate logistic regression models. Stratified analyses were performed to determine optimal GWG ranges according to quartiles of heavy metals. Optimal GWGs for underweight, normal weight and overweight women were found to be 10.0 to <14.0 kg, 6.0 to <12.0 kg and 4.0 to <8.0 kg, respectively. However, the benefits of optimal GWG were attenuated in women exposed to high concentrations of mercury (Hg), lead (Pb) and cadmium (Cd). Despite being within optimal GWG, underweight women with Hg > 5.21 ng/g and overweight women with Hg 3.67-5.21 ng/g, Pb > 7.31 ng/g and Cd > 0.66 ng/g had null effects. Heavy metals can modify the associations between GWG and outcomes, particularly for underweight and overweight women. Because of the complex interactions of environmental toxicants with pre-pregnancy BMI, GWG and adverse outcomes, GWG guidelines should be interpreted cautiously. Environmental toxicants may influence the determination of a clinical guideline.

Toxic metal exposure as a possible risk factor for COVID-19 and other respiratory infectious diseases

Multiple medical, lifestyle, and environmental conditions, including smoking and particulate pollution, have been considered as risk factors for COronaVIrus Disease 2019 (COVID-19) susceptibility and severity. Taking into account the high level of toxic metals in both particulate matter (PM2.5) and tobacco smoke, the objective of this review is to discuss recent data on the role of heavy metal exposure in development of respiratory dysfunction, immunotoxicity, and severity of viral diseases in epidemiological and experimental studies, as to demonstrate the potential crossroads between heavy metal exposure and COVID-19 severity risk. The existing data demonstrate that As, Cd, Hg, and Pb exposure is associated with respiratory dysfunction and respiratory diseases (COPD, bronchitis). These observations corroborate laboratory findings on the role of heavy metal exposure in impaired mucociliary clearance, reduced barrier function, airway inflammation, oxidative stress, and apoptosis. The association between heavy metal exposure and severity of viral diseases, including influenza and respiratory syncytial virus has been also demonstrated. The latter may be considered a consequence of adverse effects of metal exposure on adaptive immunity. Therefore, reduction of toxic metal exposure may be considered as a potential tool for reducing susceptibility and severity of viral diseases affecting the respiratory system, including COVID-19.

Lifestyle-Related Exposure to Cadmium and Lead is Associated with Diabetic Kidney Disease

BACKGROUND

Environmental factors contributing to diabetic kidney disease are incompletely understood. We investigated whether blood cadmium and lead concentrations were associated with the prevalence of diabetic kidney disease, and to what extent lifestyle-related exposures (diet and smoking) contribute to blood cadmium and lead concentrations.

MATERIAL AND METHODS

In a cross-sectional analysis in 231 patients with type 2 diabetes included in the DIAbetes and LifEstyle Cohort Twente (DIALECT-1), blood cadmium and lead concentrations were determined using inductively coupled plasma mass spectrometry. The associations between diet (derived from food frequency questionnaire), smoking and cadmium and lead were determined using multivariate linear regression. The associations between cadmium and lead and diabetic kidney disease (albumin excretion >30 mg/24 h and/or creatinine clearance <60 mL/min/1.73 m²) were determined using multivariate logistic regression.

RESULTS

Median blood concentrations were 2.94 nmol/L (interquartile range (IQR): 1.78-4.98 nmol/L) for cadmium and 0.07 µmol/L (IQR: 0.04-0.09 µmol/L) for lead, i.e., below acute toxicity values. Every doubling of lead concentration was associated with a 1.75 (95% confidence interval (CI): 1.11-2.74) times higher risk for albuminuria. In addition, both cadmium (odds ratio (OR) 1.50 95% CI: 1.02-2.21) and lead (OR 1.83 95% CI: 1.07-3.15) were associated with an increased risk for reduced creatinine clearance. Both passive smoking and active smoking were positively associated with cadmium concentration. Alcohol intake was positively associated with lead concentration. No positive associations were found between dietary intake and cadmium or lead.

CONCLUSIONS

The association between cadmium and lead and the prevalence of diabetic kidney disease suggests cadmium and lead might contribute to the development of diabetic kidney disease. Exposure to cadmium and lead could be a so far underappreciated nephrotoxic mechanism of smoking and alcohol consumption.

Urinary metals and incident diabetes in midlife women: Study of Women's Health Across the Nation (SWAN)

INTRODUCTION

Environmental exposure to metals may play a role in the pathogenesis of diabetes; however, evidence from human studies is limited. We prospectively evaluated the associations of 20 urinary metal concentrations and their mixtures with incident diabetes in the Study of Women's Health Across the Nation, a multisite, multiethnic cohort study of midlife women.

RESEARCH DESIGN AND METHODS

The sample included 1237 white, black, Chinese and Japanese-American women, aged 45-56 years, free of diabetes at baseline (1999-2000) who were followed through 2016. Concentrations of 20 metals (arsenic, barium, beryllium, cadmium, cobalt, chromium, cesium, copper, mercury, manganese, molybdenum, nickel, lead, antimony, tin, thallium, uranium, vanadium, tungsten and zinc) were measured in urine specimens at baseline. Incident diabetes was identified annually by fasting glucose ≥126 mg/dL, self-reported doctor-diagnosed diabetes, or self-reported use of antidiabetic medications. A non-parametric clustering method, k-means clustering, was used to identify subgroups with different exposure patterns to metal mixtures.

RESULTS

After multivariable adjustment, the HR (95% CI) for diabetes associated with each doubling increase in urinary metal concentrations was 1.19 (1.10 to 1.30) for arsenic and 1.20 (1.05 to 1.37) for lead, in Cox proportional hazards models after controlling for multiple comparisons. A doubling in urinary excretion of zinc was associated with higher risk of diabetes (adjusted HR 1.31, 95% CI 1.11 to 1.53). Two distinct exposure patterns to metal mixtures-'high' versus 'low'-were identified. Participants assigned to the 'high' pattern had higher overall concentrations of all metals compared with those classified into the 'low' pattern. Adjusted HR for diabetes associated with 'high' pattern compared with 'low' was 1.42 (1.08 to 1.87).

CONCLUSIONS

Higher urinary concentrations of arsenic and lead, increased urinary excretion of zinc, as well as higher overall exposure to metal mixtures were associated with elevated risk of diabetes. Future studies should further investigate the underlying mechanisms.

A Colorimetric Aptamer Sensor Based on the Enhanced Peroxidase Activity of Functionalized Graphene/Fe3O4-AuNPs for Detection of Lead (II) Ions

Lead (II) is regarded as one of the most hazardous heavy metals, and lead contamination has a serious impact on food chains, human health, and the environment. Herein, a colorimetric aptasensor based on the graphene/Fe3O4-AuNPs composites with enhanced peroxidase-like activity has been developed to monitor lead ions (Pb2+). In short, graphene/Fe3O4-AuNPs were fabricated and acted as an enzyme mimetic, so the color change could be observed by chromogenic reaction. The aptamer of Pb2+ was decorated on the surface of the amine magnetic beads by streptavidin–biotin interaction, and the complementary strands of the aptamer and target Pb2+ competed for the binding Pb2+ aptamer. In the presence of Pb2+, aptamers bonded the metal ions and were removed from the system by magnetic separation; the free cDNA was adsorbed onto the surface of the graphene/Fe3O4-AuNPs composites, thus inhibiting the catalytic activity and the color reaction. The absorbance of the reaction solution at 652 nm had a clear linear correlation with the Pb2+ concentration in the range of 1–300 ng/mL, and the limit of detection was 0.63 ng/mL. This assay is simple and convenient in operation, has good selectivity, and has been used to test tap water samples, which proves that it is capable for the routine monitoring of Pb2+.

Serum Selenium and Lead Levels: a Possible Link with Diabetes and Associated Proteinuria

The study assessed trace element selenium (Se) and a heavy metal lead (Pb) in patients with type II diabetes mellitus (T2DM) and its associated proteinuria. Total 275 subjects aged between 30 and 90 years were studied: 93 T2DM, 98 T2DM with proteinuria, and 84 as controls. Serum Se and Pb were analyzed by inductively coupled plasma optical emission spectrometer (ICP-OES) and other biochemical indices by ROCHE module COBAS 6000 analyzer. Statistical analysis was done by one-way analysis of variance (ANOVA) at P < 0.0001 followed by Tukey's honest test. Pearson's correlation coefficient was applied to observe the effects of Se and Pb on FPG and ACR. Decreased Se levels were observed in T2DM and T2DM with proteinuria with no significant difference and serum Pb was found within reference range in both groups. Se showed no significant association with FBG and ACR while mid-upper tertile of Pb was significantly associated with ACR of T2DM with the proteinuria group (P < 0.01). Se is known to have a U-shaped relationship with T2DM. Low Se levels in both groups may be due to the effect of disease and its related inflammation. Detected levels of Pb suggest that studied population had lower exposure to it. Association of Pb with ACR showed consistency with the classical studies that even low levels of Pb may cause the renal deterioration.

Prenatal Lead Exposure, Type 2 Diabetes, and Cardiometabolic Risk Factors in Mexican Children at Age 10-18 Years

CONTEXT

Several cross-sectional studies have assessed the association of lead exposure with type 2 diabetes and cardiometabolic risk factors in adults; however, studies of such associations in childhood are rare.

OBJECTIVE

We assessed the prospective associations of prenatal exposure to lead with type 2 diabetes and cardiometabolic risk factors in children.

DESIGN

The Early Life Exposure in Mexico to Environmental Toxicants is a birth cohort study of pregnant women and their offspring.

SETTING

Public hospitals in Mexico City.

PATIENTS OR OTHER PARTICIPANTS

Women were recruited during pregnancy; their offspring were recruited for a follow-up visit at age 10 to 18 years (n = 369).

MAIN OUTCOME MEASURES

We measured fasting serum markers of type 2 diabetes and cardiometabolic risk factors in children, including fasting glucose, insulin, and lipids. The index of insulin resistance was calculated.

RESULTS

The geometric mean of maternal blood lead levels (BLLs) during pregnancy was 4.3 µg/dL (95% confidence interval [CI]): 4.0-4.6 µg/dL) in the entire sample. In boys, those with maternal BLLs ≥ 5 µg/dL (compared with those with BLLs < 5 µg/dL) had significantly lower z scores for total cholesterol (β = -0.41, 95% CI: -0.71, -0.12), high-density lipoprotein cholesterol (β = -0.32, 95% CI: -0.59, -0.05), and low-density lipoprotein cholesterol (β = -0.52, 95% CI: -0.81, -0.22), adjusting for covariates. No associations were detected in girls.

CONCLUSIONS

In our study, we found that higher prenatal exposure to lead was associated with lower levels of cholesterol in children following a sex-specific pattern. Further studies with a larger sample size that examine whether sex is a potential modifier are needed to confirm our findings.

Multiple metal concentrations and gestational diabetes mellitus in Taiyuan, China

BACKGROUND

The association between multiple metal concentrations and gestational diabetes mellitus (GDM) is poorly understood.

METHODS

A total of 776 women with GDM and an equal number of controls were included in the study. Concentrations of metals in participants' blood (nickel (Ni), arsenic (As), cadmium (Cd), antimony (Sb), thallium (Tl), mercury (Hg), lead (Pb)) were measured using inductively coupled plasma-mass. We used unconditional logistical regression models to estimate the associations between metals and GDM. We also employed weighted quantile sum (WQS) regression and principal components analysis (PCA) to examine metal mixtures in relation to GDM.

RESULTS

An increased risk of GDM was associated with As (OR = 1.49, 95% CI: 1.11, 2.01 for the 2nd tertile vs. the 1st tertile) and Hg (OR = 1.43, 95% CI: 1.09, 1.88 for the 3rd tertile vs. the 1st tertile). In WQS analysis, the WQS index was significantly associated with GDM (OR = 1.20, 95% CI: 1.02, 1.41). The major contributor to the metal mixture index was Hg (69.2%), followed by Pb (12.8%), and As (11.3%). Based on PCA, the second principal component, which was characterized by Hg, Ni, and Pb, was associated with an increased risk of GDM (OR = 1.46, 95% CI: 1.02, 2.08 for the highest quartile vs. the lowest quartile).

CONCLUSIONS

Our study results suggest that high metal levels are associated with an increased risk of GDM, and this increased risk is mainly driven by Hg and, to a lesser extent, by Ni, Pb, and As.

The Role of Antioxidant Activity of Chitosan-Pinus merkusii Extract Nanoparticle in against Lead Acetate-Induced Toxicity in Rat Pancreas

Lead is one of the heavy metals with oxidative stress that causes toxicity in human and animals. The aim of this study was to evaluate the antioxidant activity of Chitosan-Pinus merkusii extract nanoparticle on lead acetate-induced toxicity in rat pancreas. Chitosan-Pinus merkusii nanoparticles were identified by Particle Size Analysis (PSA) and Scanning Electron Microscope (SEM). The male rats used were divided into a control group (treated with distilled water), lead acetate group (injected with lead acetate at 20 mg/kg BW i.p), and the treatment group (treated orally with Chitosan-Pinus merkusii nanoparticle at 150 mg; 300 mg; 600 mg/kg BW and injected with lead acetate at 20 mg/kg BW i.p). Blood samples were taken to measure glucose and insulin level. The pancreas tissues were also collected to evaluate the malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), and histological evaluations of cell damage. The PSA showed that the size of Chitosan-Pinus merkusii nanoparticle was 530.2 ± 38.27 nm. The SEM images revealed an irregular shape, and the morphology showed a rough surface. Administration of lead acetate resulted in a significant increase in glucose and MDA levels as well as a decrease in the level of insulin, SOD and GPx when compared with the control group, while that of 600 mg/kg BW of Chitosan-Pinus merkusii nanoparticle gave a polar result. The lead acetate induced loss of pancreatic cells normal structure and necrosis, while Chitosan-Pinus merkusii nanoparticle inhibited it. It could be concluded that Chitosan-Pinus merkusii nanoparticle has a potential to be a powerful agent and may be useful as an antioxidant against free radical-induced oxidative stress and pancreatic cell damage mediated by lead acetate intoxication.

Examining environmental contaminant mixtures among adults with type 2 diabetes in the Cree First Nation communities of Eeyou Istchee, Canada

Type 2 diabetes mellitus (T2DM) disproportionately affects Indigenous populations. It is possible that exposure to complex mixtures of environmental contaminants contribute to T2DM development. This study examined the association between complex environmental contaminant mixtures and T2DM among Canadian Indigenous communities from the Eeyou Istchee territory, Quebec, Canada. Using data from the cross-sectional Multi-Community Environment-and-Health Study (2005–2009) Principal Component Analysis (PCA) was used to reduce the dimensionality of the following contaminants: 9-polychlorinated biphenyl congeners; 7-organic pesticides; and 4-metal/metalloids. Following this data reduction technique, we estimated T2DM prevalence ratios (PR) and 95% confidence intervals using modified Poisson regression with robust error variance across derived principal components, adjusting for a priori covariates. For both First Nation adult males (n = 303) and females (n = 419), factor loadings showed dichlorodiphenyltrichloroethane (DDT) and lead (Pb) highly loaded on the second principal component (PC) axis: DDT negatively loaded, and Pb positively loaded. T2DM was significantly associated with PC-2 across all adjusted models. Because PCA produces orthogonal axes, increasing PC-2 scores in the fully adjusted model for females and males showed (PR = 0.84; 95% CI 0.72, 0.98) and (PR = 0.78; 95% CI 0.62, 0.98), respectively. This cross-sectional study suggests that our observed association with T2DM is the result of DDT, and less likely the result of Pb exposure. Further, detectable levels of DDT among individuals may possibly contribute to disease etiology.

Risk of Lead Exposure from Transport Stations to Human Health: A Case Study in the Highland Province of Vietnam

Lead (Pb) is a heavy metal that negatively affects human health. Many studies have shown the relationship between lead exposure and various human activities, of which automobile service stations with gasoline emissions are considered the main cause. However, a limited number of studies have specifically considered lead exposure from automobile stations in Vietnam, as well as its impact on human activities and the surrounding natural resources. The objective of this study was to assess the possible risks of lead exposure to the surrounding agricultural and non-agricultural farms of a bus station located in the center of Dalat city, Lamdong province, Vietnam. To address this objective, 45 samples were collected from the soil, irrigated water resources, and vegetable crops of areas both close to and far away from the bus station. These samples were tested using the atomic absorption spectrometry technique. Our findings demonstrated higher lead concentration levels from all three types of samples collected from areas near the bus station. Of which, soil and water samples showed higher than normal exposure values of lead, but these were still under the allowed limits established by the Vietnam standard. Different from the soil and water, vegetable samples surrounding the bus station presented greater lead contamination than the permitted limit. High risk quotient (RQ) indexes were detected to point out that accumulative consumption of leaded vegetables over time could cause lead poisoning and harm human health. This study not only provides significant inferential evidence of the risk of lead exposure to agricultural activities and human health in Vietnam, but also delivers a real-life example for a real-world context.

Decreased Insulin Secretion but Unchanged Glucose Homeostasis in Cadmium-Exposed Male C57BL/6 Mice

Cadmium (Cd) is a well-known toxic metal element that is largely distributed in the environment. Cd causes toxicity to most organs. Accumulating evidence suggests that Cd exposure is associated with islet dysfunction and development of diabetes, but the association remains controversial. The aim of this study is to evaluate the possible effects of chronic Cd exposure on glucose metabolism in male C57BL/6 mice. Mice were intraperitoneally injected with CdCl₂ solution (1 mg.kg⁻¹) twice a week for 24 weeks. Fasting blood glucose (FBG) levels and body weights were measured weekly. After 24 weeks, the intraperitoneal glucose tolerance test (IPGTT), intraperitoneal insulin tolerance test (IPITT), and fasting serum insulin (FSI) level test were performed. The insulin resistance index (HOMA-IR) and pancreatic β cell function index (HOMA-β) were calculated and analyzed. The expression of insulin receptor (IR) in mouse liver was detected by real-time PCR. Pancreatic tissue was collected for histological examination. The results demonstrated that FBG, IPGTT, HOMA-IR, and HOMA-β were identical between Cd exposure and control mice. In contract, mean fasting serum insulin level, area under the curve (AUC) of IPITT, and IR expression in livers of Cd-exposed mice decreased significantly compared with control mice. Cd administration induced islet atrophy and decreased islet area. The results suggested that Cd exposure decreased insulin secretion and maintained glucose homeostasis in male C57BL/6 mice and that pancreatic functions should be monitored in populations chronically exposed to Cd.

Genomic Tools for Environmental Epigenetics and Implications for Public Health

Epigenetics refers to the study of mitotically heritable and potentially reversible changes in gene expression unrelated to the DNA sequence itself, influenced by epigenetic marks including chromatin modifications, non-coding RNA and alterations to DNA itself via methylation and hydroxymethylation. Epigenetics has taken center stage in the study of diseases such as cancer, diabetes, and neurodegeneration; however, its integration into the field of environmental health sciences and toxicology (e.g. Toxicoepigenetics) is in its infancy. This review highlights the need to evaluate surrogate and target tissues in the field of toxicoepigenetics as the National Institute of Environmental Health Sciences (NIEHS) multi-phased Toxicant Exposure and Response by Genomic and Epigenomic Regulators of Transcription (TaRGET) consortia make headway, and the emergence of non-coding RNA biomarkers. The review also discusses lead (Pb) as a potential toxicoepigenetic exposure, where pre- and post-natal Pb exposure is associated with reprogramming of DNA methylation, histone modifications, and microRNA expression, representing potential biomarkers or predictors for Pb-induced health outcomes. Finally, new advances in epigenome editing, highlighting the potential of small ncRNA, will be explored for environmental health sciences research.