Blood Concentrations Of Heavy Metals Research Articles

Population-based study of environmental heavy metal exposure and hearing loss: A systematic review and meta-analysis.

Previous studies have shown an association between environmental exposure to heavy metals and hearing loss. However, the findings regarding the relationship between exposure to different metals and hearing loss development are inconsistent. To address this, we conducted a meta-analysis to explore the link between common heavy metal exposures and hearing loss. This study examined the effects of lead (Pb), cadmium (Cd), and mercury (Hg) pollution on hearing loss at various levels, and systematically reviewed the literature on manganese (Mn), barium (Ba), arsenic (As), and hearing loss. We conducted systematic searches in five major databases, including PubMed, Web of Science, Embase, Cochrane Library, and Scopus. In addition, we searched three Chinese digital libraries: CNKI, Wanfang Data, and Wipu. From an initial pool of 649 articles, we carefully screened and selected 15 articles for further analysis. The effect sizes from these selected studies were synthesized through a meta-analysis to calculate the overall effect size. Our findings showed that: (1) There was a significant association between Pb and Cd exposure and hearing loss; (2) There is a proportional relationship between the increase of metal index detected in blood and hearing loss; (3) In the PTA measurement of hearing loss at different frequencies, the 4 kHz high frequency range had a stronger correlation with hearing loss than the low frequency, with OR 1.44 (1.22, 1.71); and (4) There was a more significant correlation between Barium (Ba) levels in nails and hair than in urine. The study presented evidence of a significant association between human hearing loss and exposure to lead (Pb) and cadmium (Cd). It not only revealed a positive correlation between blood heavy metal concentrations and the incidence of hearing loss but also highlighted that long-term exposure indicators of heavy metals were more indicative of the correlation with hearing loss. Lastly, the study recommends utilizing high frequency 4 kHz for the effective assessment and diagnosis of hearing loss caused by exposure to heavy metals.

Association between maternal blood or cord blood metal concentrations and catch-up growth in children born small for gestational age: an analysis by the Japan environment and children’s study

BackgroundCatch-up growth issues among children born small for gestational age (SGA) present a substantial public health challenge. Prenatal exposure to heavy metals can cause adverse effects on birth weight. However, comprehensive studies on the accurate assessment of individual blood concentrations of heavy metals and their effect on the failure to achieve catch-up growth remain unavailable. This study aimed to evaluate the effects of uterine exposure to toxic metals cadmium, lead, and mercury and essential trace metals manganese and selenium at low concentrations on the postnatal growth of children born SGA.MethodsData on newborn birth size and other factors were obtained from the medical record transcripts and self-administered questionnaires of participants in the Japan Environment and Children’s Study. The blood concentrations of lead, cadmium, mercury, selenium, and manganese in pregnant women in their second or third trimester were determined by inductively coupled plasma mass spectrometry. These heavy metal concentrations were also assessed in pregnant women’s cord blood. Furthermore, the relationship between each heavy metal and height measure/catch-up growth in SGA children aged 4 years was analyzed using linear and logistic regression methods. These models were adjusted for confounders.ResultsWe studied 4683 mother–child pairings from 103,060 pregnancies included in the Japan Environment and Children’s Study. Of these, 278 pairs were also analyzed using cord blood. At 3 and 4 years old, 10.7% and 9.0% of children who were born below the 10th percentile of body weight had height standard deviation scores (SDSs) below 2, respectively. Cord blood cadmium concentrations were associated with the inability to catch up in growth by 3 or 4 years old and the height SDS at 3 years old. In maternal blood, only manganese was positively associated with the height SDS of SGA children aged 2 years; however, it was not significantly associated with catch-up growth in these children.ConclusionCadmium exposure is associated with failed catch-up development in SGA children. These new findings could help identify children highly at risk of failing to catch up in growth, and could motivate the elimination of heavy metal (especially cadmium) pollution to improve SGA children’s growth.

Neurological risks arising from the bioaccumulation of heavy metal contaminants: A focus on mercury.

This study investigated the concentrations of heavy metals in the water sources of the upstream region of the Huangpu River, the Yangtze River Estuary, and various areas in Shanghai, as well as the heavy metal concentrations in the blood of Shanghai residents. It aimed to analyze the heavy metal elements absorbed by the human body and the resulting pathological effects. The results revealed that surface water primarily contains five heavy metals: copper (Cu), lead (Pb), zinc (Zn), arsenic (As), and mercury (Hg), while water sediments primarily contain seven heavy metals: Cu, cadmium (Cd), Pb, chromium (Cr), Zn, As, and Hg. The main heavy metals present in the human body are Pb, Hg, As, and Cd. By reviewing previous articles, it was found that heavy metal concentrations in human blood are higher than those in surface water, suggesting uncertainties in the heavy metal content of surface water and its tendency to settle at the bottom. Furthermore, a comparison of heavy metal content in sediments revealed that Hg is the most readily absorbed heavy metal by the human body and is also a toxic environmental pollutant. Within the cell, Hg is highly toxic to mitochondria and may cause oxidative stress and neurodegenerative disease. This study concludes that water sediments serve as the major source of pollution in the human body and pose significant health risks, thereby necessitating the implementation of effective preventive measures.

Adequate Intake of Dietary Fiber May Relieve the Detrimental Impact of Blood Lead on Dyslipidemia among US Adults: A Study of Data from the National Health and Nutrition Examination Survey Database.

Lead (Pb) exposure is a well-established risk factor for dyslipidemia, and people are exposed to it in multiple ways daily. Dietary fiber is presumed to improve lipid metabolism disorders, but it is still unknown whether it can relieve the detrimental impact of Pb on dyslipidemia. We used publicly accessible data from the 2011-2016 cycles of the National Health and Nutrition Examination Survey (NHANES). A total of 2128 US adults were enrolled for the subsequent analysis. Heavy metal concentrations in blood were measured using inductively coupled plasma mass spectrometry (ICP-MS). A weighted logistic regression was conducted to calculate odds ratios (ORs) and 95% confidence intervals (CIs). The dose-response relationship between blood heavy metals and dyslipidemia was explored using a weighted restricted cubic spline (RCS) analysis. After fully adjusting for potential confounding factors (age, gender, race, education level, ratio of family income to poverty, marital status, body mass index, physical activity, waist circumference, smoke, alcohol drinking and history of metabolic syndrome, hypertension, and diabetes), a positive association between blood Pb levels and dyslipidemia risk was revealed (OR = 1.20, 95% CI: 1.03-1.40). Dietary fiber intake may significantly modify the association between blood Pb levels and dyslipidemia (p-interaction = 0.049), with a stronger association (OR = 1.26, 95% CI: 1.05-1.52) being revealed in individuals with an inadequate intake of dietary fiber (<14 g/1000 kcal/day), but a null association (OR = 1.01, 95% CI: 0.72-1.42) being observed in those with an adequate intake of dietary fiber (≥14 g/1000 kcal/day). Moreover, the weighted RCS analysis showed that compared with the average blood Pb exposure level (4.24 µg/dL), a lower blood Pb exposure level (3.08 µg/dL) may contribute to the risk of dyslipidemia in the group with an inadequate dietary fiber intake. Our findings suggest that Pb exposure in blood may be a risk factor for dyslipidemia. However, an adequate dietary fiber intake may offset the risk of dyslipidemia caused by blood Pb exposure. Since avoiding Pb exposure in daily life is difficult, increasing dietary fiber intake in the future might be a promising approach to alleviate dyslipidemia caused by Pb exposure.

Associations between exposure to cadmium, lead, mercury and mixtures and women’s infertility and long-term amenorrhea

BackgroundCadmium (Cd), lead (Pb), and mercury (Hg) have been shown to exhibit endocrine disrupting properties. Their effects on women’s reproductive health, however, remain elusive. Here, we investigated associations between blood concentrations of Pb, Cd, Hg, and their mixture and infertility and long-term amenorrhea in women aged 20–49 years using the US National Health and Nutrition Examination Survey (NHANES) 2013–2018 cross-sectional survey.MethodsA total of 1,990 women were included for the analysis of infertility and 1,919 women for long-term amenorrhea. The methods of log-transformation and use of quartiles were used to analyze blood heavy metal concentrations. Statistical differences in the covariates between the outcome groups were evaluated using a chi-squared test for categorical variables and a t-test for continuous variables. Multiple logistic regression models were used to examine the associations.ResultsThe blood concentrations of Pb and heavy metal mixtures were significantly higher in ever-infertile women than pregnant women, but the concentrations of Cd and Hg were comparable. After full adjustment, multiple logistic regression analyses revealed a significant and dose-dependent positive association between blood Pb concentrations and women’s historical infertility, a negative association between Cd and women’s long-term amenorrhea, and no associations between Hg and heavy metal mixture and women’s infertility or long-term amenorrhea.ConclusionsOur study suggests that exposure to heavy metals exhibit differential associations with history of infertility and amenorrhea, and Pb may adversely impact women’s reproduction and heighten the risks of infertility and long-term amenorrhea.

Blood Levels of Environmental Heavy Metals are Associated with Poorer Iron Status in Ugandan Children: A Cross-Sectional Study

BackgroundIron deficiency (ID) and environmental exposure to metals frequently co-occur among Ugandan children, but little is known about their associations, although iron and other divalent metals share the same intestinal absorption transporter, divalent metal transporter 1 (DMT1). ObjectivesWe examined associations between iron status and blood concentrations of lead, manganese (Mn), cobalt (Co), and cadmium, both singly and as a mixture. MethodsWe used data on sociodemographic status, iron biomarkers, and blood concentrations of heavy metals collected from a cross-sectional survey of 100 children aged 6–59 mo in Kampala, Uganda. We compared blood concentrations of metals in ID with iron-sufficient children. We examined associations between a metal mixture and iron biomarkers using multiple linear regression and weighted quintile sum regression. ResultsThe median (interquartile range) blood Mn (μg/L) was higher in ID children defined by soluble transferrin receptor (sTfR) and ferritin (ID compared with iron-sufficient children): (sTfR [21.3 {15.1, 28.8}, 11.2 {8.6, 18.5}], ferritin [19.5 {15.0, 27.2}, 11.2 {8.8, 19.6}]; P < 0.001 for both). Similarly, the median (interquartile range) blood Co (μg/L) was higher in ID children by ferritin ([0.5 {0.4, 0.9}, 0.4 {0.3, 0.5}], P = 0.05). Based on the multiple linear regression results, higher blood Co and Mn were associated with poorer iron status (defined by all 4 iron indicators for Co and by sTfR for Mn). The weighted quintile sum regression result showed that higher blood concentrations of a metal mixture were associated with poorer iron status represented by sTfR, ferritin, and hepcidin, mainly driven by Co and Mn. ConclusionsOur study findings suggest that poorer iron status is associated with overall heavy metal burden, predominantly Co and Mn, among Ugandan children. Further prospective studies should confirm our primary findings and investigate the combined effects of coexposures to neurotoxicants on the neurodevelopment of young children.

Blood multiple heavy metals exposure and lung function in young adults: A prospective Cohort study in China

The content of single heavy metal in blood is associated with lung function decline, but there is little evidence on the joint effect of multiple heavy metals on lung function. To explore whether heavy metal mixture exposure is associated with lung function reduction among young adults. The study based on a cohort of 518 students recruited from a college in Shandong, China. We measured their lung function and blood heavy metal concentrations. The BKMR model was used to analyse the association between blood heavy metals mixture levels and lung function, and to identify the critical single heavy metal which contributes most to joint effects. As the sensitivity analysis, we used quantile g-computation model and GLM to explore the joint effect and independent effects of heavy metals. Our findings revealed a significant reduction of FVC and FEV1 levels after exposure to heavy metals mixture. An IQR increase in Cu was associated with a 0.079 L and 0.083 L decrease in FEV1 and FVC, respectively. And an IQR increase in Fe was associated with 0.036 L higher FEV1 and 0.033 L higher FVC. For adults, reducing blood heavy metals concentration might be an effective intervention to protect lung function.

Determination of blood heavy metal concentrations and oxidant-antioxidant capacities in Angora cats at different age and gender

This study was conducted to investigate heavy metal concentrations and oxidative status of plasma and erythrocytes in Angora cats at different ages and gender. Sixteen young (less than 1 year old) and 14 adult (1–6 years old) cats were also grouped according to gender as male (n = 17) and female (n = 13). The separated plasma samples from cat’s blood were analyzed for selected heavy metals and total oxidant and antioxidant capacities (TOC and TAC) and calculated for oxidative stress index (OSI). The erythrocyte hemolysates were also evaluated for malondialdehyde (MDA), and super oxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX). Results of the study showed that most of the measured metals were not varied statistically according to age or gender. However, adult cats had significantly (P&amp;lt;0.01) higher Cu and lower Fe levels compared to young cats. Plasma levels of TOC, TAC and OSI, and erythrocyte MDA concentrations in young cats were significantly (P&amp;lt;0.05) higher than that of adults. While the SOD activity was decreased by the age, GPX activity was increased (P&amp;lt;0.05). However, the activity of CAT was changed by only gender, which was higher in males (P&amp;lt;0.01). In conclusion, metals, especially trace elements, are required for many kinds of physiological processes and the synthesis of antioxidant enzymes. Therefore, it can be suggested that the periodic measurement of metals and the addition of common antioxidant supplements to the diet of adult Angora cats will support weakening antioxidant mechanisms by age.

Periconceptional diet quality and its relation to blood heavy metal concentrations among pregnant women: The Japan environment and Children’s study

BackgroundDiets contain toxic chemical contaminants as well as essential nutrients, both of which influence the intrauterine environment for foetal growth. However, whether a high-quality diet that is nutritionally healthy also results in lower exposure to chemical contaminants is unknown. ObjectiveWe examined associations between periconceptional maternal diet quality and circulating concentrations of heavy metals during pregnancy. DesignDietary intake over the year prior to the first trimester of pregnancy was assessed using a validated, self-administered food frequency questionnaire among 81,104 pregnant Japanese women who participated in the Japan Environment and Children's Study. Overall diet quality was determined using the Balanced Diet Score (BDS) based on the Japanese Food Guide Spinning Top, the Healthy Eating Index-2015 (HEI-2015), the Dietary Approaches to Stop Hypertension (DASH) score and the Mediterranean diet score (MDS). We measured whole-blood concentrations of mercury (Hg), lead (Pb) and cadmium (Cd) during the second or third trimester of pregnancy. ResultsAfter controlling for confounders, all diet quality scores were positively associated with blood Hg concentrations. By contrast, higher BDS, HEI-2015 and DASH scores were associated with lower concentrations of Pb and Cd. Although the MDS was positively associated with concentrations of Pb and Cd, when dairy products were classified as a beneficial (rather than detrimental) food component, these associations were attenuated. ConclusionA high-quality diet may reduce exposure to Pb and Cd but not Hg. Further studies are required to determine the optimal balance between mercury exposure risk and nutritional benefits of high-quality diets prior to pregnancy.

Periconceptional maternal diet quality influences blood heavy metal concentrations and their effect on low birth weight: the Japan Environment and Children’s Study

BackgroundBoth poor maternal nutrition and toxic heavy metal exposure influence foetal growth and development. However, whether consumption of a variety of healthy foods modifies the association between prenatal heavy metal exposure and foetal growth is unknown. ObjectiveWe examined whether long-term maternal diet quality in periconception modifies the associations between maternal circulating concentrations of heavy metals and foetal growth. DesignData of 72,317 Japanese women who delivered singleton infants was extracted from the Japan Environment and Children’s Study. Maternal diet over a 1-year before the first trimester of pregnancy was assessed using a validated food frequency questionnaire, and overall diet quality was determined using the balanced diet score based on the Japanese Food Guide Spinning Top. Maternal whole-blood concentrations of mercury (Hg), lead (Pb) and cadmium (Cd) were measured during the second/third trimester of pregnancy. Bayesian inference of multiple linear regression analysis was performed to evaluate the relationships between maternal diet quality and the blood concentrations of heavy metals; Bayesian logistic regression was used to analyse the risk of low birth weight (LBW; <2,500 g). ResultsAfter controlling for confounders, a high maternal balanced diet score was associated with low concentrations of blood Pb and Cd and high Hg. While all heavy metals assessed were positively associated with LBW risk, a higher maternal balanced diet score was negatively associated with LBW risk. A high-quality maternal diet attenuated the effect of Pb on LBW, an effect that was more marked at high blood Pb concentrations. ConclusionA high-quality, ‘well-balanced’ diet prior to conception may reduce exposure to some heavy metals and mitigate the elevated risk of LBW associated with prenatal Pb exposure in Japanese mother–child pairs.

Lead acetate versus cadmium sulfate in the modulation of main physiological pathways controlling detrusor muscle contractility in rat

Heavy metals have a deleterious effect on lower urinary tract functions. Scant data has been reported about metals’ effect on altering detrusor muscle contractility. Rats were given lead acetate (3, 30 mg/kg), cadmium sulfate (0.1, 1 mg/kg) or ferrous sulfate-iron overload-(3, 30 mg/kg), in a subacute toxicity study (21 days, ip). In-vitro tension experiments were conducted using isolated rat detrusor muscle. Measurement of heavy metal concentrations in blood and tissue homogenates was performed, as well as histopathological examinations. Subacute toxicity induced by treatment with lead and cadmium was manifested as a decrease in EFS, ACh, and ATP-mediated contraction of isolated detrusor muscle. Iron overload only decreased EMAX of EFS and ACh-mediated contraction. Lead (30 mg/kg) caused an upward shift in the dose response curve of isoprenaline-induced relaxation, with a significant decrease in EMAX. Lead (30 mg/kg) or cadmium (1 mg/kg) inhibited adenosine (10−5 M)-induced relaxation. Comparisons to control tissues showed a selective accumulation of metals in the detrusor muscle. Histopathological examinations revealed edema and inflammation in the urinary bladder. Directly added lead (10 mM) inhibited detrusor muscle contraction in-vitro, and its effect was decreased in presence of atropine, and potentiated in presence of TEA, L-NAME, or MB. Cadmium's (0.1 mM) inhibitory effect was reduced in presence of nifedipine or trifluoperazine. In conclusion, lead, cadmium, or iron induce detrusor hypoactivity: The inhibitory effect of lead may be mediated by modulating muscarinic receptors but not the K+/NO/cGMP pathway, whereas cadmium inhibitory effect may be mediated by inhibiting the Ca2+/calmodulin pathway.

Effect on blood heavy metal concentration in gas poisoning by combustion of ignition coal: Pilot study

Purpose: It is known that the most common cause of gas poisoning in Korea is suicide attempts by burning ignition coals. Ignition coals are made from waste wood, and studies have been reported that heavy metals are emitted when this coal is burned. However, there was no study on how much heavy metal poisoning occurs in the human body through this, so this study was planned to find out whether the concentration of heavy metals in the blood increased in patients exposed to ignition coal combustion. Methods: From April 2020 to April 2021, blood lead, mercury, and cadmium concentrations were investigated in carbon monoxide poisoning patients who visited one regional emergency medical center in Seoul, and their association with exposure time, source of poisoning, and rhabdomyolysis were investigated. Results: During the study period, a total of 136 carbon monoxide poisoning patients were tested for heavy metals, and 81 cases of poisoning by ignition coal were reported. When comparing poisoning caused by combustion of ignition coal and other substances, there was no difference in the concentrations of lead, mercury, and cadmium in the blood, and there was no difference in the number of patients above the reference range. However, the patients exposed to more than 5 hours of ignition coal gas exposure are more frequent than those in the group less than 5 hours in lead (51.4% vs. 23.9%, p=0.012). Conclusion: Compared to poisoning with other combustible substances, the blood concentration of lead, mercury, and cadmium does not increase further in patients with gas poisoning by ignition coal. However, prolonged exposure may result in elevated levels of lead.

Dietary fiber intake is inversely related to serum heavy metal concentrations among US adults consuming recommended amounts of seafood: NHANES 2013–2014

AbstractHeavy metals such as mercury (Hg), cadmium (Cd), and lead (Pb) have profound deleterious effects on human health, with seafood being the primary dietary source. Dietary fiber (DF) has been reported to bind heavy metals in animal models, thus promoting their excretion. However, little is known about such effect in human subjects. To examine the relationship between DF intake and blood heavy metal concentrations in adults consuming adequate amounts of seafood, a sample of adults (n = 422), with a mean age of 48 years (SE = 1.14), who consumed at least eight servings of seafood per month were selected from the National Health and Nutrition Examination Survey (NHANES, 2013–2014). Average intake of DF was computed from two 24‐h recalls. Linear regression analyses were completed to assess the relationship between each of the three heavy metals and DF intake while adjusting for age, biological sex, race/ethnicity, and ratio of family income to poverty. Results showed that after adjusting for covariates, serum Cd and Pb levels were inversely related to DF intake among US adults meeting the recommendations for seafood consumption. Every 10 additional grams of DF intake is associated with 6.72% less serum Cd (p = 0.0010) and 5.65% less serum Pb (p = 0.0019) concentrations, respectively. Asian adults had significantly higher serum levels of Hg, Cd, and Pb (p &lt; 0.0005) as compared to non‐Hispanic White adults. Age was positively related to serum heavy metal levels (p &lt; 0.0001). Future research is warranted to investigate the mechanism of action.

Influence of the Levels of Arsenic, Cadmium, Mercury and Lead on Overall Survival in Lung Cancer.

The effects of heavy metals on cancer risk have been widely studied in recent decades, but there is limited data on the effects of these elements on cancer survival. In this research, we examined whether blood concentrations of the heavy metals arsenic, cadmium, mercury and lead were associated with the overall survival of lung cancer patients. The study group consisted of 336 patients with lung cancer who were prospectively observed. Blood concentrations of heavy metals were measured to study the relationship between their levels and overall survival using Cox proportional hazards analysis. The hazard ratio of death from all causes was 0.99 (p = 0.94) for arsenic, 1.37 (p = 0.15) for cadmium, 1.55 (p = 0.04) for mercury, and 1.18 (p = 0.47) for lead in patients from the lowest concentration quartile, compared with those in the highest quartile. Among the patients with stage IA disease, this relationship was statistically significant (HR = 7.36; p < 0.01) for cadmium levels in the highest quartile (>1.97–7.77 µg/L) compared to quartile I (0.23–0.57 µg/L, reference). This study revealed that low blood cadmium levels <1.47 µg/L are probably associated with improved overall survival in treated patients with stage IA disease.

Exposure to waterpipe smoke and blood heavy metal concentrations

Waterpipe (WP) smoking is a global phenomenon, with the most consumers in Middle East countries and China. Heavy metals exposure related to WP smoking has been associated with many adverse health effects. However, the association of lifestyle factors and smoking habits with blood heavy metals concentration in WP smokers is unclear yet. Therefore, we aimed to investigate the relationship of lifestyle factors (i.e., diet and physical activity) and smoking habits (i.e., duration of the use of WP and times of smoking WP per week) with blood concentrations of lead (Pb) and cadmium (Cd). This cross-sectional study was based on 86 WP smokers in Khalkhal, Iran (2018). Graphite furnace atomic absorption spectrometry (GFAAS) was used to measure heavy metals. The median (interquartile range (IQR)) of Pb and Cd concentrations were 39 (24) and 1.3 (1.2) μg/L. The blood Pb and Cd levels were significantly higher in participants with lower education level (P-value = 0.049 and 0.041, respectively). An IQR increase in physical activity per week was associated with −0.12 μg/L (95% confidence interval (CI): −0.23, −0.01, P-value = 0.04) decrease in Pb concentration. An increase in the times of consuming fruit per week was negatively associated with the concentration of Cd. Overall, our findings suggested that physical activity and healthy diet have been associated with lower blood heavy metal concentrations in WP smokers; however, further studies are needed to confirm these findings.

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.

Association Between Blood Heavy Metal Concentrations and Dyslipidemia in the Elderly.

Our objective was to evaluate the relationship of blood metal levels including strontium, cadmium, lead, vanadium, aluminum, cobalt, and manganese with dyslipidemia in the elderly Chinese population. In this study, stratified cluster sampling was adopted in the elderly in two communities of Lu'an City from June to September 2016, and 1013 participants were finally included. The inductively coupled plasma mass spectrometry (ICP-MS) was used to measure the metals' concentrations in whole blood. After multivariable adjustment, the odds ratios (95% confidence interval [CI]) of dyslipidemia associated with the highest quartile of metal concentrations were 1.32 (0.89 ~ 1.96), 1.28 (0.83 ~ 1.97), 1.86 (1.23 ~ 2.80), 0.80 (0.55 ~ 1.16), 0.76 (0.51 ~ 1.13), 0.76 (0.53 ~ 1.11), and 1.14 (0.78 ~ 1.67) for strontium, cadmium, lead, vanadium, aluminum, cobalt, and manganese, respectively, compared with the lowest quartile. After reducing the dimensionality of metal elements by principal component analysis, we found that the combined exposure of aluminum, cobalt, and vanadium was the protective factor of non-dyslipidemia, while the combined exposure of cadmium, strontium, and lead was the risk factor of dyslipidemia.

Association of Urinary and Blood Concentrations of Heavy Metals with Measures of Bone Mineral Density Loss: a Data Mining Approach with the Results from the National Health and Nutrition Examination Survey.

Osteoporosis and its consequence of fragility fracture represent a major public health problem. Human exposure to heavy metals has received considerable attention over the last decades. However, little is known about the influence of co-exposure to multiple heavy metals on bone density. The present study aimed to examine the association between exposure to metals and bone mineral density (BMD) loss. Blood and urine concentrations of 20 chemical elements were selected from 3cycles (2005-2010) NHANES (National Health and Nutrition Examination Survey), in which we included white women over 50years of age and previously selected for BMD testing (N= 1892). The bone loss group was defined as participants having T-score < - 1.0, and the normal group was defined as participants having T-score ≥ - 1.0. We developed classification models based on support vector machines capable of determining which factors could best predict BMD loss. The model which included the five-best features-selected from the random forest were age, body mass index, urinary concentration of arsenic (As), cadmium (Cd), and tungsten (W), which have achieved high scores for accuracy (92.18%), sensitivity (90.50%), and specificity (93.35%). These data demonstrate the importance of these factors and metals to the classification since they alone were capable of generating a classification model with a high prediction of accuracy without requiring the other variables. In summary, our findings provide insight into the important, yet overlooked impact that arsenic, cadmium, and tungsten have on overall bone health.

Longitudinally monitored lifetime changes in blood heavy metal concentrations and their health effects in urban birds

Urban heavy metal pollution can impair the health of humans and other organisms inhabiting cities. While birds are suggested as one of the appropriate bioindicators for essential and non-essential trace element monitoring, the process of particular elements' accumulation in blood and its possible adverse health effects during ageing of individuals remain unexplored. We have investigated lifetime changes in blood lead (Pb), cadmium (Cd), arsenic (As) and zinc (Zn) concentrations and searched for links to health-related traits in sub-urban free-living great tit (Parus major) population monitored over a long period of time. The blood As concentrations were under the limit of detection in most samples. The blood Pb levels showed a non-linear relationship to individuals age, where the highest Pb concentrations were measured in nestlings and in a very small group of highly senescent birds (over 7 years old), while no clear trend was observed for the majority of the adult age stages. No age-related patterns were found for blood Cd or Zn concentrations. The positive relationship between date of capture and blood Cd and Zn levels may reflect seasonal changes in diet composition. We did not reveal any anaemia-like conditions (decreased total erythrocyte count or increased immature erythrocyte count) in relation to blood heavy metal concentrations in the investigated birds. Total leukocyte counts, heterophil/lymphocyte (H/L) ratio and total heterophil and lymphocyte counts increased with increasing Pb, Cd and Zn concentrations in blood. This study demonstrates the suitability of avian blood for actual heavy metal spatial and temporal biomonitoring even in situations when the precise age of the individuals remains unknown.

Relationships of Lead, Mercury and Cadmium Levels with the Timing of Menarche among Korean Girls.

PurposeThis study utilized data from the Korean National Health and Nutrition Examination Survey (KNHANES) to explore differences in the timing of menarche in Korean girls according to blood heavy metal concentrations.MethodsThis study performed a secondary analysis of cross-sectional data from the sixth KNHANES. Data from 179 female children and adolescents aged 10~18 were included in this study. The relationships of blood heavy metal concentrations (lead, mercury, and cadmium) with age of menarche were analyzed using complex sample multiple logistic regression.ResultsIn the participants of this study, the geometric mean values of blood lead, mercury, and cadmium concentrations were 1.15±0.04 μg/dL, 1.80±0.08 μg/L, and 0.30±0.03 μg/L, respectively. Mercury poisoning (>5 μg/L) was found in 1.5% of participants. Furthermore, significant relationships were found between blood lead and mercury concentrations and age at menarche (p for trend: p<.001 and p=.015, respectively).ConclusionThrough an analysis of national big data, this study found evidence that Korean girls showed a younger age at menarche in response to higher blood lead and mercury concentrations. To prevent and manage precocious puberty in Korean children and adolescents, a systematic policy that monitors both exposure to environmental hazards and blood heavy metal concentrations is needed.