Maternal Lead Levels Research Articles

Maternal prenatal lead levels and neonatal brain volumes: Testing moderations by maternal depressive symptoms and family income

There is considerable evidence that prenatal lead exposure is detrimental to child cognitive and socio-emotional development. Further evidence suggests that the effects of prenatal lead on developmental outcomes may be conditional upon exposure to social stressors, such as maternal depression and low socioeconomic status. However, no studies have examined associations between these co-occurring stressors during pregnancy and neonatal brain volumes. Leveraging a sample of 101 mother-infant dyads followed beginning in mid-pregnancy, we examined the main effects of prenatal urinary lead levels on neonatal lateralized brain volumes (left and right hippocampus, amygdala, cerebellum, frontal lobes) and total gray matter. We additionally tested for moderations between lead and depressive symptoms and between lead and family income relative to the federal poverty level (FPL) on the same neurodevelopmental outcomes. Analyses of main effects indicated that prenatal lead was significantly (ps < 0.05) associated with reduced right and left amygdala volumes (βs = −0.23- -0.20). The testing and probing of cross-product interaction terms using simple slopes indicated that the negative effect of lead on the left amygdala was conditional upon mothers having low depressive symptoms or high income relative to the FPL. We interpret the results in the context of trajectories of prenatal and postnatal brain development and susceptibility to low levels of prenatal lead in the context of other social stressors.

Maternal Metals Exposure and Infant Weight Trajectory: The Japan Environment and Children's Study (JECS).

To our knowledge, the association of maternal exposure to metallic elements with weight trajectory pattern from the neonatal period has not been investigated. The goals of this study were to identify infant growth trajectories in weight in the first 3 y of life and to determine the associations of maternal blood levels of lead, cadmium, mercury, selenium, and manganese with growth trajectory. This longitudinal study, part of the Japan Environment and Children Study, enrolled 103,099 pregnant women at 15 Regional Centres across Japan between 2011 and 2014. Lead, cadmium, mercury, selenium, and manganese levels were measured in blood samples collected in the second (14-27 wk gestational age) or third trimester (). Growth trajectory of 99,014 children was followed until age 3 y. Raw weight values were transformed to age- and sex-specific weight standard deviation (SD) scores, and latent-class group-based trajectory models were estimated to determine weight trajectories. Associations between maternal metallic element levels and weight trajectory were examined using multinomial logistic regression models after confounder adjustment. We identified 5 trajectory patterns based on weight SD score: 4.74% of infants were classified in Group I, very small to small; 31.26% in Group II, moderately small; 21.91% in Group III, moderately small to moderately large; 28.06% in Group IV, moderately large to normal; and 14.03% in Group V, moderately large to large. On multinomial logistic regression, higher maternal lead and selenium levels tended to be associated with increased odds ratios (ORs) of poor weight SD score trajectories (Groups I and II), in comparison with Group III. Higher levels of mercury were associated with decreased ORs, whereas higher levels of manganese were associated with increased ORs of "moderately large" trajectories (Groups IV and V). Maternal lead, mercury, selenium, and manganese blood levels affect infant growth trajectory pattern in the first 3 y of life. https://doi.org/10.1289/EHP10321.

Biomarkers of maternal lead exposure during pregnancy using micro-spatial child deciduous dentine measurements

BackgroundLead is a toxic chemical of public health concern, however limited biomarkers are able to reconstruct prior lead exposures in early-life when biospecimens are not collected and stored. Although child tooth dentine measurements accurately assess past child perinatal lead exposure, it has not been established if they reflect maternal exposure in pregnancy. AimTo assess the prenatal relationship between child tooth dentine and maternal blood lead measurements and to estimate maternal lead exposure during the 2nd and 3rd trimesters of pregnancy from weekly child dentine profiles. MethodsWe measured early-life lead exposure in child tooth dentine and maternal blood from 419 child-mother dyads enrolled in the Programming Research in Obesity, Growth, Environment and Social Stress (PROGRESS) cohort. We employed the Super-Learner algorithm to determine the relationship of dentine lead data with maternal blood lead concentrations and to predict maternal lead from child dentine lead data in blinded analyses. We validated and quantified the bias of our results internally. ResultsMothers had moderate blood lead levels (trimesters: 2nd = 29.45 ug/L, 3rd = 31.78 ug/L). Trimester-averaged and weekly child dentine lead measurements were highly correlated with maternal blood levels in the corresponding trimesters. The predicted trimester-specific maternal lead levels were significantly correlated with actual measured blood values (trimesters: 2nd = 0.83; 3rd = 0.88). Biomarkers of maternal lead exposure discriminated women highly exposed to lead (>mean) with 85 % and 96 % specificity in the 2nd and 3rd trimesters, respectively, with 80 % sensitivity. DiscussionWeekly child dentine lead levels can serve as biomarkers of past child and maternal lead exposures during pregnancy.

Association of maternal lead exposure with the risk of preterm: a meta-analysis

Background The relationship between maternal lead level and risk of preterm birth (PTB) remained controversial. Therefore, herein we performed this meta-analysis to investigate the association of maternal blood, urine and cord blood lead level with the risk of PTB using observational studies. Methods A systematic search was conducted in PubMed, EMBASE and Ovid Medline databases from inception to August 2019, and sixteen studies with 65600 participants investigating the association between maternal lead level and PTB were included in our meta-analysis. Odds ratios (ORs) and 95% confidence intervals (95% CI) were calculated for the highest versus lowest lead level by random-effects model. Results Overall, the pooled OR of all included articles for the highest versus lowest PTB score was 1.29 (95% CI = 1.14–1.46; I2 = 80.4%, p < .001), and the results revealed a direct and significant relationship between second and third trimester blood lead level (BLL) and PTB (OR 2nd trimester= 1.61, 95% CI = 1.08–2.40, OR 3rd trimester= 1.57, 95% CI = 1.11–2.23). Conclusion Results of this meta-analysis showed that maternal BLL is directly associated with the risk of PTB.

Analyses of maternal plasma cadmium, lead, and vanadium levels in the diagnosis and severity of late-onset preeclampsia: a prospective and comparative study

Introduction Cadmium, lead, and vanadium, important pollutants produced from anthropogenic activities, have been suggested to be embryotoxic and fetotoxic in many studies. However, the causes of preeclampsia are little known and heavy metals merit further investigation. We tested whether late-onset preeclampsia (L-PrE) was associated with exposure to these metals. Methods This study was designed to determine maternal plasma cadmium, lead, and vanadium concentrations in women with L-PrE (n = 46) compared with those of normotensive women (n = 46). The concentrations of the metals were measured using inductively coupled plasma-mass spectrometry and compared. Results The groups were matched for maternal age, gestational age, and gravidity (p ≥ 0.05). Vanadium concentrations differed between the groups (p = 0.007). In contrast, there were no significant differences in the concentrations of cadmium and lead between the groups (p ≥ 0.05). There was no difference between the concentrations of the metals in patients with mild (n = 23) and severe (n = 23) preeclampsia in L-PrE (p ≥ 0.05). A significant discriminative role of vanadium for the presence of L-PrE, with a cutoff value of 1.84 µg/L, was found in ROC curve analysis. When the patients with and without small-for-gestational-age infants were compared (n = 12, and n = 80, respectively), it was determined that there were no differences between cadmium, lead, and vanadium concentrations (p ≥ 0.05). Conclusion Lower levels of vanadium might be associated with the development of L-PrE. Our findings require further investigation in other populations.

Prenatal lead exposure and cord blood DNA methylation in PROGRESS: an epigenome-wide association study.

The effects of prenatal lead exposure on child development include impaired growth and cognitive function. DNA methylation might be involved in the underlying mechanisms and previous epigenome-wide association studies reported associations between lead exposure during pregnancy and cord blood methylation levels. However, it is unclear during which developmental stage lead exposure is most harmful. Cord blood methylation levels were assayed in 420 children from a Mexican pre-birth cohort using the Illumina Infinium MethylationEPIC microarray. Lead concentrations were measured in umbilical cord blood as well as in blood samples from the mothers collected at 2nd and 3rd trimester and delivery using inductively coupled plasma-mass spectrometry. In addition, maternal bone lead levels were measured in tibia and patella using X-ray fluorescence. Comprehensive quality control and preprocessing of microarray data was followed by an unbiased restriction to methylation sites with substantial variance. Methylation levels at 202 111 cytosine-phosphate-guanine sites were regressed on each exposure adjusting for child sex, leukocyte composition, batch variables, gestational age, birthweight-for-gestational-age, maternal age, maternal education and mode of delivery. We find no association between prenatal lead exposure and cord blood methylation. This null result is strengthened by a sensitivity analysis showing that in the same dataset known biomarkers for birthweight-for-gestational-age can be recovered and the fact that phenotypic associations with lead exposure have been described in the same cohort.

Cord Blood Sex Hormones Concentration: Relation to Birth Weight and Pregnancy Complications

Objectives: Umbilical cord blood can be taken at birth and largely gives indication of fetal and maternal conditions. The aim of the study was to investigate the relation between sex hormones in cord blood and birth weight of newborns and pregnancy complications.&#x0D; Materials and methods: Fifty cord blood samples were collected from newborns at labor room of Baghdad Teaching Hospital between May and October 2018. Blood was withdrawn from their mothers for lead analysis. Five milliliters (ml) of cord blood was taken, 3 ml was used for testosterone and estradiol analysis (using enzyme-linked immunosorbent assay) and 2 ml for lead measurement by lead care analyzer. Newborns weight and head circumference were measured. Delivered women were divided into 4 groups: Women with normal pregnancy, women with preeclampsia, diabetic women and polycystic ovary syndrome (PCOS) women.&#x0D; Results: There was no significant difference in age between women in all groups (p˃0.05). Birth weights, estradiol, and testosterone were significantly different between groups. Estradiol was higher in cord blood of newborns of PCOS women (p˂0.05) than others. Testosterone was higher in cord blood of babies of PCOS and preeclampsia women compared to those of diabetes (p˂0.05). There were no significant differences between male and female neonates regarding cord estradiol (3596.27±1934.69, 3714.57±1581.47 pg/ml respectively), and testosterone (393.18±87.14, 361.43±102.14 ng/ml respectively) (p˃0.05). Maternal lead levels correlated positively with cord lead (r=0.905, p˂0.05), which correlated negatively with head circumference (r=-0.766, p˂0.05). Birth weight correlated negatively with estradiol (r=-0.295), but positively with testosterone (r=0.006) (p˃0.05). &#x0D; Conclusion: Cord blood estradiol and testosterone levels do not differ between males and females. Estradiol was high in cord blood of PCOS mothers. Testosterone was high in cord blood of PCOS and preeclampsia mothers. The increase in cord lead causes decrease in babies head circumference.

Fetal exposure to lead during pregnancy and the risk of preterm and early-term deliveries.

Studies have reported the association between lead exposure during pregnancy and preterm birth. However, findings are still inconsistent. This prospective birth cohort study evaluated the risks of preterm and early-term births and its association with prenatal lead exposure in Hubei, China. A total of 7299 pregnant women were selected from the Healthy Baby Cohort. Maternal urinary lead levels were measured by the Inductively Coupled Plasma Mass Spectrometry. The associations between tertiles of urinary lead levels and the risks of preterm and early-term deliveries were assessed using multiple logistic regression models. The geometric mean of creatinine-adjusted urinary lead concentrations among all participating mothers, preterm birth, and early-term birth were 3.19, 3.68, and 3.17μg/g creatinine, respectively. A significant increase in the risk of preterm births was associated with the highest urinary lead tertile after adjusting for confounders with odds ratio (OR) of 1.96. The association was more pronounced among 25-36 years old mothers with OR of 2.03. Though significant p trends were observed between lead exposure (medium and high tertiles) and the risk of early-term births, their ORs were not significant. Our findings indicate that the risk of preterm birth might increase with higher fetal lead exposure, particularly among women between the age of 25 and 36 years.

Placental biomarkers of PAH exposure and glutathione-S-transferase biotransformation enzymes in an obstetric population from Tijuana, Baja California, Mexico

Environmental exposures along the US-Mexico border have the potential to adversely affect the maternal-fetal environment. The purpose of this study was to assess placental biomarkers of environmental exposures in an obstetric population at the California-Baja California border in relation to detoxifying enzymes in the placenta and nutritional status. This study was conducted on consenting, full-term, obstetric patients (n=54), delivering in a hospital in Tijuana, Baja California (BC), Mexico. Placental polyaromatic hydrocarbon (PAH)-DNA adducts were measured in addition to placental glutathione-S-transferase (GST) activity and genotype, maternal serum folate, and maternal and umbilical cord blood lead and cadmium levels. A questionnaire was administered to the mothers to determine maternal occupation in a maquiladora, other exposures, and obstetric indicators. In univariate analysis, maternal serum folate levels were inversely correlated with total PAH-DNA adducts (rho=−0.375, p=0.007); adduct #1 (rho=−0.388, p=0.005); and adduct #3 (rho =−0.430, p=0.002). Maternal lead levels were significantly positively correlated with cord blood lead levels (rho=0.512, p<0.001). Cadmium levels were generally very low but significantly higher in mothers exposed to environmental tobacco smoke (ETS) (either at work or at home, n=10). In multivariate analysis, only maternal serum folate levels remained as a significant negative predictor of total DNA-PAH adducts levels in placenta. These findings affirm that placental tissue is a valuable and readily available source of human tissue for biomonitoring; and indicate that further study of the role of nutrition in detoxification and mitigation of environmental exposures in pregnant women is warranted.

Does maternal VDR FokI single nucleotide polymorphism have an effect on lead levels of placenta, maternal and cord bloods?

IntroductionIndividual susceptibility due to genetic variations appears to be an important factor in lead toxicity. As lead, ubiquitous atmospheric pollutant, behaves very similarly to calcium, gene polymorphisms in proteins involved in calcium homeostasis can affect lead toxicokinetics. Vitamin D receptor (VDR), a DNA-binding transcription factor, activates genes that encode proteins involved in calcium metabolism. Thus, the objective of this study was to determine the effect of maternal VDR FokI polymorphism on lead levels of maternal blood, placental tissue and cord blood. MethodsThe study population comprised 116 women and their respective placenta and umbilical cord. Venous blood samples were drawn from mothers to investigate both the lead levels and VDR FokI polymorphism. Cord blood samples and placentas were collected for lead levels. VDR FokI polymorphism was detected by standard polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method. Lead levels were analyzed by dual atomic absorption spectrometer system. ResultsGenotype frequencies of VDR FokI polymorphism were 49.2% FF, 44.8% Ff and 6.0% ff. The mean lead levels of maternal blood, placenta and cord blood were 36.76 ± 13.84 μg/L, 12.84 ± 14.47 μg/kg and 25.69 ± 11.12 μg/L, respectively. Maternal blood, placental and cord blood lead levels were found significantly to be higher in mothers with f allele for the VDR FokI polymorphism (p < 0.05). DiscussionThe present study indicated that this polymorphism had an effect on maternal and fetal lead levels and that mothers with F allele associated with lower lead concentration may protect their respective fetus against the toxic effects of lead exposure.

Maternal hemochromatosis gene H63D single-nucleotide polymorphism and lead levels of placental tissue, maternal and umbilical cord blood

Human hemochromatosis protein (HFE), a major histocompatibility complex class I-like integral membrane protein, participates in the down regulation of intestinal iron absorption by binding to transferrin receptor (TR). HFE competes with transferrin-bound iron for the TR and thus reduces uptake of iron into cells. On the other hand, a lack of HFE increases the intestinal absorption of iron similarly to iron deficiency associated with increasing in absorption and deposition of lead. During pregnancy, placenta cannot prevent transfer lead to the fetus; even low-level lead poisoning causes neurodevelopmental toxicity in children. The aim of this study was to determine the association between the maternal HFE H63D single-nucleotide polymorphism and lead levels in placental tissue, maternal blood and umbilical cord bloods. The study population comprised 93 mother–placenta pairs. Venous blood from mother was collected to investigate lead levels and HFE polymorphism that was detected by standard PCR–RFLP technique. Cord bloods and placentas were collected for lead levels which were analyzed by dual atomic absorption spectrometer system. The HFE H63D genotype frequencies of mothers were found as 75.3% homozygote typical (HH), 23.6% heterozygote (HD) and 1.1% homozygote atypical (DD). Our study results showed that the placental tissue, umbilical cord and maternal blood lead levels of mothers with HD+DD genotypes were significantly higher than those with HH genotype (p<0.05). The present study indicated for the first time that mothers with H63D gene variants have higher lead levels of their newborn's placentas and umbilical cord bloods.

Maternal lead exposure and risk of congenital heart defects occurrence in offspring.

Maternal lead exposure may be harmful to fetal development. However, sufficient evidence was lacked about the risk on cardiac development in offspring. To explore the association between maternal lead exposure and risks of congenital heart defects (CHDs) occurrence in fetuses, a case-control study was adopted during pregnant women making antenatal examinations. The maternal hair lead levels were measured by using inductively coupled plasma mass spectrometry (ICP-MS), and logistic regression analysis was used to calculate the odds ratio (OR). Three hundred and sixteen cases and 348 controls were eligible to the study. The median level of lead in maternal hair of case (0.670ng/mg) was significantly higher (AOR 3.07, 95% CI 2.00-4.72) than that of the control (0.461ng/mg), including the CHD cases with or without extracardiac malformations (AOR 3.55, 2.94, respectively). Maternal lead exposure is associated with the risk of some subtypes of CHDs occurrence in offspring. The potential dose-response relationship is also presented.

Very low maternal lead level in pregnancy and birth outcomes in an eastern Massachusetts population

PurposeMaternal lead exposure is associated with poor birth outcomes in populations with moderate to high blood levels. However, no studies have looked at exposure levels commonly experienced by US women. MethodsWe evaluated the relationship between maternal red blood cell (RBC) lead levels in midpregnancy and birth outcomes in 949 mother–child pairs in a prebirth cohort. We used multiple linear regression and logistic regression, adjusted for potential confounders including maternal age, race, prepregnancy body mass index, and smoking to relate maternal lead to infant birth size and risk for preterm birth (<37 weeks). ResultsMean RBC lead level was 1.2 μg/dL (range, 0.0–5.0). Mean (standard deviation) birthweight was 3505 (520) g, birthweight for gestational age z-score 0.22 (0.93), and length of gestation 39.5 (1.7) weeks. Mothers in the highest versus lowest lead quartile did not have higher odds (OR, 1.85; 95% confidence interval [CI], 0.79–4.34) of preterm delivery; after stratifying by child sex, there was an association among males (OR, 5.51; 95% CI, 1.21–25.15) but not females (OR, 0.82; 95% CI, 0.24–2.85). Maternal RBC lead was not associated with any continuous outcomes in combined or sex-stratified analyses. ConclusionsMaternal lead exposure, even at very low levels, may adversely affect some childbirth outcomes, particularly preterm birth among males.

Evidence that birth weight is decreased by maternal lead levels below 5 μg/dl in male newborns

To assess the association between birth weight and maternal blood lead (BPb) levels, 386 pregnant women and their newborn offspring were surveyed. Mean±SD (range) maternal BPb concentrations were 0.98±0.55 (0.10–3.99), 0.92±0.63 [<0.09 (limit of quantification)–3.96], and 0.99±0.66 (<0.09–3.96)μg/dl at 12, 25 and 36 weeks’ gestation, respectively. Mean±SD (range) gestational age at delivery was 38.9±1.3 (35–41) weeks. In male newborns, a significant correlation between birth weight and logBPb at 12 weeks’ gestation was observed (Spearman's rank correlation coefficient=−0.145, p<0.05). Multiple regression analysis indicated that birth weight was significantly inversely associated with logBPb at 12 weeks’ gestation, controlling for possible confounding variables. These results suggest that low-level exposure to lead in early gestation could be a risk factor for reduced birth weight in male offspring.

Adverse effects of maternal lead levels on birth outcomes in the ALSPAC study: a prospective birth cohort study.

ObjectiveTo study the associations of prenatal blood lead levels (B-Pb) with pregnancy outcomes in a large cohort of mother–child pairs in the UK.DesignProspective birth cohort study.SettingAvon area of Bristol, UK.PopulationPregnant women enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC).MethodsWhole blood samples were collected and analysed by inductively coupled plasma dynamic reaction cell mass spectrometry (n = 4285). Data collected on the infants included anthropometric variables and gestational age at delivery. Linear regression models for continuous outcomes and logistic regression models for categorical outcomes were adjusted for covariates including maternal height, smoking, parity, sex of the baby and gestational age.Main outcome measuresBirthweight, head circumference and crown–heel length, preterm delivery and low birthweight.ResultsThe mean blood lead level (B-Pb) was 3.67 ± 1.47 μg/dl. B-Pb ≥ 5 μg/dl significantly increased the risk of preterm delivery (adjusted odds ratio [OR] 2.00 95% confidence interval [95% CI] 1.35–3.00) but not of having a low birthweight baby (adjusted OR 1.37, 95% CI 0.86–2.18) in multivariable binary logistic models. Increasing B-Pb was significantly associated with reductions in birth weight (β −13.23, 95% CI −23.75 to −2.70), head circumference (β −0.04, 95% CI −0.07 to −0.06) and crown–heel length (β −0.05, 95% CI −0.10 to −0.00) in multivariable linear regression models.ConclusionsThere was evidence for adverse effects of maternal B-Pb on the incidence of preterm delivery, birthweight, head circumference and crown–heel length, but not on the incidence of low birthweight, in this group of women.

Girl or boy? Prenatal lead, cadmium and mercury exposure and the secondary sex ratio in the ALSPAC study

The aim of this study was to evaluate the effect of prenatal exposure to lead, cadmium and mercury levels on the secondary sex ratio. Whole blood samples were collected from pregnant women enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC) study at a median gestational age of 11 weeks and were analyzed for lead, cadmium and mercury. Regression analysis was used to identify associations between maternal lead, cadmium and mercury levels and the secondary sex ratio with adjustment for confounders. There was no evidence for associations between maternal lead, cadmium or mercury levels and the secondary sex ratio in this sample. It appears unlikely that alterations in the secondary sex ratio are influenced by exposure to heavy metals, but further work should be done in large cohorts in other countries to confirm these findings.

Environmental Factors Predicting Blood Lead Levels in Pregnant Women in the UK: The ALSPAC Study

BackgroundLead is a widespread environmental toxin. The behaviour and academic performance of children can be adversely affected even at low blood lead levels (BLL) of 5–10 µg/dl. An important contribution to the infant's lead load is provided by maternal transfer during pregnancy.ObjectivesOur aim was to determine BLL in a large cohort of pregnant women in the UK and to identify the factors that contribute to BLL in pregnant women.MethodsPregnant women resident in the Avon area of the UK were enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC) in 1991–1992. Whole blood samples were collected at median gestational age of 11 weeks and analysed by inductively coupled plasma dynamic reaction cell mass spectrometry (n = 4285). Self-completion postal questionnaires were used to collect data during pregnancy on lifestyle, diet and other environmental exposures. Statistical analysis was carried out with SPSS v19.ResultsThe mean±SD BLL was 3.67±1.47 (median 3.41, range 0.41–19.14) µg/dl. Higher educational qualification was found to be one of the strongest independent predictor of BLL in an adjusted backwards stepwise logistic regression to predict maternal BLL <5 or ≥5 µg/dl (odds ratio 1.26, 95% confidence interval 1.12–1.42; p<0.001). Other predictive factors included cigarette smoking, alcohol and coffee drinking, and heating the home with a coal fire, with some evidence for iron and calcium intake having protective effects.ConclusionThe mean BLL in this group of pregnant women is higher than has been found in similar populations in developed countries. The finding that high education attainment was independently associated with higher BLL was unexpected and currently unexplained. Reduction in maternal lead levels can best be undertaken by reducing intake of the social drugs cigarettes, alcohol and caffeine, although further investigation of the effect of calcium on lead levels is needed.

An association between maternal lead and cadmium levels and birth weight of the babies in North Indian population

Lead is listed as the 2nd and Cadmium as the 7th hazardous substance by the Agency for Toxic Substances and Disease Registry (ATSDR). Exposure to Lead and Cadmium above the permissible levels among pregnants may cause adverse effects on newborns in the form of Low Birth Weight and Preterm Labor, etc. The objectives of this study were to find out the level of Lead and Cadmium in maternal venous blood and cord blood and to find out the association of the levels of these metals with birth weight of babies. For this, the venous blood and cord blood were collected and quantitative estimation of Lead and Cadmium was carried out by Double Beam Atomic Absorption Spectrophotometer in 1000 women with average Body Mass Index. Results showed higher mean maternal blood Lead level (11.08 μg/dl with range of 2.6 - 21.3) than the normal recommended by Centre of Disease Control and Prevention (10 μg/dl). On the contrary, the mean Cadmium level was 0.095 μg/dl, which was below the normal value as assigned by WHO (0.1 μg/dl). In high Lead exposure group (>10 μg/dl), 43.7% of babies and in high Cadmium exposure group (>0.1 μg/dl), 46.2% of babies were found to have low birth weight. However, this was not statistically significant. Further research in this area in a larger sample size may provide information relevant enough to be transferred to decision makers to implement measures to effectively reduce heavy metals from the environment, thereby protecting future generations from their deleterious effects.

Analysis of heavy metal toxins in maternal and fetal hair

ObjectiveTo analyse maternal and fetal hair lead levels to assess chronic exposure. To evaluate if leaded petrol is associated with high levels of lead in the maternal and fetal hair.A...

The effects of metallothionein 2A polymorphism on lead metabolism: are pregnant women with a heterozygote genotype for metallothionein 2A polymorphism and their newborns at risk of having higher blood lead levels?

Numerous studies indicate that certain genetic polymorphisms modify lead toxicokinetics. Metallothioneins are protective against the toxicity of many metals, including lead. The aim of this study was to determine whether the maternal metallothionein 2A (MT2A) -5 A/G single-nucleotide polymorphism is related to the lead levels in maternal blood, placental tissue and cord blood in 91 pregnant women and their newborns. Venous blood from the mother was collected to investigate lead levels and MT2A polymorphism. Cord blood and placenta were collected for lead levels. Analyses were made using an Atomic Absorption Graphite Furnace Spectrophotometer. Standard PCR-RFLP technique was used to determine MT2A polymorphism. Blood lead levels of heterozygote genotype (AG) mothers were statistically higher than those of homozygote genotype (AA) (P < 0.05). Maternal lead levels were significantly associated with cord blood lead levels for pregnant women with AA genotype (P < 0.001). This association was not statistically significant for pregnant women with AG. In contrast, the mean value of cord blood lead level for newborns with mothers of AG genotype was slightly higher than others, though the difference was not significant. No significant difference existed in placenta lead levels between the groups. This study suggests that pregnant women with AG genotype for MT2A polymorphism might have high blood lead levels and their newborns may be at risk of low-level cord blood lead variation.