Metal mixtures in pregnant women and umbilical cord blood at urban populations-Rio de Janeiro, Brazil

Dietary intake of metals, metalloids, and persistent organic pollutants in Spanish pregnant women. ECLIPSES study

OBJECTIVE

This study aimed to describe dietary intake and important dietary sources to pollutants as well as to identify maternal socio-economic and lifestyle factors associated with high intake during pregnancy in women residing in a Mediterranean city with heavy industrial activity.

METHODS

Dietary intake during pregnancy of As, InAs, Cd, MeHg, Pb, PCDD/Fs, DL-PCBs, and NDL-PCBs in 701 pregnant women participating in the longitudinal ECLIPSES study was calculated based on a 45-item food-frequency questionnaire and a database of pollutants in food of the Catalan Food Safety Agency. Details on socio-economic, lifestyle, and anthropometric variables were also collected.

RESULTS

The mean dietary intake of pollutants per day and the food group that contributed the most (%) was: 286.51 μg of As (71.27% from white fish), 4.14 μg of InAs (70.16% from cereals-tubers), 6.27 μg of Cd (47.51% from seafood), 5.00 μg of MeHg (52.88% from blue fish), 3.32 μg of Pb (30.15% from cereals-tubers), 9.93 pg of PCDD/Fs (from many food categories), 18.39 pg of DL-PCBs (59.74% from blue fish) and 181.00 ng of NDL-PCBs (44.58% from blue fish). Adjusted multivariate analysis revealed that older age was associated with high As intake, higher educational level was related to low InAs, Cd, and DL-PCBs intake, and alcohol use and smoking were linked with high Pb intake.

CONCLUSION

The dietary intake of pollutants including As and DL-PCBs among pregnant women exceeds or almost reaches the EFSA safety threshold. These findings support the urgent need for local governments to pay special attention to this situation and develop specific prevention strategies for this vulnerable group.

Exposure of preterm neonates to toxic metals during their stay in the Neonatal Intensive Care Unit and its impact on neurodevelopment at 2 months of age

BACKGROUND

Premature neonates might be exposed to toxic metals during their stay in the neonatal intensive care unit (NICU), which could adversely affect neurodevelopment; however, limited evidence is available. The present study was therefore designed to assess the exposure to mercury, lead, cadmium, arsenic, and manganese of preterm neonates who received total parenteral nutrition (TPN) and/or red blood cell (RBC) transfusions during their NICU stay and the risk of neurodevelopment delay at the age of 2 months.

METHODS

We recruited 33 preterm neonates who required TPN during their NICU admission. Blood samples were collected for metal analysis at two different time points (admission and before discharge). Metals in the daily TPN received by preterm neonates were analyzed. Neurodevelopment was assessed using the Ages and Stages Questionnaire Edition 3 (ASQ-3).

RESULTS

All samples of TPN had metal contamination: 96% exceeded the critical arsenic limit (0.3 μg/kg body weight/day); daily manganese intake from TPN for preterm neonates exceeded the recommended dose (1 µg/kg body weight) as it was added intentionally to TPN solutions, raising potential safety concerns. All samples of RBC transfusions exceeded the estimated intravenous reference dose for lead (0.19 µg/kg body weight). Levels of mercury, lead and manganese in preterm neonates at discharge decreased 0.867 µg/L (95% CI, 0.76, 0.988), 0.831 (95%CI, 0.779, 0.886) and 0.847 µg/L (95% CI, 0.775, 0.926), respectively. A decrease in ASQ-3-problem solving scores was associated with higher levels of blood lead in preterm neonates taken at admission (ß = -0.405, 95%CI = -0.655, -0.014), and with plasma manganese (ß = -0.562, 95%CI = -0.995, -0.172). We also observed an association between decreased personal social domain scores with higher blood lead levels of preterm neonates before discharge (ß = -0.537, 95%CI = -0.905, -0.045).

CONCLUSION

Our findings provide evidence to suggest negative impacts on the neurodevelopment at 2 months of preterm infants exposed to certain metals, possibly related to TPN intake and/or blood transfusions received during their NICU stay. Preterm neonates may be exposed to levels of metals in utero.

Monitoring of metals and metalloids from maternal and cord blood samples in a population from Seville (Spain)

Nowadays there is an increasing concern about exposition during prenatal stage to environmental pollutants such as metals, that make pregnant women a vulnerable group of population. Numerous studies have shown associations between the prenatal exposition to some metals and an impact on cognitive, motor and intellectual development of the child. Metals and metalloid are ubiquitous in the environment and pregnant women are exposed to them though their diet, lifestyle factors or occupational and environmental sources. One hundred of maternal and one hundred of cord blood samples were obtained at delivery from pregnant women after signing of the informed consent to determine simultaneously levels of Al, As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Se and Zn by ICP-MS. Among these metals, essential ones (Cu, Mn, Se and Zn) can have health beneficial effects at low levels, however, in high concentration are potentially toxic. On the other hand, elements such as Al, As, Cd, Hg, Pb are classified as toxic metals, no matter what its concentration was. The aim of this study was to find the potential relationships between these metals and metalloid levels, newborn's parameters, pregnancy details and the epidemiologic information obtained using a questionnaire data from the participant pregnant women from Seville (Spain). A n = 100 of participants have been enrolled, 15.6 % of the women from Virgen del Rocio Hospital were smokers during pregnancy but only 11.1 % from Virgen de Valme had the habit. Dietary habits of all participants from both hospital were quite similar in average rice, fish and canned food consumption. The characteristics of newborns were also quite similar for both hospitals. A positive correlation between maternal and cord blood was found between all metals except for Cr and Cu. The strongest correlation was found for Hg (r = 0.779, p < 0.005). Positive but weaker correlations between maternal blood and lifestyle habits were also established.

Chemical element concentrations in cord whole blood and the risk of preterm birth for pregnant women in Guangdong, China

Maternal exposure to chemical elements, including essential and non-essential elements, have been found to be associated with preterm births (PTB). However, few studies have measured element concentrations in cord whole blood, which reflects activity at the maternal-fetal interface and may be biologically associated with PTBs. In this study, we determined concentrations of 21 elements in cord whole blood and explored the associations between element concentrations and PTB in a nested case-control study within a birth cohort in Guangdong, China. Finally, 515 preterm infants and 595 full-term infants were included. We performed single-element and multi-element logistic regressions to evaluate linear relationships between element concentrations and PTB. According to the results of single-element models, most essential elements (including K, Ca, Si, Zn, Se, Sr and Fe) were negatively associated with PTB, while Cu, V, Co and Sn were positively associated with PTB. Of the non-essential elements, Sb, Tl, and U were positively associated with PTB, while Pb was negatively associated with PTB. The multi-element model results for most elements were similar, except that the association between Mg and PTB was shown to be significantly positive, and the association for Cu became much larger. A possible explanation is that the effects of Mg and Cu may be influenced by other elements. We performed restricted cubic spline (RCS) regressions and found significantly non-linear exposure-response relationships for Mg, Se, Sr, K and Sb, indicating that the effects of these elements on PTB are not simply detrimental or beneficial. We also examined the joint effect using a Bayesian kernel machine regression (BKMR) model and found the risk of PTB decreased significantly with element mixture concentration when lnC was larger than the median. Bivariate interaction analysis suggested antagonistic effects of Sb on Zn and Sr, which may be attributed to Sb negating the antioxidant capacity of Zn and Sr. This study provides additional evidence for the effect of element exposures on PTB, and will have implications for the prevention of excessive exposures or inappropriate element supplementation during pregnancy.

Effects of prenatal exposure to arsenic on neonatal birth size in Wujiang, China

To investigate prenatal exposure to arsenic and its effect on birth size, we conducted a cross-sectional study in Wujiang City, Jiangsu, China, from June 2009 to June 2010. A total of 1722 mother-infant pairs were included in the study. A questionnaire was administered to the pregnant women and umbilical cord blood(UCB) samples were collected. Arsenic concentration in UCB was detected by inductively coupled plasma emission mass spectroscopy (ICP-MS). The birth size included birth weight, birth body length and head circumference of the newborns. The effects of arsenic exposure on birth size were assessed by multiple linear regression analysis. Arsenic concentrations in UCB ranged from 0.11 to 30.36 μg/L, the median was 1.71 μg/L. In this range of exposure, arsenic concentration was significantly negatively associated with birth weight, especially among male infants. Our results showed that prenatal exposure to arsenic level was low in Wujiang City, China. However, low prenatal arsenic exposure could have negative effects on birth weight. Our research provided evidence for the adverse effects of prenatal low-level arsenic exposure on the intrauterine growth of the fetus.

Prenatal Exposure to Metals and Neurodevelopment in Infants at Six Months: Rio Birth Cohort Study of Environmental Exposure and Childhood Development (PIPA Project)

The PIPA Project is a prospective birth cohort study based in Rio de Janeiro, Brazil, whose pilot study was carried out between October 2017 and August 2018. Arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) concentrations were determined in maternal (n = 49) and umbilical cord blood (n = 46). The Denver Developmental Screening Test II (DDST-II) was applied in 50 six-month-old infants. Metals were detected in 100% of the mother and newborn samples above the limits of detection. Maternal blood lead concentrations were higher in premature newborns (GM: 5.72 µg/dL; p = 0.05). One-third of the infants (n = 17–35.4%) exhibited at least one fail in the neurodevelopment evaluation (fail group). Maternal blood arsenic concentrations were significantly (p = 0.03) higher in the “fail group” (GM: 11.85 µg/L) compared to infants who did not fail (not fail group) (GM: 8.47 µg/L). Maternal and umbilical cord blood arsenic concentrations were higher in all Denver Test’s domains in the “fail group”, albeit non-statistically significant, showing a tendency for the gross motor domain and maternal blood (p = 0.07). These findings indicate the need to further investigate the toxic effects of prenatal exposure to metals on infant neurodevelopment.

Associations of maternal exposure to 41 metals/metalloids during early pregnancy with the risk of spontaneous preterm birth: Does oxidative stress or DNA methylation play a crucial role?

BACKGROUND

Few studies have explored the effects of multiple types of metals/metalloids on spontaneous preterm birth (SPB). A nested case-control study was conducted in Shanxi Province to investigate the associations between maternal exposure to 41 metals/metalloids during early pregnancy and the risk of SPB, and to clarify the underlying mechanisms of oxidative stress and DNA methylation.

METHODS

A total of 74 controls with full-term delivery and 74 cases with SPB were included in the nested case-control study. The metals/metalloids in serum and the DNA adducts in peripheral blood cell DNA were determined using ICP-MS and UPLC-QqQ-MS/MS, respectively. Unconditional logistic regression models were employed to estimate the associations of the risk of SPB with the metal concentrations, as well as with the levels of oxidative stress/DNA methylation. In addition, linear regression models were used to investigate the associations between the metal/metalloid concentrations and the levels of oxidative stress/DNA methylation.

RESULTS

After adjusting for potential confounders, the concentrations of Mn, Fe, Cu, Nd, Hg, and Pb in maternal serum during early pregnancy were positively associated with the risk of SPB. Compared with the lowest levels (Quartile 1) of Mn, Fe, Cu, Nd, Hg, and Pb, the odds ratios of SPB increased to 5.21 (95% CI: 1.63, 16.68), 3.47 (95% CI: 1.07, 11.21), 16.23 (95% CI: 3.86, 68.18), 10.54 (95% CI: 2.79, 39.86), 5.88 (95% CI: 1.72, 20.11), and 4.09 (95% CI: 1.31, 12.77) in the highest levels (Quartile 4), respectively. A significant increase in 8-OHdG was associated with the increased exposure to Fe, Pr, Eu, Er, and Lu. The levels of 5-MdC, 5-HmdC, and N6-MdA-the indicators of DNA methylation-were associated with exposure to multiple metals/metalloids. However, no significant associations were observed between the levels of oxidative stress or DNA methylation and the risk of SPB.

CONCLUSIONS

Exposure to multiple types of metals/metalloids during early pregnancy is positively associated with the risk of SPB. Oxidative stress and DNA methylation are significantly associated with exposure to multiple metals/metalloids. Systemic oxidative stress and DNA methylation have not been proven to be the mediating mechanisms of metals increasing the risk of SPB.