Prenatal exposure to aluminum and status of selected essential trace elements in rural South African women at delivery

Abstract: This study sought to evaluate the in utero exposure to aluminum and status of selected trace elements in South African women at delivery since aluminum is known to be toxic in all developmental stages even at low concentrations. Serum aluminum was negatively correlated with aluminum in urine, both uncorrected and corrected for creatinine, which suggests the retention of aluminum in body stores. Serum copper and zinc levels were found to be high in this study population. Serum copper levels were negatively correlated with aluminum in serum (β = −0.095; p = 0.05). There was a marginal negative correlation between aluminum levels in serum and manganese levels in whole blood (β = −0.087; p = 0.08). Copper levels in maternal serum were negatively correlated with birth weight and the length of neonates. There were a number of positive correlations between maternal characteristics and birth outcomes. Mothers who consumed root vegetables frequently appeared to be protected from aluminum retention and increased body burden since their serum aluminum levels were found to be significantly lower. The findings of the current study can be used as a baseline for further research on aluminum exposure and its associated interactions and outcomes in vulnerable populations

Prenatal exposure to cadmium, placental permeability and birth outcomes in coastal populations of South Africa

BACKGROUND The impact of prenatal exposure to cadmium (Cd) on birth outcomes is an area of concern. This study aimed to assess an impact of prenatal Cd exposure on birth outcomes in distinct coastal populations of South Africa. METHODS Cadmium was measured in maternal blood (CdB) (n = 641), cord blood and in maternal urine (n = 317). This investigation assessed the associations between CdB (non-transformed) and birth outcomes across the 25th, 50th, and 75th percentile for birth weight, birth length and head circumference, to test for a linear trend. Associations between natural log-transformed maternal CdB, size at birth and other factors were further evaluated using linear mixed-effects modelling with random intercepts. RESULTS The average gestational age in the total sample was 38 weeks; 47% of neonates were female, average birth weight was 3065 g and 11% were of low birth weight (< 2500 g). The geometric mean (GM) of the maternal CdB level was 0.25 μg/L (n = 641; 95% CI, 0.23– 0.27). The cord blood Cd level was 0.27 μg/L (n = 317; 95% CI, 0.26–0.29) and urine (creatinine- corrected) Cd level was 0.27 μg/L (n = 318; 95% CI, 0.24–0.29). The CdB cord:maternal ratio in the sub-cohort was 1, suggesting that the placenta offers no protective mechanism to the foetus. An inverse association was found between CdB and the lower birth weight percentile in female neonates only (β = - 0.13, p = 0.047). Mothers who reported eating vine vegetables daily had lower levels of CdB (β = - 0.55, p = 0.025). Maternal smoking was associated with an elevation in natural log-transformed CdB levels in both male and female cohorts. DISCUSSION Significant inverse associations between prenatal Cd exposure and birth anthropometry were found in female neonates but not in male neonates, suggesting potential sex differences in the toxico-kinetics and toxico-dynamics of Cd.This research was funded in part by the National Research Foundation (NRF), South Africa (Grant 64528) and the Arctic Monitoring and Assessment Programme (AMAP), Norway.http://www.plosone.orgam201

Evaluation of in utero exposure to arsenic in South Africa

Early life exposure to inorganic arsenic (iAs) has been shown to interfere with foetal and early childhood development, and is associated with morbidity and mortality in adulthood. The purpose of this study was to evaluate exposure to As in utero, to determine the association between maternal and cord blood of As and birth outcomes in South African populations. Total arsenic was measured in maternal blood of a total cohort (n=650) and in paired cord blood and urine of a subset cohort (n=317). Overall, the geometric mean (GM) of As in maternal blood was 0.62μg/L (n=650; 95% CI, 0.58-0.66). In the subset cohort, the GM of maternal blood As was 0.96μg/L (n=350; 95% CI, 0.91-1.02); in paired cord blood, the GM was 0.78μg/L (n=317; 95% CI, 0.74-0.83); and in urine (creatinine-corrected), the GM was 14.26μg/g creatinine (n=317; 95% CI, 12.64-16.09). A linear correlation was found between log maternal blood As and log cord blood As (rho=0.80, p<0.001). Birth outcomes showed geographical differences. in gestational age (p<0.001), birth length (p=0.019), head circumference (p<0.001), Apgar score at 5min (p<0.001) and parity (p<0.002). In a multivariate analysis, no association between maternal blood (AsB) levels and birth outcomes were found. However, the lower the gestational age, the higher the levels of maternal AsB (β=-0.054; 95% CI-0.087 to -0.020) and mothers who had had at least one child were less likely to have higher AsB if compared to those who had never had any child (β=-0.177; 95CI-0.322 to 0.031). In both univariate and multivariate analyses, being single, and drinking water from communal outdoor taps, boreholes and rivers was associated with higher As levels. The findings suggest that more research is needed to evaluate the impact of low level As exposure on postnatal development.The Research Council of Norway and the National Research Foundation (NRF), South Africa (Grant 64528); the Arctic Monitoring and Assessment Programme (AMAP); and the Norwegian Royal Ministry for Foreign Affairs.http://www.elsevier.com/locate/scitotenv2018-01-31hb2017School of Health Systems and Public Health (SHSPH

In utero exposure to aluminium and other neurotoxic elements in urban coastal South African women at delivery : an emerging concern

Aluminium (Al) is a non-essential neurotoxicant and there is limited information regarding exposure to Al in utero. This study sought to evaluate the in utero exposure to Al in urban South African women, its e ects on birth outcomes and possible synergistic e ects between Al, essential and neurotoxic elements such as lead (Pb), mercury (Hg) and arsenic (As), as well as a a potential sex-dependent response to these elements in neonates. This study has found elevated levels of Al in urban women at delivery. The Spearman’s rank correlation coe cients (p-value) of the association between maternal serum Al and birth outcomes (gestational age and parity), and between maternal serum Al and Cu, Zn and Se, were statistically significant. However, in the general and the stratified models, no association was found between any of the birth outcomes and maternal serum Al. The association between maternal serum Al and neurotoxic elements at delivery showed a significant positive correlation for Pb only (rho = 0.361; p < 0.001) which was found to be sex-dependent in neonates (males, rho = 0.285; p < 0.004 and females, rho = 0.444, p < 0.001). Our preliminary findings indicate that in utero exposure to Al is an emerging concern requiring further research and directives from public health authorities.The National Research Foundation (NRF), South Africa, the Research Council of Norway, the Arctic Monitoring and Assessment Programme (AMAP) and the Norwegian Royal Ministry for Foreign Affairs.http://www.mdpi.com/journal/ijerpham2020School of Health Systems and Public Health (SHSPH

Prenatal exposure to DDT in malaria endemic region following indoor residual spraying and in non-malaria coastal regions of South Africa

Exemption was granted by the Stockholm Convention in 2004 for use of DDT by indoor residual spraying (IRS) as a malaria vector control. South Africa endorsed the use of DDT in its Malaria Control Programmes in malaria endemic regions and IRS remains a primary method of controlling malaria transmitting mosquitoes in this country. This study examines the impact of IRS on the levels of DDT and its metabolites in maternal blood of delivering women as a measure of prenatal exposure. We report on the concentrations of DDT and its metabolites (p,p′- DDE, p,p′-DDT, o,p′-DDE, o,p′-DDD, p,p′-DDD, and o,p′-DDT) in maternal plasma of 255 delivering women residing in three sites along Indian Ocean, namely in malaria endemic where IRS takes place, low risk and non-malaria sites. Concentrations of measured compounds were found to be significantly higher in the malaria endemic site (p = 0.0001): the geometric mean concentration (95% confidence intervals; n = 91) for o,p′-DDE was 9 ng/g lipids (7–10); for p,p′-DDE, 3840 ng/g lipids (3008–4902); for o,p′-DDD, 8 ng/g lipids (6–9); for p,p′-DDD, 26 ng/g lipids (20–32); for o,p′-DDT, 168 ng/g lipids (127–221) and for p,p′-DDT, 2194 ng/g lipids (1706–2823). These compounds were also detected in women residing in other sites but in lower concentrations. The maternal characteristics, age, IRS, number of children and breastfeeding were significantly associated for both p,p′-DDE and p,p′-DDT levels in the malaria area where exposure through IRS is predominant. There was no association between maternal characteristics and DDT levels in the low risk and non-malaria area. Results presented are of particular value to the policy decision makers and regulatory toxicology organizations as they characterise the extent of controlled exposure to DDT used exclusively for IRS purposes. Furthermore, findings of this study will form a base for further investigation of foetal exposure to pollutants.Research Council of Norway and National Research Foundation, South Africa (Grant 64528), the Arctic Monitoring and Assessment Programme (AMAP), the Royal Norwegian Ministry for Foreign Affairs and the SA Medical Research Council.http://www.elsevier.com/locate/scitotenvhb2013ay201

Regional variation in pesticide concentrations in plasma of delivering women residing in rural Indian Ocean coastal regions of South Africa

Exposure to pesticides places pregnant women and the developing foetus at the highest risk. The objective of this study is to obtain an exposure assessment by investigating levels of pesticides in blood plasma of delivering women. We report on the concentrations of a, b, g HCH, endosulfan, HCB and the pyrethroids: cis-permethrin, cyfluthrin, cypermethrin and deltamethrin found in the maternal blood plasma of delivering women (n ¼ 241) in three coastal sites of KwaZulu Natal. g-HCH and endosulfan 1 and 2 were the most dominant pesticides in all three sites. Significantly, higher levels of g-HCH and endosulfan were found in site 3 (vicinity of Empangeni) compared to the other two sites (p < 0.05). The GMlevels for g-HCH, endosulfan 1 and 2 were 956, 141 and 21 ng g 1 lipids in site 3, respectively. The pyrethroid pesticides, HCB, a-HCH and b-HCH were detected in less than 31% of the samples in all sites. g-HCH correlated positively and strongly to both endosulfan 1 and 2 (r > 0.47), indicating a common source of exposure. The high levels of g-HCH and endosulfan in maternal plasma samples in site 3 indicate the current and on-going exposure, which is of great concern for reproductive health and prenatal exposure.Part of this work was presented at the Environmental Health Conference 2011 – Resetting our Priorities, Salvador, Brazil, 6–9 February 2011.The Research Council of Norway and the National Research Foundation, South Africa (Grant 64528), the Arctic Monitoring and Assessment Programme (AMAP), the Royal Norwegian Ministry for Foreign Affairs and the SA Medical Research Council.http://www.rsc.org/jemam2013ay201

Prenatal exposure to DDT and other selected environmental contaminants and their predictors in malaria and non-malaria areas in coastal KwaZulu Natal, South Africa

Prenatal exposure to environmental toxicants is of major concern, as foetal development is one of the most sensitive life stages for endogenous and exogenous insults. Permeability of the placenta allows not only for environmental contaminants, but also contaminants released from maternal body stores during pregnancy, to be transferred to the foetus. Most of the exposure assessments in pregnant women and birth outcome studies have been performed in developed industrialised countries, mainly in the northern hemisphere. There is a lack of such assessments from developing countries and countries that are in transition, therefore the study was initiated. In addition, the reintroduction of controlled indoor residual spraying (IRS) of DDT for malaria control in 2001 in malaria endemic regions in South Africa (SA), provided an opportunity to assess prenatal exposure and enhance the current understanding of DDT and other selected contaminants in malaria and non-malaria regions situated along the coast. This thesis evaluated the extent of concomitant exposure to selected organic compounds and mercury (Hg) in utero in three very distinctive rural study sites, namely, site 1 - a malaria endemic site; site 2 - a non-malaria site; and site 3 - an intermittent malaria site. In the malaria endemic site, as expected, elevated levels of DDT from IRS were found. In addition, substantial concentrations of Hg, γ-HCH and endosulfan were also detected. In the intermittent and non-malaria sites, the p,p'-DDE/p,p'-DDT ratios indicate recent on-going use of DDT, possibly illegal use, since DDT use is only allowed in designated areas. Furthermore, high levels of the now banned γ-HCH and endosulfan were also found in the intermittent malaria site, with lower levels in the malaria endemic site and non-malaria sites. Although Hg was detected in 100 % of maternal and cord blood samples analysed, it was found to be in lower concentrations than in some other countries. However, continuous low levels exposure to Hg may have the negative parallel neurotoxic effects for vulnerable groups such as the foetus, newborns and growing children. This study has confirmed that pregnant women in these study sites were exposed concurrently to a mixture of chemicals, many classified as endocrine disruptors, indicating the need for the implementation of policies that curtail the use of these chemicals

Selenium Status, Its Interaction with Selected Essential and Toxic Elements, and a Possible Sex-Dependent Response In Utero, in a South African Birth Cohort

Selenium (Se) is an essential trace element and its deficiency in utero may affect fetus development and birth outcomes. The current study aimed to assess serum Se status at delivery and examine the possible association between Se levels and birth outcomes. The interaction of Se with selected essential and toxic elements as well as possible sex-dependent responses in utero were also evaluated. The negative association between Se levels and head circumference of neonates was evident in the total cohort (β = −0.164; p &lt; 0.001) as well as in the pre-term and full-term cohorts. Significant positive correlations were found between maternal serum Se concentrations and zinc (Zn) and copper (Cu) in the total and regional cohorts. In the total cohort, the toxic elements lead (Pb) and arsenic (As) showed a negative correlation with Se levels, while mercury (Hg), aluminum (Al) and cadmium (Cd) showed a positive correlation. The study found a sex-dependent response in utero for Zn, Cu, Pb, Hg, and Al. The findings of the current study may inform reproductive health policy on Se status in South Africa and highlight the need for sensitive methods to measure Se intake during pregnancy and its complex interactions with other micronutrients and environmental pollutants

Selenium Status, Its Interaction with Selected Essential and Toxic Elements, and a Possible Sex-Dependent Response In Utero, in a South African Birth Cohort

Selenium (Se) is an essential trace element and its deficiency in utero may affect fetus development and birth outcomes. The current study aimed to assess serum Se status at delivery and examine the possible association between Se levels and birth outcomes. The interaction of Se with selected essential and toxic elements as well as possible sex-dependent responses in utero were also evaluated. The negative association between Se levels and head circumference of neonates was evident in the total cohort (β = −0.164; p &lt; 0.001) as well as in the pre-term and full-term cohorts. Significant positive correlations were found between maternal serum Se concentrations and zinc (Zn) and copper (Cu) in the total and regional cohorts. In the total cohort, the toxic elements lead (Pb) and arsenic (As) showed a negative correlation with Se levels, while mercury (Hg), aluminum (Al) and cadmium (Cd) showed a positive correlation. The study found a sex-dependent response in utero for Zn, Cu, Pb, Hg, and Al. The findings of the current study may inform reproductive health policy on Se status in South Africa and highlight the need for sensitive methods to measure Se intake during pregnancy and its complex interactions with other micronutrients and environmental pollutants