Evaluation of in utero exposure to arsenic in South Africa

Abstract

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.

A Review of the Effects of Chronic Arsenic Exposure on Adverse Pregnancy Outcomes

“…However, in sub-group analysis, there was a statistically significant negative association of −90.7 g (95% CI: −161, −20.5) between arsenic exposure and birth weight of female infants born of overweight/obese mothers. Moreover, Bloom et al [34] and Röllin et al [35] did not observe a statistically significant association between low birth weight and arsenic exposure in a longitudinal study of 501 couples from central Michigan and 650 women in South Africa respectively. However, in a subgroup analysis conducted by Bloom et al, there was a statistically significant positive association between paternal arsenic exposure and birth weight.…”

Environmental Health Research in Africa: Important Progress and Promising Opportunities

“…An association between lower maternal zinc, copper, and cadmium levels as well as cord copper levels with low birthweight newborns has also been observed (Abass et al, 2014;Rollin et al, 2015). Elevated lead and arsenic exposures may be associated with preterm birth and other birth outcomes in general (Kumar et al, 2017;Rollin et al, 2017) and cord blood mercury was significantly associated with birth weight, length, and head and chest circumference in a Nigerian study population (Obi et al, 2015). Several African countries have a high level of preeclampsia and significant associations between preeclampsia and serum levels of calcium and magnesium or excretion of high amounts of several toxic metals, especially lead, have been identified (Ikechukwu et al, 2012;Motawei et al, 2013;Elongi Moyene et al, 2016).…”

Low-Level Toxic Metal Exposure in Healthy Weaning-Age Infants: Association with Growth, Dietary Intake, and Iron Deficiency

“…For As, Cd, or Hg, prenatal low-level exposure has been reported to have unfavorable effects on intrauterine or post-birth growth in some studies [9,10,18,19,20]. However, evidence of this is inconsistent in the current literature [11,13,21]. Moreover, studies on the effects of low-level postnatal As, Cd, or Hg exposure on the postnatal growth of infants or children are scarce as well.…”