Maternal Arsenic Exposure, Arsenic Methylation Efficiency, and Birth Outcomes in the Biomarkers of Exposure to ARsenic (BEAR) Pregnancy Cohort in Mexico

Abstract

Background: Exposure to inorganic arsenic (iAs) from drinking water is a global public health problem, yet much remains unknown about the extent of exposure in susceptible populations.Objectives: We aimed to establish the Biomarkers of Exposure to ARsenic (BEAR) prospective pregnancy cohort in Gómez Palacio, Mexico, to better understand the effects of iAs exposure on pregnant women and their children.Methods: Two hundred pregnant women were recruited for this study. Concentrations of iAs in drinking water (DW-iAs) and maternal urinary concentrations of iAs and its monomethylated and dimethylated metabolites (MMAs and DMAs, respectively) were determined. Birth outcomes were analyzed for their relationship to DW-iAs and to the concentrations and proportions of maternal urinary arsenicals.Results: DW-iAs for the study subjects ranged from < 0.5 to 236 μg As/L. More than half of the women (53%) had DW-iAs that exceeded the World Health Organization’s recommended guideline of 10 μg As/L. DW-iAs was significantly associated with the sum of the urinary arsenicals (U-tAs). Maternal urinary concentrations of MMAs were negatively associated with newborn birth weight and gestational age. Maternal urinary concentrations of iAs were associated with lower mean gestational age and newborn length.Conclusions: Biomonitoring results demonstrate that pregnant women in Gómez Palacio are exposed to potentially harmful levels of DW-iAs. The data support a relationship between iAs metabolism in pregnant women and adverse birth outcomes. The results underscore the risks associated with iAs exposure in vulnerable populations.Citation: Laine JE, Bailey KA, Rubio-Andrade M, Olshan AF, Smeester L, Drobná Z, Herring AH, Stýblo M, García-Vargas GG, Fry RC. 2015. Maternal arsenic exposure, arsenic methylation efficiency, and birth outcomes in the Biomarkers of Exposure to ARsenic (BEAR) pregnancy cohort in Mexico. Environ Health Perspect 123:186–192; http://dx.doi.org/10.1289/ehp.1307476

SExual Epigenetic Dimorphism in The Human Placenta: Implications for Susceptibility During The Prenatal Period

“…Fetal sex is known to influence susceptibility to the prenatal environment and can influence differential biological signaling within the placenta [3,[5][6][7][12][13][14][15][23][24][25]27,41]. Therefore, we set out to identify sex-based differences in the placental DNA methylomes in three independent US-based birth cohorts.…”

“…For example, sex-specific perinatal and laterlife outcomes have been linked to toxic substance exposure [5,6,[13][14][15][16], maternal stress [7] and maternal immune status [9,17,18]. We hypothesize that sex-dependent health outcomes in infants may be associated with sexual dimorphism of the placenta.…”

“…For example, placentas derived from pregnancies of males and females display variation in the abundance and type of glucocorticoid transporter proteins, the expression of hormones and the production of immune-related proteins including cytokines [12,[19][20][21]. In addition, sex-based differences in response to prenatal stressors have been observed at the levels of the placental proteome, transcriptome and epigenome [3,7,14,20,[22][23][24][25][26][27]. Thus, the sexually dimorphic nature of the placenta could influence variation in toxicant transport and accumulation, hormone levels and immune future science group Research Article Martin, Smeester, Bommarito et al response experienced by the fetus.…”

Arsenic Status and Speciation in Chicken Heart Tissues

“…In vivo methylation has long been proposed as an arsenic detoxification pathway for inorganic arsenic, however, it has been shown recently that As(III) -MMA and As(III) -DMA, two intermediates in the arsenate methylation are more toxic to cells than inorganic arsenic ions As(III) and As(V) 29 . The metabolism of arsenic has an important role in its toxic effects, anyway arsenic is primarily metabolized in the liver and kidney, but not all mammalian species methylate inorganic arsenic, there is variations between species and among human populations in the rate and extent of methylation of inorganic arsenic 30 , guinea pigs, marmosets, tamarind monkeys, chimpanzees, etc. are unable to methylate arsenic 31 .…”

Aluminum and iron doped graphene for adsorption of methylated arsenic pollutants

“…In addition to the inorganic trivalent and pentavalent forms of arsenic, this is arsenous acid [iAs III , As(OH) 3 ] and arsenic acid [iAs V , AsO(OH) 3 ], respectively, the methylated forms of arsenicals appear as part of the arsenic cycle in the environment, and from the arsenic metabolism in humans and animals [4]. The exposure to methylated arsenic containing waters is associated with alterations in the birth weight and gestational age [5], skin lesions [6], lung and bladder cancer [7], renal dysfunctions [8], among other effects on the human health. The toxicity of the water soluble trivalent species monomethylarsonous acid [MMA III , CH 3 As(OH) 2 ] and dimethylarsinous acid [DMA III , (CH 3 ) 2 AsOH] is even larger than those determined for iAs III due to the improved cellular uptake for these [9]; the cellular uptake is lower for the pentavalent forms such as monomethylarsonic acid [MMA V , CH 3 AsO(OH) 2 ] and dimethylarsinic acid [DMA V , (CH 3 ) 2 AsO(OH)] in comparison with iAs V , although their toxicity remains as dangerous in long periods, and they are also reported to be carcinogens [10].…”