Publications by authors named "Akram N Alshawabkeh"

Granular activated carbon (GAC) has proven to be a highly effective material for electrochemical water treatment due to its large surface area and porous structure. This study presents a multiscale investigation combining molecular dynamics (MD) simulations, continuum-scale modeling, and experimental validation to understand how the GAC structure influences water adsorption and reactivity. MD simulations show that highly porous GAC (porosity up to 0.

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Background: Non-nutritive suck (NNS) is a measure of neurofunction sensitive to environmental exposures in utero. This study aimed to evaluate the relationship between gestational phenol exposure and NNS patterning.

Methods: Mother-infant pairs from two diverse prospective cohorts were enrolled in the Environmental influences on Child Health Outcomes Program.

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Alum sludge (AlS) has emerged as an effective adsorbent for anionic contaminants, with traditional activation methods like acid/base treatments and calcination employed to enhance its adsorption capacity. However, these approaches encounter significant drawbacks, including excessive waste generation, structural degradation, and limited efficacy for cationic contaminants. To overcome these challenges, this study proposes electrochemical activation as a sustainable method to enhance alum sludge adsorption performance by generating oxygen-containing functional groups (O-FGs) on its surface.

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The presence of micropollutants in Puerto Rico's tap water, potentially linked to nearby Superfund sites, was hypothesized to contribute to the region's higher preterm birth rate than the US mainland. This study analyzed the presence of 175 micropollutants in tap water samples collected from participant households and evaluated their association with human exposure using 14 oxidative stress and inflammation biomarkers in urine samples collected from pregnant participants, and further with the subsequent birth outcome information. Notably, three out of four oxidative stress biomarkers consistently showed negative correlations with five micropollutant categories, highlighting the oxidative stress induced by these contaminants.

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Background: Phthalate exposure during pregnancy has been associated with preterm birth, but mechanisms of action may depend on the timing of exposure.

Objective: Investigate critical periods of susceptibility during pregnancy for associations between urinary phthalate metabolite concentrations and preterm birth.

Methods: Individual-level data were pooled from 16 US cohorts (N = 6045, n = 539 preterm births).

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In-situ electrochemical remediation has emerged as a promising groundwater remediation technology. However, its application has been limited to short-term decontamination. Here, we propose an electrochemical system that combines an e-barrier with pyrite, a sulfide mineral capable of completely removing As(III), Cr(VI), and sulfanilamide continuously for one year.

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Background: The COVID-19 pandemic affected access to healthcare and social support. This especially impacted vulnerable populations like pregnant and postpartum women.

Purpose: The specific aims of the project are the following: (1) examine the impact of COVID-19 on pregnancy experiences and outcomes; (2) examine the mental health impact of COVID-19 in pregnant women and mothers of children 12 months or younger; (3) identify risk and protective factors among this population in Puerto Rico.

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Achieving net-zero emissions by 2050 requires the development of effective negative emission techniques, including ocean-based approaches for CO sequestration. However, the implementation and testing of marine CO removal (mCDR) techniques such as ocean iron fertilization (OIF) or ocean alkalinity enhancement (OAE) face significant challenges. Herein, a novel self-operating electrochemical technology is presented that not only combines OIF and OAE, but also recovers hydrogen gas (H) from seawater, hence offering a promising solution for achieving quantifiable and transparent large-scale mCDR.

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Concerns persist about the potential impact of prenatal exposure to bisphenols (BP) and their replacement analogues on childhood asthma and allergies. Previous studies on single and small cohorts had limited statistical power, few investigated analogues BPF and BPS, and even fewer examined atopic outcomes. Our objective was to assess whether prenatal exposures to individual environmental bisphenols (BPA, BPF, BPS) influence risk of childhood asthma, allergic rhinitis, and atopic dermatitis.

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Injecting HO into aquifers is a widely used chemical oxidation (ISCO) technology for groundwater remediation. Dissolved silicate was reported to decrease the reactivity of iron (Ⅲ)-bearing minerals toward HO. In this study, the effect of naturally occurring levels of dissolved silicate (≤1 mM) on the catalyzing hydrogen peroxide (CHP) with Fe(II) minerals is revaluated, and new observations that contradict with previous studies are reported.

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Article Synopsis
  • Polycyclic aromatic hydrocarbons (PAHs) are common environmental pollutants from sources like traffic and diet, and their effects on neurodevelopmental delay (NDD) have been understudied.
  • This study analyzed urine samples from pregnant women in the PROTECT birth cohort to determine the relationship between prenatal PAH exposure and NDD in children at various ages.
  • Results indicated that higher PAH exposure generally correlated with lower odds of NDD; however, male children displayed increased odds of delays, particularly in fine motor skills, highlighting a need for further research on sex-specific impacts of PAHs.
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Electrochemical oxidation has emerged as an effective and straightforward technology for groundwater remediation. While recent studies have investigated parameters such as current, electrolyte composition, and electrode materials, most have been conducted using small-scale batch or flow reactors, limiting their applicability to real-world conditions. In this study, a pilot-scale sandbox reactor was employed to simulate realistic groundwater conditions and assess the removal of sulfanilamide, a model organic contaminant.

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Recently, granular activated carbon (GAC) has shown its effectiveness as a cathode material for in situ ROS generation. Here, we present an electrochemically modified GAC cathode using electrode polarity reversal (PR) approach for enhanced HO decomposition via 2-electron oxygen reduction reaction (2e-ORR). The successful GAC modification using PR necessitates tuning of the operational parameters such as frequency, current, and time intervals between the PR cycles.

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Drinking water security in Puerto Rico (PR) is increasingly challenged by both regulated and emerging anthropogenic contaminants, which was exacerbated by the Hurricane Maria (HM) due to impaired regional water cycle and damaged water infrastructure. Leveraging the NIEHS PROTECT (Puerto Rico Testsite for Exploring Contamination Threats) cohort, this study assessed the long-term tap water (TW) quality changes from March 2018 to November 2018 after HM in PR, by innovatively integrating two different effect-based quantitative toxicity assays with a targeted analysis of 200 organic and 22 inorganic pollutants. Post-hurricane PR TW quality showed recovery after >6-month period as indicated by the decreased number of contaminants showing elevated average concentrations relative to pre-hurricane samples, with significant difference of both chemical and toxicity levels between northern and southern PR.

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Article Synopsis
  • - The study presents a model for reducing and precipitating hexavalent chromium (Cr(VI)) using electrocoagulation with iron electrodes, assuming negligible adsorption or direct reduction at low chromium concentrations.
  • - A batch reactor simulation is developed to account for various chemical reactions, validated through previous experimental data, considering factors like initial chromium concentration, pH, and current density.
  • - The model integrates ionic transport in MATLAB with geochemical reactions in PHREEQC and suggests specific operational parameters for effective chromium removal, indicating an ideal current density of 0.05-0.3 mA/cm.
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Preterm birth is a leading cause of neonatal mortality and presents significant public health concerns. Environmental chemical exposures during pregnancy may be partially to blame for disrupted delivery timing. Polycyclic aromatic hydrocarbons (PAHs) are products of incomplete combustion, exposure to which occurs via inhalation of cigarette smoke and automobile exhaust, and ingestion of charred meats.

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Electrochemical advanced oxidation processes (EAOPs) are effective in removing persistent contaminants from groundwater. However, their practical applicability depends significantly on various site-specific characteristics. Therefore, the primary objective of this investigation was to study the feasibility of EAOPs and pyrite, which is a sulfide mineral, to effectively remove the mixture of arsenic (As (III)), chromium (Cr (VI)), and sulfanilamide in groundwater.

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Importance: The prevalence, pathophysiology, and long-term outcomes of COVID-19 (post-acute sequelae of SARS-CoV-2 [PASC] or "Long COVID") in children and young adults remain unknown. Studies must address the urgent need to define PASC, its mechanisms, and potential treatment targets in children and young adults.

Observations: We describe the protocol for the Pediatric Observational Cohort Study of the NIH's REsearching COVID to Enhance Recovery (RECOVER) Initiative.

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Background: Phthalate exposure may contribute to hypertensive disorders of pregnancy (HDP), including preeclampsia/eclampsia (PE/E), but epidemiologic studies are lacking.

Objectives: To evaluate associations of pregnancy phthalate exposure with development of PE/E and HDP.

Methods: Using data from 3,430 participants in eight Environmental influences on Child Health Outcomes (ECHO) Program cohorts (enrolled from 1999 to 2019), we quantified concentrations of 13 phthalate metabolites (8 measured in all cohorts, 13 in a subset of four cohorts) in urine samples collected at least once during pregnancy.

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Prenatal per- and poly-fluoroalkyl substances (PFAS) exposure may influence gestational outcomes through bioactive lipids─metabolic and inflammation pathway indicators. We estimated associations between prenatal PFAS exposure and bioactive lipids, measuring 12 serum PFAS and 50 plasma bioactive lipids in 414 pregnant women (median 17.4 weeks' gestation) from three Environmental influences on Child Health Outcomes Program cohorts.

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Background/aim: Heavy metals are known to induce oxidative stress and inflammation, and the association between metal exposure and adverse birth outcomes is well established. However, there lacks research on biomarker profiles linking metal exposures and adverse birth outcomes. Eicosanoids are lipid molecules that regulate inflammation in the body, and there is growing evidence that suggests associations between plasma eicosanoids and pregnancy outcomes.

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Exposure to phenols and parabens may contribute to increased maternal inflammation and adverse birth outcomes, but these effects are not well-studied in humans. This study aimed to investigate relationships between concentrations of 8 phenols and 4 parabens with 6 inflammatory biomarkers (C-reactive protein (CRP); matrix metalloproteinases (MMP) 1, 2, and 9; intercellular adhesion molecule-1 (ICAM-1); and vascular cell adhesion molecule-1 (VCAM-1)) measured at two time points in pregnancy in the PROTECT birth cohort in Puerto Rico. Linear mixed models were used, adjusting for covariates of interest.

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A laboratory-scale, flow-through, undivided cell electrochemical reactor hosting a stainless steel wire mesh cathode and downstream Ti/MMO anode was evaluated for its ability to degrade the dissolved explosives with diverse chemical properties and reactivities. Degradation efficiencies of RDX, NQ, DNAN, MNA, 2,4-DNT, HMX, TNT, and NTO were dependent on applied current, and 80-100% removal efficiency was achieved after a ~5.5 min detention time.

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Electrochemical water remediation technologies offer several advantages and flexibility for water treatment and degradation of contaminants. These technologies generate reactive oxidative species (ROS) that degrade pollutants. For the implementation of these technologies at an industrial scale, efficient, scalable, and cost-effective ROS synthesis is necessary to degrade complex pollutant mixtures, treat large amount of contaminated water, and clean water in a reasonable amount of time and cost.

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Background: Phthalate exposures are ubiquitous during pregnancy and may contribute to racial and ethnic disparities in preterm birth.

Objectives: We investigated race and ethnicity in the relationship between biomarkers of phthalate exposure and preterm birth by examining: ) how hypothetical reductions in racial and ethnic disparities in phthalate metabolites might reduce the probability of preterm birth; and ) exposure-response models stratified by race and ethnicity.

Methods: We pooled individual-level data on 6,045 pregnancies from 16 U.

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