The Exposome | Student Projects | 2017

METHYLATION CAPACITY, FOLATE INTAKE AND GENERAL COGNITIVE ABILITIES AMONG URUGUAYAN SCHOOL CHILDREN EXPERIENCING LOW-LEVEL ARSENIC EXPOSURE

Gauri Desai, Gabriel Barg, Elena I Queirolo, Marie Vahter, Fabiana Peregalli, Nelly Mañay, Katarzyna Kordas
factory in Montevideo.

Introduction

Human exposure to As and its compounds occurs primarily through ingestion of As-contaminated food and water. About 200 million people worldwide are exposed to As levels exceeding the international limit of 10 µg/L in water. Among children, exposure to As is associated with deficits in intelligence, neurobehavioral function, and development.

In the human body, As is metabolized when arsenite (AsIII) is methylated to form monomethylarsonic acid (MMAV), which is then reduced to form monomethylarsonous acid (MMAIII). Another methylation cycle converts MMAIII to dimethylarsinic acid (DMAV). These methylation reactions are catalyzed by As methyltransferase (AS3MT), wherein S-adenosylmethionine (SAM) acts as a methyl donor. Biosynthesis of SAM depends on folate for donating the methyl group.

See the Full Poster

Project Links

  • 9/25/19
    Childhood exposure to metals, pesticides and other neurotoxins can result in irreversible neuropsychological impairments. Whereas metal exposures have declined in the general U.S. population and significant progress has been made in the reduction of certain metals in the environment, other environmental exposures, like pesticides and air pollution, are continuing to be a problem. These exposures often occur in the context of low family resources, poor nutrition, or unsafe neighborhoods.