Overview

• Researchers analyzed data from nearly 14,000 mother-infant pairs in the NIH’s ECHO Cohort, estimating prenatal arsenic exposure from water quality records and residential histories.
• Infants whose mothers faced low-level arsenic exposure, even below the federal 10 μg/L limit, were more likely to be born preterm, have lower birthweight or be smaller than expected for gestational age.
• The link between low-level arsenic and adverse birth outcomes persisted across racial and ethnic groups, with the greatest impacts observed among babies born to Black parents.
• This study is the first large-scale assessment of public water arsenic in a cohort of this size, extending research beyond prior private well and smaller population studies.
• Most U.S. residents rely on public water, so lowering regulatory arsenic limits could reduce risks for infants nationwide.