A recent study has raised concerns that arsenic, a harmful toxin found in tap water, may be endangering the health of children across the United States. Researchers from Columbia University found that this toxic element is present in the drinking water of up to 280 million households reliant on public water systems.
The study indicates that even minimal exposure to arsenic in drinking water during pregnancy significantly increases the likelihood of premature births and lower birth weights. Infants born preterm or underweight can face a range of lifelong health challenges, including cognitive impairments, developmental delays, and an increased risk of chronic illnesses such as diabetes and heart disease.
Arsenic can penetrate the placenta, ultimately disrupting fetal development by interfering with crucial hormones, DNA expression, and organ formation. Additionally, it hampers nutrient absorption, which can stifle growth and induce inflammation, thereby escalating the chances of early delivery.
Currently, the Environmental Protection Agency (EPA) sets the maximum contamination limit (MCL) for arsenic in drinking water at 10 micrograms per liter (μg/L). However, the study revealed that ‘Higher prenatal public water arsenic was associated with lower birth weight, reduced birth weight–for–gestational age…and a higher risk of low birth weight even at concentrations less than 5 μg/L.’ Among expectant mothers exposed to arsenic levels exceeding 5 μg/L, 69 percent identified as White, and their infants carried a heightened risk of low birth weight.
Arsenic typically infiltrates groundwater supplies, tainting the water that families ultimately consume. The study estimates that around 2.1 million individuals in the U.S. may be drinking water from domestic wells that contain elevated arsenic levels. Notably, arsenic contamination has been detected in municipal water sources across all 50 states, with a particular concern for systems in the Southwest where arsenic-rich geological formations pose higher risks.
The research, financed by the National Institutes of Health (NIH), analyzed data from the ECHO Cohort, a nationwide study monitoring over 69 groups of pregnant women and children throughout the U.S. and Puerto Rico. The findings particularly highlighted that White mothers experienced greater exposure to higher arsenic levels in public water, with approximately 69 percent of lower birth weight cases occurring within this demographic. Of the 14,000 births tracked, nearly 1,190 were preterm, 840 were critically small, and 1,400 were underweight for their gestational age.
The study also uncovered disparities in birth outcomes among different racial and ethnic groups. Hispanic/Latino mothers tended to have healthier babies with higher birth weights compared to their non-Hispanic counterparts, while infants born to Black mothers were, on average, 245 grams lighter and more vulnerable to preterm births and low birth weight.
Dr. Anne Nigra, a PhD and environmental health scientist at Columbia’s Mailman School of Public Health, emphasized the significance of the study’s findings, stating, ‘Most U.S. residents rely on public drinking water, and our findings suggest that further reducing arsenic in public water systems could be an important step to improve infant health across the U.S.’ She further noted that even low arsenic levels in drinking water are associated with adverse birth outcomes.
The long-term impacts of arsenic exposure are alarming, with links to various forms of cancer and heart disease. Inorganic arsenic, commonly found in drinking water, can inflict substantial harm on cardiovascular health through oxidative stress and inflammation, leading to serious complications.
To arrive at these conclusions, Columbia researchers meticulously examined arsenic exposure in 14,000 pregnancies by correlating data from EPA water systems between 2006 and 2019 with participant residency during pregnancy. They tracked monthly water arsenic levels against four key birth outcomes: preterm delivery, low birth weight, small gestational size, and birth weight scores. The analysis accounted for factors such as maternal age and education, while intentionally highlighting racial and ethnic variations.
The research identified that even minimal increases in arsenic levels (one μg/L) raised the risk of low birth weight by three percent, while greater exposures (five μg/L) resulted in a 16 percent increase in risk. While the majority of ECHO participants were urban dwellers, the researchers noted that arsenic exposure estimation was based on local water systems, which may not fully reflect actual exposure due to consumption patterns not limited to home environments.
These essential findings were published in the journal JAMA Network Open.