Pregnant Women Warned Over Arsenic in Tap Water

Rising Concerns About Arsenic and Maternal Health

A major national study has triggered warnings for pregnant women regarding arsenic in drinking water—an element long-known to pose risks but now shown to affect birth outcomes even at legally “safe” levels. The findings, published in JAMA Network, emerged from research led by Columbia University, which analyzed data from nearly 14,000 pregnancies across 35 sites under the NIH’s Environmental influences on Child Health Outcomes (ECHO) program.

Researchers found that even low-level exposure to arsenic during pregnancy can increase the likelihood of premature birth and low birth weight—both significant predictors of infant mortality and long-term health issues. The study scrutinized arsenic levels currently deemed acceptable by the Environmental Protection Agency (EPA), specifically the maximum contaminant level (MCL) of 10 micrograms per liter, a threshold set in 2001.

Understanding Arsenic’s Reach in Drinking Water

Arsenic occurs naturally in soils, sediments, and groundwater. It often seeps into water systems through natural processes, especially in regions with arsenic-rich geology such as sedimentary rocks or glacial deposits. This means communities relying on groundwater sources—like private wells or smaller municipal systems—face a higher chance of contamination.

Brett A. Poulin, an environmental toxicologist at UC Davis, explained: “Arsenic levels tend to be higher in drinking water that comes from groundwater sources, such as community wells or private household wells.” He added that in regions like Michigan, South Dakota, Nevada, and California, groundwater often contains arsenic above 5 micrograms per liter.

The Longstanding Health Risks of Arsenic Exposure

Though this latest study focuses on pregnancy, arsenic’s dangers span well beyond birth outcomes. The CDC has classified arsenic as a carcinogen, and studies link it to various cancers—bladder, skin, liver, lung, and pancreas—as well as cardiovascular and neurological issues.

“Arsenic can cause a variety of cancers…as well as cardiovascular effects, and neurologic effects,” said Poulin. This broad spectrum of risk reinforces the concern that even minimal exposure can contribute to serious health outcomes across populations.

EPA’s Regulatory Dilemma: Public Health vs. Practical Feasibility

Despite mounting evidence, the EPA remains bound by the balancing act between public health ideals and practical constraints. The agency’s Maximum Contaminant Level Goal (MCLG) for arsenic sits at zero—indicating no exposure level is risk-free. However, the enforceable MCL of 10 micrograms per liter reflects cost and implementation limitations.

An EPA spokesperson noted, “The MCLG is identified in the act as the maximum level of a contaminant in drinking water at which no known or anticipated adverse effect on the health of persons would occur.” Yet, MCLGs are only advisory and do not carry regulatory weight.

The current MCL, the spokesperson explained, emerged from a cost-benefit analysis balancing public health against feasibility: “The EPA must set the enforceable Maximum Contaminant Level as close as feasible to the MCLG taking cost into consideration.”

In 2024, the Biden administration reviewed the MCLs again but declined to revise arsenic standards, citing ongoing health risk assessments.

Expert Warnings: Filters Advised for Pregnant Women

In light of these findings, several experts now advocate for proactive steps, particularly among pregnant women. They recommend water filtration as a precaution where arsenic levels might be elevated—even when they fall within legal limits.

“In situations with high risk of lead or arsenic, filters are recommended,” said Marc Edwards, a civil engineering professor at Virginia Tech. He added that elevated arsenic, while less common than lead, is detectable through consumer confidence reports provided by water utilities.

Natalie Exum from Johns Hopkins Bloomberg School of Public Health emphasized the vulnerability of pregnancy to environmental risks. “It is well known that pregnancy is a highly vulnerable time for environmental exposures,” she said. She urged those in arsenic-affected areas to use filters capable of removing the contaminant to non-detectable levels.

Balancing Caution with Context

While experts agree the study highlights serious implications, they also encourage measured concern. Marci Lobel, a psychology and reproductive medicine professor at Stony Brook University, advised: “Pregnant women should not be unduly alarmed.” She stressed that while the findings matter, the health effects are “not large.”

Still, Lobel underscored the broader social responsibility at stake: “This research underscores our responsibility as a society to protect the health of pregnant women.” Her position aligns with calls for improved water safety standards while acknowledging the complex interplay of health, policy, and infrastructure.

Where Responsibility Lies: Policy, Awareness, and Public Action

This study adds momentum to a wider debate over how water safety regulations should evolve with science. Marc Edwards believes this research “should be considered in future revisions of the regulated arsenic level.” Meanwhile, Brett Poulin acknowledged that achieving lower MCLs may be technically and economically difficult, but not impossible.

The EPA maintains that any regulatory changes must undergo a rigorous feasibility assessment. Yet, as awareness spreads, community demand may pressure regulators to act. For now, the onus often falls on individuals, particularly those in high-risk areas, to protect themselves through informed decisions and filtration options.

The Role of Reverse Osmosis and Whole-Home Water Conditioners

For pregnant women and households in regions with known arsenic exposure, reverse osmosis systems offer one of the most effective methods for reducing this contaminant. These systems can remove arsenic to levels below detection, providing a critical line of defense. Reverse osmosis works by forcing water through a semi-permeable membrane that traps contaminants, including arsenic.

Whole-home water conditioners can also help, particularly when combined with reverse osmosis units for drinking water. While conditioners typically target hardness and scale, some models include filtration media capable of reducing arsenic and other harmful substances.

By installing such systems, families in vulnerable areas can reduce health risks without waiting for regulatory updates. These technologies serve as practical tools to bridge the gap between scientific findings and safe household practices.

Source: Newsweek