Study Detects Mifepristone in Tap Water From Two U.S. Cities and Other Tested Water Sources

Researchers reported finding the abortion drug mifepristone in nearly all sampling categories examined across three U.S. cities, raising questions about wastewater treatment and possible long-term environmental and health effects.

By yourNEWS Media Newsroom

A newly published study has reported detectable concentrations of mifepristone in water samples collected across three U.S. cities, including municipal tap water in two locations.

The research, published in Issues in Law and Medicine, examined water gathered in Austin, Texas; Blacksburg, Virginia; and Carbondale, Illinois. Investigators collected samples from municipal water systems as well as locations upstream and downstream from wastewater treatment facilities.

Mifepristone is a synthetic steroid used in medication abortions through 10 weeks of pregnancy. It is commonly administered with a second drug and works by blocking progesterone, causing the uterine lining to break down and the pregnancy to end.

Researchers organized the collected water into nine sampling classes and reported “significant levels of mifepristone” in all but one category. The findings included measurable mean concentrations in tap water from two of the three cities examined.

The study did not establish what effects, if any, the detected concentrations could have on people consuming municipal water. The authors nevertheless raised concerns that repeated environmental exposure could allow the drug to accumulate in humans or wildlife.

Researchers said possible consequences could include effects on fertility and reproductive development. They also cited previous studies suggesting that prolonged exposure to low doses may be associated with reproductive abnormalities and cancer, while noting possible links to autism.

The authors emphasized that those potential outcomes have not been established for the concentrations found in drinking water and said additional research is necessary to determine whether environmental exposure presents a meaningful risk to human health or wildlife.

The findings also raised questions about whether standard municipal treatment systems are equipped to remove endocrine-disrupting compounds from wastewater and drinking water.

“Conventional water treatment was not effective for removing this EDC [endocrine-disrupting chemical] from water in all cities we tested,” the study stated. “Two cities showed significant mean concentrations even in tap water. Conventional treatment systems are primarily designed to remove infectious agents such as bacteria and viruses, with secondary treatment, according to the US Environmental Protection Agency, required to address hormones.”

Wastewater facilities are generally designed first to control pathogens and remove conventional contaminants. The researchers said additional treatment processes may be needed to address pharmaceutical residues and hormone-disrupting chemicals that can remain after standard treatment.

The authors called for further investigation into how mifepristone enters municipal and environmental water systems, how long it persists and whether it accumulates in living organisms. They also urged researchers to study potential effects on reproduction, development and long-term health.

The study further recommended evaluating treatment technologies capable of removing mifepristone and similar pharmaceutical compounds before treated water is discharged or distributed for public use.

Although the research identified the drug in multiple water categories, it did not determine whether the measured amounts pose an immediate danger. The findings instead establish a basis for additional testing, broader geographic sampling and closer examination of pharmaceutical contamination in U.S. water systems.