December 8, 2025

expert reaction to PFAS-contaminated drinking water harms in infants

A study published in PNAS looks at PFAS-contaminated drinking water and harms in infants. 

Dr Ovokeroye Abafe, Lecturer in Environmental Sciences, Civil and Environmental Engineering, Brunel University of London:

“The findings of the study are concerning though not unexpected as PFAS have been associated with several negative health outcomes including low birth weight, infant mortality etc. However, I would be cautious in interpreting the results of the study as many of the health outcomes reported can be caused by other types of pollutants and or chemical mixtures and driven by cofounding factors that have not been fully explored in this study though some are recognised as limitations of the study.  The diet is recognised as the main pathway of human exposure to PFAS, however, only drinking water related exposure is described in this study.”  

Prof Neena Modi, Professor of Neonatal Medicine, Imperial College London, said:

“The authors of this paper are to be congratulated on an important and rigorous analysis using real-world data. They showed that exposure through contaminated drinking water to per and polyfluoroalkyl substances (PFAS) during pregnancy increased extremely preterm births (<28 weeks gestation), births below 1000g, and infant deaths (deaths to age one year) by substantial amounts ranging from 168% to 190%.

The analysis is rigorous because it was carefully designed to minimise the likelihood of confounding; in other words, it maximises the likelihood that there is a true causal relationship between PFAS exposure and adverse outcomes. Additionally, those mothers most highly exposed and most adversely affected were from more advantaged socioeconomic strata, which lends strength to the inference of causality because preterm birth is strongly associated with lower socioeconomic status. Of note, and even greater concern, is that by adopting an appropriately cautious analytical approach, the size of effects identified are likely to be an underestimate.

The authors do not provide details of the causes of infant deaths. However, extremely preterm birth is the major cause of low birthweight and infant death. Therefore, the focus of interest must be upon preterm birth. The authors also do not provide data on stillbirths, another highly relevant pregnancy outcome when considering environmental toxins.

The study is important because the adverse effects of PFAS on fetal and newborn health are a major global concern and, despite widespread efforts, preterm birth rates have remained static worldwide for the last decade. Though widely considered a medical issue, the major causes of preterm birth more likely lie in environmental and societal conditions. This study provides proof of concept for the former premise, namely that PFAS exposure during pregnancy is a significant contributor to preterm birth.

The authors calculate that PFAS contamination imposes annual social costs to the United States of approximately $8 billion and point out that this sum far exceeds even upper-end estimates of around $3.8 billion of the cost of cleaning up PFAS.

Cost and a paucity of evidence of causality are often cited as arguments against environmental hygiene. This study provides refutation against both arguments. The study also indicates the need for research to unravel the biological mechanisms by which PFAS exposure results in preterm birth.”

‘PFAS-contaminated drinking water harms infants’ by Robert Balujaa et al. was published in PNAS at 20:00 UK time on Monday 8^th December 2025. 

DOI: https://doi.org/10.1073/pnas.2509801122

Declared interests

Prof Neena Modi: I have no conflicts of interest to declare

For all other experts, no reply to our request for DOIs was received.