Science Friday: New Jersey PFAS Drinking Water Standards Cut PFAS Levels by 55%, Rutgers Study Finds

PFAS drinking water policy reduces forever chemicals in New Jersey

In the podcast, Science Friday speaks with Rutgers researcher Hari Iyer about a state-led effort to curb PFAS in drinking water. The study finds a 55% reduction in average PFAS concentrations in public water systems after New Jersey adopted its drinking water standards.

• PFAS levels dropped by 55% after policy implementation
• The study analyzes public water systems, not private wells
• Health indicators such as liver enzymes and kidney function are being explored in relation to PFAS exposure
• Findings may inform best practices for other states

Overview and key finding

In the podcast, Ira Flatow chats with Hari Iyer, an assistant professor at the Rutgers Cancer Institute of New Jersey, about a study that evaluates state-level PFAS drinking water policies in New Jersey. The researchers crunched data to determine whether the state's standards achieved their intended public health impact. The main result highlighted is a 55% reduction in average PFAS concentrations in public drinking water after the policy was put in place. This outcome is presented as an important demonstration of how regulatory action can produce measurable improvements in environmental health. The discussion also emphasizes that while this decline is encouraging, it is centered on public water systems and does not automatically extend to private wells, which serve a portion of the population and are tested far less frequently. The hosts and guest acknowledge the evolving understanding of long-term PFAS health risks and the need to interpret what current levels mean for residents who may have consumed water with higher PFAS concentrations in the past.

"We found a 55% reduction in average concentrations after the policy was implemented." - Hari Iyer

PFAS exposure, water, and health implications

The podcast explains the concept of biological magnification in PFAS exposure. Hari Iyer describes how water enters the body and passes through organs such as the kidneys and liver, where health effects are increasingly studied. Emerging evidence links PFAS exposure to changes in kidney function and liver enzyme levels, with researchers trying to connect these biomarkers to downstream health outcomes such as cancer risk and other chronic diseases. The discussion underscores that while administrative standards can reduce detected water concentrations, the health implications of historical exposures remain a critical area of investigation and public concern.

"the concentration in the water can be magnified by orders of magnitude" - Hari Iyer

How New Jersey reduced PFAS in water and study limitations

The episode details actions taken by water systems in anticipation of the policy, including identifying wells with excessive PFAS levels and offline shutoffs, and employing granulated activated carbon (GAC) to remove PFAS after treatment. A key limitation noted is that the Rutgers study focused on public water systems, leaving home private wells underrepresented in testing. This means the 55% reduction is demonstrated for public supply, not necessarily for all residents, since approximately one in ten New Jersey residents rely on private wells and their testing frequency is much lower.

"pulling them offline so they're no longer going to be serving people at their home" - Hari Iyer

Implications for policy and future research

Looking ahead, the podcast covers how this local experience might inform other states. Hari Iyer and the hosts stress the value of sharing best practices and learning from policy experiments that can be adapted to different contexts. The researchers are pursuing methods to reconstruct historical PFAS exposure by building predictive models that estimate past PFAS levels and link them to residential histories, enabling a better assessment of long-term cancer risk and health outcomes. The discussion also places the PFAS story in a broader historical perspective, acknowledging how past reliance on chemicals with desirable properties can lead to public health trade-offs, as illustrated by the asbestos comparison, and highlighting the need for balancing technological progress with precautionary health considerations.

"the power of doing something like this and being able to publish these findings is that it can lead to exactly what you're describing. Best practices can be shared from states." - Hari Iyer