This NYC Climate Week, scientists want you to know a few things about PFAS (perfluoroalkyl and polyfluoroalkyl substances): They’re all around us but are virtually undetectable. They’re getting into our brains. And they appeared to raise the risk of Type 2 diabetes in a recent study of New Yorkers. But there are things you can do to lower your exposure.
What are PFAS?
PFAS have been used in consumer and industrial goods since the 1950s, due to their ability to resist heat, water, grease and stains. They’re found in nonstick frying pans and ponchos, makeup and dental floss, electronics and the foam firefighters use.
More insidiously, they’re now found in drinking water — though a study in 2024 found that New York City still had nearly undetectable levels in our tap water. They’ve been nicknamed “forever chemicals” because they can stay in the environment, whether in the soil, water or the human body, for a long time.
How PFAS may harm your health
Research has piled up in recent years showing a growing list of risks to human health. Peer-reviewed studies have shown that exposure to certain levels of PFAS may lead to reproductive and developmental issues, increased risk of certain cancers and high cholesterol, and a decreased immune response, to name a few.
In July, a team of Mount Sinai researchers found that the level of PFAS in your body can even predict with surprising accuracy how likely you are to develop Type 2 diabetes. What was especially concerning in this study of New York residents was that this was true even when accounting for factors like body mass index (BMI) and smoking status that are risk factors for diabetes.
“The astonishing, surprising or concerning part is that these are a relatively healthy population and they are not particularly vulnerable,” said lead author Vishal Midya, assistant professor of environmental medicine at the Icahn School of Medicine. The study participants who were more likely to develop Type 2 diabetes were not part of a subgroup such as adolescents or pregnant people.
“It is sad, but at the same time there is also hope” in measuring the effects of certain PFAS levels, Midya said. “If we can quantify it, only then can you prevent it.”
What policymakers in Washington and NY are doing about the PFAS problem
Alarm has been growing over PFAS in recent years. In 2024, under the Biden administration, the Environmental Protection Agency announced standards for drinking water. But in April, the Trump administration delayed enforcement of the drinking water limits for PFAS and PFOS (perfluorooctane sulfonic acid, a type of PFAS) until 2031. It also cut over $15 million in funding for research on “forever chemicals.”
Meanwhile, local policymakers have recently taken a number of steps to reduce PFAS exposure. Some of these measures include:
- Firefighting equipment and protective gear: A law Gov. Kathy Hochul signed in May will restrict the sale and manufacture of some firefighting personal protective equipment, starting Jan. 1, 2028.
- Firefighting foam: A New York State Senate bill, if passed, would require manufacturers to recall Class B firefighting foam containing PFAS and ban its sale or distribution.
- Food packaging: A New York State Assembly bill, if passed, would ban PFAS in food packaging as well as firefighting equipment and firefighting foam.
- Disclosure and monitoring: A New York State Assembly bill, if passed, would mandate that certain permit holders must monitor and report PFAS discharges.
The link between PFAS and Type 2 diabetes
We spoke with Midya about what New Yorkers should know about PFAS and Type 2 diabetes. Edited excerpts from our conversation with Midya:
Epicenter NYC: What first inspired your team to study the link between PFAS and diabetes?
Midya: At Sinai, our group studies chemical exposures — pesticides, insecticides, heavy metals and PFAS — particularly in vulnerable populations like children and pregnant people. We wanted to know: what happens in general adults?
We wanted to quantify whether PFAS levels could predict disease. We focused on type 2 diabetes, though PFAS has also been linked to liver disease and neurodevelopmental disorders.
Epicenter NYC: In a nutshell, how did you conduct the study and what did you find out?
Midya: This study was based at Mount Sinai Hospital. We took a subpopulation of patients from the Mount Sinai biobank, looked at their blood and measured how much PFAS they had. All of them had some PFAS in their system — that was expected.
What we didn’t expect was that the amount of PFAS could actually predict who would develop type 2 diabetes years later. And some of them did.
The concerning part is that this was a relatively healthy population. These were not vulnerable groups like pregnant people; they were general adults, just like you and me. Yet PFAS exposure still predicted diabetes risk.
Epicenter NYC: Do we know, or are there hypotheses, about why there’s that correlation?
Midya: This isn’t the first study linking PFAS to harmful effects. What was new here was that we looked at PFAS levels years before the disease was diagnosed.
Animal studies suggest PFAS may deregulate fat and glucose synthesis, which are precursors to type 2 diabetes. So it’s like a chain reaction: PFAS alters fat and glucose metabolism, which eventually increases diabetes risk.
Now, this was a population-based study, so we can only hypothesize about the mechanism. But previous studies — including ones on women and adolescents — back up this idea. The novel part here is that we found this effect in normal, healthy adults.
Epicenter NYC: Your study involved a diverse group of New Yorkers. Did the risk look the same for everyone?
Midya: One caveat is that our sample size was small [360 participants in total: 180 patients with Type 2 diabetes and 180 controls of similar age, sex and ancestry]. We did see some differences by subgroup, but they weren’t strong enough to draw conclusions. We’re now doing a larger study to replicate the results and look more closely at subpopulations.
Epicenter NYC: Individuals with diabetes are often blamed for their condition due to their diet or lifestyle choices. Would you say your findings challenge that idea?
Midya: They do. For example, it’s very difficult to separate PFAS from diet, because PFAS is used in food packaging. It’s in most plastic sandwich bags, in some bottled water and in many types of packaging. So even if you eat healthy, PFAS can still enter your body without your control.
That challenges the notion that it’s all about lifestyle. Yes, eating well is beneficial, but PFAS exposure isn’t something we can fully control.
Epicenter NYC: Are there ways people can reduce their risk of exposure — for example, choosing PFAS-free products?
Midya: Personally, I use filtered water — some filtration systems can remove PFAS. I avoid nonstick cookware. I try to buy personal care products labeled PFAS-free or “perfluorochemical-free.” I also limit packaged food and plastic use.
But realistically, there’s only so much you can do, because PFAS are so widespread.
Epicenter NYC: So if someone has higher PFAS levels in their blood, does that make them more likely to develop diabetes?
Midya: Exactly. The National Academy of Sciences has even issued recommendations based on PFAS blood levels — minimal, moderate and high. Our sample fell in the moderate-risk group. So yes, it’s proportional: the more PFAS you have, the greater your risk.
Epicenter NYC: For most people, there’s no test available to check PFAS blood levels, right?
Midya: Not yet. But that’s where policy should step in. Should PFAS testing be part of clinical checkups? Should physicians follow up with lipid profiles or check for dyslipidemia (abnormal levels of lipids, or fats, in the blood, such as cholesterol and triglycerides)? Those are the conversations we should be having.
PFAS is a silent killer — it may take years to show effects, but it will.
Epicenter NYC: Do you know if there’s a push to have insurance providers cover PFAS tests?
Midya: Not that I know of. But those conversations should happen.
Epicenter NYC: Were there specific PFAS chemicals that raised stronger concerns?
Midya: Yes:
- PFOS (which can be found in carpets, rugs, upholstered furniture, nonstick cookware, leather products and some firefighting foams)
- PFHxS [Perfluorohexanesulfonic acid, a common environmental toxin]
These are legacy PFAS. We didn’t look at the newer generation in this study, but that’s something we plan to do.
Epicenter NYC: What do you mean by “newer generation”?
Midya: Older PFAS are being phased out, and companies are producing new ones with similar properties, hoping they’ll be less harmful. But we don’t know yet — they haven’t been studied as long. PFAS is an artificial compound; it doesn’t evolve naturally. So newer versions are just replacements, and their health impacts are still uncertain.
Epicenter NYC: There are concerns about deregulation of PFAS under the current administration. Do you have recommendations on that?
Midya: Policy is important, but awareness is just as critical. Most people don’t even know what PFAS are. The more people understand, the more pressure there will be on corporations and governments to act. It’s like what happened with lead: Once the public understood the risks, there was a pushback.
Epicenter NYC: How would you explain to people why awareness matters, if PFAS are everywhere anyway?
Midya: Because PFAS don’t only affect diabetes — they’re linked to many diseases. Unlike genetics, which we can’t change, PFAS exposure is something we can reduce. Simple choices, like avoiding nonstick cookware, can lower risk. Small lifestyle changes can add up over the long run.
Epicenter NYC: Do scientists fully understand how PFAS contribute to diabetes biologically, or is it still a mystery?
Midya: It’s still somewhat of a mystery, but we have an idea. PFAS interfere with metabolism — especially fat and glucose processing — which cascades into diabetes. That’s the working hypothesis.
Epicenter NYC: What would you and your fellow researchers most like to see happen next?
Midya: More awareness campaigns. Clear labeling on food packaging to show whether PFAS were used. People need the ability to make informed choices. On the policy side, more regulation is needed, but awareness is the first step.
Epicenter NYC: So there’s a dual responsibility: government and corporations on one side, and individual awareness and choices on the other?
Midya: Exactly. Both matter.
