What's Known (And Still Unknown) About PFOA

Apr 1, 2016

State environmental officials continue to investigate the presence of the chemical PFOA in the drinking water of some southern New Hampshire communities.

Results are in for a total of 107 wells in Litchfield and Merrimack and while almost all water sources contain some background levels of PFOA, a total of 26 wells are above the 100 parts-per-trillion threshold the state has set as qualifying for free bottled water.

Meanwhile, questions remain about the long-term health effects of the chemical and what amount, if any, is safe to drink.

Dr. Richard Clapp is a professor of epidemiology at the Boston University School of Public Health.

He’s done extensive research on PFOA, and he joined Morning Edition to talk about what he’s learned.

Let’s start out with a definition of what PFOA is exactly.

PFOA is a 8-carbon chained chemical that has fluorine attached to it at every possible place, so it’s a very stable, long-lasting chemical in the environment and human bodies, as well.

What’s it used for?

It was originally used for nonstick surfaces. It was used in the production of Teflon, the coating of fry pans for example, to keep food from sticking. It’s also been used in other nonstick or nonstain type applications.

Now, in those applications where it doesn’t get into the blood stream, it doesn’t have any effect at all, is that correct?

Right. If it doesn’t get ingested, either by being on food or drinking water, then it wouldn’t have an effect on humans.

But because it’s such a long-lasting compound and it doesn’t break down in the environment, it’s become a real issue and it’s actually been detected in low levels in just about everybody, isn’t that true?

Yes. There’s a national sample of blood samples taken from U.S. citizens every couple years. In the recent results from that, they’ve looked for PFOA and found it in virtually everybody.

You co-authored a review of PFOA research last year. What were the takeaways from that study?

The review was really looking at the literature up through the beginning of 2014 and there’s been a lot of published in recent years, so it was a summary of what we’ve learned recently, that It looks like PFOA is linked to cancer in humans, two kinds of cancer in particular: kidney and testicular. There’s also a connection to several other diseases, including hypertension during pregnancy, thyroiditis, colitis, and high cholesterol. There are some other studies that have shown other health effects even on the immune response and other types of cancer that are more inconsistent.

We should also point out these studies do link it with some types of cancer, but do not prove it conclusively, but the studies point towards that, is that true?

Yes, it’s called a probable human carcinogen. The studies done in West Virginia conclude there’s a probable link between two types of cancer and PFOA.

We’re seeing different reactions from states dealing with this. Here in New Hampshire, environmental officials are providing bottled water to those who wells tested higher than 100 parts per trillion.

But in Vermont, officials there say anything more than 20 parts per trillion isn’t safe to drink.

What does the research suggest?

The provisional level that the EPA has set for short-term exposure is 400 parts per trillion. The EPA is expected to lower that for long-term exposure to 100 parts per trillion. Anything above that in drinking water should be avoided.

The provisional level that the EPA has set for short-term exposure is 400 parts per trillion. The EPA is expected to lower that for long-term exposure to 100 parts per trillion. Anything above that in drinking water should be avoided.

What do we know about the prevalence of PFOA in drinking water systems around the country?

It’s been found in many different locations. For example, where there are manufacturing companies like DuPont and like Saint-Gobain in the northern New England states and upstate New York, where those have existed and not handled their waste properly and has been dumped into the ground or ground water or bodies of water like rivers, it’s polluting people’s water supply if they drink ground water in many parts of the country.

You’ve done a lot of research on PFOA, but what are still the biggest unknowns?

The biggest one is the immune effect. That’s an effect seen children who are just getting their vaccinations, and if that’s true, if that’s repeated in other populations by other researchers, that means there’s an effect at a very low level and these provisional standards the EPA and states are setting need to be revisited.

The other thing is as we learn more about PFOA as a cause of cancer, there’s a different federal law that says if something is known to cause cancer, the goal is to have zero levels in drinking water. That’s called a Maximum Contaminant Level Goal for carcinogens, zero parts per trillion. If that’s the case, as it turns out we have carcinogens in our drinking water now and that’s because the law says if it’s feasible technically and economically feasible, the level should be zero. And for some of these things, it’s not feasible technically or economically. That might be a sort of compromise that affects PFOA if it’s found to be a known human carcinogen, but again that would lower the levels below what’s being proposed now.

So is the consensus that this chemical needs to be phased out over time?

It has been phased out, actually. In fact, I think most of the companies in the U.S. that make it, they’re in the process of phasing it out or have already phased it out. So yes, I think that is the right answer that there’s got to be a way of getting nonstick properties without a chemical that’s as harmful as PFOA.