GenX: A Question Of Chemistry

Jun 20, 2017

New Hanover County Commissioners adopted a resolution Monday calling on Chemours to stop production of GenX. Brunswick County Commissioners adopted a resolution the same day -- asking Chemours to stop the discharge of the GenX chemical into the Cape Fear River.  That’s largely because  there is still a lot about GenX that we don’t know. It’s all about chemistry. Which means for many of us, it can be somewhat difficult to grasp.

“As a scientist, I rely on data, to inform my approaches, and my evaluations, and I don’t have the data yet.”

Dr. Susanne Brander is a toxicologist at UNC Wilmington.

She says to understand GenX, one needs to look at its predecessor.

“And so the only way to have an idea of what could be expected from exposure to a chemical like that is to look at what is known about a similar chemical, and there has been a lot of talk about how GenX was the replacement for another chemical known as C8, also known as Perfluorooctanoic acid. A PFOA.”

C8 is a confirmed carcinogen. It’s been linked to a wide range of diseases and cancers. That’s why GenX was developed. C8 is a long chain of carbon–fluorine bonds. In GenX chemists added an oxygen atom to the middle of the chain. The thinking was this would make the compound less persistent, and it would pass through the body more quickly.

Dr. Phillippe Grandjean is with the Harvard University School of Public Health, and also chair of Environmental Health at the University of Southern Denmark.

“We know that they appear to have a short half-life meaning they are eliminated very rapidly. But the fact of the matter is yes they do leave the bloodstream, but that is because they are accumulated in the body, the liver the kidneys the lungs, and so just because some of them appear to disappear from the blood rapidly, that may not indicate that they have disappeared from the body as a whole.”  

He says GenX is easily absorbed.

“So if you drink contaminated water these compounds will rapidly move into your bloodstream and be circulated so that they can reach all the organs of the body. We also know that these compounds can cause liver cancer, in rodents.”

It’s when the GenX molecule attaches to other cells, that health issues can arise, albeit years down the road. Dr. Larry Cahoon is with UNC Wilmington.

“This is a molecule, GenX and its congeners, that is going to tend to bind to cell membranes including some of the receptors that normally would bind with the hormone molecules or some of the other signaling molecules.”

And, Cahoon says, they are resilient.

“These compounds don’t break down. Biologically they are not broken down. Once they are loose in the environment, they are loose in the environment and that’s it. You are not going to get rid of them, these compounds are persistent as they possibly could be.”

Again, Dr. Grandjean.

“So this is very parallel to what we knew about PFOA, C8, in the 1990s, and my concern is that if these new GenX compounds if they have properties, I would be concerned that there might be additional toxic effects.”

The levels of GenX in the Cape Fear River remain a mystery. This week the state’s Department of Environmental Quality began a series of tests at 13 locations between the Chemours facility, and Wilmington. Those results should be available in a few weeks.