Even Alligators Might Be Harmed by PFAS ‘Forever Chemicals’
News Article: “Even Alligators Might Be Harmed by PFAS ‘Forever Chemicals’”
Scientific Article: “Blood concentrations of per- and polyfluoroalkyl substances are associated with autoimmune-like effects in American alligators from Wilmington, North Carolina”
Per- and polyfluoroalkyl substances (PFAS) are highly stable organic compounds with fluorinated aliphatic backbones. Because of their enhanced stability, these substances have become persistent and global contaminants in both terrestrial and aquatic environments. PFAS contamination largely originates from anthropogenic activities such as fluorochemical production, manufacturing, wastewater treatment, and fire suppressants. Through human epidemiology studies, elevated PFAS exposure has been linked to immunotoxicity and altered immune functions such as increased incidence in childhood infection, decreased antibody production, thyroid disease, inflammatory bowel diseases, and the list goes on. The mechanisms of PFAS induced immunotoxicity and its role in autoimmunity is still poorly understood.
The academic article published in Frontiers in Toxicology aims to study the effect of long-term PFAS exposure on biomarkers of immune health by using the alligators in Cape Fear River as a predictive sentinel species. Located in North Carolina, about 5.2 million people rely on the Cape Fear River Basin in rural and urban communities. Several PFAS derivatives and their terminal breakdown products have been recently detected in the drinking water and blood samples of people living near the Cape Fear River. The authors of the academic paper report the characterization and comparison of the PFAS serum concentration profiles of alligators from two watersheds: the Cape Fear River basin (high PFAS exposure) and the Lumber River basin (lower PFAS exposure). They then go on to evaluate the immune health endpoints in alligators from these two watersheds.
Using several bioanalytical tools described in the materials and methods section, the authors were looking for specific biomarkers of immunotoxicity. They discuss that increased PFAS concentrations in adult alligators in the Cape Fear River correlated with increased lysozyme activity, which is essential to anti-bacterial immune activity. Since the researchers also observed slowed wound healing, vasculitis, abnormal red blood cell phenotypes (schistocytes), and lower numbers of thrombocytes in the Cape Fear River alligator population, they postulated that hallmark phenotypes seen with human autoimmune disorders would be more common in these Cape Fear alligators. This hypothesis was correct. Their RT-PCR analysis of type 1 interferon responsive gene expression in alligator blood samples found high expression of four different signature genes implicated in pathology of human autoimmune diseases (e.g., lupus erythematosus). These are just a few of the findings that represent a significant health concern for wildlife and humans exposed to PFAS.
I think the US News article is short and sweet and did several things right. It identifies the problem in the first sentence: that PFAS exposure can lead to immune system harm. Throughout the article, the author also defines terms that might be confusing to readers, including what a sentinel species is and what an INF-alpha protein is. The article also gives background about where PFAS come from and how ubiquitous they are in our daily lives (the article actually ends with an EPA link for readers to learn more). Most importantly, the discussion of data, while brief, was digestible to a vast audience, using direct quotes from one of the authors of the academic article. While this wasn’t the most information-dense article, in my opinion, when it comes to sci comm, people need to learn how to communicate their science succinctly.
Even so, the article does have some shortcomings. While the problem was communicated to the general audience, no solutions were given. The authors of the academic article take a stance in their conclusion, that their findings “reaffirm the need to reduce exposure and cease production and use of a chemical class that […] is a global environmental health concern.” This conclusion was not mentioned in the US News article, which I think increases anxiety and feelings of helplessness in some readers. I also think there could have been more geographical context in the US News article. The academic article mentions fluorochemical production activity in the Cape Fear River basin several times throughout the article, and also mentions that millions of people rely on that water. I think adding this information to the US News article would have further pushed the severity of the problem onto the readers. With all of this in mind, I give this article a 7/10.
Hi Sabrina! This is a really interesting article, I'm so glad you chose it! While our previous articles have mostly focused on human health, I appreciated a study that instead focuses on other species and how they are affected by anthropogenic pollution (even if the alligators are just functioning as sentinel species). It's also interesting that you bring up the lack of solutions that are offered in the US News article, especially when the scientific paper has a take-home message regarding the use of PFAS. This seems to be the opposite of what we've seen previously, where the scientific paper will just provide data and results, and the popular news article will offer further subjective interpretation and solutions.
ReplyDeleteGreat evaluation of the article! What do you suggest that could have been included in the news article to ease the sense of anxiety that could be created from their current conclusion? Would it be helpful to include more data from the science article? Or include a quote from one of the collaborators on the study? A statement from water treatment government workers in North Carolina?
ReplyDeleteThank you for sharing Sabrina! I agree that succinct communication of science is often better than unnecessarily dense texts. I am curious what you think some of the advantages of short news articles about science are compared to longer ones? Likewise, what are some of the disadvantages in your opinion? Do you think this mantra should be applied to scientific communication to other experts too (the trend has been shifting to long 10+ page papers from the half page Tetrahedron Lett. and 2 page JACS articles of old)? Also, out of curiosity, how often are alligators used as models to understand potential human health effects? This is the first example I have seen.
ReplyDeleteHey mike! I'm a huge proponent of shorter communications in news articles. I don't know if I feel the same way about academic articles though. I think there's nothing more frustrating than reading through a scientific article and having no idea how they went about setting up their experiments or when scientists don't publish the shortcomings of a method. So I guess I appreciate shorter news articles as long as the thorough information can be found at the original source.
DeleteAlso, to respond to your section question, the academic article mentions that the American alligator has been used for more than four decades as an aquatic biomonitoring and predictive sentinel species. This was news for me too!
DeleteHi, Sabrina! Great work analyzing these articles. I also agree with you that the news article probably could have concluded with a "next steps" paragraph that tied everything together with why this is important to fix and what we can do for that to happen. Since these PFAS have generally serious effects on human health, and this article mentioned it various times throughout, it seems almost necessary to add a section about how we can try and mitigate this. Do you think this is something that would have maybe strengthened the article or would it have been too much, deterring from the scientific findings?
ReplyDeleteHey sofia! Like I said above, I think even though the academic article only briefly touched on the need to remedy PFAS contaminations in our ecosystems, the article could and should have touched on that.
DeleteThis was a really interesting article to read and a great evaluation as well. I was surprised to also notice that despite the journal article referencing a possible solution/call to action for individuals, the news article failed to include this point. I wonder if it would be helpful for the audience if this was included - often times I have noticed that news articles only serve to increase anxiety and as a way to get as many clicks as possible. I think the article could have better presented some of the data, even though it included direct quotes, it could have gone further to include better synthesize some of the data collected and results produced. Overall, I would agree with the rating you gave it.
ReplyDeleteHi Sabrina, thanks for sharing these articles! One thing that I would have liked to see in the news article would have been a relation to human health. The author mentioned a few times that alligators can be viewed as a sentinel species, but I think it would have been especially convincing if they could have related the levels of PFAS detected in the animal's blood to the equivalent value in human bodies. Studies of PFAS in human blood have been conducted, so I think a comparative note on the exposure and uptake of these chemicals would have been an interesting take-away!
ReplyDeleteHey madeline! I agree that this would have been a great addition to the academic article. What the article did say was that for certain per- and polyfluoroalkyl species like PFOS, it accounted for over 70% of the total PFAS present in alligator serum samples from both sampling areas, the Cape Fear River and Lake Waccamaw. They then go on to say that "The relative composition of long and short chain PFAAs and PFEAs detected in blood of Cape Fear River American alligators were in general agreement with those found in the blood of the adults and children exposed to PFAS from drinking water in Wilmington, NC."
DeleteThanks for sharing these article. I know that there is currently issues with toxic chemicals in the fish we eat (such as DDT in farm salmon). A quick search told me that Cape Fear River is a good fishing source for bass, catfish, etc. I was wondering if there was a similar issue here where the fishes people eat was containing PFAS?
ReplyDeleteHey david! This is a great point. The authors of the academic article discuss their previous findings tracking the effect of PFAS on striped bass from the Cape Fear River. They actually linked higher concentrations of PFAS with elevated lysozyme activity in striped bass as well.
DeleteHey Sabrina thanks for the great analysis. Most of the studies we've seen so far in class focus on measuring pollutant levels directly in the atmosphere/water, so it's really cool to see the ways that they can also be measured in things such as animals. In the paper they emphasize that alligators are optimal animals to study when it comes to biomonitoring because they are non-migratory, but I'm curious to know if there are any other species that can be studied in a similar way. In areas that don't have native alligator species do you think there are other animal populations that could serve as indicators for elevated PFAS levels?
ReplyDeleteHey ben! It's my understanding that alligators are reliable sentinel species not only because they're non-migratory but also because they're apex predators that coexist in the same human habitats with PFAS, with a life span exceeding 60 yrs. After giving it a quick google search, I found that most other aquatic sentinel species are fish populations.
DeleteHey Sabrina! Great post! I was curious do you think the reader will have more or less of a call to action when this article is regarding alligator health vs. what we normally see - human health?
ReplyDelete