Let's Talk About Forever... Chemicals on Reddit and Twitter

Title: Understanding Public Perceptions of Per- and Polyfluoroalkyl Substances: Infodemiology Study of Social Media

Author(s) and Year: Hao Tian, Christy Gaines, Lori Launi, Ana Pomales, Germaine Vazquez, Amanda Goharian, Bradley Goodnight, Erica Haney, Christopher M Reh, Rachel D Rogers

Journal: J Med Internet Res

TL;DR: Twitter and Reddit users increasingly expressed alarm over the health risks posed by PFAS exposure and confusion about how the government was alleviating PFAS risks. The authors argue this gap in knowledge can be filled by public health agencies engaging with social media users and monitoring trends in social media to understand social media users’ current PFAS concerns.

Why I chose this paper: As a North Carolina resident, where PFAS are highly elevated in certain regions, I’m interested in learning more about PFAS and effective science communication techniques to disseminate PFAS information to local communities and the public.

Even if you haven’t heard of Per- and Polyfluoroalkyl Substances (PFAS) or ‘forever chemicals’, you’ve probably interacted with them. Found in everything from non-stick pans, period underwear, drinking water, and even your blood, these manmade chemicals were initially created in the 1940s and used in countless products. PFAS earned their moniker ‘forever chemicals’ from their ability to take a long time to degrade, which means they can accumulate in the environment and people. Research suggests that PFAS exposure can cause a myriad of health concerns including increasing the risk of some cancers and disrupting the endocrine and immune systems.


Despite being phased out in the early 2000s, PFAS are still ubiquitous and have lately received increased media attention. Tian and colleagues wanted to understand how social media users engage and share PFAS information on Twitter and Reddit. Their goal was to identify public concerns and learn how the government can harness social media to effectively share public health information.


The Details


Dr. Tian and authors noticed that social media users previously turned to Twitter and Reddit to learn about public health information related to e-cigarettes. Reddit users crowd-sourced information on alternatives to e-cigarettes, whereas Twitter users exchanged scholarly information about e-cigarette policies. Given this difference in social media uses and the growing trend of people seeking public health information from social media, these researchers wondered how social media users communicated about PFAS on Twitter and Reddit, and how the communication differed geographically, over time, and between these two social media platforms.


The Results


Dr. Tian and his colleagues analyzed over 100,000 PFAS-related public posts on Twitter and Reddit from May 2017- April 2019 in the US. They found that PFAS-related content on social media generally increased over time. Twitter had far more PFAS-related content, over 98,000 posts, compared to Reddit’s approximately 3,000 posts. But Reddit users engaged more frequently, held more follow-up discussions, and provided anecdotal information, compared to Twitter users on PFAS-related posts.


They realized geographic areas impacted by PFAS contamination or near recent PFAS events covered by local media, had an elevated volume of PFAS-related content on Twitter and Reddit. Specifically, Washington DC, New Hampshire, and Michigan had the highest number of PFAS posts per 100,000 people across both Twitter and Reddit. A high amount of PFAS posts in New Hampshire and Michigan were over PFAS events or sites in their respective regions.


These researchers identified 3 common subtopics of PFAS Twitter and Reddit posts:

  • PFAS as an immediate public health concern

  • Asking for clarification on the government’s role in PFAS mitigation

  • A general distrust of PFAS-related information


They observed 9 ( 3 on Twitter, 6 on Reddit) spikes on PFAS-related content as seen in Figure 1. Tian and colleagues traced these spikes to the social media users reacting to EPA summits and publications, peer-reviewed scientific publications, and international, national, and local news articles on PFAS, such as this New York Times article on military family exposure to PFAS.

Graph showing number of Tweets and Reddit posts over two year period of the study. 9 Spikes are labeled with proposed corresponding PFAS media publication or event
Figure 1: Increases in Tweets and Reddit posts often followed PFAS articles published. [Fig. 2 in Tian et al., 2022; Figure used under CC BY 4.0]

The Impact


Many of these analyzed PFAS posts contained both alarm over the immediate health threat of PFAS and also confusion over the current state of government PFAS research and mitigation. Users asked for clarification on the government’s role in alleviating PFAS exposure and wanted to know more about the human and environmental health risks from PFAS, as well as personal steps to take to reduce exposure to PFAS.


Dr. Tian and colleagues view this gap in knowledge and eagerness for more information from Twitter and Reddit users as an enormous public health response opportunity. They argue that the government can use social media to:

  1. Stay up to date on current health concerns relating to PFAS by monitoring trends in PFAS content on social media,

  2. Create an interactive forum to disperse reliable information on PFAS research and resources for communities severely impacted by PFAS exposure

These results are limited to users in the US. Due to logistics or lack of content, other social media platforms such as Facebook, Pinterest, Youtube, and Imgur, as well as some Reddit posts, were excluded from the study. The authors remind us that these findings can’t be extrapolated to the general population. The authors also view the data as a snapshot of an ever-changing landscape of social media, where posts, likes, and comments can be deleted or added at any moment.


Science communicators can use these findings to understand the interests and concerns of their audience, by searching trends in PFAS posts on Twitter and Reddit. For instance, audiences might be more receptive to PFAS information in regions near elevated PFAS contaminations, or after a breaking news story about PFAS. The insights gained from this study, such as the finding that Reddit is conducive to more user engagement than Twitter, can better prepare public health agencies and the government to use social media for effective public health outreach over PFAS


Edited by Niveen Abighannam and Stephanie Deppe

Cover image credit: kaboompics ; Figure 1 used under CC BY 4.0.