EXAMPLE POST: Microplastics Circulating through the Biospheres

 

CNN news article: https://www.cnn.com/2021/04/13/world/atmospheric-plastics-study-intl-hnk-scli-scn/index.html

PNAS research paper: https://www.pnas.org/content/118/16/e2020719118

 

The news article I chose from CNN, titled “Microplastics in our air 'spiral the globe' in a cycle of pollution, study finds” and published in April 2021, covered a research paper from the Proceedings of the National Academy of Sciences in the United States of America (PNAS) that was published earlier this year. The paper, titled “Constraining the atmospheric limb of the plastic cycle,” concerned the transport and deposition rates of microplastics (MPs) from the hydrosphere and geosphere into the atmosphere. According to an article from the National Oceanic and Atmospheric Association (NOAA), MPs are defined as “small plastic pieces less than five millimeters long which [could] be harmful to our ocean and aquatic life.”

Upon first reading the news article, I was impressed overall with how the author communicated problems with anthropogenic waste and how it could lead to plastics being released into the environment and form MPs. Additionally, I liked how they took the time to explain how the MPs could move in between biospheres and keep “[spiraling] around the globe.” The title was obviously overstated and meant to act as click-bait, but the author did not make any lofty conclusions that were loosely based on the research paper’s results.

Image showing different sources of MPs into the atmosphere and their percent contributions.

Once I started to read the research paper, however, I discovered that there were gaping holes in the news article. Although the paper mentions how plastics are cycled through the biospheres in its introduction, its primary focus was over modeling MP transportation and deposition rates from the land and sea into the air. The main sources of MP reemissions were hypothesized to be mechanical ones, including vehicle tires, agricultural dust, and sea spray aerosols (SSA). By inputting data collected from 11 observation sites into the Community Atmospheric Model (CAM), which was modified to work with MPs, the researchers estimated that vehicle tires, SSA, and agricultural dust contributed 82.5%, 4.0%, and 3.4% of the annual MP deposition into the atmosphere respectively. The researchers also made it clear that their report was not meant to give conclusive results, but rather “to combine the limited observations of atmospheric microplastics with models to better identify the open research questions.” In fact, the reported uncertainty for the deposition of MPs into the atmosphere were 30% for road emissions and 100% for all other sources.

The model’s global estimates of A) sources of MP reemission into the atmosphere and 

B) daily concentration of MPs deposited at different geographic areas.

In addition to finding sources of MPs into the atmosphere, the model also computed how long the MPs stay in the atmosphere (1 hour—6.5 days) and where MPs end up after they are deposited out of the atmosphere (oceans received the vast bulk of MPs). Though all of these results were insightful, the researchers themselves noted “our first study on the relative importance of different sources leads to more questions than it definitively answers.” Many societal and environmental factors were not included in the model, and it was implicated that there was much more work to be done before trustworthy results could be secured.

Looking back at the news article, my opinion changed from one of high esteem to disappointment. The majority of the article focused on information from the research paper’s introduction/background section rather than the true purpose of the study; in fact, the news article attributed certain facts from previous studies that were cited in the background section to the research paper’s authors. The most prominent example I found was when the news article stated “the research team collected atmospheric microplastic data from the western United States from 2017 to 2019, and found an estimated 22,000 tons of microplastics are being deposited across the US each year,” when this research was truly published by a different team in 2020. I will note that both studies had the same first author, but all of the other authors were different; thus, I would say that they are two separate studies with different research teams.

Overall, I’d give this news article a 5/10 rating in the context of how well it communicated the results and purpose of the research paper. The article did great job at explaining many of the concepts discussed in the paper. However, it did not convey the overall purpose of the paper, it did not specify that the results from the study were most likely inaccurate and highly inconclusive, and it incorrectly credited past research to the authors of the PNAS research article. I also deducted points more heavily since access to the PNAS article is behind a paywall, and in my opinion this means the journalist had an even greater responsibility to report the information from the research article accurately.