Microplastics could trigger cloud formation and affect the weather, new study suggests
Abby Ayala
CNN Article (Microplastics could trigger cloud formation and affect the weather, new study suggests)
https://www.cnn.com/2023/11/15/weather/microplastic-pollution-weather-study-climate/index.html
ES&T Letter (Characterization of Microplastics in Clouds over Eastern China)
https://pubs-acs-org.proxy.lib.umich.edu/doi/full/10.1021/acs.estlett.3c00729
Clouds are essentially blobs of droplets that have condensed from water vapor in the atmosphere. Water molecules are too small to easily form droplets themselves, thus hydrophillic particulate matter often act as cloud condensation nuclei (CCN) to assist in the formation of these droplets. CCN could include species such as dust, salt, or as will be the focus of today’s post, microplastics (MPs, < 5 mm in diameter). Plastics are heavily integrated into today’s society and the degradation of these materials result in MPs that can infiltrate many environmental spheres. MPs can even under long-range atmospheric transportation, as seen by their existence not only in urban areas like Paris,1 but also remote mountain ranges.2
Mary Gilbert, a writer and meteorologist for CNN, discusses a 2023 paper in Environmental Science & Technology Letters by researchers (Xu et al.) at Shandong University in China.
Xu et al. collected cloud water samples using an Active Cloud Fog Collector3 at the top of Mt. Tai in eastern China over a one-month interval in 2021. These samples were filtered, digested, and separated to isolate the MPs for analysis where the researchers wanted to determine not only the quantity of MPs, but also their identity. Xu et al. used Fourier transform infrared (FTIR) and Raman spectroscopy for identification and scanning electron microscopy with energy-dispersive X-ray (SEM-EDX) spectroscopy to look at elemental composition and metal adsorption associated with aging of the particles. Also, Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to determine the path that the clouds took and potentially where these MPs originated from.
Xu et al. found an average of 463 MPs per liter of cloud water collected which corresponds to 0.21 MPs per meter cubed of air.
The modeling followed two cloud events originating from different directions and the samples were then divided to represent said events. The samples with the highest concentration of MPs originated from more populated areas in the southwest of the country. They also stated that more dense clouds and clouds that traveled lower had higher MP concentrations, and although that would make sense, I don’t think that their results strongly support that.
In the section “What are microplastics?”, Gilbert pulls quotes from Judith Enck, the president of an environmental policy advocation group. I tend to be weary of such organizations for dissemination information, however Enck was a regional administrator of the EPA and now faculty at a college teaching about plastic pollution. Going to her as a source of information instead of the authors probably had to do with ease of access.
When discussing atmospheric MPs, people often bring up climate and/or health impacts. Because of the topic of the article, I expected only climate to be discussed, however Gilbert included some links regarding health, one being a CNN article titled “Microplastics in drinking water ‘don’t appear to pose health risk,’ WHO says”. This really underplays the research on this topic and it’s unfortunate that it was included. I wish the focus had been just on how MPs impact the climate so the reader would have a clear storyline.
Gilbert did a good job introducing cloud formation but then completely lost the plot by including “unanswered questions” that would misguide the reader to think that more atmospheric MPs could result in cooling and thus be beneficial. This along with the low health risk article really downplays the harms associated with this pollutant. She then talks about how MPs get into the atmosphere, which I think would make more sense before talking about cloud formation.
Although Gilbert did mention that modeling suggested that MPs originated from highly populated areas, at no point did she state how many MPs were found or what they were, which is a major portion of the Xu et al. letter.
The story that Xu et al. were able to construct was something I found very interesting. They told us not just how much MPs were found in the cloud water, but what they were, where they came from, and how they could have changed over time. Plastic is not a category of pollution that people find extremely difficult to grasp and Gilbert left out all the characterization in the Xu et al. letter, which is disappointing. This along with the misleading questions and poor choice of links leads me to rate the article a 5/10.
Additional References:
(1) Dris, R.; Gasperi, J.; Rocher, V.; Saad, M.; Renault, N.; Tassin, B. Microplastic Contamination in an Urban Area: A Case Study in Greater Paris. Environ. Chem. 2015, 12 (5), 592–599. https://doi.org/10.1071/EN14167.
(2) Allen, S.; Allen, D.; Phoenix, V. R.; Le Roux, G.; Durántez Jiménez, P.; Simonneau, A.; Binet, S.; Galop, D. Atmospheric Transport and Deposition of Microplastics in a Remote Mountain Catchment. Nat. Geosci. 2019, 12 (5), 339–344. https://doi.org/10.1038/s41561-019-0335-5.
(3) Du, P.; Nie, X.; Liu, H.; Hou, Z.; Pan, X.; Liu, H.; Liu, X.; Wang, X.; Sun, X.; Wang, Y. Design and Evaluation of ACFC—An Automatic Cloud/Fog Collector. Atmosphere 2023, 14 (3), 563. https://doi.org/10.3390/atmos14030563.
I agree that the headers were a nice addition to the CNN article, but like you mentioned, the misleading questions and the lack of real conclusion is disappointing. I feel that the article should have mentioned the other potential consequences of MP's acting as cloud nuclei, such as adsorbing heavy metals like mercury or lead. Framing it as just cloud formation does not provide the full context and could lead a reader to be unaffected or less concerned about MP's than before the article. I agree that mentioning that MP's do not appear to have health effects in drinking water is counterintuitive and disjointed, but I feel that mentioning that MP's are prevalent even in drinking water could help raise awareness for some of the other consequences to plastics. I doubt people want compounds they are unfamiliar with entering their body. For these reasons, I would actually give this article closer to a 3 or 4 out of 10.
ReplyDeleteThanks for the comment Nate!
DeleteI think I'm a bit hesitant with the news article talking about metals is because there wasn't a lot of data presented in the ES&T letter. Only one of the cloud MPs had EDX data in the main text. The other three SEM images in the main text did have EDX analysis in the SI, but those of course had lower metal contents.
I agree that the public should be informed on microplastic metal adsorption but I'm not sure this letter is the best resource to lean on.
I agree with your assessment of the article. The CNN post really downplays the nuanced climate impacts as discussed in the Xu et al. paper. As with Nate's comment, I fear that the article does not do the science justice as it frames MPs as solely cloud-seeding and ends with this. CCN clearly have an influence on the atmosphere, but as the clouds precipitate out they also have impacts on other cycles like the hydrological cycle. MP-seeded clouds in one location can travel and be deposited in another region. Highly polluting regions may cause additional pollution elsewhere, as you noted in your introduction. As such, there are plenty of political concerns needed to address this kind of pollution, and I think the CNN article was worse off for missing this consequence. I do wish to ask one question: due to the low level of MPs present in air (0.21 MPs per meter cubed of air), should this be a pressing concern or should we worry prioritize other issues?
ReplyDeleteThat's a good point Joe. There's a lot of stuff in the air, and the majority of it is dust, soot, salt, and not plastic. Concentrations of plastic have been shown to be higher in populated areas, although you're right, it still is a small percentage.
DeleteThis study did do filtering, digesting, and density separation to isolate the MPs and these processes have the potential to lose some of the smaller MPs. I also think the main characterization techniques are more suitable for MPs larger than 10-20 µm.
The atmospheric microplastic research bubble is not as robust and there's still room to catch up. I wouldn't say it's more important than other aerosol research, but I do think it's important enough to study.
Microplastics are also a much easier concept to understand than secondary organic aerosols from VOCs emitted from trees. I think the general public gets a bit more freaked out thinking about breathing in plastic than they do other harmful aerosols.
Nice job on this blog post. I agree with you that Gilbert made it easy for the reader to take away information from the article, yet missed including key points from the research paper. The CNN article felt like an example of the science being simplified too much for the audience, resulting in misleading questions (like linking MPs to cooling) including irrelevant information (like the part about MP health effects) and very little of the science from the paper being explained. I think the part about toxic metals adsorbing to the microplastics would have been interesting to include in the CNN article, as well as emphasize the potential sources of the MPs more
ReplyDeleteI really like the headings; I feel like they make the article so much easier to read and I wish they would incorporate them more into the articles. I think it is a bit weird of the article to not mention aerosols at all, but upon reading the research article I saw that they only mentioned aerosols a total of eight times. This is very strange to me as microplastics in the air, and especially when talking about cloud formation are due to aerosols, so the fact that these are hardly mentioned does bother me quite a bit. I agree with your overall assessment of the CNN article, it seemed a bit too much like they were trying to fear-monger with mentioning health effects when the true story wasn't related to that at all.
ReplyDeleteI agree with you Kayleigh that atmospheric microplastics should be discussed more explicitly as aerosols in both scientific literature and popular media.
DeleteWith the pandemic and recent wildfires, I feel like people are familiar enough with the word aerosol that using the term wouldn't cause a barrier of entry.
This was a thoughtful analysis and I agree with a lot of your points! I was a bit confused on why the news article ignored most of the microplastic characterizations, especially since it could help explain what microplastics are in their "What are microplastics" section instead of just quoting Enck. Like aerosols, which Kayleigh makes a good point that the news article doesn't mention, microplastics is a broad term and there would be a real benefit to include some mention of shape or composition. I'm going to be honest and say that I didn't really notice the headings until I read your blog post and went back to see that there were headings. I think they could be more useful in an information-dense news piece but this could also be person dependent.
ReplyDeleteI think your 5/10 rating is a fair assessment of this article. The CNN article started out with solid and understandable background information, but it really lacked in reporting the actual results of the research paper. I was very surprised that the CNN article didn't include a single statistic from the paper, plus they didn't even link the research article (am I just not seeing it?). It almost felt like the article was published halfway through writing and the author hadn't started talking about the results yet. If you were the author of this very interesting and meaningful research, would you consider reaching out to CNN/the author of this article to fix some of its issues? Or would you be happy that your research made it to CNN, even if it's missing some key details?
ReplyDeleteThis comment has been removed by the author.
DeleteThanks for the comment Baker!
DeleteYou're right, they did not link the article. I'm not familiar with how people who aren't affiliated with a university go about reading scientific articles that aren't open access, but I assume that linking wouldn't be helpful for many people. But even with just the abstract, someone could get far more information about the study than from the entire CNN article.
I don't know if fighting with popular media is a good use of researchers time, unless obviously something egregious has been stated. This is a really good question that I hope others chime in on.
I don't turn to sources like CNN to get scientific news, and overall I do a very poor job of keeping up with popular news sources. Their pieces often feel rushed, and as we can see with this article, lackluster. I do however turn to resources like National Geographic and NPR Shortwave to learn about topics I'm not as familiar with, but they have lower exposure.
I would be far happier being accurately mentioned in a Shortwave episode than be the focus of a poorly written CNN article.
I think you did a great job breaking down the CNN article and comparing it to the original study. I agree with your points about how the article oversimplified the research by Xu et al. I found it frustrating that Gilbert didn’t include key details, like the actual number of microplastics found or their specific characteristics. That information is crucial because it gives readers a better understanding of how widespread this issue is and how microplastics interact in the atmosphere.
ReplyDeleteI also felt that bringing in health-related links, like the WHO statement on drinking water, took away from the climate focus. It’s almost like she was trying to downplay the environmental impact by shifting attention elsewhere.
I think your point about the "unanswered questions" section is spot on too. Suggesting that more microplastics could lead to cooling feels like a dangerous oversimplification, especially when the overall harm of plastics is clear. Overall, you made a strong case for why the article didn’t fully do the research justice.
I see where you're coming from with your criticism of the CNN article, but I think her role as a meteorologist means she's most qualified to write about clouds and weather. I partially agree with you on why she went to Enck for a quote. Ease of access is likely a contributing factor, but I also think that the journalistic tradition of finding multiple sources may be at play as well. I think her choices of what to link regarding health impacts were interesting. Like you noted, the link to the CNN article was odd. I wonder if it was a poor attempt at "showing both sides." She does, in the same paragraph, link to a journal article which discusses the potential harms of microplastics. I think this is a poor choice, though, because the first link is to something easily digestible for the general public and the other is definitely not. I would have liked it if she had included two similar sources, rather than a CNN article and one on PubMed. The other issue you brought up -- the lack of information on the amount and source of the MPs -- is even more concerning. Meteorology is ultimately a science, one in which experts generally spends a great deal of time communicating with the public. This article I think fails at this goal. She may have communicated with the public, but the science got lost along the way.
ReplyDeleteI like your input on the quotes from Enck. I hadn't thought of it that way and I would like to add onto it.
DeleteIn my mind, the goal of news articles like this is to give context on the area and then a plain language summary of the paper's results. I guess I have more faith in researchers and peer reviewed journals than I do CNN, but to someone outside of the sciences, I could see how that could be flipped. They'd be reading from journals they've never heard of with references they probably don't have access to.
Gilbert writes primarily about devastating weather events including hurricanes and forest fires. I think her background is suited, as you said, to speak on cloud formation, but almost nothing else pertaining to the article. I wish she would have partnered with a scientific correspondent to fill in those gaps.
As you and many other commenters have stated, I agree with the fact that the headers were an extremely nice addition. It made following along easier and helped with the flow with the article. Though, something that really stood out was how abruptly the article ended. I felt like it was a really awkward way to end the article. In fact, it came off as someone just deleting the rest of the article due to where the author decided to end it and as a reader, this was extremely off putting. I was left with wanting to know more about the study and given no links to direct me to studies or even other articles on similar topics.
ReplyDeleteI wish Gilbert spent more time diving into the results of the paper and actually showed to us readers why we should care about the fact that microplastics are in clouds. This article felt more like an article that was trying to report what microplastics are and how they impact your health rather than how they are impacting cloud formation, which is what the original study was about. As you mentioned, the Xu et al. paper mentioned so much more about microplastics in the clouds than just the fact they were found in the clouds. I think the article would have been strengthened greatly if Gilbert took the time to write about where these microplastics were coming from that were found in the study, what specific types they were, and the environmental implications rather than the health implications, which are important in itself but distract from the main point of the article as they took up what seemed like half the article.
I generally agree with your assessment of this CNN article, but with a few caveats. The linked article about how 'microplastics don't appear to pose a health risk' focuses on the effort to decrease microplastic pollution and the potential for undiscovered health impacts. It is generally a responsible article, so I wonder if a non-author person titled it for clickbait, as we discussed in class. The Gilbert articles hyperlinks it with text that says the health effects are "worrisome but still unclear", so I believe there was a genuine commitment to the truth by the two authors that was compromised for clicks. The CNN article reads to me as more of an overview of microplastics than a report on one specific study, especially considering the paper was never directly linked. Additionally, the ending of the article was very abrupt, with no clear conclusion.
ReplyDeleteI really enjoyed this article as I found it gave the information in a very digestible way. I do agree with you in the terms of how the CNN article broke down sections making it very easy to follow. I think you are right also in how you say the article is somewhat misleading stating that one piece of microplastic can chain grow into a cloud which the author then relates microplastics to excess rain and global cooling. I think it would be nice to include more information from the actual paper in terms of results, statistics, and where these plastics are coming from.
ReplyDeleteI like the point made previously that the non-open source nature of the paper kind of complicates the ability of the CNN article writer to write an in-depth analysis of the paper for a larger audience. As with the previous article, there is little attention given to examining the implications of microplastics in the atmosphere, which I think is the primary criteria for evaluating an article such as this. I think your rating is fair.
ReplyDelete