Not a breath of fresh air: study finds sewage bacteria in ocean spray
Link to Environmental Science and Technology Paper
The article "Not a breath of fresh air: study finds sewage bacteria in ocean spray" was published at the beginning of March in 2023. It publicizes to the general population some of the information from the research paper "Bacterial and Chemical Evidence of Coastal Water Pollution from the Tijuana River in Sea Spray Aerosol" which was published on the same day in 2023.
The research comes from Matthew Pendergraft, out of Kimberly Prather's lab, at Scripps Institution of Oceanography. The research focuses on supporting the concept that sewage dumped into the water can aerosolize and travel inland as marine aerosol. Marine aerosol, or sea spray aerosol (SSA), primarily comes from bubble bursting and wave breaking, which releases seawater aerosol containing various substances from the water, such as bacteria. As the research paper pointed out, there has been many prior studies showing that SSA can travel very far, even hundreds of kilometers. The main concern is that near Tijuana, the Tijuana River greatly pollutes the costal waters with sewage. While swimming and drinking the water is highly studied and discouraged, little is known about how much of the sewage aerosolizes, as well as the potential health ramifications from those aerosols. To support their concerns, Pendergraft identified tracer bacteria in the water that were unique to the sewage and then searched for those bacteria from aerosol samples collected from more inland (Figure 1). They linked 26 of the tracer bacteria to the sewage with confidence.
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The Guardian article, by Katharine Gammon, uses more poetic language to focus on some key findings of the research, while adding additional quotes from the authors as well as links to other news articles. Gammon herself is an award winning author and has a degree in anthropology and environmental studies from Princeton and has a masters in science writing from MIT, so the eloquent language and clear story are no surprise. However, while the article does its purpose of summarizing the research for a general audience, there are a few issues. The article starts off very nicely, with a general way to envision the process of the sea making aerosols and a description of the problem with a link to a news article, from a different source, about the Tijuana beach closures. Then it gets into the research, which is where some of the trouble starts. The overview is described nicely but then it states that "They found that three-quarters of the bacteria in the air came directly from the sewage in the surf zone" which is a horrible over-simplification. Not only could it have come directly from the sewage plant as mentioned in the research paper, but the bacteria on average only amounted to 41% of the samples, in some cases it was up to 76% (Figure 1) which is where the article likely obtained the number and used it for the shock factor. The link to the article itself is also a link to the citation, which while helpful, is not very assessable for the average person who wouldn't want to put more effort in to search up the information. Another pro however is that the research paper is open access so if someone has the time they can look into it on their own. Another link is to a source showing bacteria levels can be high for days, but the source is just a water advisory from Los Angles, with no scientific source. As mentioned before, there are a lot of quotes from not only the PI but a few other of the authors that add more flavor and information to the piece. However, occasionally it is hard to tell what was quoted or paraphrased because there will be information without quotes followed by "Prather says" and immediately after there will be a quote with quotations. Also, as a student is is disheartening to see the first author, Pendergraft, described as a "recent graduate" "who obtained his doctorate under the guidance of Prather" with no mention that it is his paper or his research. It sounds like he is someone who was in the lab who can offer one comment on it, rather than the first author, which would be devastating after working so hard on a paper.
In short, the article and the research agreed on the overall problem, methods, findings, and importance. Both claim that the Pendergraft article is one of the first looking into SSA pollution from sewage in the water, and both do a great job showing just how important aerosols could be to public health. I really enjoy the additional quotes the article in the Guardian added since it helped to gain insight into why they researched what they did and how important they view their own work. However, the article used inflated numbers to drive their point instead of the average determined by the research which is not very honest reporting. Also, the article focused on quotes and information from the PI and another professor and barely reported any comments from the first author, and when they did they didn't even mention his involvement with the paper. Overall, I do think the article achieves its purpose of making the research more assessable to a general audience, however its shortcomings cannot be ignored. I would give it a 6/10 since it does help make the idea of aerosols and their importance more tangible to a general audience, but it should've been more honest in doing so.
I completely agree that the article brings to the public eye some pretty important areas of research that are perhaps understudied, but that the way in which they go about presenting the information is a bit subpar. I feel that it is very important for those outside of the scientific community to be exposed to science, but not for that work to be oversimplified. Especially when the study is as captivating as this one! I would be SO interested to learn more about the impacts of these aerosols on the environment of these communities that are the most effected. I'm sure there has been plenty of work done to look at the enviro impact of the sewage getting dumped, but the implications of that on air quality could be incredibly informative to research.
ReplyDeleteI agree with you! It is always frustrating to see science dumbed down to the point where it is no longer true. I think media should focus on ways to make science assessable without stripping it of its importance and honesty. The Prather lab does a lot of really interesting work so I recommend looking at some more of their papers if this kind of stuff is interesting to you!
DeleteI did appreciate the inclusion of direct quotes from scientists and agree that they help show why they were studying this and why it is important. But I also agree with you that it is misleading and somewhat irresponsible for the article to report only the highest values instead of the actual range or an average. I was also thinking about where else this type of study could be applicable and interesting, especially considering our proximity to the Great Lakes.
ReplyDeleteMisleading a general public who won't go further into the article is a frustrating thing to read. Thankfully it is not super harmful, but it still makes the credibility of the author get severely diminished, as they could lie about something with a greater impact.
DeleteAs far as great lakes research, there are quite a few scientists here at UMICH as well as other institutions like Wayne State doing research on aerosols. The lakes are interesting because instead of sea spray aerosol, we get lake spray aerosol, which is similar but from the freshwater. Since it is freshwater the biological activity is quite different!
The idea that sea spray can cause bacteria and other pathogens to enter our breathable air is certainly an interesting and potentially important thing to discuss, but I agree with this criticism that the clearly more significant concept here would be to find out whether or not these bacteria have health implications for those who breath the air containing these aerosols. Without that information, the article begs the question "so what?", because we just don't yet know what the ramifications are of the bacteria in these aerosols. Apart from that, the rest of the article was fairly well done, and the article itself even somewhat admitted that the bigger issue to focus on is the potential health risks that the microbes may pose to those who live in close proximity.
ReplyDeleteIt was defiantly anticlimactic to get into the research only to discover the stuff they found wasn't very impactful yet. However, I do think it was important to show that you could backtrack aerosols and that sewage does get into the air. I really hope in the future they can show if the more dangerous aspects of sewage also get into the air. It would also be interesting to see if inhalation is more or less toxic than other forms of ingestion of the bacteria.
DeleteI think that this The Guardian article does a decent job of pulling on different avenues of information in order to synthesize a piece that isn't just swept under the rug. While it does not accurately represent the Pendergraft paper in its entirety, it does help to drive the paper's point home. I absolutely agree with you in that the Prather quotes might be diminishing the meaning of a "first author" paper, but I must say that I do not believe that this was intentional, but rather an attempt to expand reputability of the article (i.e. "see, many scientists agree!"). My last point, that I am not sure if I missed in both the article and paper, ties into your criticism as to bacterial identity and potential to infection: were any of these bacteria clustered to concentrations that can cause harm or are the bacteria alive during analysis? Similarly, I did not see if this paper references bacteria with very conditional infectious properties (e.g. most people have Candida fungus in their mouths, but the infection "thrush" only occurs when this yeast grows out of control, often due to a weakened immune system; if Candida fungus was in this study (I don't believe it was), would it be important to study it if it was present in amounts that compare to the standard mouth concentration?) and would be interested to see more of a breakdown in this regard.
ReplyDeleteYou bring up some great points. I don't believe they mention clearly if their clustering was at harmful levels. They mention their rate of sampling and their results so if the toxic levels were known perhaps you could deduce. The only problem is if people are used to looking at the bacteria in water, it could act very differently when inhaled by lungs. Based on my knowledge of aerosol collection likely by analysis they were dead, if not doing the amplicon sequencing probably killed them in order to get their DNA. Something else to consider: would lysed bacteria pose a greater risk since the toxins/pathogens they make would be released and potentially able to travel through the air easier? The Canadian fungus is very interesting. Personally I would like to see if the lungs of people living near the sewage contains more of these tracer bacteria than the average person.
DeleteI appreciate the way you summarize key information from the research paper; namely, specific data not mentioned in the article, as well as a general description of the key takeaways from the research. Thank you for bringing this sort of research to our attention, as it surely seems to be an area that many people don't spend much time considering or reading about; not to mention the potential effects this sort of research can have on communities and the overall well-being and health of the population, mainly of those living in coastal areas. The article is obviously on the shorter end but does a satisfactory job of identifying the major issues presented in the research paper. I certainly do agree with your critique of the article using fabricated data because it isn't difficult to simply report the exact numbers that the researchers reported in their paper. I suppose this is meant to make the public more reactive to the study, but it is just not necessary and quite careless. Nevertheless, I tend to agree with your rating of the article, as there is a lot that could have been changed, whether the author added extra significant information or deleted unnecessary or even false information. Either way, I did learn from the article upon reading it before the research paper (the direct quotes were helpful, of course), and it still did compliment the paper despite its drawbacks.
ReplyDeleteI entirely agree. While the article has some significant shortcomings, I like that it draws attention to an underrepresented area of science and highlights the importance to the everyday person. If the author had used the true data it still would've been impactful and also made it more credible. I am glad though that time was taken to give such important research a spotlight.
DeleteI agree this article did a really good job of helping to shine a light on a lot of understudied research. i also really appreciated how the author of the article pulled a lot of direct quotes from different scientist to help convey the message of why the research was being done rather than paraphrasing in a way that would allow for a lot of information to be lost. However i think the fact that the article only reported on the highest values rather than the full spectrum negates all good work, and credibility the author had.
ReplyDeleteThe news article actually doesn't mention the percentage (or any range) of bacteria that were associated with coastal water pollution out of the total bacterial population found in aerosol samples. I think that's a pretty key piece of data to leave out of the news article. I also think its strange the scientific article didn't mention at all how they characterized aerosols as sea spray aerosols? Generally, to my understanding, SSA is largely composed of an inorganic salt core and can have organic coatings due to bubble bursting. If this study didn't analyze their aerosols to determine if inorganic salts were present, can they really say it was SSA that contained sewer bacteria?
ReplyDeleteI like how you not only critiqued the news article, but also criticized the research paper for where you think it fell short. I do think the original paper does a good job of not only reporting their results in a clear manner, but also manages to communicate the urgency of why the study matters to the public. However, I also take issue with it being unspecific in certain aspects. I was also bothered by how it took out the nuance of the data and chose to go with the 76 percent figure in the abstract. I think it's this lack of nuance in the abstract that led to the author of the news article also misrepresenting the actual data.
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ReplyDeleteAn innovative study by researchers at the Scripps Institution of Oceanography reveals that after a rainstorm, coastal communities may be exposed to harmful bacteria from sewage in the ocean, which can be carried into the air as salt spray, particularly exacerbated by storm runoff. This study, which focused on the area south of San Diego near the US-Mexico border, where a wastewater treatment plant often releases sewage into the Tijuana River, demonstrates that a significant portion of the bacteria in the air originates from contaminated seawater. What innovative methods can be developed to mitigate the health risks associated with inhaling airborne pathogens from sewage-contaminated coastal air? While the health risks remain uncertain, this discovery underscores the need to investigate potential health impacts. It also marks the first time scientists have linked such pollution to coastal sea spray, shedding light on a previously overlooked exposure pathway. How might this new understanding of airborne microbial pollution impact coastal communities' public health policies and practices? The implications for human health are a critical area for future research, as well as the possibility of issuing air quality warnings on days when inhaling salt-laden coastal air could be harmful, similar to existing pollution alerts. What measures can coastal communities implement to protect residents and visitors from potential health hazards posed by contaminated sea spray, and how can these measures be communicated effectively?
I really appreciate your critique on the study itself. You bring up a very important factor that I don't believe was thoroughly considered in the study: how easily certain bacteria is to aerosolize due to its behavior in water and in the air. Yes, they can use these high tech instruments to analyze aerosolized bacteria from these sea salt sprays, but the study lacks a correlation to the properties of the actual bacteria being analyzed. I also had a slight issue with this study for a different reason. They bring up how stormwater runoff is a major factor in ground chemical and bacteria are carried to the larger bodies of water. They also make the argument that costal water pollution can travel inland and effect human health. How do they know that the bacteria and chemicals are not becoming aerosolized closer to the source? What I would like to understand more from both the article and the research paper is, how can you say with confidence that the bacteria or chemical is coming from a sea salt spray. This is a cool article, thank you for sharing it.
ReplyDeleteI found that the article, while it omitted some key details and oversimplified some of the important findings of the paper, did a good job at communicating the intentions of the research paper. The writing style of the article is unexpected when compared to the language used in the referenced research paper, but I actually think that this benefits the article. It makes the content a lot more palatable to a reader that might not have prior knowledge about SSA. However, I think that the (unfortunately common) issue of the links in this article leading to dead ends and unreliable sources could be reflective of the audience that the authors article was written for expect to read it.
ReplyDeleteI also agree with your assessment of the research paper, and found that the included figures did not effectively communicate the data. The data itself was described well in the paper, which also was clearly organized, however the figures, which were meant to show the data, did not do so well. Including 40 graphs and an unclear legend in one figure was not a good idea. One part of the paper I did find interesting was how they had a section that talked about the anthropogenic contribution to aerosol contamination. The paper wrote "we annotated 160 drugs, 21 drug metabolites, 179 food compounds, 15 food additives, 36 biocides, 487 natural products, and 6 compounds from personal care products in our LC–MS/MS dataset as Level 2 IDs". I am wondering if it would be possible in future research to trace these pollutants to their sources to try and mitigate wastewater at the originating location.
I really enjoy this topic! I've been doing quite a bit of literature review lately on Sea Spray Aerosol and what species they contain. Fascinatingly, as you stated, even bacteria can be present in aerosols (and therefore potentially in the air we breathe!). I think to the average person this may be disconcerting since people usually think of bacteria in a "don't touch that" or "wash your hands after touching X" context, overlooking the dynamic transports of these microorganisms as well as all the other incredibly diverse stuff that's in the air! Here's another fun fact. Bacteria can also serve as ice nucleation particles, with some bacteria acting as better nucleation sites for ice than mineral dust! I also like your summary of the Guardian article.
ReplyDeleteI found the guardian very interesting and didn't even catch their inflated numbers! This is a perfect example of a very well worded and intentioned piece meant to make science accessible to a general audience but going astray where it matters most. I agree that overall, they did a good job communicating the larger impacts. I never expect an article meant for the general public to get into the nitty gritty of exact methodology and all of the ancillary experiments done in order to corroborate their findings. I will say, my opinion comes from the lense of a scientist. Morality aside, from a policy makers perspective, I would probably give this article a 10/10 because the ultimate goal for articles such as this is to spark public awareness and relate the science to their own lives and well being. This article certainly does that. Thanks for sharing!
ReplyDeleteI found this very interesting. It was nice that the paper did a pretty good job at communicating the overarching ideas and goals from the paper, but I agree that it could have been a bit more detailed and include more from the paper. It was well intentioned as other have put, but it definitely missed the mark and was a bit misleading. It does a great job of getting people talking at the very least and putting something new on people's radar despite not being fully fleshed out which is something I suppose.
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