Applying Air Pollution Research to Community: Imperial LTN Case Study
Introduction: In health policy and urban planning, select scientific reporting is sometimes used to justify political decisions on the notion that science presents strong or irrefutable evidence. However, as scientific research operates on a different set of principles than how knowledge and evidence may be developed in these public realms, there are risks of studies being used to justify high impact political decisions outside of the scope of the research.
Why this lesson is important: Researchers focus on isolating specific inquiries or relationships to test hypotheses and suggest links, such as how one set of variables correlates, causes, or impacts another. When study results get repurposed within more applied practices, such as local governance and urban planning, individual study conclusions often have the potential to have much higher impacts than is appropriate, with impacts on communities even outside of the realm of what the researchers themselves might have pictured. Advocates understanding how to identify these situations, critique them, and work with the institutional researchers involved is important for mitigating these effects.
Story: This story paraphrases the discussion between Daniel Akinola-Odusola (Centric Lab), Prof Ilan Kelman (UCL), Dr Julia Pescarini (LSHTM), and Araceli Camargo (Centric Lab).
Daniel: In this lesson, we’re looking at how science and scientific reporting are translated for community health and urban planning. We’ll explore a 2022 Imperial College LTN study by Yang et al. on whether LTNs displace traffic and pollution, plus an article reflecting on the study. We’ll use our Macro Environmental Data for Health Justice framework:
(1) Context of data creation,
(2) Reasons and mechanisms for collecting it,
(3) Ethical communication of results
Daniel:
Ilan, what do you think of how they’ve presented the study’s context?
Ilan:
Both the paper and the news report give context realistically. The difficulty is communicating scientific nuance without losing people’s attention but still ensuring that everything is there so that people do understand the limitations of it. I like that the paper includes “highlights” as three bullet points for quick takeaway. I think that's a really positive development because it means that people can read the full abstract if they want or just read the three bullet points.
The journalists did an excellent job trying to distil very complicated science for a wide audience.The news article’s headline and first paragraph match the study’s conclusions exactly. These summaries are useful if you lack time to read everything, but they inevitably generalise. In that sense, I think both the journalists and the scientists have done exceptionally well in giving you the very quick, rapid takeaway that you can use. Just be aware that, as always, there is an hour's worth of nuances, subtleties and provisos to put within the specific context of where the study was conducted, why that was chosen, how it was conducted and especially what was not covered.
Daniel:
In our circles, the LTN debate is layered. Reducing traffic is widely supported, but traffic and pollution displacement concerns are important. Advocates like David Smith (“Little Ninja”) have shown other reasons why displacement does not get included in overarching campaigns for LTNs. This paper isn’t meant to solve the whole argument but make something propositional towards that conversation that people can use.
Ilan:
Exactly—it’s about balance. Scientists have certain skills, certain worldviews and certain approaches. It's not that they're better or worse than the approaches, skills and worldviews of community activists or politicians or civil servants. The science looks technically correct to me. That does not mean it matches people's experience in living in the location. Intriguingly, some of the comments on the news article actually indicate that. They're not trying to undermine the science, nor should they. Comments on the article show local residents interpreting it differently. We must work together, valuing both measurable data and lived experience, without dismissing either.
Daniel:
Let’s talk about data collection. They chose to look at traffic volume and NO₂ as metrics, based on monthly averages. When we work with chronic stress, we do PM2.5, but they would have their reasons why they've chosen NO2. How do you feel about the utility of using these two factors or variables?
Ilan:
Their choices aren’t right or wrong—just scoped. Any study has boundaries, which can be critiqued. In the paper, the scientists are completely open, detailed and appropriate regarding the limitations of their work. That drops out to a large extent in the news article, as it has to be. The news article is not a scientific paper. We should ask: are the data appropriate for the problem? For some, the answer may be no. Science is valuable but partial—it opens more questions. We need to identify what data actually serve a community's needs. Maybe PM2.5 would be more relevant. Frequency, scale, and location of measurement also matter. The starting point has to be collaborating to come up with the appropriate questions.
Daniel:
Right. This is why we looked at both the paper and the article. The public often encounters the media version, not the study. The policy question—should we close this road?—isn’t scientific. The study’s authors acknowledge other benefits, like social interaction, beyond pollution reduction. That connects with broader community priorities.
Tying into some of the questions that we're going to ask about the communication [of results and conclusions] is this wider question of what role and responsibilities scientists have when the study is now being handed off to the commons. Should they remain involved when studies are used in policy or media? I also noticed shifts in how co-authors presented their findings and conclusions between the study and the article.
Ilan:
This is a long-standing question that we've struggled with since the beginning of science and the beginning of knowledge. To me [as a scientist], this is what society has to tell me. Should I be advocating for policy or should I be giving options and consequences of taking certain options? How much responsibility, ethical and other practical aspects should I have for the science I produce and provide open access to the public? The Royal Society of the UK had a brilliant report on genetically modified organisms. What they said is science has to be a major input into the policy decision.
Science should inform policy but not be its only input. We must separate science (a process) from scientists (flawed humans). We can see in climate change where many climate change scientists who are absolutely brilliant within their speciality have then become public figures advocating far beyond what they've ever researched, far beyond what they actually know, far beyond what they understand, which is highly damaging and dangerous. I see some climate change scientists deliberately getting arrested by breaking the law because they're opposing policy decisions.
I'm definitely accountable in some ways to the public, but not in a democratic manner. I've not set out there to get my job on a policy platform. I've not set out there to get my job by being elected by the people who are affected by my policies. Personally, I won’t dictate policy; I see my role as presenting options and consequences—but misinterpretation is a risk. For example, the article quotes a co-author saying the research “effectively disproves” that LTNs necessarily cause an increase in traffic and air pollution in neighbouring streets.. The way that's phrased is perfectly technically correct. The challenge is that in a political environment, it would be so easy to misinterpret or deliberately pivot to reach the conclusion that all low traffic neighbourhoods in all circumstances should be implemented because they always lower pollution. Scientists must be careful in public communication, but also accept that we can’t control all uses of our work.
Circling right back to the nuclear bomb, the physics was absolutely brilliant. We have gained so much from society through the physics and the chemistry that were done to produce a nuclear bomb. But yet, we still have that nuclear bomb and almost all the scientists involved were appalled at what they produced, and spent their life campaigning against its use. We don't have straight answers. We still struggle with it.
*Julia joins the conversation*
Daniel:
Julia, thoughts on scientists’ roles and the report/article?
Julia:
I think sometimes we draw too many conclusions from studies that are quite unique and quite related to one specific setting. Then policies are made or identified based on one specific study. Even once this policy is made, not enough effort is done to evaluate the policy and the impacts on people who were imagined to be affected by the policy and the general population. The media can misinterpret findings and scientists aren’t always consulted on coverage.
For instance, alcohol use. Many years ago, we had specific studies coming out saying that alcohol, or having wine, was beneficial for some specific populations. Then the media took it to be widespread that having a few glasses of wine was beneficial. But many systematic reviews, which are studies that combine multiple studies, have shown that that's not the case. Alcohol is majorly bad for almost everyone, depending on alcohol. But now people still think that having a few glasses of wine a week is good for your health.
So in that sense, I think we need to be careful how we draw conclusions from some specific studies and how we translate that to the public. Sometimes what a scientist says in one study is also misinterpreted by others and by the media when there is not very good communication between the media and the scientists who made the study. We are often, as scientists, approached by the media to talk about our studies. When we see the media article that comes out in the newspapers, it's quite different.
Many times we're not consulted about what is being written and published in the newspapers. We are not sure how policy makers are actually looking at the study or if they're just taking conclusions from newspaper articles. We must monitor policies over time, assess both intended and unintended effects, short term and long term, including mental health and social impacts.
Daniel:
That connects to our experience—smaller, longitudinal, trust-based engagement keeps work grounded. It prevents policy from feeling like a top-down surprise. This also relates to the “intellectual gap” between science, policy, and daily life. Araceli, you had a framing for that?
Araceli:
Saying it’s 13°C outside is mathematical, scientific knowledge. For a person with arthritis that temperature might mean it's very cold, but for another person, 13°C might mean it's quite mild. Assigning a number or a scientific intellectualisation to something doesn't necessarily mean it will have a direct, literal application at a policy level or to day-to-day life. Communities are told “science says” and “policy says,” but impacts vary. Any comments?
Julia:
What I sometimes see missing from the policy perspective is having a deep understanding on how this will translate into different levels and will actually affect the individual.
Ilan:
All knowledge is subjective, including numbers. The standard mantra is if you turn on the oven and stick your feet in it and put your head in the freezer your average body temperature is excellent. It doesn't mean you're healthy, so NO₂ may be reduced in LTNs and all around the areas. That might or might not mean that air pollution has been reduced in all these areas. It might or might not mean that traffic is safer in all these areas. It might or might not mean that pedestrians, cyclists, scooter drivers and vehicle drivers are actually behaving in a healthier and safer manner. So it really is a question of do we want a good average body temperature or do we want to avoid being frozen and on fire. Do we simply want to reduce the measurements of air pollution or are we seeking healthier safer healthier safe places to live? With different types of traffic, sources of what's happening to our air, our light, our water, our soil, our noise—it's always contextual.
NO₂ reduction may not equal healthier streets. It’s like having an “average” good body temperature while your head’s in the freezer and feet in the oven. Context matters—do we want lower NO₂ or healthier, safer places? One study’s findings may be correct but still not answer the real question.
Daniel:
Hopefully this conversation shows advocates that scientists can be allies. How often are you invited into policy or implementation processes?
Ilan:
Scientists can be friendly, but we’re human and can’t know everything. I live in the borough studied, so I share its concerns. Collaboration means recognising everyone’s expertise. Not everyone experiences the same environment the same way. What’s good for me today might not be for my neighbour tomorrow.
Julia:
Some scientists are involved in policymaking, especially in the UK, but not always. Ideally, policies are co-created by scientists, policymakers, and communities, with feedback loops. That’s not always the case—but it should be. Scientists can and do have personal political views. Outside formal research, I’m politically active. It’s hard to fully separate personal beliefs from science, but we aim for neutrality in testing hypotheses. Dialogue, critique, and combining multiple studies can lead to policies supported by diverse perspectives.
Learning Points:
Scientific studies are smaller concise investigations that draw from a more complex set of conditions and contribute back to the wider scientific discourse around a topic.
The ability to translate conclusions of studies to community application through planning and policy is not guaranteed to be in the skill set or job responsibilities of a researcher.
The LTN study looked at traffic and nitrous dioxide as variables in the study which are much more specific than the wide range of factors people use to determine health in practice. This argument does not negate the quality of work produced with their chosen variables.
It is entirely possible that research done within a field relevant to your advocacy (e.g. air pollution, heatwaves, food scarcity) doesn’t directly affect decisions that are related to you.
How the results and conclusion from the study were represented, including by one of the coauthors, highlights the difference in communicating the same outcomes to a different audience with a different purpose.
More collaboration between community and formal researchers could help outcomes be better understood.
Segueing into the next Lesson theme: The next lesson centres two Centric Lab reports covering approaches to two important structural injustices where air pollution is a factor, amongst others. These reports showcase using other sources of data to support understanding the impacts and identifying solutions.