Ondřej Mikeš works at the RECETOX center as an environmental epidemiologist in the Human Exposure and Risk Assessment group, focusing on external exposures in epidemiological research. He primarily focuses on the advanced use of spatial data and sensor technologies to better understand overall and individual air quality, significantly utilizing citizen science and science-to-policy approaches. In the interview, he explains what air pollution research in Brno entails, how researchers communicate measurement results to politicians and the public, and why scientists are now trying to create a digital model of the entire city.
How would you describe the area you focus on as a scientist?
My research focuses on the external exposome, which is the set of environmental influences we are exposed to and the assessment of their impacts on human health. In Pavel Čupr’s research group at RECETOX, I study and analyze the occurrence of diseases in space and time, and I do very similar work for our ELSPAC and CELSPAC cohorts. Then there’s one niche where I feel very comfortable, and that’s regional, urban, sensor, and personal studies. In 2017, through the ICARUS study, I first started focusing on personal air pollution, we conducted a multi-sensor campaign and tried to figure out how we as individuals are exposed to external influences and how we personally influence our surroundings. We also characterized Brno in terms of pollution sources (emissions) and communicated the issue with politicians and modeled various future scenarios more generally.
What did this project lead to?
First and foremost, we learned a lot from it and were able to build on it with other projects. For example, we developed a new sensor with a private company that worked even better, and we started collaborating with the Faculty of Economics and Administration on a project for better air quality in Brno. In the Tromso project, in the winter and summer of 2023, we measured pollution with small sensors in collaboration with children from elementary schools from first to ninth grade. We approached it educationally and held several interactive lectures, and all the children and parents received personalized outputs with explanations after the project ended. We are now evaluating and refining the data from this measurement for scientific articles. Another project from the Norwegian funds, AIRSENS, involved a static campaign on local heating in small municipalities and two urban districts of Brno. Air quality is typically monitored by reference stations, but there aren’t many of them. Although Brno is an exception and has several stations within its territory, there is only one within 50 km around it. In the AIRSENS study, we wanted to show that sensors, which are many times cheaper than reference stations, can serve as an alternative in less accessible places or an interesting spatial complement.
Can sensors be relied upon to measure values accurately?
Of course, they are not as accurate as reference monitoring stations, but when we compare them with professional equipment outdoor, we can calibrate the sensors before and after the campaign and thus obtain relatively accurate data within the possibilities. Sensors are very sensitive to meteorological conditions, such as humidity, and in some cases, some of them need to be excluded. So, they can be trusted, but their results need to be checked and calibrated.
Do you focus only on dust when measuring, or are you interested in other pollutants as well?
Our main interest is really airborne particulate matter, mainly PM 2.5 and PM1. For example, in the AIRSENS project, we expanded these measurements. In each municipality, there were four sensors, supplemented by a superlocation where a meteorological sensor was capable of monitoring wind speed and direction, as well as air temperature and humidity. In addition, we used a sampling device with a filter, which was collected every week and later analyzed for polycyclic aromatic hydrocarbons, i.e., carcinogenic substances that are produced by incomplete combustion.
What did you find out?
It clearly showed us that the placement of stations and the lack of measurement in some municipalities are very important aspects. For example, in one of the municipalities, we measured really high values, but this was also because it has a valley character, which can create a smog situation under suitable or rather unsuitable conditions. In another municipality, it happened that the values at two places close to each other differed by up to five times, precisely because of the terrain and prevailing directions of polluted air spread. Reference stations do not detect some specific situations in smaller municipalities because they stand statically in one place, whereas these small sensors can be mounted almost on any lamp in agreement with the municipality. When we then add time, space, flow, and wind direction, we can suddenly create field visual maps and show and explain to municipalities what and why the concentrations are in certain places, what it looks like in the morning when there is traffic peak, how it looks around six in the evening when heating starts, or that when the air flows from a certain place, it is relatively clean, while when it flows from another place, the values are always high. This can also help identify the source of pollution.
Are you able to get the data you have collected to the municipal leadership and possibly to the citizens?
All municipalities, of course, received detailed reports. We offer other ways of communicating the results, and they usually also want us to come in person, but it varies. In some municipalities, we made reports for local newspapers, in others, we hold lectures, show and explain the data. Interest varies, sometimes local residents come, sometimes only the council, but it also happens that some municipalities are not very interested in a lecture. Fortunately, this is rather an exception, and we often agree later on some form of analysis mediation. This part of our work is important because even though we don’t tell exactly politicians what and how to act, we can prove and show that the problem really exists and needs to be addressed. In addition to data on pollution itself, colleagues from the Faculty of Economics and Administration also conducted surveys among residents in each municipality, asking what they think about air pollution and what their motivations are to replace an old boiler, or why they don’t have the motivation. Thanks to this, mayors also have an overview of whether and what support programs need to be promoted.
It is generally known that the biggest problem with air quality in the Czech Republic is emissions from local heating. Are there any legislative measures that could be enforced on households?
It has been a long-standing problem, and even in politics, there was a lack of will to address local heating because it is very difficult to control who burns what, the mayor has to come with the police and catch the person in the act. From September 2024, boilers of the 1st and 2nd emission classes (the oldest ones) were banned nationwide, here we are talking about the quality of technology. This makes the potential penalty easier, there is no need to catch people burning something they shouldn’t, using old boilers can result in a fine of up to 50,000 CZK. As for legislation, the situation is also complicated with sensor measurements. The values measured by them are only indicative and supplementary, it cannot be said that an air quality limit has been exceeded based on them because they are not recognized as reference measuring devices. At meetings with representatives of ministries, we try to show that it is a tool that has potential and can help identify hotspots and problematic areas in urban agglomerations, but also in remote areas. When we then appropriately supplement the monitoring network with sensors, we obtain a large amount of data to create more comprehensive models of the entire area, which is also our current plan.
Can you tell us a bit more about this plan?
In the new DTRIP4H project, we will be creating a so-called digital twin, which is a model image of Brno that should, among other things, help target policies more effectively to improve air quality. The long-term vision of RECETOX is that we want to make Brno a so-called Living Lab, and this project is one of the significant steps. We need a relatively large amount of input data to create really high-quality models. We provide expertise, data flow, and together with a number of companies that are also involved in the project and have experience with the use of machine learning, virtual reality, and other tools, we are figuring out how to model it all in the best possible way.
What will the project bring to the residents of Brno?
Among other things, one of the outcomes could be much more precise characterizations down to the street level. As part of the project, we will also have twenty new static stations, and we are currently negotiating to include nitrogen dioxide in addition to particulate matter in the measurements. Then we want to create an “Agent-based modeling” approach, through which we will simulate the behavior of individuals in the environment and how they influence each other. The current analysis of population exposure risks to ambient air quality assigns exposures only to their place of residence, but they move around during the day. This way, we can capture reality much better; agents will function as simulations of the population, and if we have sufficiently good data, it can be really comprehensive. Based on such a model, political measures can also be simulated, for example, we will see how the resulting concentrations change with fewer cars in the city, and so on.
What stage is the project at now?
The project started in January. Recently, we launched a model campaign in Lužánky, where we have static sensors on lamps in three places, which is a lot for such a small area. In addition, we have agreed with students from the Ludvík Daněk Sports Gymnasium that whenever they go running in the park, they will take portable sensors with them. We plan to create a spatiotemporal map of the park, which will also be interesting for the City Greenery Administration and athletes because it will provide information on where running is or isn’t ideal, or where additional greenery could be planted. This way, we want to show on a micro-scale what we will later do at the city level.
Returning to a general level, how do you think the public perceives the risks of air pollution?
Most people think that air quality is important and can be a problem. But when it comes to measures that require their active steps or would otherwise affect them, they are not very willing. Surprisingly, even in some municipalities that we assessed as heavily polluted, especially during the heating season, most locals didn’t think there was a problem. In my opinion, people understand that it is one of the main things that should be addressed because you simply can’t stop breathing, but they don’t think it affects them that much. On the other hand, I think that the public’s reactions to other environmentally-oriented measures are even weaker.
Do you also focus on indoor environments besides outdoor monitoring?
Indoor environments are mainly handled by my colleague Lisa Melymuk, but we do overlap in some areas, for example, in the ICARUS project, we also had home sensors, and we still use valuable results from the measurements in lectures. It was interesting in this regard to look at a case where a household used aerosol sprays extensively and created concentrations that normally don’t exist at home. Indoors, dust, polycyclic aromatic hydrocarbons, flame retardants, PFAS, and some other substances are monitored.
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