— Why did you select pollen as your research subject? I've heard that some of your palynology colleagues have personal stories behind their choice. For instance, aerobiologist Charles Blackley, who discovered the connection between hay fever and pollen, himself suffered from pollinosis…
— I don't have a particularly intriguing personal story. My dissertation was dedicated to the systematics of a rather fascinating parasitic plant, the dodder. However, it turned out that I could only continue working at the department on short-time contract only, specifically palynology. So I joined a group that was conducting research on pollen. Back then, it had nothing to do with aerobiology. We compiled morphological descriptions and created pollen atlases for different regions, primarily for forensic expertise.
Then, towards the end of the 1980s, my colleague, Sergei Yazvenko, attended a major palynological conference in Sweden. There, he befriended one of the pioneers of aerobiological research in Europe, Professor Siwert Nilsson. He lent Sergei a pollen trap, which we used to start our monitoring. Later, Sergei moved to Canada, and I ended up "inheriting" the trap.
I can't say that I was fond of it at first. It's quite an hard work that demands a high level of organization. You have to perform a series of mandatory procedures at the same time every day, and it's not something you can postpone. Well, technically you can postpone it, but then the monitoring data becomes meaningless because no one is interested in what happened long ago, they want to know what's happening here and now. But eventually, I started doing the monitoring and gradually got drawn into it. Perhaps it's in my nature to find orderliness appealing. You know exactly what you'll be doing the next day.
You know, it's funny, I've been doing this for 30 years, since 1992, but the beginning of every season is always a big event. I look forward to it. The first couple of months are particularly exciting as there is the most diverse spectrum [of pollen grains], the analysis is the most challenging, and there are the most discoveries and surprises. By the end of the season, around September, it does get a bit tiring... But still.

— When does the season start?
— It largely depends on the weather each year. But generally, we try to set the pollen trap up before the March holidays. Of course, we're not using the same trap we once borrowed, although it's still in excellent condition and fully functional. Now we have our own traps in various locations.

— Are they significantly different from the one you were given before?
— No. Only two companies manufacture these traps. One is in the UK (Burkard), and the other is in Italy (Lanzoni). These are what's known as Hirst-type volumetric traps. The functional design is essentially the same, the only difference is in the appearance.

— As I understand it, a trap is a sort of tape that pollen sticks to...
— Yes. To put it simply, it's like a vacuum cleaner with a clock mechanism. Inside the device is a drum onto which a transparent tape is wound. The surface of the tape is then coated with a sticky substance, usually silicone oil. The rotating unit runs at a constant speed relative to a slit through which air and everything circulating in it is sucked in. The suction rate is about ten liters per minute — roughly the intensity with which an adult breathes.

— Is it done intentionally?
— I'm not entirely sure. It's more like it's just the way it is. Actually, speed isn't that important. What's crucial is that it remains constant. Since we know the air suction rate and the unit rotation speed, we can always determine which part of the tape corresponds to which time period and thus measure the concentration of pollen grains.

— I suppose analyzing all of this is the really challenging part.
— Absolutely. It's a significantly more demanding process. Firstly, you need a team, because working alone from March 1 to October 1 without any vacations... I mean, we can't take vacations in winter or autumn. We all work at the university, teach, and are involved in the educational process. University employees mostly have their vacations in the summer, but here we need to take measurements every day. Of course, it's not very appealing. Secondly, the team needs to be well-trained, which takes many years. I've been observing pollen every season for 30 years, and every time there is something I don't know. These are, of course, individual pollen grains that don't play a significant role in shaping the pollen spectrum, but every time it's still a challenge.
Every time there are sudden peaks in pollen concentration, and you don't understand where they came from or what they're related to. You start trying to readjust things, look at air circulation models, build trajectories of air masses, and dig into different atlases. It's funny, really. There are neural networks and image databases everywhere these days. But in palynology, scientists still identify everything visually, by themselves...

— Honestly, you sound just like a detective right now!
— Yes, it's exactly always like that! Especially in palynology. [Laughs]

— Have any seasons greatly surprised you?
— Yes, quite a few to be honest. For example, in 2012 there was so much pollen that it was collected in several layers in our samples. There were incredible concentrations of pollen. There were 20,000 pollen grains per cubic meter of air per day, while the average is 3,000–4,000 pollen grains per cubic meter... Analyzing one sample usually takes an hour or two, depending on the intensity of pollen release. During that remarkable season, we spent the entire day analyzing samples and had to take turns doing so.
In 2020, we started seeing pollen as early as January. This was because pollination in Europe had begun earlier than usual, and we detected these pollen grains in Russia due long-distant transport. Interestingly, this was around the same time the COVID-19 outbreak occurred.
Before the pandemic even began, a group of researchers from various countries including Germany, Sweden, the Netherlands, Switzerland, and the UK published a comprehensive study in the journal Allergy. Scientists tried to understand how atmospheric pollen impacts the population generally, not only people who suffer from allergies. Imagine you're not allergic, but you're in an area with a high pollen count. Will it have any effect on you? It turns out that it will indeed have an effect. Primarily, it leads to a decrease in the production of type I and III interferons. As a result, your antiviral immunity weakens, making you more susceptible to viruses.
And then the coronavirus struck! That got aerobiologists all excited, as it was a unique opportunity to test their hypothesis in real-world conditions. Particularly since, as I mentioned earlier, the 2020 pollination season in Europe started unusually early. For instance, hazel trees began to release pollen as early as December. As COVID-19 spread, scientists started collecting data, attempting to correlate pollen concentration peaks with increases in disease rates. And it all fell into place! It turns out that spikes in pollen concentration are indeed followed by increases in disease rates but with a delay of three to four days.

— How often do you actually get to test your models in real life and see everything align and come together so perfectly?
— The models we're trying to build largely rely on meteorological data and forecasts. So, much like with weather forecasts, we seldom achieve a hundred percent accuracy. However, in aerobiology, we have a fair ability to predict the onset of the pollen season. Based on accumulated positive temperatures, we can estimate with an accuracy of about two or three days when a specific plant will start to release pollen.

— It's just like weather forecasts then.
— Yes, indeed. There is an 80% chance that tomorrow will be the same as today, but if it were always so, nothing would ever change. Therefore, predicting the next day's concentration is challenging. We can probably forecast global trends. For instance, we can anticipate a lot of pollen arriving from somewhere tomorrow based on the movement of air masses. Such models do exist. For example, the Finnish Meteorological Institute's model, SILAM. But even it can sometimes be significantly off. The issue is that it's well adapted to Scandinavia and adjusted to that specific region, but making predictions for Russia's territory is somewhat more difficult. There aren’t many locations where constant monitoring is conducted and where there are long-term observation series and phenological data as well. We do some small-scale modeling for local conditions on our own, but it's nothing compared to SILAM.

— What about the geography of research in Russia? What's it like?
— That's a hard question. There are quite a few purely scientific studies where a researcher just wants to see what's circulating in the air in a specific region and understand an overall picture rather than conduct daily monitoring. However, such studies are short-term and mostly associated with writing a thesis. For example, an allergist or palynologist wants to study their home region, so they conduct observations. The data seldom cover more than three years. Very often, they use the so-called gravimetric traps instead of volumetric traps, where pollen simply settles on glass. These traps are quite decent and can be used to reliably determine the qualitative composition of particles. However, nothing can be said about the quantitative composition because it's unclear from what volume of air the particles are settling. You have ten pollen grains today, and tomorrow it's twenty. But why? Is it because the pollination intensity has doubled? Or is it simply the air volume from which the pollen has settled?
With volumetric traps, it's more complicated. For a long time, they were quite difficult to purchase. Then, Lanzoni's official dealer appeared in Russia and imported some devices. Now the traps are permanently operational in Ryazan, St. Petersburg, Krasnodar, Tyumen, Perm, and Moscow — at Moscow State University and on the roof of the Institute of Allergology. There are also traps in Rostov-on-Don and Stavropol. But, as far as I know, no other places in our country conduct daily monitoring and publish data daily. It’s only us. It's not very common worldwide either, simply because it's quite a task, very labor-intensive.

— Is there a way to automate the measurements?
— This is every aerobiologist's dream to have a device that automatically catches and analyzes pollen in real-time, just like a thermometer shows the temperature. Yes, things are moving in that direction.

— How far are scientists from being able to go on vacation peacefully?
— I think we're still a long way off, although we do have such a trap already. At the end of 2021, the university bought us an automatic trap via the [University’s] Development Program, and we even tested it in 2022. But this device needs to function a bit first. It needs to be calibrated. Then we need to build a neural network based on the data obtained and train it... This will take us another couple of years according to my estimates. But even that doesn't mean I can go on vacation! [Laughs] Because there will still be a regular volumetric trap next to it. After all, our long series of observations (and 30 years is a long time) needs to be continued. Moreover, we will have to somehow evaluate the neural network we build, won't we? How accurately does it identify what's actually flying in the air? I trust what I see with my own eyes more, to be honest. In the new trap, everything is based on the pollen air stream being bombarded by multiple lasers. The shape and size of the particles are evaluated, and the secondary fluorescence emitted by these particles is captured. Particles are identified based on all these parameters. But it's still not very clear how well pollen grains that are similar in morphology can be identified. It's not going so well so far, but we're working on it and hoping for the best. There are few such traps in the world right now, so scientists are still trying to find an algorithm and adapt to this new reality.

— It seems palynology is at a turning point right now.
— Yes. I really do hope that we're just a couple of steps away from change... And then our main job will be not to sit and count pollen on glass but to think. We'll have much more time for truly scientific tasks because right now a lot of energy  is spent on analysis.

— What do you enjoy most about your job in general?
— I like working with a microscope. I truly enjoy it. When you start exploring the world of pollen, you encounter incredibly beautiful objects, and it's impossible not to be impressed by this variety of fantastic shapes. I also like it when I come across unusual pollen spectra. It's always very inspiring. I immediately want to understand where something came from and why.

— Do you have any favorite plants? Maybe one that you find particularly beautiful.
— I would say that my sympathy, or rather antipathy, stems not from the beauty of pollen grain. It's determined by completely different characteristics. When the pollen season begins, I look at thousands, sometimes hundreds of thousands of pollen grains. Some are very numerous and keep appearing in the spectrum, which I hate. I can name two plants that I particularly dislike.

— Is birch one of them?
—Yes. Surprisingly, the second one is nettle. It's quite abundant in the air. Do you know what else is problematic? With birch, it's simple. It triggers allergies in many people, so it needs to be monitored. But nettle doesn't cause allergies. However, we still monitor it but don't publish the data. Because why frighten people with alarming figures? Surely not to instill fear in them. We typically don't disclose information about pollen types unless they induce pollinosis.

— Your affection, or rather lack of it, is quite logical!
— Exactly. I feel thrilled when I see large pollen grains or those with distinct morphological characteristics. Take sunflowers for instance! Their pollen grains are superb — large, spiky, and easy to identify. Or pumpkins. Their pollen never floats in the air because it's too large. But it's incredibly beautiful! [Laughs] Of course, there are some utterly exotic forms, but we don't encounter them in real life. I'm not someone who works with a single type of pollen or the pollen of a specific taxon. I'm interested in diversity, and my joy or disappointment comes from evaluating it. When I see something extraordinary, I'm happy. But when birch levels are over the top, and there is nothing else in the samples but birch, my happiness vanishes.

— What can pollen tell us about the world in general?
— Quite a lot. It depends on the field of research. Palynology is a field where different professionals sometimes speak different languages. There are paleopalynologists who investigate paleospectra and the morphology of pollen from bygone eras, as well as engage in stratigraphy. There are palynologists who examine the morphology of contemporary pollen, its intricate structure, and the development of its pollen wall. There are even palynologists who study honey composition.

— Is there really a separate field called honey palynology?
—Well, it's actually called melissopalynology. But yes, analyzing pollen in honey is one of the ways to evaluate honey quality. There are palynologists who conduct forensic investigations. This field is called forensic palynology, and it pertains to forensic studies. And then there are aerobiologists who focus on atmospheric pollen.

— Shall we take a closer look at these fields?
— Paleopalynology studies extremely ancient samples, and our understanding of the earliest evolutionary stages of many higher plant groups is solely based on the morphology of their spores. The first thing that appears in the geological chronicle is spores, followed by macrofossils such as imprints or petrified remains. Based on the overall morphology and structure of spore wall (sporoderm), we can pinpoint the time different groups emerged and try to build [phylogenetic] trees. If we study not very ancient fossil pollen grains, for example, from Holocene deposits, we use contemporary concepts about taxa. We understand which plants this pollen belonged to, what these plants looked like, and the conditions they grew in. By analyzing such a spore-pollen spectrum, we can reconstruct the vegetation of that era. And based on such reconstructions, we can draw conclusions about how the climate changed, what people ate, whether they raised livestock, and the type of agriculture they practiced. We can even determine what mammoths ate.

— So it's like reconstructing the ancient world.
— The ancient world of plants.

— What about forensic studies?
— This topic is fascinating. All forensic palynological research is built on the analysis of spore-pollen spectra. It can be used to make several types of conclusions. The first type is reconstructing vegetation and defining vegetation zones. If the vegetation is specific enough, it can be then associated with a specific region. For instance, pollen spectra of broad-leaved forest zones will significantly differ from those of the taiga. The other type of conclusion is identifying a plant community. Based on the spectrum composition, it's possible to determine where it was obtained, in a forest, a swamp, or perhaps a meadow. Even within the same vegetation zone. Sometimes you can link the spore-pollen spectrum to a specific location, and sometimes you can't.

— So theoretically, you can determine where a person was analyzing pollen.
— Yes. Almost all forensic expertise revolves around whether the person was in a certain region. That, or could that particular shovel have been used to dig that particular hole.

— How do you take pollen samples from a person? Do you take it from their clothing?
— You’re correct. Most often it's the clothes that are swabbed. But generally, you can collect pollen from anywhere you like! Hair, both mine and yours, are excellent pollen traps. Moreover, even if you wash your hair twice, there will still be pollen in the second rinse. It's also possible to collect pollen from the nasal sinuses because the swab taken from there contains the pollen spectrum from the air the person had been breathing for the past 40–60 minutes. Boots and dirt under the fingernails are often examined too. Pollen lasts for a long time, and there is plenty of it. For instance, a single grasses plant (just a single plant!) can produce up to five million pollen grains. Only a very small portion of pollen goes directly towards fulfilling the biological function of fertilization, while the rest simply settles. The pollen walls degrade very slowly, and under certain conditions, they don't degrade at all. They're practically eternal. All this is thanks to sporopollenin, a highly inert biopolymer that "passes unscathed through fire and flood" and forms the outer shell of a pollen grain. It's thanks to sporopollenin that we are now able to study even Silurian spores.

— Can pollen analysis help determine the timing of a certain event?
— Absolutely. If the pollen spectrum didn't form over a long period (as it’s the case if you're studying soil where pollen accumulates over years), then you can say, for instance, in which season it formed, spring, summer, or autumn. Sometimes you can even pinpoint the exact month.

— Surely this can be applied beyond just forensics.
— Definitely. For instance, in studying works of art. I have a funny story about it. We once had a manuscript, or rather a tiny piece of it, brought to us from the Roerich Museum. They asked us about the pollen on the manuscript and if we could tell them anything about the pollen. We took a look. Fantastic! The only thing we could say was, "When was the last time you opened this manuscript?" It turned out that the manuscript was taken out of storage and someone worked with it in a room with open windows during the period when birch pollen was at its peak, and the whole fragment was simply covered with it. The pollen was modern and beautifully preserved. That's how it sometimes goes. [Laughs]

— Were there any works that you remember exceptionally vividly? I once heard that palynologists were able to reconstruct the history of the Pompeian catastrophe with the help of pollen. It amazed me.
— Yes, that work was splendid! Maybe not in terms of the result, but the idea itself is beautiful. It was performed by Austrian palynologists, who studied spore-pollen spectra from skulls found during the excavations of Pompeii.
The story is as follows. We all know that the eruption of Vesuvius is dated August 79 AD based on the letters of Pliny the Younger. But over time scientists had accumulated facts that contradicted this dating and indicated that the eruption occurred later. During the excavations, they devised a way to obtain plaster casts of human bodies buried under layers of lava and ash. This way they were able to reconstruct not only the bodies but also the clothes, which turned out to be unexpectedly warm for August. In addition, there were reports that by the time of the eruption, the harvesting of nuts and grapes had already been completed, which also didn't correspond to the date suggested by Pliny the Younger. In an attempt to determine the exact timing of the eruption, palynologists were given the task of examining spectra from the nasal cavities of the town's inhabitants. There was already a hypothesis suggesting that the eruption likely happened in autumn, specifically towards the end of October. Three skulls were selected for the research, one belonging to an adult male and two to children. The skulls were swabbed, and the pollen spectra were isolated and analyzed. The pollen was remarkably well-preserved as if it had just been shaken from an anther. It remained untouched throughout all this time!

— So even the volcano couldn't affect it.
— Exactly! The pollen grains were simply entombed beneath a layer of volcanic ash. It was a beautiful study, but sadly, the palynologists couldn't answer the main research question. During the eruption, a single mixture of flowering plant pollen, ash, and other particles, including pollen that had been re-suspended in the air, filled the atmosphere. In their final hours, people inhaled this mixture. The resulting spectrum was all-season, making it impossible to definitively determine whether it was August or October when the catastrophe happened. Interestingly, children were found to have high concentrations of ivy pollen in their noses, a plant that blooms in the fall. This seemed like direct evidence! However, researchers didn't find the same concentration in the spectrum from the male skull. In the end, they concluded that the inhabitants of Pompeii likely used ivy as a medicinal plant, possibly as a remedy for children's runny noses. However, the design of the study was indeed very elegant.

— Let's now discuss the Allergotop website. How did it all start? Did you receive a request from your colleagues?
— We've spent a long time monitoring atmospheric pollen from a scientific perspective. For the first decade, we didn't analyze samples daily, which was the wrong thing to do. However, we were still gradually accumulating data and filling in the gaps. Eventually, doctors and pharmaceutical company representatives approached us with offers to fund our work. The first company to do so was Nycomed. They contributed greatly to the development of aerobiological monitoring in Russia, including purchasing the first ten traps, importing them into the country, and organizing staff training. For a while, pollen monitoring data was published on the Nycomed website. Later, Takeda took over this role in the monitoring structure. However, not long ago, Dmitry Akhaev, Deputy Dean for Financial Policy and Innovations at the Faculty of Biology of Moscow State University, decided to establish a company that would bring together biologists and physicians. I am now part of that company.

— Do you know how many users Allergotop has at the moment?
— I can't give you an exact number. After all, I merely provide data for the website, my role is different... I can say it probably has at least several tens of thousands of users.

— It's always gratifying to know that your work is in demand.
— It is, especially when monitoring became a daily task and people started regularly visiting the website, sending emails, and asking questions like, "What should I do? Where should I go? What do you think?" At that point, it became clear that my work was urgently needed. I don't think a lot of scientists get to feel that. And it's incredibly gratifying. You're not just studying third-row bristles on some creature's twenty-fifth leg! You're studying something that people need right now. This has certainly been a great motivator for me in recent years.

— Is it invigorating?
— Absolutely! Every year, people ask questions that are not always easy to answer. Sometimes I have to do some additional monitoring, check foreign websites, or write to my colleagues. In short, it's not always easy and sometimes requires additional work. I try to give the most accurate answers possible because people are asking these questions out of necessity, not just out of curiosity. Even faculty members who suffer from pollinosis sometimes come and ask, "What do you think will happen tomorrow?" or "Where should I go and when?"

— By the way, what's the pollen situation like in Moscow?
— Based on our 30-year observations, the pollen season in Moscow extends by one day each year, and the intensity of pollen dispersion increases annually. The total pollen production increases by 7.7% each year. This is unfortunate news for those with allergies.

— As a palynologist, what would you suggest planting in the city to make life easier for allergy sufferers?
— That's a very good and relevant question. When they planted birch trees in Zaryadye Park and created a beautiful grove behind the GES-2, I nearly shed a tear at the thought there might be birch allergy sufferers in the House on the Embankment! Yes, birch trees are beautiful! It's a beautiful symbol of our country as well. But this is absolutely wrong in terms of allergies. In fact, in many countries with strong patient communities, there is a fight against such mindless landscape gardening. Which plants are more suitable? Primarily those that are not pollinated by the wind. Because it's the pollen from wind-pollinated plants that floats in the air and causes pollinosis. All plants whose pollen is not carried by the wind will be beneficial for people suffering from allergies. For example, rowan, which pollen is almost never found in the air. Or horse chestnuts. Or even linden trees! Although linden pollen is regularly found in the spectrum, its quantity is insignificant compared to birch or alder pollen.

— I hope one day the needs of highly allergic individuals will be taken into account. Finally, I'd like to ask if you have any grand scientific dreams.
— Speaking about aerobiology — the field closest to me — I'd love for our Moscow station not to be the only one out there. I dream of a network connected by a unified research methodology and similar, comparable equipment. It would be great if traps were installed in all cities with a population of over a million, as urban residents suffer the most from allergies. And I hope that the funding for this network comes not from private donations or scientific grants but from a state support program. That, I suppose, is my dream.