From Face Masks to Fireworks

Protective face masks have become part of the so-called new normal – the phase of living with Covid-19 until there is a vaccine or medicine. Slovenian scientists have been testing their quality.

Interview with Anton Gradišek, PhD, assistant professor at the Faculty of Mathematics and Physics, University of Ljubljana. He works at the Jožef Stefan Institute, Slovenia’s leading, and world-renowned scientific research institute, covering a broad spectrum of basic and applied research.

There has been a lot of fuss regarding protective face masks. In order to test them, the JSI rearranged a lab, specialized in measuring nanoparticles. Who turned to you with the request of plunging into testing face masks?

Indeed, masks have been a hot topic for a couple of months now. We were first contacted by medical doctors (Mladi zdravniki association), who were desperate to find some provisional protection equipment for the work on the frontline, as their regular protection equipment was running out. We have experimental equipment to monitor aerosol nanoparticles, typically the research projects focus on air pollution due to the use of pyrotechnics, such as the fireworks for New Year’s Eve or during the sports events, we just published a paper on that. But it turned out that the machinery is also well-suited to measure the particle removal efficiency of the face masks.

The study focuses on testing their quality. How are you measuring it and what are the results showing?

Essentially, we have a nanoparticle generator, which generates quartz powder particles in the size range from about 20 to 500 nm. For scale comparison, a coronavirus is somewhere between 100 and 150 nm in size. We have a special chamber where we put a manikin head on which we put the mask. Then we sample the air that flows through the mask and checks how many nanoparticles, and what size, get through. There are too many results to tell you here, but it is interesting to see how, for example, different fabrics have different filtration rates. Of course, this is not the only criterion regarding the mask quality. You should still be able to breathe while wearing the mask, among other things.

Which masks should we, therefore, use in everyday life and how?

I am not the one to give any kinds of guidelines, I should stress that. There are roughly two types of masks. One is the surgical masks and homemade face masks which are intended for the wearer not to spread the (virus-carrying) droplets while coughing or even speaking. If everyone wears those, there will be a limited spread of the virus. Here I should mention that those masks do not represent total protection for the wearer since they do not fit tightly to the face and some air gets around. There are also some compelling reasons against everyone wearing masks, for example, if you do not take care of basic hygiene (such as regularly washing the homemade masks), then bacteria can start growing and you are doing yourself more harm than good. It is a really complex question. Follow the guidelines of your local health authority.

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A major part of your research work is related to the use of artificial intelligence in medicine. What projects are you currently working on, and how can AI be beneficial in that field?

We are working on two types of projects. One, we want to use the sensor readings, especially from wearable sensors, together with the algorithms of artificial intelligence, to better understand some chronic diseases, such as diabetes or chronic heart failure. For example, we are trying to develop some coaching tools that could allow the patients to better manage their condition, resulting in a higher quality of life. The second type of projects is related to data mining of the large amounts of medical data, these projects are intended for policy-makers, such as ministries or insurance companies, in order to better see some trends in the population.

You are very enthusiastic about your work and often take on some side projects out of pure fun. What are some of those and what is for you the most fun part of being a scientist?

Last year, my colleague and I went to see a football match, equipped with the nanoparticle detectors (the ones I mentioned above). The fans were burning torches five times in total, the stadium was filled with smoke. Great results, nanoparticle-wise. For health, not as good. Nanoparticles also contained several heavy metals used for color effects.

Another project that started as a fun side project and then developed into rather serious research involves bumblebees. Currently, we are working on a study of thermoregulation in the nest. It is important that bumblebees keep the nest warm so that the larvae can develop properly. We were using a bunch of sensors for the study last year, now we are analyzing the data. I also had a bumblebee colony in my garden last year, but this year they somehow did not want to settle.

You are also an active Rotarian and a former Rotaractor. What did Rotaract teach you and what are for you the benefits of being part of such an organization?

I have many fond memories of my Rotaract years. Many new friendships, in Slovenia and worldwide, learning through various projects we carried out, leadership skills, interaction with people from vastly different range of backgrounds and professions … It broadens your horizons.

What is your favorite Rotaract memory?

If I have to pick one, that will probably be the charity concert we organized in 2008. My sister was the club president then. It took place in the Ljubljana Philharmonic Hall and the a cappella group Perpetuum Jazzile was performing. We had blue balloons for decoration and during the last song, Oh Happy Day, people started throwing them in the air; the entire concert hall was filled with joy. Unforgettable.

To conclude with masks – what kind of a mask do you wear and how are you getting used to it? Have you thought of getting one with a fun motive?

We have some surgical-style masks at work and I have two homemade masks. One of them has a color pattern but nothing fun yet. One of these days I saw some masks that are partially transparent, so you can see if the other person is smiling. Maybe this is an interesting thing to explore.

Anton Gradišek holds a PhD in physics and is an assistant professor at the Faculty of Mathematics and Physics, University of Ljubljana. He works at the Jožef Stefan Institute in Ljubljana, at the Department of intelligent systems and Solid state physics department. His research interests include NMR (nuclear magnetic resonance), hydrogen storage, liquid crystals, applications of artificial intelligence in medicine, and bumblebees. He is the current president of Rotary Club Ljubljana Tivoli.

Photo: personal archive