Dhruv Mitroo is a postdoctoral researcher for Dr. Nathan Ravi and is currently working on the recent VA funded project “Toxicology study of Emissions from a Burn Pit Simulator”.
Mitroo’s specialty is in Aerosol Science. He also has formal training in chemical engineering and completed his PhD and first post-doctorate looking at Atmospheric Chemistry.
Learn more about Dhruv Mitroo and his research in the interview below:
What made you choose this specialty or got you interested in chemical engineering and aerosol science?
I loved chemistry as a kid, and I was very lucky that in high school I had a chemistry teacher, Mr. Evans, who cared deeply and made me realize, not only was I good at it, I also really loved it. So, when it was time to apply for college, I thought well why not try a mix of chemistry and chemical engineering. Little was known to me, that there was quite a stark difference between the two. So, I happened to go into Chemical Engineering and I really loved it. It was very challenging for me; but what I learned from it - critical thinking, teamwork, and the concept of scale - I try to carry to this day.
Throughout undergrad, I starting working in a lab doing research on aerosols and that’s how I got involved in this little world that many know or many speak of anecdotally, through things such as spray cans, but few know their real impact in the ever changing world that we live in.
So that got me to the point where I was wanting to continue to work on basic science and really advance our understanding of aerosol behavior because it’s something that is really important, and I think to some degree underappreciated. A prime example recently, were their role in California wildfires. Another example going on now is their role in COVID-19: there is a lack of communication between Aerosol Scientists and Medical Doctors because it seems to me everybody thinks transmission is primarily by fomites like surfaces or direct contact, whereas now I think there is more of a consensus that droplet infection really matters and is an important mode of transmission.
Can you describe the current project you are working on, the Burn Pit Simulator study?
I approached Dr. Ravi as I hoped to apply my knowledge of aerosol science to improve our understanding of their impact on human health. He has decades of experience treating VA patients. Upon seeing the onset of chronic illnesses from close exposure to military burn pits, we worked together to determine if we could address these issues. I wanted to work alongside Dr. Ravi and help veterans, whether they are in the older generation from the 1991 wars (the Gulf war) or more recently returning from Iraq, Afghanistan, Syria, etc. My hope is that we can really help them out so that they don’t have to live decades with chronic conditions.
The current project I am working on with Dr. Ravi is the Burn Pit Study. We have assembled a fantastic team of individuals with expertise in Aerosol Science, Combustion, Toxicology, and Molecular Biology. We are looking at simulating burn-pit emissions (both aerosol and gas). The whole idea is to form a real gas/aerosol mixture in a controlled environment, and see how that affects human cells, or what type of mechanism it produces inside a cell that leads to toxicity. In the future, we hope to then build upon that.
What would you say is the most important part of this study and how it will impact veteran health and well-being?
Definitely the understanding of mechanisms in the cells. We can look at the genome and proteome expressions and see the exposure to different doses and different types of combustion products lead to chronic toxicity. For example, say you get a whiff from a back-yard fire pit, you might cough a little bit and then you recover. However when you are dealing with these acre-wide pits in forward operating bases, service members are exposed to it daily and then they come back on US soil with anything from pulmonary illnesses to endocrine disruption, then that is something that needs to be understood or it can lead to a real decrease in quality of life and that is the aspect that I think is most important to the study.
Because burn pits vary in composition (and in how the materials are piled up) and lit with jet fuel, we want to have our burn pit simulator be flexible so that it can cover a range of emissions, for instance, low-temperature versus high-temperature combustion.
If funding wasn’t an issue, what would be the ultimate goal you’d want to reach with this study?
Testing on going from an invitro model, to an organoic model, to an animal model is something that would really help us understand toxicity, mutagenicity, etc. in as close to a human model as possible so that we could really understand how it works and how we could then target treatment for Veterans. Is a simple prophylactic good enough? Or is some form of holistic medicine appropriate or is something that targets lipid cells as opposed to other cells appropriate? So, if funding wasn’t an issue, I think we would go through the whole series of things.
Do you think it’s possible to ever get to the human aspect?
It definitely is, and that’s why we’re kind of taking a bottom-up approach and form the basic understanding building blocks. If you start from the top-down, and take, say, a cohort and see how many exposed vs how many have issues, you could get a correlation, but you couldn’t get a causality. Whereas doing it from the bottom up, like were doing, you can get a causality assuming you have a good hypothesis to test. If you get a causality, targeting a treatment is more efficient and we can get there faster.
Is there anything else from this specific study that you want to mention?
I do think that depth and expertise in a specific field is important, but what this research highlights, is the unique collaboration between individuals of different disciplines. Such as toxicology, combustion science, aerosol science etc. And it really should serve as a model in the future to tackle problems that have become increasingly complex and increasingly intradisciplinary.
So, if there is something, I would like bring attention to, is it’s important to know and become an expert on the fine details of your subject matter, however, the big picture should never be lost. And the big picture in this case is Veteran health.
What’s the most important thing you’ve learned working on this project, in research in general, or working with Dr. Ravi?
There are many important things, of course the rigor or which you do the experiments, the ethics by which you abide when you do these studies, but I think the most important thing is probably at least from a practical pragmatic point of view is to get the results as efficiently as possible. Are results perfect? No. should you strive for perfection? Yes. So where is the happy medium?
I think the optimization problem here is minimize the time from when we start research to when veterans can get help. Dr. Ravi is an amazing mentor who gets genuinely involved in my thinking process and the struggle between progress and perfection. Without a doubt I’m in his debt for taking the patience to help me become (hopefully in the future) a scientific investigator. He always asks me what I plan to do in the future, and how I will achieve it. Keeping me honest.
Tell me about a dream study that you have?
I was very fortunate to learn early on about reactors and I think a core chemical engineering foundation is reactor design. I don’t know what draws me to it, it is just fascinating to me. How different vessels are engineered physically to maximize or to optimize a certain property, how different flow rates, how mixing patterns, affect the chemistry itself. Because one can think, ‘hey molecule A reacts with molecule B, molecule B maybe reacts with molecule B again to form Molecule C and so and so’ and hey that’s just chemistry. However, mixing really affects how the ultimate product is formed so, I took that sort of chemical-engineering concept and I applied it to my PhD studies where I worked on a oxidative flow reactor (nowadays called OFRs colloquially), which essentially mimics photo-chemical aging. So, in the atmosphere the air we are breathing is constantly changing and constantly on the go of photo-chemical reactions. But the problem is, if we actually sampled air, you have to take into account meteorology and dilution, sources, dispersion, interferences, and so on. Back to the laboratory, you can actually not only replicate the chemistry you wish to investigate with OFRs, but you can accelerate it so that in about 5 minutes you study what happens what happens in 1 month in the real atmosphere. And so, what I want to do, or what my dream would be to do is, to take that and apply it in the medical field. Take this project, were looking at fresh admissions. So, these admissions will impact within 0 to 1 hour our Veterans out in the field. accounting for transport, accounting everything that happens within the base, but what about from the bigger point of view? What about within a day or two? What about bases downstream? What about the communities down the stream? What about pollution at large? It would be great to actually couple an OFR to a burn pit simulator and so we can look at not only the fresh emission impact on human health but the so-called ‘aged’ ones as well.
Tell Me about yourself. Family, hobbies, anything?
I am originally from Italy. I came to America when I was 18, so I’ve been here for almost 15 years. I am really fortunate have come to St. Louis straight out of undergrad. I went to Undergrad in New York and then came to St. Louis for Grad school. And you know I’ve always lived in big cities like New York or Milan and this was the first time that I lived in sort of a mid-western smaller city and I’m thankful for it. Everyone here really treats me like family and I’m very lucky and fortunate to have made many friends both inside and outside the my academic/ work field. My hobby is Brazilian jujitsu but that has taken a pause recently with COVID, so I also enjoy gardening with my wife.
The Burn Pit study is a pilot study and employs the first version of the simulator. The simulator is currently housed at Washington University in St. Louis as it needs to be in the safest conditions possible for the operators such as Dhruv and Dr. Ravi.