Environmental Science: Processes & Impacts blog

Shantanu Jathar is an Assistant Professor in Mechanical Engineering and also an affiliate of the Energy Institute at Colorado State University. He leads the Laboratory for Air Quality Research (http://tinyurl.com/aerosol-csu) that performs research at the intersection of energy and the environment. By leveraging laboratory and field experiments and regional air quality models, his group studies the atmospheric evolution and properties of air pollutants arising from energy and combustion systems, all in the interest of addressing future energy and environmental policy. He has a Ph.D. from Carnegie Mellon University where he used numerical models and laboratory experiments to understand the atmospheric formation of organic aerosols from combustion sources. He worked as a post-doctoral scholar at the University of California, Davis where he worked on improving the treatment of particulate matter in air quality models used for regulatory purposes. Shantanu hails from the suburbs of Mumbai, India. He is married to Poorva (an electrical engineer) and is enjoying parenthood with two energetic sons. In his spare time, he likes to run, bike, hike, and play the bansuri (bamboo flute).

Read his latest Emerging Investigator Series “Oxidative Potential of Diesel Exhaust Particles: Role of Fuel, Engine Load, and Emissions Control” and find out more about him in the interview below:

Your recent Emerging Investigator Series paper focuses on oxidative potential of diesel exhaust particles and the role of fuel, engine load, and emissions control. How has your research evolved from your first article to this most recent article?

My first project, as a graduate student at Carnegie Mellon University nearly a decade ago, examined the influence of an updated treatment on the global distribution of organic fine particles in a climate model. This study was motivated by the need to reduce the large uncertainties linked to fine particles in climate models. Over the years, my research interests have broadened to think about the impacts of fine particles on human health. In this study, we probed how the oxidative reactivity (proxy for toxicity) of particles generated by a modern-day diesel engine varied as we changed the fuel and engine operation. We found that biodiesel and the use of an emissions control device (particle filter) significantly lowered the oxidative reactivity of diesel exhaust particles and we suspect that the reduced oxidative reactivity might be from lower soot emissions. Our work provides some evidence that wider adoption of biofuels and stricter regulations on diesel vehicles may reduce their harmful impacts on human health.

What aspect of your work are you most excited about at the moment?

It has to be wildfires. Wildfires are a growing concern in the western United States as rising temperatures have been linked to more frequent and bigger wildfires. Unlike burning fossil fuels in a controlled environment (think of the internal combustion engine), the variability in fuel and environmental conditions under which fires burn results in large variability in their emissions. As a result, there are large uncertainties surrounding the atmospheric evolution and impacts from wildfire emissions. We have a project supported through the National Oceanic and Atmospheric Administration (NOAA) where we are studying the atmospheric evolution of wildfire emissions in a controlled environmental chamber and using computer models trained on the laboratory data to predict the evolution in real wildfire plumes.

In your opinion, what are the most important questions to be asked/answered in this field of research?

Fine particles when inhaled deposit in our respiratory system and have been linked to lung and cardiovascular disease. However, little is understood about what properties of the particle — defined by their size and composition — are responsible for those diseases and how they might affect different individuals over different periods of time. This, I believe, is an open question and we are not going to figure the answer to this anytime soon.

What do you find most challenging about your research?

Very broadly, I study the sources and impacts of air pollution arising from energy and combustion sources. What I find most challenging with this research area is to keep abreast of the breadth and depth of topic areas it encompasses: physics, chemistry, biology, mathematics, engineering, statistics, public health, and more. Thankfully, the vastness is humbling and I rely on collaborations with some very smart people at Colorado State University and elsewhere to bring their expertise to the topic.

In which upcoming conferences or events may our readers meet you?

I usually don’t miss the annual American Association for Aerosol Research Conference (AAAR), which will be in Portland, OR this year in October. It’s the perfect place to get my scientific fix for fine particle research and catch up with collaborators and colleagues.

How do you spend your spare time?

My wife and I have a 5.5 and a 1.5 year old and we like to spend as much time as we can get with them when we are not working. Summers are the best because we spend a lot of time outdoors hitting the trails and pools.

Which profession would you choose if you were not a scientist?

I have thought about this question a lot and my answer hasn’t changed in a while. I would like to host and produce a science radio show, similar to Radiolab, that mixes physical and social sciences with personal stories. The one thing I would do differently would be to focus on geographies, cultures, and topics relevant to the developing world.

Can you share one piece of career-related advice or wisdom with other early career scientists?

The one thing I would tell early-career scientists is that don’t take any advice (including this one!) too seriously. Listen, but forge your own path. Don’t be afraid to make mistakes and don’t hold any regrets.

Dr. Elliott Gall is an assistant professor at Portland State University in the department of Mechanical and Materials Engineering. Dr. Gall’s research and teaching seeks to improve the sustainability of the built environment through an understanding of the intersection of indoor air quality, urban air pollution, and human exposure to air pollutants. Research areas include: i) laboratory and field studies of air pollutant transport and transformation, ii) air pollution exposure assessment through modeling and personal exposure studies, and iii) evaluation of building technology and design with respect to indoor environmental quality. Active research includes application of chemical ionization – time of flight – mass spectrometry to the study of indoor environments; a current focus is measurement of source, sink, and transformation processes from traffic related air pollution, wildfire emissions, and wood stove heating emissions. Dr. Gall is also studying the fate and transport of indoor ozone and other oxidants; he was acknowledged with the 2018 Yaglou Award from the International Society for Indoor Air Quality and Climate for his work on indoor ozone chemistry. Finally, an ongoing research area investigates and critically evaluates the impact of vegetation, e.g., green roofs and houseplants, on indoor and urban air quality.

Previously, Dr. Gall received a B.S.E in Environmental Engineering from the University of Florida, an M.S. degree in Environmental & Water Resources Engineering from the University of Texas, and his Ph.D. in Civil Engineering from the University of Texas. From 2013 to 2016, he was a postdoctoral researcher in Singapore as part of a joint research program between UC Berkeley, NUS, and NTU, where he studied indoor air quality of buildings in tropical climates. He has authored or co-authored nearly thirty peer-reviewed journal publications. His work at Portland State has been featured in local and national media, including The Atlantic, the Willamette Week, Oregon Public Broadcasting, and he has been interviewed on the nationally syndicated Top of Mind radio program. More information can be found at his lab group website, www.pdx.edu/green-building or on twitter @etgall. 

Read Elliott Gall’s Emerging Investigator article “Primary emissions, ozone reactivity, and byproduct emissions from building insulation materials” and find out more about him in the interview below:

Your recent Emerging Investigator Series paper focuses on primary emissions, ozone reactivity, and byproduct emissions from building insulation materials. How has your research evolved from your first article to this most recent article?

The major evolution from some of my earlier work is the analytical methods my lab uses in this study. We designed these experiments to be similar in scope to prior work testing building materials because we’re integrating a proton transfer reaction – time of flight – mass spectrometer (PTR-TOF-MS) into the effort. A major focus of my start-up at Portland State has been learning chemical ionization mass spec with an Ionicon PTR-TOF-MS, with which we have also been working with multiple ionizing reagents. This research was the first major, research-grade study that we conducted with the instrument. Prior to that, the lab team and I spent a great deal of time learning, reading, and running preliminary tests. It’s been a fascinating, and at times, frustrating, journey learning time of flight-mass spectrometry. With this effort completed, and more broadly our increasing capability with TOF-MS, I’m excited about where we can continue contributing to the field.

What aspect of your work are you most excited about at the moment?

Our work with time of flight-mass spectrometry, and the general trend towards real-time measurements in the field, is exciting. The ability to see information on the gas and particle species in air in real-time has been fascinating and, I think, will really enable important new approaches both in field and lab studies. I’m hopeful that we can use the dynamic information from our PTR-TOF-MS to both better understand physics and chemistry of indoor spaces and to develop automated, high-throughput methods that will let us scale out test matrices to include many more samples and with better replication. I’m also excited about bridging indoor and outdoor air quality issues. There’s been a general increase in attention to indoor air quality in the past decade or so, which is leading to exciting new developments in the field.

In your opinion, what are the most important questions to be asked/answered in this field of research?

I believe establishing better understanding of health effects associated with exposures to indoor sources air pollution would drive better research questions as well as enable better actions to be formulated and recommended or incorporated into building code. Understanding indoor air pollutant levels and dynamics is one part of this, but it will require more collaboration with health scientists and funding for larger-scale studies than have been conducted to date.

I also think better understanding of indoor air pollutant cycling, over short and long time frames, will improve understanding of air pollution exposures and also other routes of exposures like dermal uptake. There are high surface area to volume ratios indoors. There exist many knowledge gaps in understanding how these surfaces interact with indoor air and may act as reservoirs for air pollutants, or as transformation pathways, especially for their role in indoor reactions of nitrogen containing compounds and impacts on indoor radical species.

What do you find most challenging about your research?

Indoor air studies (and air quality studies in general) are characterized by a very complex matrix of gas and particle-phase pollutants. Since I started at PSU, a majority of our research effort has been focused on developing lab capabilities to measure things (e.g. organics via the PTR-TOF-MS) in that matrix. We’ve set up the lab to a point where we can measure a range of key parameters of interest: particle size distributions, some approaches for particle composition, and organic and inorganics in the gas-phase. Especially given my position in a Mechanical Engineering department, there’s often student interest and excitement for development of automation, instrumentation, and other tools. The field as a whole has obviously made really important advancements in our understanding of air quality due to improvements in instrumentation. Collecting data is central to what we do, but I’d like to ensure we keep a balance of learning and incorporating methods for data generation and collection while not losing sight of designing studies for generalizable, lasting, and impactful knowledge. Part of that is accepting that you will likely never have all the information you want. I try to keep a sense of humor about the somewhat famous quote “All science is either physics or stamp collecting”, and use it as little reminder to try and think about what kind of information a particular effort is going to yield.

In which upcoming conferences or events may our readers meet you?

I’ll be at AAAR in October 2019 in Portland, OR and I plan to attend Indoor Air in Seoul in 2020.

How do you spend your spare time?

My wife and I were thrilled to be able to move to the Pacific Northwest for my work at Portland State. We spend our free time hiking and camping in all the fantastic mountains, coasts, and deserts that the area has to offer. The mountain biking opportunities in the area are world-class, and coming from Florida and Texas, I’ve been able to improve a lot as a mountain biker. While summer is a great time to get research done, the perfect weather (outside of our recent spate of wildfires) make it way too alluring to get outside. I’ve been kicking around an indoor air quality in camping tents study in my head as an excuse to bridge work and fun.

Which profession would you choose if you were not a scientist?

I can’t get enough time on a mountain bike, but I’ve also always been pretty cautious person, so I don’t think anyone would pay to see such unexciting riding – but maybe a guide or trainer? More likely, if I wasn’t a scientist I would probably pursue advocacy related to the environment and conservation – maybe cycling-based urban planning. So many win-wins (including for air quality!) if we could redesign our cities around bikes instead of cars.

Can you share one piece of career-related advice or wisdom with other early career scientists?

It’s an obvious one, but being active and intentional about time management. What you choose to spend your time on impacts every aspect of your career, and inevitably also much of your personal life. There’s no one-size-fits all answer to this, but in my opinion, it’s important to give time management consideration on a daily basis regarding tasks at hand, but also to dedicate time to for bigger picture thinking on a regular basis. It took me some time to appreciate just how long lead time initiating new research can be, and so what you do day to day now can impact what you will be working on years from now, who you are collaborating with, etc. Giving this thought regularly has helped me focus and be more effective, and also with that all too difficult task of declining opportunities, to ensure I’m working on things that I think will be productive and meaningful.

Akane Yamakawa completed her undergraduate studies at Kobe University, and graduate studies (master) at University of Tokyo, and PhD at Okayama University, Japan. Under the supervision of Dr. Katsuyuki Yamashita, she developed chemical separation of transition metals, and highly sensitive Cr isotopic measurement in meteorites using thermal ionization mass spectrometry. She spent one and a half years as a postdoctoral position, CO with Dr. Qing-zhu Yin in UC Davis at Geology Department. She is now a senior researcher at National Institute for Environmental Studies (NIES), Tsukuba, Japan, working in Fundamental Analytical Chemistry Section of Center for Environmental Measurement and Analysis. Her current researches focus on using isotope geochemistry to better understand emission sources and atmospheric behavior of mercury using Hg isotope, emission sources of long-range transport of particulate matter using Pb isotope, fish ecology using Sr isotopic measurement of otolith, etc. She also involves a project to create environmental reference materials at NIES.

Read Akane Yamakawa’s Emerging Investigator Series article “Investigation of Mercury Emission Sources Using Hg Isotopic Compositions of Atmospheric Mercury at the Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS), Japan” and read more about her in the interview below:

Your recent Emerging Investigator Series paper focuses on Mercury Emission Sources Using Hg Isotopic Compositions of Atmospheric Mercury. How has your research evolved from your first article to this most recent article?

I started my carrier as a Cosmochemist. I studied about the early evolution of solar system by Cr isotopic measurement of various meteorites. I learned all manners about research from Dr. Katsuyuki Yamashita, Okayama University. After postdoc, I extended my research field to geochemistry and environmental chemistry. Although the research fields are largely different, research philosophy does not change. About atmospheric mercury research, my previous paper is focusing on methodology of Hg isotopic measurement of gaseous elementary mercury, and I applied the method to this most recent article.

What aspect of your work are you most excited about at the moment?

I like to develop and use new techniques. I recently stayed at University of Pau, and learned highly sensitive Hg isotopic measurement. I was lucky to learn the cutting edge technology in this field.

In your opinion, what are the most important questions to be asked/answered in this field of research?

Environmental dynamics of mercury. Especially the interrelationship between atomic mercury and reactive mercury, and the mechanism of methylation-demethylation.

What do you find most challenging about your research?

In order to understand environmental dynamics of mercury, it is essential to have discussions with experts in various fields, and I have to identify my role. Hg isotopic measurement will be a tracer to understand environmental dynamics of atmospheric mercury. It requires many analytical challenges to assure the quality of the research.

In which upcoming conferences or events may our readers meet you?

I plan to present my resent work at AGU Fall Meeting 2019 (San Francisco).

How do you spend your spare time?

I love to spend my time with family. I especially like to play with my dogs. They make me smile. I also enjoy playing and watching tennis when I have spare time.

Which profession would you choose if you were not a scientist?

I have not thought about this question… Maybe tennis player…?

Can you share one piece of career-related advice or wisdom with other early career scientists?

Find your mentor or advisor. I was fortunate to meet Dr. Yamashita at undergraduate research project. He had many interesting collaboration works, and led me to participate in some researches. Although I was such like a C grade student, he did not give up teaching. If you find a wonderful mentor or advisor at an early stage of your career, he/she will bring you nice projects with nice collaborators. All you need to do is show your enthusiasm and effort, and keep your motivation high.

Laura Carter is a University Academic Fellow at the University of Leeds, UK. Laura’s research focuses on understanding the fate and uptake of emerging contaminants in the natural environment, with particular focus on soil-plant systems.  Since completing her PhD at The University of York, Laura has spent time as a Risk Assessor at Unilever’s Safety and Environmental Assurance Centre (SEAC) and as a Postdoctoral Research Fellow at the Commonwealth Scientific Industrial Research Organisation (CSIRO) in Adelaide, Australia where she investigated the biological effects of pharmaceutical uptake into plants. From 2016 – 2018 Laura worked as a Postdoctoral Researcher at the University of York, UK where she contributed to the European iPiE project on the intelligent assessment of pharmaceuticals in the environment, developing soil sorption models and monitoring pharmaceuticals in river catchments. At the University of Leeds, Laura is currently working on projects to increase our understanding of the effects of pharmaceuticals on soil and plant health.

Read Laura’s Emerging Investigator article “Towards a framework for establishing the impacts of pharmaceuticals in wastewater irrigation systems on agro-ecosystems and human health” and find out more about her in the interview below:

Your recent Emerging Investigator Series paper focuses on the impacts of pharmaceuticals in wastewater irrigation systems on agro-ecosystems and human health. How has your research evolved from your first article to this most recent article?

The first publication from my PhD centred on exploring the role of chemical fate in the uptake of pharmaceuticals by plants. This involved pot experiments to consider the sorption, persistence and bioavailability of pharmaceuticals in soil systems and the influence of this on plant uptake. My research then moved on to explore the factors and processes, which control the fate and uptake of pharmaceuticals in terrestrial systems including the potential for pharmaceuticals to induce sub-lethal toxicity. Our recently published article takes a more holistic approach to considering pharmaceutical exposure in agro-ecosystems accounting for the complexity and connectivity between different sources and receptors. The proposed framework allows us to begin to piece together individual research outputs to quantify the agricultural and human health risks associated with pharmaceutical exposure in agro-ecosystems.

What aspect of your work are you most excited about at the moment?

I have recently started at the University of Leeds as a University Academic Fellow. I am excited about the opportunity to develop my own research group and an independent programme of research centred on exploring the fate and uptake of contaminants in terrestrial systems.

In your opinion, what are the most important questions to be asked/answered in this field of research?

As highlighted in our recent publication we are unable to currently assess the risk of pharmaceuticals in agro-ecosystems because we do not have a high level of understanding of many of the processes and compartments involved in the exposure of pharmaceuticals. Work is urgently needed to understand the fate and transport of pharmaceuticals in arable soils systems and the effects of chronic, low level exposure to these substances on microbes, invertebrates, plants, wildlife and humans. In addition, research pertaining to the fate, uptake and effects of pharmaceutical mixtures and metabolites is lacking.

Ultimately, it is not feasible to experimentally determine all the data we need to fill the identified knowledge gaps, so a key focus is the need to develop and validate models to predict the uptake of pharmaceuticals by non-target organisms. This will enable us to have a better understanding of the exposure of pharmaceuticals in terrestrial systems and provide basis for understanding any potential risk.

What do you find most challenging about your research?

I find translating results from laboratory experiments to understand the impacts of pharmaceuticals in our natural environment a particularly challenging aspect about my research. This is an inherently complex topic and trying to account for the complexity of environmental matrices across spatial and temporal scales, such as differences in soil properties, makes for a significant, yet interesting, challenge.

 In which upcoming conferences or events may our readers meet you?

I will be attending the 2019 Society of Toxicology and Environmental Chemistry (SETAC) conference in Helsinki where I will be presenting some recent work on the potential for pharmaceutical translocation to beehives.

How do you spend your spare time?

I love to spend my spare time exploring new places with my family; this usually involves a lot of ice cream and trying to keep up with my two-year-old son.

Which profession would you choose if you were not a scientist?

I am a naturally inquisitive person and wanted to pursue a career in journalism when I was at school but this soon changed to a passion to pursue a career in science.

Can you share one piece of career-related advice or wisdom with other early career scientists?

Pursue opportunities for multi-disciplinary collaboration to facilitate the sharing of expertise across complementary subject areas. This enables you to develop novel and interesting hypotheses. Some of my most interesting research has involved collaborating with plant biologists, analytical chemists and mathematical modellers.

Nathaniel Warner is currently an Assistant Professor at The Pennsylvania State University in the Department of Civil and Environmental Engineering. Previously, Dr. Warner received a BA from Hamilton College where he majored in Geology, an MS in Hydrogeology from Miami University in Oxford, Ohio and a PhD in Earth and Ocean Sciences from Duke University. He was the Joseph B Obering Postdoctoral Fellow, Dartmouth College, Department of Earth Sciences from 2013-2015. His current research focuses on using B, Sr, and Ra isotope geochemistry to better understand the processes controlling 1) salinization of freshwater 2) the fate and transport of metals in oil and gas produced waters once released to the environment, and 3) treatment technologies for oil and gas produced waters. Dr. Warner’s lab group has used Sr and Ra isotopes to trace the accumulation of metals associated with oil and gas wastewaters in both sediment and freshwater bivalves. His work has been published in Proceedings of the National Academy of Sciences-USA, Environmental Science and Technology, Applied Geochemistry, Geochimica et Cosmochimica Acta, Chemical Geology and Environmental Science: Processes and Impacts.

Read Dr Nathanial Warner’s Emerging Investigator article “Radium accumulation in carbonate river sediments at oil and gas produced water discharges: implications for beneficial use as disposal management” and read more about him in the interview below:

Your recent Emerging Investigator Series paper focuses on radium accumulation in carbonate river sediments at oil and gas produced water discharges. How has your research evolved from your first article to this most recent article?

Based on the results from the first article we expected oil and gas discharges to behave in a similar way, but that was not the case with our recent findings. Instead of radium being associated with barite (which is commonly discussed in the literature) in the most recent study we found the control on radium in sediments was the carbonate precipitation. This leads us to think that each oil and gas basin has varying geochemistry of its produced waters and each could have a different story to tell about fate and transport of radium (or other contaminants of concern) once discharged to the surface.

What aspect of your work are you most excited about at the moment?

Treatment technologies for the high salinity brines. It’s a challenge, but breakthroughs and the chance to make a big difference in how these waters are managed is exciting.

In your opinion, what are the most important questions to be asked/answered in this field of research?

How do we get radium out of high salinity fluids in an economic way? And where does the radium ultimately end up once released to the surface?

What do you find most challenging about your research?

Environmental samples, especially for radium often have large natural variations that can make clear trends or impacts difficult to quantify. We therefore need to make multiple measurements on a variety of samples to get at a reliable data set.

In which upcoming conferences or events may our readers meet you?

Goldschmidt – Barcelona and WRI16 – Siberia

How do you spend your spare time?

Outdoor activities, biking hiking, running.

Which profession would you choose if you were not a scientist?

Astronaut- but I suppose most of those folks are scientists…. How about an artist? I really enjoy creating things with my hands so maybe I would be sculpting.

Can you share one piece of career-related advice or wisdom with other early career scientists?

Don’t give up on your career goals, but also don’t be afraid to take an indirect path to get there. All of the experiences along the way will make you a better researcher.