Jul 19, 2021 | Announcements, News releases
Reno, Nev. (July 19, 2021) – Scientists with the Desert Research Institute (DRI) Organic Analytical Laboratory, led by Andrey Khlystov, Ph.D., have been awarded a $1.5M grant from the National Institutes of Health (NIH) to study the formation of dangerous compounds by electronic cigarettes (e-cigarettes).
E-cigarettes have grown in popularity in recent years, and emit nicotine and other harmful compounds including formaldehyde, a dangerous human carcinogen. However, the production of these chemicals may differ across different e-cigarette devices, use patterns, and e-liquid (“juice”) formations – and scientists currently lack a thorough understanding of how these chemicals form and how to best test for their presence.
DRI’s study, which will run for three years, will test popular e-cigarette types and devices under a wide range of use patterns to resolve questions about harmful and potentially harmful substances produced by e-cigarettes. Among other things, the research team will investigate interactions between flavoring compounds and coils at different ages, temperatures, and e-liquid formations, and how different combinations of power, puff topography, and e-liquid viscosity affect emissions.
“This project will identify the most important parameters underlying the formation of harmful and potentially harmful constituents produced by e-cigarettes – and thus help inform the public and policymakers regarding health safety of different e-cigarette devices and e-liquid formulations,” Khlystov said.
Information gained from this project is needed to advise the public on potential health risks of different devices and configurations, to establish standardized testing protocols, and to inform policymakers on regulating certain e-cigarette designs and/or e-liquid constituents.
Additional Information:
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About DRI:
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
May 25, 2021 | News releases, Research findings
Does Cold Wildfire Smoke Contribute to Water Repellent Soils in Burned Areas?
May 25, 2021
RENO, NEV.
By Kelsey Fitzgerald
Soil Science
Wildfires
Hydrology
Above: After a wildfire, soils in burned areas often become water repellent, leading to increased erosion and flooding after rainfall events. The hillside shown here burned in California’s Loyalton Fire during August 2020.
Credit: Kelsey Fitzgerald/DRI.
A new DRI pilot study finds severe water repellency in sand samples after treatment with both hot and cold smoke.
After a wildfire, soils in burned areas often become water repellent, leading to increased erosion and flooding after rainfall events – a phenomenon that many scientists have attributed to smoke and heat-induced changes in soil chemistry. But this post-fire water repellency may also be caused by wildfire smoke in the absence of heat, according to a new paper from the Desert Research Institute (DRI) in Nevada.
In this pilot study (exploratory research that takes place before a larger-scale study), an interdisciplinary team of scientists led by DRI Associate Research Professor of Atmospheric Science Vera Samburova, Ph.D., exposed samples of clean sand to smoke from burning Jeffrey pine needles and branches in DRI’s combustion chamber, then analyzed the time it took for water droplets placed on the sand surface to be absorbed – a measure of water repellency.
A new pilot study by an interdisciplinary team from DRI exposed samples of clean sand to smoke from burning Jeffrey pine needles and branches, then analyzed the time it took for water droplets placed on the sand surface to be absorbed — a measure of water repellency. After exposure to smoke, water droplets sometimes remained on the sand surface for more than 50 minutes without soaking in.
Credit: Vera Samburova/DRI.
The pilot study investigated the effects of smoke and heat on water repellency of the sand and was the first study to also incorporate an analysis of cold smoke. In the experiments, sand was used in place of soil because it could be cleaned thoroughly and analyzed accurately, and Jeffrey pine for a fuel source because it represents a common wildland fire fuel in the Western U.S.
Before exposure to Jeffrey pine smoke, water droplets placed on the surface of the sand samples were quickly absorbed. But after exposure to smoke, the sand samples showed severe-to-extreme water repellency, in some cases retaining water droplets on the sand surface for more than 50 minutes without soaking in. It made little difference whether or not samples had been exposed to heat and smoke, or just cold smoke.
“The classic explanation for fire-induced water repellency is that it is caused as smoke diffuses under rather hot conditions and settles down into the soils, but our work shows that the smoke does not have to be hot to turn the sand hydrophobic — simply the presence of the chemical substances in the smoke is enough,” Samburova said. “This is something we really need to look deeper into because soil water repellency leads to increases in flooding, erosion, and surface runoff.”
Above, left: Jeffrey pine needles and sticks were used as a fuel source in the new DRI study because Jeffrey pine represents a common wildland fire fuel in the Western U.S.
Credit: Vera Samburova/DRI.
Above, right: Jeffrey pine needles and branches burn inside of the combustion chamber at DRI during a new study that investigated the effects of smoke and heat on water repellent of sand samples.
Credit: Vera Samburova/DRI.
This study built on previously published work by former DRI postdoctoral researcher Rose Shillito, Ph.D., (currently with the U.S. Army Corps of Engineers), Markus Berli, Ph.D., of DRI, and Teamrat Ghezzehei, Ph.D., of University of California, Merced, in which the researchers developed an analytical model for relating soil water repellency to infiltration of water.
“Our earlier paper focused on how fire changes the properties of soils, from a hydrology perspective,” Berli explained. “In our current study, we were interested in learning more about the chemistry behind the process of how soils come to be hydrophobic. We’re bringing together geochemistry and organic geochemistry with soil physics and hydrology to understand the impact of fire-induced water repellency on hydrology.”
The project team is now working on a larger proposal to further investigate questions touched on by this study about the roles of heat and smoke in fire-induced water repellency. Among other things, they would like to know how long soil water repellency lasts after a fire, and gain a better understanding of the detailed processes and mechanisms through which cold smoke affects the soil.
DRI’s combustion chamber, pictured here, is a specialized facility that has been designed and built for the open combustion of solid fuels under controlled conditions. In this experiment, it was used to expose samples of clean sand to Jeffrey pine smoke.
Credit: Kelsey Fitzgerald/DRI.
Gaining a thorough understanding of the process that leads to fire-induced soil water repellency is important because land managers need this information in order to accurately predict where soils are likely to be hydrophobic after a fire, Berli explained.
“We still don’t really understand the processes that lead to this fire-induced soil water repellency,” Berli said. “Depending on what we find, the measures to predict fire-induced water repellency might be different, and this can have a significant impact on how we can predict and prevent flooding or debris flows that happen after a fire.”
“This study was one big step forward, but it highlights the importance of future research on how fires affect soil, because wildfires are affecting thousands and thousands of square kilometers of land each year in the Western U.S., ” Samburova added. “Some of our future goals are to find out how exactly this soil water repellent happens, where it happens and how long it lasts.”
Additional Information:
This study was made possible with support from DRI and the National Science Foundation. Study authors included Vera Samburova, Ph.D., Rose Shillito, Ph.D. (currently with U.S. Army Corps of Engineers), Markus Berli, Ph.D., Andrey Khlystov, Ph.D., and Hans Moosmüller, Ph.D., all from DRI.
The full text of the paper, Effect of Biomass-Burning Emissions on Soil Water Repellency: A Pilot Laboratory Study, is available from Fire: https://www.mdpi.com/2571-6255/4/2/24
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About the Desert Research Institute
The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu
Sep 16, 2019 | News releases, Research findings
RENO, Nev. (Sept. 16, 2019) – The same chemicals responsible for the pungent smell of a cannabis plant may also contribute to air pollution on a much larger scale, according to new research from the Desert Research Institute (DRI) and the Washoe County Health District (WCHD) in Reno, Nev.
In a new pilot study, DRI scientists visited four cannabis growing facilities in Nevada and California to learn about the chemicals that are emitted during the cultivation and processing of cannabis plants, and to evaluate the potential for larger-scale impacts to urban air quality.
At each facility, the team found high levels of strongly-scented airborne chemicals called biogenic volatile organic compounds (BVOCs), which are naturally produced by the cannabis plants during growth and reproduction. At facilities where cannabis oil extraction took place, researchers also found very high levels of butane, a volatile organic compound (VOC) that is used during the oil extraction process.
“The concentrations of BVOCs and butane that we measured inside of these facilities were high enough to be concerning,” explained lead author Vera Samburova, Ph.D., Associate Research Professor of atmospheric science at DRI. “In addition to being potentially hazardous to the workers inside the cannabis growing and processing facilities, these chemicals can contribute to the formation of ground-level ozone if they are released into the outside air.”
Although ozone in the upper atmosphere provides protection from UV rays, ozone at ground-level is a toxic substance that is harmful for humans to breathe. Ozone can be formed when volatile organic compounds (including those from plants, automobile, and industrial sources) combine with nitrogen oxide emissions (often from vehicles or fuel combustion) in the presence of sunlight. All of these ozone ingredients are in ample supply in Nevada’s urban areas, Samburova explained – and that impacts our air quality.
“Here in our region, unfortunately, we already exceed the national air quality standard for ground-level ozone quite a few times per year,” Samburova said. “That’s why it is so important to answer the question of whether emissions from cannabis facilities are having an added impact.”
A scientist from the Desert Research Institute measures air quality inside of a cannabis growing facility. Credit: Vera Samburova/DRI. 2019.
At one of the four cannabis growing facilities visited during this study, the team measured emission rates over time, to learn about the ozone-forming potential of each individual plant. The results show that the BVOCs emitted by each cannabis plant could trigger the formation of ground-level (bad) ozone at a rate of approximately 2.6g per plant per day. The significance of this number is yet to be determined, says Samurova, but she and her team feel strongly that their findings have raised questions that warrant further study.
“This really hasn’t been studied before,” Samburova said. “We would like to collect more data on emissions rates of plants at additional facilities. We would like to take more detailed measurements of air quality emissions outside of the facilities, and be able to calculate the actual rate of ozone formation. We are also interested in learning about the health impacts of these emissions on the people who work there.”
The cannabis facility personnel that the DRI research team interacted with during the course of the study were all extremely welcoming, helpful, and interested in doing things right, Samburova noted. Next, she and her team hope to find funding to do a larger study, so that they can provide recommendations to the growing facilities and WCHD on optimum strategies for air pollution control.
“With so much growth in this industry across Nevada and other parts of the United States, it’s becoming really important to understand the impacts to air quality,” said Mike Wolf, Permitting and Enforcement Branch Chief for the WCHD Air Quality Management Division. “When new threats emerge, our mission remains the same: Implement clean air solutions that protect the quality of life for the citizens of Reno, Sparks, and Washoe County. We will continue to work with community partners, like DRI, to accomplish the mission.”
This research was funded by the WCHD and DRI. Members of the DRI team included Vera Samburova, Ph.D., Dave Campbell, M.Sc., William R. Stockwell, Ph.D., and Andrey Khlystov, Ph.D. To view this study online, please visit: https://www.tandfonline.com/doi/full/10.1080/10962247.2019.1654038
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The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
The Washoe County Health District has jurisdiction over all public health matters in Reno, Sparks, and Washoe County through the policy-making Washoe County District Board of Health. The District consists of five divisions: Administrative Health Services, Air Quality Management, Community and Clinical Health Services, Environmental Health Services and Epidemiology & Public Health Preparedness. To learn more, visit https://www.washoecounty.us/health/
Jun 25, 2019 | Blog, Featured researchers
Meet Dante Staten, a Ph.D. student in environmental science with an emphasis in environmental chemistry. Staten recently graduated from the University of Nevada, Reno with a Master’s Degree in environmental science. At DRI, Staten is working with Dr. Andrey Khlystov in the Organic Analytical Laboratory to study the human-caused air pollutant emissions and their effects on public health.
DRI: What brought you to DRI?
DS: I was brought to the Desert Research Institute following the pending completion of my master’s degree in environmental science at the University of Nevada, Reno, where I focused on chemistry and the public health implications of nicotine containing products. I have a lot of experience with analytical devices used in chemistry and have a strong interest in public health implications in general. After a tour of Professor Andrey Khlystov’s laboratory, a brief about some of the work that is being done there, and an overview of the incredible range of instruments they have available, there was no question about joining the laboratory. I am excited to be a part of their team for my PhD track.
DRI: What are you studying?
DS: Currently I am working on a PhD in environmental science with an emphasis in environmental chemistry. More so, I am interested in chemistry and human-caused pollutant emissions into the environment that lead to public health implications.
Staten poses with friends and family at his recent graduation from the University of Nevada, Reno.
DRI: What research projects are you working on? And who are you working with here at DRI?
DS: I am currently working in the organic analytical laboratory run by Professor Andrey Khlystov. I am hoping to eventually collaborate with another one of his students on electronic cigarette work, and I am finishing a thesis defense from my master’s degree where I focused on manufacturer discrepancies found within smokeless tobacco products in regards to the accuracy of contaminant labeling. My major research project is coming within the next few months under a grant—I cannot discuss this project in depth, but it is relevant to forest fires and the public health implications resulting from them!
DRI: What are your short-term and long-term goals while at DRI?
DS: I believe that the people that I am working with here at DRI are very smart. I believe that is a very important quality of the work environment, especially in a competitive field such as science and academics. To be surrounded by such people is inspiring. Regarding my goals both short-term and long-term, they are simply to become the best scientist and best version of myself with the help of my colleagues.
DRI: Tell us about yourself. What do you like to do for fun?
DS: I enjoy a bunch of things, including binge-watching shows on Netflix, volleyball, taking pictures, skateboarding, good food, the gym, and studying!
Apr 2, 2019 | OAL
Emissions from wildland fires and biomass fuel use contribute to regional air pollution events, global scale radiative forcing and climate change, and cause severe health effects. However, the role of organic compounds in these processes is still largely unknown and underestimated.
For this reason, the OAL team performs combustion experiments in the DRI’s combustion chamber to characterize in details chemical and physical properties of biomass-burning emissions, especially organic compounds.
Moreover, to study atmospheric aging of combustion pollutants, OAL students operate the oxidation the flow reactor (OFR) that needs only 1-2 minutes to mimic 7 days of oxidation in real atmospheric conditions.
This work is supported by NSF (grant no. AGS-1544425, P.I.: V. Samburova, co-PIs: H. Moosmüller and A. Khlystov), NASA (grant no. NNX15AI48G, P.I.: H. Moosmüller, co-P.I.: V. Samburova), and DRI’s Wildland Fire Science Center (WFSC)
Gallery:
The OAL team use Malaysian peat fuel for a combustion experiment.
Students Chiranjivi Bhattarai, Michaelene (Miki) Iaukea-Lum, and Deep Sengupta preparing eucalyptus for burning experiment in the DRI’s combustion chamber.
TIGF filters sampled with biomass-burning emissions from combustion of Malaysian peat.
OAL’s oxidation flow reactor
OAL “biomass-burning” team
OAL Assistant Research Professor Vera Samburova is starting the combustion experiment with Malaysian peat fuel.
Mar 26, 2019 | OAL
Drs. Andrey Khlystov and Vera Samburova participated in the DRI Day at the NV Legislature today. They met with Senator Heidi Gansert, Assemblywomen Heidi Ann Swank and Lisa Krasner, and educated many members of NV State Legislature on dangers of flavoring compounds in e-cigarettes. Dr. Khlystov attended the recognition of DRI from the floor of the NV Senate by the State Senator Heidi Gansert.
Feb 23, 2019 | OAL
The Organic Analytical Lab was well represented at the Society for Research on Nicotine and Tobacco 2019 Annual Meeting in San Francisco. Drs. Andrey Khlystov, Vera Samburova and Yeongkwon Son attended the meeting and Yeong presented three (!!!) posters. Please visit https://cdn.ymaws.com/www.srnt.org/resource/resmgr/SRNT19_Abstracts.pdf to see the abstracts (POS2-8, POS2-17 and POS4-47). The posters generated a lot of interest and created new opportunities for collaboration with governmental agencies and educational institutions.
Feb 13, 2019 | OAL
Our paper “Physical and chemical characterization of aerosol in fresh and aged emissions from open combustion of biomass fuels”, Aerosol Science and Technology, vol 52, No 11, by Bhattarai C. et al., senior author A. Khlystov, (https://doi.org/10.1080/02786826.2018.1498585) is among the Top Ten most downloaded since November 2018! Well done!
Feb 5, 2019 | OAL
February 4-6, 2019 – Dr. Andrey Khlystov presented results of the HEI-sponsored study at the 9th CRC Mobile Source Air Toxics Workshop in Sacramento.
Jan 21, 2019 | OAL
OAL graduate students, Deep Sengupta and Chiranjivi Bhattarai have been selected to become Teaching Assistants in UNR Physics for Scientists and Engineers courses! Deep is a TA for three different groups taking course PHYS 181L; Chiranjivi is a TA in PHYS 180L and PHYS 180 recitation. Congratulations and good luck, Chiranjivi and Deep!
Sep 28, 2018 | OAL
OAL scientists Drs. Vera Samburova and Yeongkwon Son attended the 2018 Nevada Public Health Association annual conference in Las Vegas. They gave presentations on potential hazards of e-cigarette use to the broad audience of health care providers, clinicians, educators, and researchers. The talks generated a lot of interest among the attendees and initiated productive discussions. Well done, Yeong and Vera!
Sep 17, 2018 | OAL
The recent OAL publication “Aldehydes in Exhaled Breath during E-cigarette Vaping: Pilot Study Results” in the open access journal Toxics is highlighted in the DRI news release! Please read the full story here.
Sep 14, 2018 | OAL
Dr. Andrey Khlystov was invited to give a keynote speech at the 25th International Conference on Aerosol Science and Technology (ICAST) in Tainan, Taiwan. His presentation “Light-absorbing organic carbon in biomass burning aerosols, its properties and transformation” highlighted NSF-sponsored research done at the OAL.
Sep 5, 2018 | OAL
Deep Sengupta presented a poster “Semi-Volatile Organic Compounds in Fresh and Laboratory-Aged Biomass Burning Aerosols” and gave a talk “Estimation of Snow Albedo Reduction due to Deposition of Light Absorbing Aerosols Using a Monte Carlo Radiative Transfer Model” at the 10th International Aerosol Conference in St.Louis, USA. Well done, Deep!!
Aug 27, 2018 | OAL
A Warning About Vaping
OAL’s e-cigarette research is on the front page of Reno Gazette Journal!
Aug 21, 2018 | OAL
The latest OAL publication by Vera Samburova et al. on aldehydes in exhaled breath attracted the attention of all major local media outlets! Please click “Continue reading” to see image gallery and enable links to videos.
Reno Gazette Journal (RGJ) story: https://www.rgj.com/story/news/2018/08/20/vaping-leaves-cancer-causing-chemicals-lungs-study/1015582002/ and RGJ Facebook Live: https://www.facebook.com/RGJmedia/videos/301882897057641/
RGJ reporter interviews OAL team for FB live
KTVN Channel 2 news story: http://www.ktvn.com/story/38910498/pilot-study-shows-significant-amount-of-carcinogens-stay-in-lungs-after-vaping
KTVN2 reporter interviews Dr. Vera Samburova
News 4-Fox 11 story: https://mynews4.com/news/local/dri-scientists-e-cigs-leave-dangerous-amounts-of-cancer-causing-chemicals-in-lungs
Fox 11 reporter and cameraman interviews Dr. Khlystov
Aug 15, 2018 | News releases, Research findings
Above: Dr. Vera Samburova works in the organic analytical lab at Desert Research Institute, in Reno, Nev., on Tuesday, Feb. 20, 2018.
Photo by Cathleen Allison/Nevada Momentum
Reno, NV (August 15, 2018) – E-cigarettes have become increasingly popular as a smoke-free alternative to conventional tobacco cigarettes, but the health effects of “vaping” on humans have been debated in the scientific and tobacco manufacturing communities. While aldehydes—chemicals like formaldehyde that are known to cause cancer in humans—have been identified in e-cigarette emissions by numerous studies, there has been little agreement about whether such toxins exist in large enough quantities to be harmful to users.
Now, a recently published pilot study by a team of researchers from the Desert Research Institute (DRI) and the University of Nevada, Reno shows that significant amounts of cancer-causing chemicals such as formaldehyde are absorbed by the respiratory tract during a typical vaping session, underscoring the potential health risks posed by vaping.
“Until now, the only research on the respiratory uptake of aldehydes during smoking has been done on conventional cigarette users,” said Vera Samburova, Ph.D., associate research professor in DRI’s Division of Atmospheric Sciences and lead author of the study. “Little is known about this process for e-cigarette use, and understanding the unique risks vaping poses to users is critical in determining toxicological significance.”
Samburova and fellow DRI research professor Andrey Khlystov, Ph.D., have been investigating the health risks associated with e-cigarettes for several years. In 2016, they published findings confirming that dangerous levels of aldehydes are formed during the chemical breakdown of flavored liquids in e-cigarettes and emitted in e-cigarette vapors.
In this study, Samburova and her team estimated e-cigarette users’ exposure to these hazardous chemicals by analyzing the breath of twelve users before and after vaping sessions using a method she and Khlystov have developed over the course of their work together. Through this process, they determined how much the concentration of aldehydes in the breath increased. Researchers then subtracted the concentration of chemicals in exhaled breath from the amount found in the vapors that come directly from the e-cigarette.
The difference, Samburova explains, is absorbed into the user’s lungs.
E-cigarettes in the Organic Analytical Lab at DRI.
“We found that the average concentration of aldehydes in the breath after vaping sessions was about ten and a half times higher than before vaping,” Samburova said. “Beyond that, we saw that the concentration of chemicals like formaldehyde in the breath after vaping was hundreds of times lower than what is found in the direct e-cigarette vapors, which suggests that a significant amount is being retained in the user’s respiratory tract.”
The research team took care to ensure that the test conditions of the study mirrored real-life vaping sessions as much as possible. Most participants used their own e-cigarette devices during the study, used e-liquid flavors that were familiar to them, and inhaled for the amount of time that they ordinarily would, which allowed the research team to understand how e-cigarettes are typically used by regular users. Because they tested “normal” vaping experiences, researchers confirmed that the high concentrations of aldehydes found in other studies aren’t limited to laboratory conditions.
“Our new pilot study underlines the potential health risk associated with the aldehydes generated by e-cigarettes,” said Samburova. “In the future, e-cigarette aldehyde exposure absolutely needs to be studied with a larger set of participants.”
The study, “Aldehydes in Exhaled Breath during E-Cigarette Vaping: Pilot Study Results,” was published on August 7th in the journal Toxics and is available here: https://www.mdpi.com/2305-6304/6/3/46/htm#app1-toxics-06-00046. DOI: 10.3390/toxics6030046
This research was independently funded by DRI and conducted in DRI’s Organic Analytical Laboratory located in Reno, Nevada. For more information about the Organic Analytical Lab, visit: https://www.dri.edu/labs/oal/.
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The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Jun 27, 2018 | OAL
Congratulations to Chiranjivi Bhattarai who successfully defended his Master of Science in Atmospheric Chemistry thesis on June 27th, 2018, at the Desert Research Institute! Chiranjivi has joined the OAL in fall 2014, and conducted a detailed study of “Physical and Chemical Characterization of Fresh and Aged Biomass Burning Emissions” under the supervision of Dr. Andrey Khlystov. Results of this study will be published in the journal Aerosol Science and Technology, stay tuned! Update Feb 2019: the paper was published in November 2018 (AS&T vol 52 No 11) and is among the Top Ten downloaded despite its limited accessibility!
Jun 21, 2018 | OAL
DRI President Dr. Kristen Averyt presented Dr. Vera Sumburova with the NSHE Rising Researcher Award during a ceremony at the DRI’s Las Vegas location on June 21, 2018.
Jun 8, 2018 | OAL
A DRI team (DAS Executive Director Marc Pitchford and OAL scientists Drs. Andrey Khlystov and Vera Samburova) traveled to Carson City to meet with the officials from the Nevada Department of Health and Human Services. Dr. Khlystov presented results of OAL’s study on the hazardous levels of toxic aldehydes in e-cigarette flavorings and the new OAL’s findings on emissions from very popular JUUL e-cigarettes. While having relatively low carbon monoxide and formaldehyde emissions, JUUL pods subject users to very high concentrations of nicotine, a known addictive substance. Active discussion followed the presentation, and a visit by NV DHHS representative to DRI is expected in the near future. Nevada leads the nation in juvenile e-cigarette use, causing serious concern among state health officials. E-cigarette emissions research done by the OAL at DRI helps to educate and empower the lawmakers.
May 24, 2018 | OAL
The OAL team is a part of the “Drone-based Remote-sensing Experiments and Atmospheric Measurements” (Lead: Dr. Adam Watts).
Today we had our first fly test!
Apr 6, 2018 | OAL
Dave Campbell, Associate Research Scientist at the DRI’s Division of Atmospheric Sciences and the Organic Analytical Lab member, participated in a 5-week long monitoring campaign near Paramount, CA, sponsored by the South Coast Air Quality Management District and conducted in collaboration with Aerodyne Research Inc.
Dave used Steam-Jet Aerosol Collector – long Pathlength Absorbance Spectroscopy (SJAC-LPAS) instrument developed by Dr. Khlystov to perform real-time on-line measurements of hexavalent chromium concentration in the air, while riding aboard Aerodyne Mobile Laboratory.
Mar 1, 2018 | OAL
The Nevada System of Higher Education (NSHE) Board of Regents this week awarded Vera Samburova, Ph.D., an assistant research professor of atmospheric chemistry and air pollution at DRI, with its annual Rising Researcher Award.
She was recognized for her early-career accomplishments and leading a new and exciting area of research at DRI looking at inhalation and indoor air quality related health effects. The honor is given annually to one NSHE faculty member from DRI, UNR, and UNLV.
Reno, Nev. (Thursday, March 1, 2018) – The Nevada System of Higher Education (NSHE) Board of Regents this week awarded Vera Samburova, Ph.D., an assistant research professor of atmospheric chemistry and air pollution at DRI, with its annual Rising Researcher Award.
She was recognized for her early-career accomplishments and leading a new and exciting area of research at DRI looking at inhalation and indoor air quality related health effects. The honor is given annually to one NSHE faculty member from DRI, UNR, and UNLV.
As a member of the DRI’s Organic Analysis Laboratory, Samburova’s research focuses on the collection and analysis of atmospheric organic species, characterization and quantification of organic emissions from various sources like biomass burning and fossil fuels.
She recently initiated an internally funded research project investigating the emissions from e-cigarettes. Her research team found that the aerosols (commonly called vapors) produced by flavored e-cigarettes liquids contain dangerous levels of hazardous chemicals known to cause cancer in humans. Their research was published in Environmental Science & Technology (ES&T), a journal of the American Chemical Society.
“The health impacts of e-cigarettes are still widely unknown and not researched,” said Samburova. “I am incredibly honored to be recognized for this important work and everything that our team at DRI has done to advance this important and emerging field of research.”
Samburova has authored a total of 35 peer-reviewed publications, 20 since joining DRI, and seven of which she was the first author. She has served as a principal investigator, and co-principal investigator, and a key personnel/scientist for 15 projects that have received over $2 million in external research funding.
She is also actively involved in the Atmospheric Sciences Graduate Program at the University of Nevada, Reno where she has taught classes every year starting in 2008 and has been the Deputy Director of that program for the last five years.
Samburova received her Ph.D. in Environmental Organic Chemistry from the Swiss Federal Institute of Technology, Zurich in 2007, after which she was recruited at Desert Research Institute as a Post Doc and subsequently transitioned to an Assistant Research Professor.
Feb 22, 2018 | OAL
Dr. Andrey Khlystov has been named a “2018 New Investigator Award Winner for Best Abstract” by the Society for Research on Nicotine & Tobacco for his presentation “The Effect of Puff Topography and Power Settings on Aldehyde and Carbon Monoxide in E-cigarette Aerosols”. The award was presented at the Society’s annual meeting in Baltimore, MD. Dr. Khlystov is the Director of the Organic Analytical Laboratory and a Research Professor of Atmospheric Chemistry at DRI. Two other OAL members presented posters at the SRNT meeting: Dr. Vera Samburova (“Carbonyl Compounds in Exhaled E-cigarette Aerosols”) and Dr. Yeongkwon Son (“Indoor Air Quality in Electronic Cigarette Vape Shops”).
Nov 23, 2016 | OAL
In the Organic Analytic Laboratory at DRI, our main specialty is sampling and detailed chemical analysis of organic air pollutants. Our team has more than 20 years of experience in this area.
E-cigarette research is new for us but involves similar sampling and analytical techniques. Having seen advertisements for e-cigarettes that claimed they are safe because liquids contain only FDA approved ingredients, we decided to apply our expertise to see what is in e-cigarette vapors. This resulted in the publication of the first set of results concerning the role of flavorings in aldehyde formation during vaping.
Following the publication of our paper, we received a lot of attention from media, the blogosphere, and individual vapers. This shows the importance of the problem and we are pleased to have made a contribution to the ongoing discussion of the pros and cons of vaping.
While the news coverage was generally accurate, we noticed some misunderstanding and misrepresentation of the study, especially in comment sections of media articles and on some blogs. For example, we were amazed to see some commenters suggesting that our study was sponsored by the tobacco industry. This is completely untrue. This was an internally funded study. None of us, nor the Desert Research Institute has any connection to the tobacco industry.
A recent blog post by Dr. Farsalinos was also brought to my attention. In his post, Dr. Farsalinos states that our “results contradict previous research on aldehyde emissions” and he makes other assertions that I would like to address here in more detail. By making this statement, Dr. Farsalinos revealed that (a) he is not up-to-date with the current literature, and (b) has not read our paper carefully, because we explicitly compare our results to other studies.
Aldehyde Concentrations
Our paper states (from the top of the right column of page four): “For example, maximal formaldehyde emissions observed in this study are approximately 2−7 times lower than the steady-state emissions measured by Sleiman et al.,9 who reported values ranging from 13000 to 48200 ng/mg. In terms of emissions per puff, our formaldehyde data [0.12−50 μg/puff (Table S3)] are comparable to values of 0.05−50 μg/puff reported by Gillman et al.6 and 30−100 μg/puff reported by Sleiman et al.9”
Yes, the highest observed concentrations in our study, which seem to have caused disbelief in some such as Dr. Farsalinos, are actually several times lower than those reported in another recent study (Sleiman et al.). In Sleiman et al., it is reported that the first few puffs significantly underestimate aldehyde emissions as the coil temperature needs time to come to steady state. Most if not all of the previous studies that reported low aldehyde concentrations did not include warm-up puffs. This is also discussed in our paper.
Flavoring Compounds
Our study also clearly states – “our results do not suggest that PG or VG produces no aldehydes, but that flavoring compounds are responsible for the main part of the emitted toxic aldehydes. Nondetects for unflavored liquids reported in this study are likely due to the small number of puffs that we have used in our measurements. By collecting more puffs per measurement, we could have quantified emissions for unflavored liquids. This quantification, however, is of minor consequence, as the flavored liquids produce significantly more aldehydes than unflavored ones do” (top of the left column on page 5).
We are not contesting the contribution of PG/VG to aldehyde formation. Our point is that flavorings cause significantly higher emissions.
The standard excuse (written about here – http://www.nejm.org/doi/full/10.1056/NEJMc1502242) of a “dry-puff” to explain aldehyde emissions cannot be applied to our study.
There is only one peer-reviewed paper that asserts that high aldehyde concentrations are due to dry puffs only and that these cause aversion in users. That paper was reviewed in just 11 days and methodological problems have been identified by other researchers – see a review by Shihadeh et al. here http://onlinelibrary.wiley.com/doi/10.1111/add.13066/full.
As was discussed above, the evidence is mounting that aldehyde levels in e-cigarette vapors could be dangerously high.
Reproducibility
While we do agree with Dr. Farsalinos that the strength of science lies in reproducibility of experimental results and we wish anyone success in reproducing our study, we strongly believe that science requires impartiality and an open mind. Statements such as “I should note that it is impossible to convincingly identify something that went wrong in this study” are derogatory and assume that our study is wrong.
We would also suggest Dr. Farsalinos reproduce studies by Sleiman et al., Gillman et al., and Jensen et al.
It should be also noted that aldehydes and their DNPH adducts are chemically unstable. Experience and utmost care are required to obtain accurate results.
While we are not interested in proving or disproving Dr. Farsalinos’ dry puff study, we have collected some preliminary data that contradicts conclusions of that study regarding high aldehyde levels causing an “unpleasant” sensation during vaping.
We are collecting data for secondary aldehyde exposure associated with vaping. To estimate secondary emissions, we collected exhaled breath from three research volunteers, who were asked to vape as they normally do in a real-life scenario. The results are shown in the unpublished graph below (DO NOT CITE).
The levels are comparable to what we have measured per puff. One volunteer produced higher concentrations because a different device was used. None of our volunteers complained about anything unpleasant during their vaping.
Drypuff
We continue working on characterizing other pollutants in e-cigarette vapors and have data collaborating the effect of flavoring additives we reported in the ES&T.
Stay tuned for more exciting results and important research findings from our team!
– Andrey Khylstov, Ph.D
Nov 21, 2016 | Labs, OAL
Scientists stress need for thorough research into flavored e-liquids
RENO – Building on more than 30 years of air quality research in some of the most polluted urban environments on Earth, a team of atmospheric scientists at the Desert Research Institute (DRI) has turned their attention toward the growing e-cigarette industry and the unidentified effects of vaping on human health.New research published today in Environmental Science & Technology (ES&T), a journal of the American Chemical Society, reports that the aerosols (commonly called vapors) produced by flavored e-cigarettes liquids contain dangerous levels of hazardous chemicals known to cause cancer in humans.
The study “Flavoring compounds dominate toxic aldehyde production during e-cigarette vaping” confirms that these toxic aldehydes, such as formaldehyde, are formed not by evaporation, but rather during the chemical breakdown of the
“How these flavoring compounds in e-cigarette liquids affect the chemical composition and toxicity of the vapor that e-cigarettes produce is practically unknown,” explained Andrey Khlystov, Ph.D., an associate research professor of atmospheric sciences at DRI. “Our results show that production of toxic aldehydes is exponentially dependent on the concentration of flavoring compounds.”
E-cigarette liquids have been marketed in nearly 8,000 different flavors, according to a 2014 report from the World Health Organization. Recent reports have shown that many flavors, such as Gummy Bear, Tutti Fruitty, Bubble Gum, etc., were found to be especially appealing to adolescents and young adults.
The U.S. Food and Drug Administration (FDA) reports that 16-percent of high school and 5.3-percent of middle school students were current users of e-cigarettes in 2015, making e-cigarettes the most commonly used tobacco product among youth for the second consecutive year. In 2014, 12.6-percent of U.S. adults had ever tried an e-cigarette and about 3.7-percent of adults used e-cigarettes daily or some days.
Khlystov and his colleagues measured concentrations of 12 aldehydes in aerosols produced by three common e-cigarette devices.
To determine whether the flavoring additives affected aldehyde production during vaping, five flavored e-liquids were tested in each device. In addition, two unflavored e-liquids were also tested.
“To determine the specific role of the flavoring compounds we fixed all important parameters that could affect aldehyde production and varied only the type and concentration of flavors,” explained Vera Samburova, Ph.D., an assistant research professor of chemistry at DRI.
Samburova added that the devices used in the study represented three of the most common types of e-cigarettes – bottom and top coil clearomizers, and a cartomizer.
The study avoided any variation in puff topography (e.g., puff volume, puff velocity, interval between puffs) by utilizing a controlled sampling system that simulated the most common vaping conditions. E-cigarette vapor was produced from each device by a four-second, 40-ml controlled puff, with 30-second resting periods between puffs. The e-cigarette devices were manually operated to replicate real-life conditions and all samples were collected in triplicate to verify and confirm results. Specific care was taken to avoid “dry puff” conditions.
e-cigarettes provide further proof that the flavoring compounds, not the carrier e-liquid solvents (most commonly propylene glycol and/or vegetable glycerin) dominated production of aldehydes during vaping, the authors performed a series of experiments in which a test flavored e-liquid was diluted with different amounts of the unflavored e-liquid. Liquids with higher flavor content produced larger amounts of aldehydes due to pyrolysis of the flavoring compounds.
In all experiments, the amount of aldehydes produced by the flavored e-cigarette liquids exceeded the American Conference of Governmental Industrial Hygienists Threshold Limit Values (TLVs) for hazardous chemical exposure.
“One puff of any of the flavored e-liquids that we tested exposes the smoker to unacceptably dangerous levels of these aldehydes, most of which originates from thermal decomposition of the flavoring compounds,” said Khlystov. “These results demonstrate the need for further, thorough investigations of the effects of flavoring additives on the formation of aldehydes and other toxic compounds in e-cigarette vapors.”
This research was independantly funded by the Desert Research Institute and conducted in DRI’s Organic Analytical Laboratory located in Reno, Nevada.
“Flavoring Compounds Dominate Toxic Aldehyde Production During E-cigarette Vaping”
DOI # – 10.1021/acs.est.6b05145 – http://pubs.acs.org/doi/abs/10.1021/acs.est.6b05145
DRI scientists used a controlled sampling system to simulate the most common vaping conditions. E-cigarette vapor was produced from each device by a four-second, 40-ml controlled puff, with 30-second resting periods between puffs. Credit DRI.
DRI scientists measured concentrations of 12 aldehydes in aerosols produced by three common e-cigarette devices shown here. Credit DRI
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