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Biosketches
| Doris Betancourt | Jim Jetter |
| John Chang | Ken Krebs |
| Timothy Dean | Mark Mason |
| Ivan Dolgov | Marc Menetrez |
| Dale Greenwell | Ron Mosley |
| Zhishi Guo | Richard Perry |
Doris Betancourt
Doris Betancourt is an environmental microbiologist. She joined EPA in 2002. Her current research deals with indoor biocontaminants. Doris is responsible for the identification and characterization of molds , bacteria, and their metabolites in indoor environments. Likewise, her research focuses in the development of methods for the control of microbial populations.
Doris earned a BS degree in Biology from the University of Puerto Rico and an MS and Ph.D. in Microbiology from North Carolina State University.
John Chang
John Chang conducts research on characterizing VOC emissions from indoor materials and products. He is responsible for performing experiments with environmental chambers and a test house and developing source/sink models. John has published more than 50 papers and 7 patents. The most recent publications include subjects such as VOC emissions from latex and alkyd paints, mass transfer based emission models, and fungal growth in indoor environments.
John earned his BS degree from Taiwan University, MS from West Virginia University, and Ph.D. from the University of Texas at Austin in Chemical Engineering.
Timothy Dean
Timothy Dean is a microbiologist working in the areas of microbial identification and decontamination. Current areas of interest include molecular analysis of molds, in the form of ribosomal DNA sequencing, to generate a “fingerprint” for positive microbial identification. Additional projects include testing the efficacy of microbial decontaminants under numerous environmental conditions. Prior to joining the Agency in 2002 Timothy received his B.S. from West Chester University and his Ph.D. in microbiology from North Carolina State University.
Ivan Dolgov
Ivan M. Dolgov is a electronic technician in the Indoor Environmental Management Branch. His responsibilities include collecting samples, and operation, calibration, and repair of air sampling instruments in the large environmental test chamber. Ivan assists scientists in performing experiments in the large chamber, and collects, retrieves, and enters experimental data into spread sheets.
Ivan has 25 years of experience in the semiconductor manufacturing field at IBM's East Fishkill Plant. His main responsibility consisted of process development for the Metal Evaporation Sector. Other positions held were electronic technician, photoresist technician, diffusion technician, and manufacturing engineer scientist).
Dale Greenwell
Dale Greenwell manages and operates the particulate matter (PM) chamber providing experimental data in support of Fine PM Program research. Current studies are looking at entry and deposition rates of ambient PM into the indoor environment.
Prior to joining the EPA in May of 1999, Dale worked for and served in the US Navy for more than 20 years. Within the Navy's research laboratories, his most recent work involved studying the air quality onboard nuclear-powered submarines.
Zhishi Guo
Zhishi Guo is an environmental scientist. Since joining the Agency in 1997, his research emphasis has been on indoor source characterization, modeling, and indoor air quality simulation. His most recent research projects include characterization of indoor sources for fine particulate matter, determination and modeling of overall mass transfer coefficients for VOC emissions from aqueous solutions, and development of a Windows-based indoor air quality simulation software package.
Prior to joining the EPA, Zhishi worked for an environmental service firm for 10 years. He has a Ph.D. in Environmental Sciences and Engineering from the University of North Carolina at Chapel Hill, and a B.S. in Chemistry from Inner Mongolia University.
Jim Jetter
Jim Jetter is a research project engineer who has been working with EPA since 1991, and has been with IEMB since 2000. His current research interests are in characterizing fine particulate matter emissions from indoor environment sources and evaluating methods for measuring emissions. Prior to joining IEMB, his interests were in assessing systems for reducing greenhouse gas emissions, evaluating technologies for reducing stratospheric ozone depletion, and evaluating health and environmental impacts of automotive air-conditioning systems.
Jim has a B.S. in Mechanical Engineering from North Carolina State University, has an M.S. in Environmental Engineering from the University of North Carolina, and is a licensed Professional Engineer.
Ken Krebs
Ken Krebs is an analytical chemist responsible for the collection and analysis of trace compounds in air. This has involved samples from our in-house facilities as well as from the field. Ken also has extensive experience in operating the small chamber facility.
Ken has a B.S. degree in chemistry and a certificate in computer programming from North Carolina State University.
Mark Mason
Mark Mason's current research focuses are on investigation of the interactions of ozone and volatile organic compounds in indoor environments and investigation of the transport and fate of semivolatile compounds, such as pesticides, in the indoor environment. He has been involved in the development of technologies and methods to characterize sources of indoor air contaminants for the past 15 years. Research activities include development and validation of small chamber technologies and test methods, characterization of organic emissions from sources, design and construction of large environmental test chambers, investigation of source management strategies used in the design and construction of large buildings, investigation of ozone/volatile organic compound (VOC) interactions in indoor environments, and development and evaluation of biological methods of source emissions characterization. Mark has been involved in environmental research since receiving a Bachelor of Science (Zoology) degree from Oregon State University in 1972.
Marc Menetrez
Marc Menetrez joined the U.S. EPA as an environmental engineer in 1991. His duties are to direct research and development programs involving indoor biological contamination, including toxigenic molds, endotoxin, and allergens; biological particulate matter detection, transport, and risk management; indoor dynamics influence of pressure differential, ventilation, and moisture; and operation and maintenance of HVAC components. Marc's responsibilities include directing and managing research activities, providing technical guidance of overall project planning and performance, evaluating project activities, and overseeing and supervising research and development activities.
Marc earned a B.S. in Biology from Long Island University, an M.S. in Environmental Management from Duke University, an M.S. in Environmental Engineering from Duke University, and a Ph.D. in Environmental Engineering from North Carolina State University.
Ron Mosley
Ronald Mosley is a member of the Particulate Matter Team and serves as the Principal Investigator for EPA's studies of the relationship between indoor and outdoor concentrations of fine particles. He is in charge of studies performed in the in-house fine particle research chambers. Over the years, he has published more than 60 papers and holds two U.S. Patents.
Ron earned his B.S. in Physics from Berea College, and an MS and Ph.D. in Physics from Auburn University.
Richard Perry
Richard B. Perry is a senior mechanical engineering technician in the Indoor Environmental Management Branch. His responsibilities include managing, operating, and maintaining the large environmental test chamber. Richard retrieves and transfers the performance data from the large chamber computer to spread sheets that enable him to evaluate and ensure that the test parameters supplied by the principal investigator are met. With 36 years of experience in a research environment, Richard has acquired training and experience with all aspects of integrating laboratory computer programs, control systems, and equipment. Prior experience with the EPA includes 19 years in the Combustion Research Branch; 5 years in the Stratospheric Ozone Protection Branch; and 6 years in the Indoor Environment Management Branch assigned to radon barriers research project, which resulted in a paper he authored and presented at the 1996 International Radon Symposium.