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Neil Klepeis

Neil Klepeis

Senior Research Scientist


Neil Klepeis, PhD, is a Senior Research Scientist at ETR. He specializes in secondhand smoke exposure arising from tobacco and cannabis consumption. He has been a principal investigator and co-investigator on many tobacco-related state and federal grants that seek to understand and reduce secondhand smoke exposure occurring in casinos, multi-unit housing, vehicles, single-family homes, and the outdoors. He is an expert in the real-time measurement and analysis of air quality and human activity data.

Dr. Klepeis has wide-ranging interests in exploring how technology can improve health and well-being via behavioral interventions and education. In his current work, he explores many kinds of sensors and smart devices that can be used to provide real-time feedback and move people towards specific target behaviors and environmental health goals. Dr. Klepeis is also developing mathematical models of environmental and behavioral phenomena that can be used in data analysis, adaptive intervention management, simulations, and serious games.

Dr. Klepeis received a PhD in Environmental Health Sciences from the University of California at Berkeley. He holds a BA and MS in Chemistry. Throughout his education and career, Dr. Klepeis has incorporated Computational Science and Data Science into his research.

Current Projects

  • California Clean Air Project (CCAP)
  • Research Services
  • Air Quality and Exposure Education and Feedback
  • Real-Time Adaptive Behavioral Interventions
  • Simulations and Serious Games for Health


Posis AI, Bellettiere J, Liles S, Alcaraz J, Berardi V, Klepeis NE, Hughes S, Wu T, Hovell M (2019) Indoor cannabis smoke and children’s health, Preventive Medicine Reports, Preventive medicine reports, 14, p.100853.

Hovell MF, Bellettiere J, Liles S, Nguyen B, Berardi V, Johnson C, Matt GE, Malone J, Boman-Davis MC, Quintana PJE, Obayashi S, Chatfield D, Robinson R, Blumberg EJ, Ongkeko WM, Klepeis NE**, Hughes S** (2019) Randomised controlled trial of real-time feedback and brief coaching to reduce indoor smoking, Tobacco Control, DOI: 10.1136/tobaccocontrol-2018-054717. **Senior author and study co-investigator.

Berardi V, Carretero-González R, Klepeis NE, Machiani SG, Jahangiri A, Bellettiere J, Hovell M. (2018) Computational model for behavior shaping as an adaptive health intervention strategy, Translational Behavioral Medicine, ibx049,

Hughes SC, Bellettiere J, Nguyen B, Liles S, Klepeis NE, Quintana JE, Berardi V, Obayashi S, Bradley S, Hofstetter CR, Hovell MF, (2018) Randomized trial to reduce air particle levels in homes of smokers and children. Am J Prev Med. DOI: .

Chan WR, Logue JM, Wu X, Klepeis NE, Fisk WJ, Noris F, Singer BC (2017). Quantifying fine particle emission events from time-resolved measurements: Method description and application to 18 California low-income apartments. Indoor Air. DOI: 10.1111/ina.12425. URL:

Klepeis NE, Bellettiere J, Hughes SC, Nguyen B, Berardi V, Liles S, et al. (2017) Fine particles in homes of predominantly low-income families with children and smokers: Key physical and behavioral determinants to inform indoor-air-quality interventions. PLoS ONE 12(5): e0177718. DOI:

Klepeis NE, Dhaliwal N, Hayward G, Acevedo-Bolton V, Ott WR, Read N, Layton S, Jiang R, Cheng KC, Hildemann LM, Repace JL, Taylor S, Ong SL, Buchting FO, Lee JP, Moore RS (2016). Measuring indoor air quality and engaging California Indian stakeholders at the Win-River resort and casino: Collaborative smoke-free policy development. Int. J. Environ. Res. Public Health 13, no. 1: 143. DOI: 10.3390/ijerph13010143.

Dacunto P, Klepeis NE, Cheng KC, Acevedo-Bolton V, Jiang RT, Repace L, Ott WR, Hildemann LM (2015) Determining PM2.5 calibration curves for a low-cost particle monitor: Common indoor residential aerosols. Environmental Science: Processes & Impacts, 17, 1959 – 1966. DOI: 10.1039/C5EM00365B

Berardi V, Carretero-Gonzalez R, Klepeis NE, Palacios A, Bellettiere J, Hughes S, Obayashi S, Hovell MF, (2015) Proper orthogonal decomposition methods for the analysis of real-time data: Exploring peak clustering in a secondhand smoke exposure intervention. Journal of Computational Science, 11, 102-111. DOI: 10.1016/j.jocs.2015.10.006.

Logue JM, Sherman MH, Lunden MM, Klepeis NE, Williams R, Croghan C, Singer BC (2015) Development and assessment of a physics-based simulation model to investigate residential PM2.5 infiltration across the US housing stock. Building and Environment. DOI: 10.1016/j.buildenv.2015.06.032

Bellettiere J, Hughes SC, Liles S, Boman-Davis M, Klepeis NE, Blumberg E, Mills J, Berardi V, Obayashi S, Allen T, Hovell MF (2014) Developing and Selecting Auditory Warnings for a Real-Time Behavioral Intervention. American Journal of Public Health Research. DOI: 10.12691/ajphr-2-6-3.

Logue JM, Klepeis NE, Lobscheid AB, Singer BC (2014) Model-based exploration of natural gas stove and oven burner emissions in southern California residences: Pollutant levels, exposures, and the effects of proximity and range hood use. Environmental Health Perspectives, 122:43–50 DOI:10.1289/ehp.1306673.

Klepeis NE, Hughes SC, Edwards RD, Allen T, Johnson M, Chowdhury Z, Smith KR, Boman-Davis M, Bellettiere J, Hovell MF (2013). Promoting smoke-free homes: A novel behavioral intervention using real-time audio-visual feedback on airborne particle levels. PloS ONE. 8(8): e73251.

Cheng KC, Acevedo-Bolton V, Jiang RT, Klepeis NE, Ott WR, Kitanidis PK, Hildemann LM. (2013). Stochastic modeling of short-term exposure close to an air pollution source in a naturally ventilated room: An autocorrelated random walk method. Journal of Exposure Science and Environmental Epidemiology. DOI: 10.1038/jes.2013.63.

Dacunto PJ, Cheng KC, Acevedo-Bolton V, Jiang RT, Klepeis NE, Repace J, Ott WR, Hildemann, L. (2013). Real-time particle monitor calibration factors and PM2.5 emission factors for multiple indoor sources. Environmental Science Processes & Impacts. 15:1511-1519.

Dacunto PJ, Cheng KC, Acevedo-Bolton V, Jiang RT, Klepeis NE, Repace JL, Ott WR, Hildemann LM (2013). Identifying and quantifying secondhand smoke in source and receptor rooms using multiple measures: Logistic regression and mass balance approaches. Indoor Air. DOI: 10.1111/ina.12049

Dacunto PJ, Cheng KC, Acevedo-Bolton V, Jiang RT, Klepeis NE, Repace JL, Ott WR, Hildemann LM (2013). Identifying and quantifying secondhand smoke in residential units with tobacco smoke odor complaints. Atmospheric Environment. 71:399–407.

Acevedo-Bolton V, Ott WR, Cheng KC, Jiang RT, Klepeis NE, Hildemann L. (2013) Controlled experiments measuring personal exposure to PM2.5 in close proximity to cigarette smoking. Indoor Air, DOI:10.1111/ina.12057.

Ott WR, Acevedo-Bolton V, Cheng KC, Jiang RT, Klepeis NE, Hildemann L. (2013) Outdoor fine and ultrafine particle measurements at six bus stops with smoking on two California arterial highways. Journal of the Air and Waste Management Association. DOI: 10.1080/10962247.2013.832712.

Klepeis NE, Omoto J, Ong SL, Omoto HS, Dhaliwal N (2012). Small proportions of actively-smoking patrons and high PM2.5 levels in southern California tribal casinos: Support for smoking bans or designated smoking areas. BMC Public Health, 12:819, DOI:10.1186/1471-2458-12-819.

Apelberg BJ, Hepp LM, Avila-Tang E,Gundel L, Hammond SK, Hovell MF, Hyland A, Klepeis NE, Madsen CC, Navas-Acien A, Repace J, Samet JM, Breysse PN. (2012). Environmental monitoring of secondhand smoke exposure, Tobacco Control, DOI:10.1136/tobaccocontrol-2011-050301

Acevedo-Bolton V, Cheng KC, Jiang RT, Ott WR, Klepeis NE, Hildemann LM (2012). Measurement of the proximity effect for indoor air pollutant sources in two homes. Journal of Environmental Monitoring, 14(1):94-104.

Jiang RT, Cheng KC, Acevedo-Bolton V, Klepeis NE, Ott WR, Hildemann LA (2011). Effect of relative humidity on response of an aerosol monitor: Gravimetric scaling factors for secondhand smoke. Aerosol Science and Technology, Submitted.

Rosen LJ, Guttman N, Hovell MF, Noach MB, Winickoff JP, Tchernokovski S, Rosenblum JK, Rubenstein U, Seidmann V, Vardavas CI, Klepeis NE, and Zucker DM (2011). Development, design, and conceptual issues of Project Zero Exposure: A program to protect young children from tobacco smoke exposure. BMC Public Health, 11:508, DOI:10.1186/1471-2458-11-508.

Jiang RT, Cheng KC, Acevedo-Bolton V, Klepeis NE, Ott WR, Hildemann LA (2011). Determination of response of the real-time Sidepak AM510 monitor to secondhand smoke, other common indoor aerosols, and outdoor aerosol. Journal of Environmental Monitoring, DOI: 10.1039/c0em00732c.

Cheng KC, Jiang RT, Acevedo-Bolton V, Klepeis NE, Ott WR, Hildemann LA (2011) Modeling exposure close to air pollution sources in naturally-ventilated residences: Association of turbulent diffusion coefficient with air change rate. Environmental Science and Technology, 45, 4016–4022, DOI: /10.1021/es103080p.

Repace JL, Cheng KC, Jiang RT, Acevedo-Bolton V, Klepeis NE, Ott WR, Hildemann LA (2011) Fine particle and secondhand smoke air pollution exposures and risks inside 66 US casinos, Environment International, 111:473–484, DOI: 10.1016/j.envres.2011.02.007.

Kaufman P, Zhang B, Bondy SJ, Klepeis NE, Ferrence R (2011) Not just ‘a few wisps’: real-time measurement of tobacco smoke at entrances to office buildings, Tobacco Control, DOI:10.1136/tc.2010.041277.

Cheng KC, Jiang RT, Acevedo-Bolton V, Ott WR, Klepeis NE, Hildemann LA (2010) Model-based reconstruction of the time response of electrochemical air pollutant monitors to rapidly varying concentrations. Journal of Environmental Monitoring. DOI: 10.1039/b921806h.

Jiang RT, Cheng KC, Acevedo-Bolton V, Klepeis NE, Repace JL, Ott WR, Hildemann LA (2010). Measurement of fine particle concentrations and smoking activity in a statewide survey of 36 California Indian casinos. Journal of Exposure Science and Environmental Epidemiology. DOI: 10.1038/jes.2009.75.

Klepeis NE, Gabel EB, Ott WR, Switzer P (2009) Outdoor air pollution in close proximity to a continuous point source. Atmospheric Environment, 43(20): 3155-3167.

Ferro AR, Klepeis NE, Ott WR, Nazaroff WW, Hildemann LM, Switzer P (2009). Effect of interior door position on room-to-room differences in residential pollutant concentrations after short-term releases. Atmospheric Environment, 43(3): 706-714.

Ott WR, Klepeis NE, Switzer P (2008) Air change rates of motor vehicles and in-vehicle pollutant concentrations from secondhand smoke. Journal of Exposure Science and Environmental Epidemiology. 18:312–325.

Klepeis NE, Ott WR, and Switzer P (2007) Real-time measurement of outdoor tobacco smoke particles. Journal of the Air and Waste Management Association. 57:522-534.

Klepeis NE and Nazaroff WW (2006) Modeling residential exposure to secondhand tobacco smoke. Atmospheric Environment 40(23):4393-4407.

Klepeis NE and Nazaroff WW (2006) Mitigating residential exposure to secondhand tobacco smoke. Atmospheric Environment 40(23):4408-4422.

Ott WR, Klepeis NE, Switzer P (2003) Analytical solutions to compartmental indoor air quality models with application to environmental tobacco smoke concentrations measured in a house. Journal of the Air and Waste Management Association 53:918-936.

Klepeis NE, Apte MG, Gundel LA, Sextro RG, Nazaroff WW (2003) Determining size-specific emission factors for environmental tobacco smoke particles. Aerosol Science & Technology 37(10): 780-790.

Klepeis NE, Nelson WC, Ott WR, Robinson J, Tsang AM, Switzer P, Behar JV, Hern S, and Engelmann W (2001). The National Human Activity Pattern Survey (NHAPS): A resource for assessing exposure to environmental pollutants. Journal of Exposure Analysis and Environmental Epidemiology 11(3):231-252.

Klepeis NE, Ott WR, and Repace JL (1999) The effect of cigar smoking on indoor levels of carbon monoxide and particles. Journal of Exposure Analysis and Environmental Epidemiology 9(6): 622-635.

Klepeis NE (1999) Validity of the uniform mixing assumption: Determining human exposure to environmental tobacco smoke. Environmental Health Perspectives 107(Supp2): 357-363.

Klepeis NE (1999) An introduction to the indirect exposure assessment approach: Modeling human exposure using micro environmental measurements and the recent national human activity pattern survey. Environmental Health Perspectives 107(Supp2): 365-374.

Klepeis NE, Ott WR, and Switzer P (1996) A multiple-smoker model for predicting indoor air quality in public lounges. Environmental Science and Technology, 30(9): 2813-2820.

Klepeis NE, East ALL, Csaszar AG, Allen WD, Lee TJ, and Schwenke DW (1993) The [FHCl]- molecular anion - structural aspects, global surface, and vibrational eigenspectrum. Journal of Chemical Physics 99(5):3865-3897.

Book Chapters

Klepeis NE "Modeling Human Exposure to Air Pollution," In: Human Exposure Analysis, edited by Wayne R. Ott, Lance A. Wallace, and Anne Steinemann, CRC Press, 2006.

Nazaroff WW and Klepeis NE "Environmental Tobacco Smoke Particles," In: Indoor Environment: Airborne Particles and Settled Dust, edited by Lidia Morawska and Tunga Salthammer, Wiley-VCH, Weinheim, October 2003.

Repace JL, Ott WR, and Klepeis NE “Indoor Air Pollution from Cigar Smoke,” In: Cigars: Health Effects and Trends, Smoking and Tobacco Control Monograph No. 9, edited by Donald R. Shopland, National Cancer Institute, National Institutes of Health, February 1998.

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