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Stephen J. Reynolds, Ph.D.

Professor and Associate Department Head,
Occupational and Environmental Health

Office: 154B Environmental Health (EH)
Office Phone: 970-491-3141


Dr. Reynolds is a Professor and Associate Head in the Department of Environmental and Radiological Health Sciences, Colorado State University.  He is also faculty in the Department of Environmental and Occupational Health of the Colorado School of Public Health.   He is Director of the High Plains Intermountain Center for Agricultural Health and Safety - HICAHS (one of 10 national centers funded through the Centers for Disease Control and Prevention/National Institute for Occupational Safety and Health), and was founding Co-Director, now Deputy Director for the Mountain and Plains Education Research Center (MAP ERC), providing graduate training and continuing education for occupational health professionals. Dr. Reynolds heads the Industrial Hygiene training program. He chaired AIHA’s International Affairs Committee (2004-2005) and was named a Fellow of the American Industrial Hygiene Association in 2010.   He served as Chair of ACGIH in 2010 (Board of Directors 2008 – 2011).  

He is board certified in Industrial Hygiene and has more than 30 years of experience in exposure assessment and occupational health.  In 1993 – 1996 he was a Special Emphasis Research Career Award recipient (US PHS) conducting research in Uzbekistan and Turkmenistan focused on environmental health, and was a Fullbright Senior Specialist in 2007 and continues research on pesticides and birth defects in Armenia.   He is internationally recognized for his research involving exposure and health effects of organic dusts, bioaerosols, and endotoxins particularly in agricultural settings.  This research has focused on improving exposure assessment methods for organic and biological aerosols with a particular focus on evaluating Gram-negative bacterial endotoxins and their role, along with genetic and other risk factors, in lung disease among agricultural workers. Studies on pulmonary function and pro-inflammatory responses in workers, have also included in vitro studies on human lung cells.  Recent research involves application of new molecular biology techniques to investigate microbiome, and antimicrobial resistance in agricultural environments. This research has led to recommendations for occupational exposure guidelines (OELs) for workers in the swine, poultry, and related livestock production industries, and to current research on cost-effective interventions to reduce lung disease.   Since 2001 Dr. Reynolds and his colleagues at HICAHS have worked closely with the dairy industry to build partnerships and capacity to address the major health concerns of the industry. Current projects within HICAHS include research to identify factors contributing to illness and injury, evaluation of interventions and training to reduce risks and increase productivity, and development of regional and international partnerships to share knowledge and resources.  In 2011 he led the establishment of the International Dairy Research Consortium to foster sharing of knowledge and best practices.


Ph.D.: Environmental Health, The University of Minnesota, Minneapolis, MN: 1990

M.S.: Environmental Health, The University of Minnesota, Minneapolis, MN: 1983

B.A.: Chemistry, Carleton College, Northfield, MN: 1977

International Collaboration

Canada; University of Saskatchewan; Canadian Centre for Health and Safety in Agriculture International Program; Adjunct professor and student advisor to PhD candidate

Armenia; Fulbright ; Teaching and research on environmental, occupational and agricultural health

Sweden; Various projects researching agricultural lung disease, organic aerosals and endotoxin

Australia; Various projects researching agricultural lung disease, organic aerosals and endotoxin

Canada; Various projects researching agricultural lung disease, organic aerosals and endotoxins

Sweden; Swedish University of Agricultural Sciences, International Dairy Research Consortium; To address common health and safety needs on dairy farms in the U.S. and Europe. To produce articles in dedicated issue of Journal Of Agromedicine.


Professional : American Board of Industrial Hygiene - Certified Industrial Hygienist

Selected Publications

Autenrieth, D.A., Brazile, W.J., Sandfort, D.R., Douphrate, D.I., Román-Muñiz, I.N., & Reynolds, S.J. (2016). The associations between occupational health and safety management system programming level and prior injury and illness rates in the U.S. dairy industry. Safety Science, 84, 108-116.

Lee S. Newman, Kaylan E. Stinson, Dianne Metcalf, Hai Fang, Claire Brockbank, Kimberly Jinnett, Stephen J. Reynolds, Margo Trotter, Roxanna Witter, Liliana Tenney, Adam Atherly, Ron Goetzel. Implementation of a Comprehensive Worksite Wellness Program Targeting Small Businesses:  The Pinnacol Assurance Health Risk Management Study. JOEM Jan. 2015; 57(1):14-21.  Online Jan. 6, 2015 doi:10.1097/JOM.0000000000000279

KB. Mulloy, C Rose, SA. Sumner, GA. Conway, SJ. Reynolds, M Davidson, B Nelson, DS. Heidel, PM. Layde.  Renewable Energy and Occupational Health and Safety Research Directions: A White Paper from the Energy Summit, Denver Colorado, April 11-13, 2011. AJIM 2013 DOI 10.1002ajim.22184

Brie Hawley, Joshua Schaeffer, Jill A. Poole, Gregory P. Dooley, Stephen Reynolds, and John Volckens. Differential Response of Human Nasal and Bronchial Epithelial Cells upon Exposure to Size-fractionated Dairy Dust.  Journal of Environmental Health and Toxicology Part A, 78:583-594, 2015.

Reynolds SJ, Nonnenmann MW, Basinas I, Davidson M, Elfman L, Gordon J, Kirychuck S, Reed S, Schaeffer J, Schenker M, Schlunssen V, Sigsgaard T. Systematic Review of Respiratory Health Among Dairy Workers. Journal Agromedicine 18: 219-243, 2013

N Comstock, M Towle, A Warner, SJ Reynolds, L Durso, C Campbell, M Kiefer, SA. Bosch. Epidemiologic and Occupational Investigation of an Escherichia coli O111 Outbreak Associated with a Correctional Facility Dairy — Colorado, 2010.  MMWR March 9, 2012.

Reynolds SJ, Lundqvist P, Colosio C. Editorial - International Dairy Health and Safety. Journal Agromedicine 18:179-183, 2013. (Guest Editor - Journal of Agromedicine Special Issue “A Global Perspective on Modern Dairy: Occupational Health and Safety Challenges and Opportunities. Vol. 18, No. 3 2013

Reynolds SJ,  Clark ML, Koehncke N, von Essen S, Prinz L, Keefe TJ, Mehaffy J, Bradford M, Cranmer B,Davidson M, Yang IV,Burch JB. Pulmonary Function Reductions Among Potentially Susceptible Subgroups of Agricultural Workers in Colorado and Nebraska. JOEM 2012: 54(5)632-

Poole JA, Dooley GP, Saito R, Burrell AB,   Bailey KL, Romberger DJ, Mehaffy J, Reynolds SJ. Muramic Acid, Endotoxin/3-OHFA, and Ergosterol Explain Monocyte and Epithelial Cell Inflammatory Responses to Agricultural Dusts.  J Toxicol Environ Health A.  2010; 73(10): 684-700.  PMID: 20391112

Sprince NL, Lewis MQ, Whitten PS, Reynolds SJ, Zwerling C.  2000.  Respiratory symptoms: associations with pesticides, silos, and animal confinement in the Iowa Farm Family Health and Hazard Surveillance Project.  Am J Ind Med 38:455-462.

Kent W Thomas, Mustafa Dosemeci, Jane A Hoppin, Linda S Sheldon, Carry W Croghan, Sydney M Gordon, Martin L Jones, Stephen J Reynolds, James H Raymer, Gerald G Akland, Charles F Lynch, Charles E Knott, Dale P Sandler, Aaron E Blair and Michael C Alavanja.  Urinary biomarker, dermal, and air measurement results for 2,4-D and chlorpyrifos farm applicators in the Agricultural Health Study.   J Expo Sci Environ Epidemiol 20: 119-134; doi:10.1038/jes.2009.6. Volume 20, Issue 2 (March/April 2010)

Reynolds SJ, Nakatsu J, Tillery M, Keefe T, Mehaffy J, Thorne PS, Donham KJ, Nonneman M, Golla V, O’Shaughnessy P. Field and Wind Tunnel Comparison of Four Aerosol Samplers using Agricultural Dusts. Ann Occ Hyg.  doi:10.1093/annhyg/mep021, pp. 1 – 10, 2009 

Burch JB, Svendsen E, Siegel PD, Wagner SE, Von Essen S, Keefe T, Mehaffy J, Serrano Martinez A, Bradford M, Baker L, Cranmer B, Saito R, Tessari J, Prinz L, Andersen C, Christensen O , Koehncke N, Reynolds SJ. Endotoxin Exposure and Inflammation Markers among Agricultural Workers in Colorado and Nebraska. J Tox Env Health Part A, 73:1,5-22, 2009. 

Clark, Maggie L., Peel, Jennifer L., Burch, James B., Nelson, Tracy L., Robinson, Matthew M., Conway, Stuart, Bachand, Annette M. and Reynolds, Stephen J.(2009) Impact of improved cookstoves on indoor air pollution and adverse health effects among Honduran women, International Journal of Environmental Health Research,19:5,357—368

Tadevosyan A, Reynolds SJ, Kelly KM, Fuortes L, Mairapetyan A, Tadevosyan N, Petrosyan M, Beglaryan S, Organochlorine Pesticide Residues in Breast Milk in Armenia. J Clinical and PreClinical Medicine 1(1):84-88, 2007.

Curwin BD, Hein MJ, Sanderson WT, Striley C, Heederick D, Reynolds SJ, Ward EM, Alavanja MC.  2006.  Urinary pesticide concentrations among children, mothers, and fathers living in farm and non-farm households in Iowa.  Annals Occup Hygiene pp.1-13, Sept. 19, 2006

Clark ML, Peel JL, Burch JB, Conway S, Bachand A, Reynolds SJ.  (2006)  Indoor Air Pollution Assessmentand Cookstove Quality in Two Honduran Communities. Epidemiology 17(6) S351

Reynolds SJ, Milton DK, Heederik D, Thorne PS, Donham KJ, Croteau EA, Kelly KM, Douwes J, Lewis D, Whitmer M, Connaughton I, Koch S, Malmberg P, Larsson BM, Deddens J, Saraf A, Larsson L. Interlaboratory evaluation of endotoxin analyses in agricultural dusts – comparison of LAL assay and mass spectrometry. J. Environ. Monit., 2005, 7, 1371 – 1377.

Merchant JA, Naleway AL, Svendsen ER, Kelley KM, Burmeister LF, Stromquist AM, Taylor CD, Thorne PS, Reynolds SJ, Sanderson WT, Chrischilles EA.  2005.  Asthma and farm exposures – a cohort of rural Iowa children.  Environ Health Perspect 113(3):350-356.

Reynolds SJ, Thorne PS, Donham KJ, Croteau EA, Kelly KM, Lewis D, Whitmer M, Heederik DJJ, Douwes J,  Connaughton I, Koch S, Malmberg P, Larsson BM, Milton DK.  2002.  Interlaboratory comparison of endotoxin assays using agricultural dusts.  AIHA J 63(4):430-438.

Reynolds SJ, Black DW, Borin SS, Breuer G, Burmeister LF, Fuortes LJ, Smith TF, Stein MA, Subramanian P, Thorne PS, Whitten P.  2001.  Indoor environmental quality in six commercial office buildings in the midwest U.S.  Appl Occup Environ Health 16(11)1065-1077.

Donham KJ, Cumro D, Reynolds SJ, Merchant JA.  2000.  Dose-response relationships between occupational aerosol exposures and cross-shift declines of lung function in poultry workers: recommendations for exposure limits.  J Occup Environ Med 42(3):260-269.

Reynolds SJ, Donham KJ, Whitten P, Merchant JA, Burmeister LF, Popendorf WJ. 1996. Longitudinal evaluation of dose-response relationships for environmental exposures and pulmonary function in swine production workers. Am J Ind Med 29:33-40.

Reynolds SJ, Milton DK.  1993.  Comparison of methods for analysis of airborne endotoxin.  Appl Occup Environ Hyg 8 (9):761-767.

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