Program staff


The Marijuana Health Monitoring Program was established in January 2014 to oversee the department’s duties outlined in  25-1.5-110 C.R.S. The Task Force Report on the Implementation of Amendment 64 recommended that this program exist to coordinate the ongoing effort of studying the health effects of marijuana use in Colorado. This includes gathering, reviewing and analyzing scientific evidence and data. Program staff are also considered technical staff who support the Retail Marijuana Public Health Advisory Committee (RMPHAC).


Wenhua Ren, PhD
Statistical Analyst

Wenhua Ren is the statistical analyst with the Marijuana Health Monitoring and Research Program. She performs surveillance of marijuana use and health effects throughout the State of Colorado. She obtained her PhD in Neurobiology from Fudan University, China and has worked for almost 20 years performing research within the fields of pain medicine, translational bioinformatics, biostatistics, and public health. In recent years, she worked primarily on statistical method development on cannabis testing data and public health surveillance on cannabis and substance use.   



Richard Holdman

Richard Holdman, MD, MPH
Project Manager and Medical Consultant

Dr. Holdman is the Marijuana Health Monitoring projects manager and medical consultant for the Colorado Department of Public Health and Environment.  Prior to taking on his role at CDPHE, Dr. Holdman obtained his Master’s in Public Health from George Washington University and has worked directly in urgent care facilities and educational roles within the medical field.  Responsibilities included conducting research and assessing data or literature to produce reports that were utilized in clinical practice and medical education.

Elyse Contreras

A. Elyse Contreras, MPH
Program Manager

Elyse Contreras is an epidemiologist and manager of the Marijuana Health Monitoring Program and Marijuana Research Grants Program at the Colorado Department of Public Health and Environment. Elyse has been involved with the Retail Marijuana Public Health Advisory Committee since its inception in 2014 and has worked continuously to distribute the committee’s findings, evidence statements and recommendations throughout Colorado and nationally. Elyse has over 10 years public health experience and holds a Master’s in Public Health degree from the University of Colorado. 


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