Please note: this is a 2-day course, held Monday, November 8, and Tuesday, November 9. By registering, you are committing to attending both days to receive credit.

The new one and two-box Well Mixed Room (WMR) models will be introduced. TEAS-Student (a student version of Task Exposure Assessment Simulator; Windows only) will be provided. Constant emission and decreasing emission models will be covered. Deterministic and probabilistic modeling methods will be used to calculate single exposures or full-shift exposure profiles. A systematic approach to calibrating a WMR model will be introduced, along with the standard generation rate algorithms. Participants are encouraged to bring modeling examples. This PDC course will concentrate on the practical application of WMR models.


Participants should have a background in IH exposure assessment and IH statistics.

Value Added

Participants will receive information on using Well Mixed Room modeling in their exposure assessments.


  • Introduction to the New WMR models
  • Deterministic and Probabilistic Modeling
  • Use of Modeling Software
  • Model Calibration and Use of Generation Rate Algorithms
  • Group Workshops
  • Evaluation of Example Exposure Scenarios
  • Modeling Melee - Group Evaluation of Several Published Scenarios

Learning Outcomes

Upon completion, participants will be able to:

  • Select an appropriate well-mixed room model.
  • Determine when to use a constant emission vs. decreasing emission model.
  • Calibrate a model using field measurements and/or default values.
  • Predict the exposure for a task or a series of different or repeated tasks.
  • Predict an exposure profile using Monte Carlo Simulation.

Transfer of Knowledge

Instructors will evaluate participants’ understanding of the materials presented based on:

  • Group activities
  • Hands-on demonstrations and practicum
  • Practice exercises
  • Workshops


Paul Hewett, Ph.D., CIH, Exposure Assessment Solutions, Morgantown, WV

Paul Hewett (Ph.D., CIH) is the founder and President of Exposure Assessment Solutions, Inc. Dr. Hewett worked for twenty-five years as an industrial hygienist for NIOSH, in the Division of Respiratory Disease Studies, where he specialized in the measurement of pneumoconiosis producing dusts. Dr. Hewett has an MS and Ph.D. in Industrial Hygiene; and is the author of several articles and chapters on exposure assessment, statistics for industrial hygiene, Bayesian Decision Analysis, censored data analysis, sampling strategy design, and the prediction of exposures through modeling.


Really enjoyed the course, and felt like I was taking away something I could put to use immediately.


Overall, awesome tool, an awesome course. Can’twait to practice and learn more.


A very important topic and content that every level of practice should become familiar with.


New critical tools for our profession. Paul has created great stuff that I can use right now.