Exposure Assessment (Essentials-Exposure Assessment Course

Video Transcription

Video Summary

Dr. John Downs, Director of the Virginia Poitin Center and Medical Director of Employee Health Services at Virginia Commonwealth University, provides an introductory overview of exposure assessment in occupational medicine. He discusses how exposure assessment guides medical surveillance, the types of environmental and biological monitoring used, and the interpretation and application of occupational exposure limits (OELs). Emphasizing that he is not an industrial hygienist but a medical toxicologist, Dr. Downs underscores the importance of collaboration with industrial hygienists for workplace air sampling.<br /><br />He explains the hierarchy of controls to mitigate hazards—elimination, substitution, engineering controls, administrative controls, and personal protective equipment. Dr. Downs reviews various OELs including OSHA’s legally binding Permissible Exposure Limits (PELs), NIOSH’s Recommended Exposure Limits, and the ACGIH Threshold Limit Values (TLVs), noting considerable differences among them and challenges in their practical application. He highlights the importance of understanding how exposure limits are derived, their intended protective effects, and the complexities in biological monitoring for workplace exposures, such as blood lead levels or cholinesterase activity for pesticides.<br /><br />Dr. Downs also touches on recent regulatory changes affecting exposure limits, the role of biomonitoring in clinical surveillance, and the use of time-weighted averages when interpreting exposure data. He concludes by encouraging critical examination of OELs within their context to better protect worker health.

Keywords

exposure assessment

occupational medicine

occupational exposure limits

industrial hygiene

hierarchy of controls

biological monitoring

medical toxicology

worker health protection