1 / 26

An Industrial Hygienist’s Encounter with Dirty Sock Syndrome:

Denise L. Daggett, MS, CIH The Scripps Research Institute daggett@scripps.edu. An Industrial Hygienist’s Encounter with Dirty Sock Syndrome:. Case Study Outline. The Scene The Situation The “Resolution” Results and Lessons Learned Outrage Control.

taylor-owens
Download Presentation

An Industrial Hygienist’s Encounter with Dirty Sock Syndrome:

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Denise L. Daggett, MS, CIH The Scripps Research Institute daggett@scripps.edu An Industrial Hygienist’s Encounter with Dirty Sock Syndrome:

  2. Case Study Outline • The Scene • The Situation • The “Resolution” • Results and Lessons Learned • Outrage Control

  3. The Scene: The Scripps Research Institute (TSRI) • Academic research • > Million square feet of lab and office space • 13 lab buildings • ~500 fume hoods • 100% fresh air

  4. What is that smell? The Situation

  5. How It All Began • Late 2005 • Reports of odors in our large chemistry building • Musty • Grandma’s attic • Wet dog, wet burlap, wet money • Locker room • Isolated to a couple of labs • Occurred around mid-day • Worsened through the winter months • Disappeared in April

  6. Symptoms • Eye irritation • Upper respiratory irritation • Taste in mouth • Headaches • Nausea • Mild to severe responses

  7. Approached as an Indoor Air Quality Project • Interviews • Questionnaires • Odor logs and phone calls to notify • Air sampling • Outrage escalated each time an episode occurred • Brought in consultants • Offered medical evaluations with our Occupational Medicine Physician

  8. Additional Complaints • In 2008, occupants in another lab building reported same condition • Always in the cooler months • Same time of day • Occupants would point to certain supply grills as the source • Some of our neighboring companies and institutions were experiencing the same problems

  9. Pinpointing Origin • During an episode • Entered the air handler unit (AHU) feeding the lab • Odor present and very strong • Ah-Ha moment

  10. Fact Finding and Data The “Resolution”

  11. Fact Finding • Searched the literature • Condition described as Dirty Sock Syndrome • Small HVAC units (cars) • Residential units • Large AHUs (sport arenas) • Odor due to bacteria and mold growth on the coils • Employees want to know • What the odor is • What is flying through the air • No description of the actual chemical composition

  12. The Experts • Spoke to: • Harvard researcher – mainly bacteria with a biofilm, odor is metabolites from mainly bacteria • Houston engineer – salts, dirt, and microbial material • Montana State University – bacteria with a biofilm • TSRI Occupational Medicine Physician – typical indoor air quality symptoms, likely will not cause permanent harm • What is a biofilm?

  13. Biofilm • forms when bacteria adhere to surfaces in aqueous environments and excrete a slimy, glue-like substance • can be formed by a single bacterial species, but more often consist of many species, debris and corrosion products • Other examples: plaque on teeth, slime on pet feed/water bowls Information and figure courtesy of the Center of Biofilm Engineering, Montana State University

  14. Sampling in an Air Handling Unit

  15. Working Theories about Causation Chemical Oxidized metal Salts Moisture Debris from fires Other debris Biological Bacteria w/ biofilm Mold Protozoa

  16. Biological and Chemical Results and Lessons Learned

  17. Sampling and Data:Chemical

  18. Sampling and Data: Biological

  19. Likely Not One or the Other but Both Chemical Biological Dew Point plays a role: When coil is damp, odor occurs. Is the smell from a wet coil (like wet pavement) or moistened biofilm?

  20. What Now? Clean the Coils

  21. Did the Cleaning Work? • First cleaning occurred in April 2009 • A few odor complaints, then gone for several months • Back in autumn • Outrage of occupants continues to simmer

  22. Managing the Outrage • One-on-one conversations • Town hall-style meeting • Angry letters and conversations • Back to one-on-one conversations to key individuals • Technical summit

  23. The Future • As predicted the odor dissipated for the summer • Odor will return • Back to experts again: RFP issued Oct 2010 • Bringing in experienced personnel • Treatment needs to be ongoing

  24. One Path - UV • After 2009 cleaning, a UV system was installed • No benefit noted • 2010: a better designed UV system installed • Benefit remains to be seen

  25. Questions? daggett@scripps.edu

  26. Movie Description:   Biofilm and Biocide Clip http://www.erc.montana.edu/Res-Lib99-SW/Movies/2005/05-M005.htm http://www.erc.montana.edu/default.htm This is a computer model simulation in which the hypothetical persister protection mechanism is active. Biofilm formation begins with the development of independent cell clusters that merge over time. An antimicrobial treatment initiated at 100 hours rapidly kills most of the live cells, but persister cells survive. When the persister cells eventually resuscitate, they give rise to new growth that begins in clonal pockets but rapidly extends throughout the biofilm.   Movie Authors:  J.D. Chambless, P.S. Stewart, S.M. Hunt Reference:  Chambless, J.D., Hunt, S.M., and Stewart, P.S. 2006. A Three-Dimensional Computer Model of Four Hypothetical Mechanisms Protecting Biofilms from Antimicrobials. Applied and Environmental Engineering, 72(3):2005-2013.

More Related