denise l daggett ms cih the scripps research institute la jolla ca daggett@scripps edu l.
Download
Skip this Video
Download Presentation
An Industrial Hygienist’s Encounter with Dirty Sock Syndrome

Loading in 2 Seconds...

play fullscreen
1 / 29

An Industrial Hygienist’s Encounter with Dirty Sock Syndrome - PowerPoint PPT Presentation


  • 160 Views
  • Uploaded on

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

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'An Industrial Hygienist’s Encounter with Dirty Sock Syndrome' - yetty


Download Now 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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
denise l daggett ms cih the scripps research institute la jolla ca daggett@scripps edu
Denise L. Daggett, MS, CIH

The Scripps Research Institute

La Jolla, CA

daggett@scripps.edu

An Industrial Hygienist’s Encounter with Dirty Sock Syndrome

case study outline
Case Study Outline
  • The Scene
  • The Situation
  • Testing and Results
  • The “Resolution” and Lessons Learned
  • Outrage Control
the scene the scripps research institute tsri
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
how it all began
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
symptoms
Symptoms
  • Eye irritation
  • Upper respiratory irritation
  • Taste in mouth
  • Headaches
  • Nausea
  • Mild to severe responses
approached as an indoor air quality project
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
additional complaints
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
pinpointing origin
Pinpointing Origin
  • During an episode
  • Entered the air handler unit (AHU) feeding the lab
  • Odor present and very strong
  • Ah-Ha moment
fact finding
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
the experts
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?
biofilm
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

working theories about causation
Working Theories about Causation

Chemical

Oxidized metal

Salts

Moisture

Debris from fires

Other debris

Biological

Bacteria w/ biofilm

Mold

Protozoa

likely not one or the other but both
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?

next step clean the coils
Next Step: Clean the Coils
  • First cleaning occurred in April 2009
    • A few odor complaints, then gone for several months
    • Back in autumn
  • Outrage of occupants continues to simmer
biofilms and antimicrobials
Biofilms and Antimicrobials
  • Biofilms are hard to breakdown and treat
  • Protection
  • Persister cells
  • Colony can reestablish in as little as 100 to 200 hours
coil facts
Coil Facts
  • Copper and other metal alloys
  • Fine fin width/huge surface area
  • 3 levels of filtration
    • Poly
    • Secondary
    • Final
  • All AHUs with problem are from the same manufacturer
coil exposure conditions
Coil Exposure Conditions
  • Constant exposure to salts, humidity
  • Wild fires in 2003, 2007
  • Dew point & temperature differential plays a role
what now
What Now?
  • As predicted the odor dissipated for the summer
  • Odor returned Oct 2010
  • Employees continue to be concerned
  • Now 5 buildings involved
pursued another path uv
Pursued Another Path - UV
  • After 2009 cleaning, a UV system was installed
  • No benefit noted
  • 2010: a better designed UV system installed
  • Unfortunately, no improvement
still a third path bring in help
Still a Third Path: Bring in Help!
  • Issued an RFP
    • Identify odor source
    • Develop control strategy
  • Awarded contract this month
  • Winning company from Texas with experience
managing the outrage
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