Evaluation of Potential Take Home Exposure during Laundering Activities: A Simulation Study of Airborne Chrysotile Concentrations Associated with Handling Clothing Exposed to Known Levels of Airborne Asbestos 1 C H R I S T Y B A R L O W P H D S E P T E M B E R 2 0 1 3
Definition: Take-home Asbestos Exposure 2 Exposures that might occur by laundering the clothes of or living with someone who works with asbestos products
Background: Take Home Asbestos Exposure Potential Studies have evaluated the potential for disease associated with reported take home asbestos exposures, but few have attempted to measure take home exposures None have compared take home exposures with the relative magnitude of occupational exposure The few existing exposure studies measured airborne asbestos in PCM, which counts all fibers rather than just asbestos fibers 3
Study Objectives Evaluate potential asbestos exposure for individuals who handle asbestos-contaminated clothing, (i.e., take home or para-occupational exposure) 4 Compare occupational (loading) concentrations with take home (handling/shake-out) concentrations
Summary of the Study Sampling was conducted on site at RJ Lee Laboratories in Pittsburgh, PA, June 12 to 17, 2011 Used a test chamber with a HEPA ventilation system Clothing was exposed to various concentrations of airborne chrysotile asbestos Following exposure, the clothing was shaken and manipulated to simulate laundry activities 5
Study Overview: Loading 6 24 Corner 6 6 6 24 6 Dust Generator/Center 6 Corner 24 For the loading events, grade 7T chrysotile asbestos concentrations in the chamber were adjusted to achieve the following targets: Low (0-1 f/cc), 6 Medium (1-3 f/cc) Corner airflow HEPA Air Filtration Device (AFD) 24 Corner Airlock High (3-5 f/cc)
Results: Loading Concentrations 7
Chamber Diagram: Shake Out 8 Bystander () A Clothes Handler (Personal) 7 Bystander () B 20 6 12 Bystander () D 7 airflow HEPA Air Filtration Device (AFD) Bystander () C Airlock Two shake-out events were conducted using the clothing from each loading concentration level (6 total)
Airborne Concentration (PCM) (f/cc) Airborne Concentration (TEM) (f/cc) Results: Active Clothes Handling 15 minutes of active handling and shaking out of clothing (1 st 15 min) followed by 15 minutes of no activity (2 nd 15 min) 9 0.14 1.0 0.12 0.8 0.10 0.6 0.08 0.06 0.4 TEM 1st 15 min (Active Shake-Out) 2nd 15 min (No Activity) ND = non-detect PCM 1st 15 min (Active Shake-Out) 2nd 15 min (No Activity) ND = non-detect 4A 4B 0.04 0.2 0.02 0.0 0.00 ND ND ND ND ND ND ND ND Low #1 Low #2 Medium #1 High #1 High #2 Low #1 Low #2 Medium #1 High #1 High #2 Loading Loading Concentration Level Level
Airborne Concentration (TEM) (f/cc) Airborne Concentration (PCM) (f/cc) Results: 30-min Personal and Bystander 30-minute concentrations for comparison to the OSHA EL of 1 f/cc 10 0.12 0.5 0.10 0.4 0.08 0.3 0.06 0.2 0.04 TEM v Personal (30 min) v Bystander (30 min) ND = non-detect PCM v Personal (30 min) Bystander (30 min) 5B 5A 0.1 0.02 0.00 ND ND ND ND ND Low #1 #1 Low #2 Medium #1 Medium #2 High #1 High #2 Loading Concentration Level
Airborne Concentration (TEM) (f/cc) Comparison: Loading and Handling/Shake- Out Concentrations by Event For all paired events, the handling/shake-out concentration was a small fraction of loading concentration Handling/shake-out concentrations below both OSHA EL (1 f/cc) and 8-hr TWA (0.1 f/cc) 11 4.0 3.5 3.0 2.5 2.0 1.5 1.0 TEM Concentration during loading (f/cc) TEM Concentration during shake -out (f/cc) OSHA PEL (30-MIN EXCURSION) 0.5 0.0 OSHA PEL (8-HR TWA) ND ND Low #1 Low #2 Medium #1 ND Medium #2 High #1 Paired Concentration Measurments for Each Event (Corresonding Loading/Shake-out Concentrations) High #2
Summary: Air Concentration Results Substantial differences observed between PCM and TEM concentrations for both loading and shake-out Loading Event Loading Sampling (TEM) 30-Minute Shake-Out Sampling a Personal Breathing Zone (TEM) Calculated 8-hr TWA Calculated 8-hr TWA (f/cc) (f/cc) Ratio (%) c Medium #1 0.0976 0.0013 1.4% Medium #2 0.2520 0.0004 e 0.2% e High #1 0.2869 0.0032 1.1% High #2 0.5491 0.0040 0.7% Calculated 8-hr TWA airborne TEM chrysotile concentrations during handling/shake-out were 0.2% - 1.4% of the corresponding loading concentrations 12
Future Considerations Ventilation rates Loading event duration Loading concentration Fiber loading method Clothing type 13
Acknowledgements Cardno ChemRisk Heather Avens Amanda Burns Brooke Donovan Gretchen DeRose Shannon Gaffney John Henshaw Jennifer Jenkins Amy Madl Josh Maskrey Dennis Paustenbach Jennifer Pierce Jennifer Sahmel 14 RJ Lee Rich Lee Matt Sanchez Drew Van Orden Matt Zock