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4/24/2012
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Matthew L. Berkheiser, DrPH, CIH, CSP
Executive Director & Chief Safety Officer
Environmental Health & Safety
May 2012
Indoor Air Quality:
Mold, Patients
and…Elevators?
Background
• Cost of hospital-acquired infections
• History on decision to
investigate the elevator shaft
Other Regulatory Requirements
• American Institute of Architects – Created in 1996. Expanded in 2001 edition of The
Guidelines for Design and Construction of Hospital and Healthcare Facilities. Created the Infection Control Risk Assessment (ICRA).
– Revised in 2003 and 2006 and 2010• An ICRA is multidisciplinary, organizational, documented
process that considers the facility's patient population and program.
• Focuses on reduction of risk from infection • Acts through phases of facility planning, design,
construction, renovation, facility maintenance.• Coordinates and weighs knowledge about infection,
infectious agents, permitting the organization to anticipate potential impact.
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Other Regulatory Requirements
• Joint Commission– Adopted AIA guidelines 2002
– Environment of Care (EC.02.06.05)• When planning for demolition, construction, or
renovation, the hospital conducts a preconstruction risk assessment for air quality requirements, infection control, utility requirements, noise, vibration, and other hazards that affect care, treatment, and services.
MD Anderson Cancer Center
• Because we are a cancer hospital, the majority of our population is immuno-compromised and therefore are susceptible to opportunistic infections that can be caused by exposure to mold spores.
• Very important that we contain mold spores to protect our patients from opportunistic infections.
• Valuable research that can be invalidated by contamination.
Minimum Precautions
• Some type of containment: surface, double flap of poly on door, zip wall, containment cube, or full containment.
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Minimum Precautions
• Room air supply should be covered and exhaust should be filtered or covered completely
• Trash must be double bagged and removed in a covered trash cart
• Terminal cleaning
once work is
complete
Minimum Precautions
• Clearance: visual, surface sampling, air sampling.
• Personal protective equipment: safety glasses, gloves, tyvek, respirator.
• Do not leave containment
wearing PPE!!!
Mold Prevention
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Mold needs 3 things to grow…
Spore
WaterFood
Eliminate any one of the three and mold cannot grow…
• Spores are ubiquitous-impossible to eliminate all of them
• Food sources exist everywhere-its impossible to eliminate all paper based products.
• So that leaves WATER!
All that effort
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Visualization of air leaving shaft
While difficult to see in the pictures… the air is leaving the shaft through the gap between the door and the floor and entering the hospital lobby and elevator car.
The Theoretical Path
Spores enter vents on roof
Into elevator shaft
Air travels through vent to
top of shaft
Vent terminates into
shaft
Elevators travel up
and down
Air escapes from shaft into
hospital around gaps b/t car
and bldg
Elevator Vulnerability Assessment
??
In Houston Cladosporium
98% frequency on spore
traps, penicillium/
aspergillus spores 91% and
basidiospores 96%
frequency
Air entering elevator
shaft
Air/spores
Enter through first
floor
HVAC air enters
On 8th floor
HEPA filtered
? = what are the frequencies and concentrations
?
?
?
?
?
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Hypothesis
• There is a positive correlation between the number of Penicillium/Aspergillus-like spores, cladosporium, ascospores, basidiospores in spores/m3 found in the hoistway vent of an elevator shaft and the levels of the same spores, sampled near simultaneously and near the outdoor intake of the elevator shaft.
• There is a positive correlation between the number of Penicillium/Aspergillus-like spores, cladosporium, ascospores, basidiospores in spores/m3 found in the hoistway vent of an elevator shaft and the levels of the same spores, sampled near simultaneously in elevator lobbies of the study location.
Hypothesis
• There is a positive correlation between the number of Penicillium/Aspergillus-like spores, cladosporium, ascospores, basidiospores in spores/m3 found in the 5th floor elevator lobby and the levels of the same spores, sampled in the 5th floor surgery recovery area collected on the same day within the same time frame.
Hypothesis
• Compare hoistway vent to outdoor environment for 0.3, 0.5, 1.0, 2.5, 5.0, 10.0 µm particle concentrations.
• Are the two areas similar or different?
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Hypothesis
• There is a positive correlation between the concentration of particles at 0.3 um, 0.5 um, 1.0 um, 2.5 um, 5.0 um, 10.0 um sizes air found in the hoistway vent of an elevator shaft and the levels of the same collection of particles found in
the elevator lobbies and other sampling locations.
Specific Aims
Aim 1: To determine if external Penicillium/Aspergillus-like spores are entering
the healthcare facility via the elevator shaft and hoistway vents.
Aim 2: To determine levels of Penicillium/Aspergillus-like spores outdoors, in
the elevator shafts, and indoors in areas possibly affected by elevator shaft air.
Aim 3: To determine if Aspergillus spores (niger, flavus, fumigatus, terreus,
versicolor) identified indoors are the same as spores found outside the healthcare facility.
Aim 4: To determine if there is a direct correlation between Aspergillus
spores/m3 of air, species occurrence and particle counts for the locations
sampled.
Aim 5: To obtain air velocity in the elevator shaft during controlled situations and calculate air flows to provide additional data that addresses the
hypotheses.
Sample/Measurement Methods
• Particle counts (0.3, 0.5, 1.0, 2.5, 5.0, 10.0 um)
• Temperature and relative humidity
• Polycarbonate filters
– Aspergillus (niger, flavus, fumigatus, terreus, versicolor)
• Spore Traps
– Penicillium/Aspergillus-like spores
– Basidiospores (>5.0 um and <5.0 um)
– Cladosporium (>5.0 um and <5.0 um)
– Ascospores (>5.0 um and <5.0 um)
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Sampling Locations
• Outside
• Hoistway
• 11th Floor Elevator Lobby
• 5th Floor Elevator Lobby
• 5th Floor Surgery Recovery Area
• 5th Floor Building Cross Connection
• 1st Floor Elevator Lobby
5th Floor Sampling Locations
Shaft Duct
Drill holes in duct to complete sampling to
capture spores and particles
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Sampling Equipment
Spore Traps
15 liters/minute
10 minutes
Polymerase Chain
Air sample on
37 mm polycarbonate filters
30 liters/minute for 34
minutes
Laser Particle Counter
2.83 liters of air collected
3 measurements averaged
Study Duration
• First sample collected April 7th, 2010
• Final sampling event was September 2nd, 2010
• A change of direction occurred in May27th, 2010 (pre/post)
Aim 6. To evaluate whether any effect is observed due to the installation of a hoistway vent damper, installed serendipitously during this study.
Damper Installed
• Installed a damper in the ductwork between the air shaft and the outdoor air
• Damper is designed to operate between 0.01 and 0.05 inches water gauge
• Stays closed unless pressure dictates opening
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Final Data Collected
• 254 PCR Cassettes
• 363 Spore Traps for seven spore types
• 2178 Particle counts
• 363 Temperature and relative humidity
• Data was divided into pre and post conditions because of the damper
installation
Analysis of Data
• Fisher’s Exact test to compare locations for positive sample frequency and determine differences between pre and post
• Spearman correlation to determine if spores and particles are correlated between two environments
• Wilcoxon Rank Sum to compare median values for differences pre and post
Geometric Mean, Penicillium/Aspergillus-like spores
97.677.7
68.4
46.533.6
52.4
101.9
0.0
50.0
100.0
150.0
200.0
250.0
300.0
350.0
400.0
Outside Hoistway 11th floor 5th floor 5th floor
recovery
5th floor
cross
connection
first floor
Pre Post
only 1 sample positive 270 spores/m3
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Outside Hoistway Vent p value
Penicillium/Aspergillus –like
spores
Pre-Installation11/21 (52%) 8/22 (36.4%)
0.364
Post-Installation26/30 (87%)
1/30 (3.3%) 0.001
Fisher’s Exact Test and Spearman Results Penicillium/Aspergillus – like spores, Comparison of Positive Samples Pre and Post Conditions
Pre Rho p Value Post Rho p Value
LOCATION
Outside 0.8008 0.0001 -0.2795 0.1347
11th Floor Elevator lobby 0.3879 0.0744 -0.2129 0.2586
5th Floor Elevator Lobby 0.8964 0.0001 -0.2149 0.2542
5th Floor Recovery 0.3699 0.0901 -0.1899 0.3149
G5P5 Cross Connection 0.3814 0.0799 -0.2033 0.2812
1st floor elevator lobby 0.3077 0.1635 -0.155 0.4135
Spearman
Fisher’s
Comparison of Particle Count Means Hoistway vs. Outside
0.00E+00
1.00E+07
2.00E+07
3.00E+07
4.00E+07
5.00E+07
6.00E+07
0.3 um 0.5 um 1.0 um 2.5 um 5.0 um 10 um
outside pre
hoistway pre
outside post
hoistway post
Comparison of Particle Count Means Pre and Post the 11th floor
0.00E+00
2.00E+06
4.00E+06
6.00E+06
8.00E+06
1.00E+07
1.20E+07
0.3 um 0.5 um 1.0 um 2.5 um 5.0 um 10 um
Pre
mean
Post
mean
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Geometric Mean Cladosporium (>5.0 um)
169.7
43.734.8 29.1
38.1 35.8
102.5
361.6
27 27 27 32.7 29.4 36.1
0
50
100
150
200
250
300
350
400
Outside Hoistway 11th floor 5th floor 5th floor
recovery
5th floor cross
connection
first floor
pre post
Geometric Mean Cladosporium (<5.0 um)
181.3
2746.5
31.9 27 30.256.7
429.5
0
27
0
27 27 27
0
50
100
150
200
250
300
350
400
450
500
Outside Hoistway 11th floor 5th floor 5th floorrecovery
5th floorcross
connection
first floor
pre
post
Additional Results
• Ascospores and basidiospores did not provide enough positive samples inside the building to be useful as a tracer during this study.
• Particle count correlations supported the hypothesis between outside and the hoistway and other floors to hoistway comparisons.
• Relative humidity inside the duct decreased from 49.3 to 37.8 following the damper installation.
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Conclusions (continued)
• Hospital areas studied were clean in relation to the outside Aspergillus species levels, particle levels and other mold spores collected
• The use of Penicillium/Aspergillus-like and Cladosporium(>5.0 um) spores and particle counts were the most effective measures for evaluating the indoor quality compared to outside levels.
• A significant correlation existed between parameters for the environment outside and inside the hoistway.
Conclusions (continued)
• Consider elevator shafts as potential spore sources.
• Evaluate and understand how the air flows through the shafts and into the buildings. The findings may prompt consideration of retrofits of similar dampers.
• Design criteria should be updated for future hospital buildings.
• The new criteria should include consideration for protecting the elevator shaft from exterior air utilizing a damper similar to the one in this study, or alternate solutions achieving the same results.
• Sharing this information with building code organizations in future comment sessions when updating elevator and building ventilation code sections may be helpful. No existing recommendations or building code requirements specifically address this issue.
QUESTIONS / COMMENTS
Matthew L. Berkheiser, DrPH, CIH, CSPExecutive Director & Chief Safety Officer
Environmental Health & SafetyMay 2012
