mercurymercury--containing containing polyurethane floors
TRANSCRIPT
11/23/2009
1
MercuryMercury--containing containing Polyurethane FloorsPolyurethane Floors
Christina Bush, MS, Michigan Dept Community Health
Carl Herbrandson, PhD, Minnesota Department of Health
Health ConsultationsHealth Consultations
OH OH –– Westerville Schools (2003)Westerville Schools (2003)MI MI –– MidMid--Michigan Mercury Floor (2004)Michigan Mercury Floor (2004)OR OR –– SalemSalem--Keizer School District 3M Keizer School District 3M Flooring (2006)Flooring (2006)MNMN
M V R l /Athl ti P lM V R l /Athl ti P l–– Mercury Vapor Release/Athletic Polymer Mercury Vapor Release/Athletic Polymer Floors (2006)Floors (2006)
–– Bethel University (2008)Bethel University (2008)
11/23/2009
3
Michigan’s ExperienceMichigan’s Experience
Letters to schoolsLetters to schools–– “…potential chemical contamination issue…”“…potential chemical contamination issue…”–– “…free screening…” “…free screening…” –– Signed by dept adminSigned by dept admin
11/23/2009
4
Questions/ChecklistQuestions/Checklist
Room dimensions, features (stage, Room dimensions, features (stage, b l t )b l t )balcony, etc.)balcony, etc.)Floor characteristics (mfr, install date, Floor characteristics (mfr, install date, modified?, surface condition)modified?, surface condition)Environment (HVAC cfm, room temps, Environment (HVAC cfm, room temps, how cleaned how used)how cleaned how used)how cleaned, how used)how cleaned, how used)
Responses from schoolsResponses from schools
Worked with Dept EdWorked with Dept Ed4 500 l tt t4 500 l tt t~4,500 letters sent~4,500 letters sent
7070--75 responses75 responses4545--50 potential +’s50 potential +’s
11/23/2009
5
Concerns related to floorsConcerns related to floors
ExposuresExposures
Disposal optionsDisposal options
New flooring over the oldNew flooring over the old
Parental and community concern Parental and community concern ––Risk CommunicationRisk Communication
After 24 years,... After 24 years,... emissions from 1 (large) gym emissions from 1 (large) gym till b ttill b t 800 i t800 i tstill about still about 800 ug per minute800 ug per minute
Equivalent to breaking 1 CFL every Equivalent to breaking 1 CFL every 44--5 minutes 5 minutes -- --
~ 280 broken CFLs per day~ 280 broken CFLs per day
11/23/2009
6
Exposure ConcentrationsExposure Concentrations
–– MixingMixing
–– Building VentilationBuilding Ventilation
–– TemperatureTemperature
No Ventilation, Fans, and Full Ventilation Different Heights NW to SE
3000
3500
5 ' h t
1000
1500
2000
2500
3000
ng/m
3
5 ' hgt noVent.15 ' hgt noVent.25 ' hgt noVent.5 w/fans
15 w/fans
25 w/fans
0
500
0 4 8 12 16 20 24 28
Locations
25 w/fans
3 Full Vent
11/23/2009
7
Temperature dependent saturation
25000
30000
35000
Temperature dependent saturation
30000
35000
Temperature dependent saturation
10000
100000
13 mg / m3
Hg
10000
15000
20000
25000
ug /
m3
13 mg / m 3
Hg0
10000
15000
20000
25000
ug /
m3
13 mg / m 3
Hg0
100
1000
ug /
m3
66 ug / m 3
PMA
0
5000
0 5 10 15 20 25 30 35
Degrees C
0
5000
0 5 10 15 20 25 30 35
Degrees C
PMA1
10
0 5 10 15 20 25 30 35
Degrees C
Chamber Temp vs Emission Rate
25 ng/m2/min
30 ng/m2/min
Chamber Temp vs Emission Rate
25 ng/m2/min
30 ng/m2/min
10 ng/m2/min
15 ng/m2/min
20 ng/m2/min
Emis
sion
Rat
e
Mich Tan (chamber)Mich Green (chamber)
10 ng/m2/min
15 ng/m2/min
20 ng/m2/min
Em
issi
on R
ate
Mich Tan (chamber)Mich Green (chamber)6°C Doubling6°C Doubling
0 ng/m2/min
5 ng/m2/min
0 5 10 15 20 25
Chamber Temp °C
0 ng/m2/min
5 ng/m2/min
0 5 10 15 20 25
Chamber Temp °C
11/23/2009
8
Reference Exposure Reference Exposure ConcentrationsConcentrations
Chronic Chronic –– EPA RfC EPA RfC –– 300 ng/m300 ng/m33
Acute Acute –– CA OEHHA CA OEHHA –– 1800 ng/m1800 ng/m33
ExposureExposure
RfC * 14 / 5 = Workplace ExposureRfC * 14 / 5 = Workplace Exposure
300 ng/m300 ng/m3 3 * 14 / 5 = 840 ng/m* 14 / 5 = 840 ng/m33
11/23/2009
9
Teacher / Student ExposuresTeacher / Student Exposures
TeacherTeacher StudentStudentTeacherTeacher StudentStudent
Event Event DurationDuration 6 hours6 hours 2 hours2 hours
Days per Days per weekweek 5 days5 days 6 days6 days
Ventilation Ventilation RateRate 1.2 m1.2 m33 / hr/ hr 1.9 m1.9 m33 / hr/ hr
Simplified inhalation modelSimplified inhalation modelInhalation Exhalation20%
Blood
80%
> 7 %
t1/2 = 14 - 25hr
InternalCompartments
t1/2 = 48 - 120 hr
Hg0 Hg++
Hg0 Hg++t1/2 = 48 hrt 58 d
Urine
2.4%
Saliva(minimal)
Dermal(minimal)
Feces
9.2 % t1/2 = 58 d
11/23/2009
10
Blood [Hg]
1.82
Teacher 3000 ng/m3 &30 hrs/wk
0.40.60.8
11.21.41.6
ug/L Daily Exposure at RfC
30 hrs/wkStudent 3000 ng/m3 &12 hrs/wk
Teacher 750 ng/m3 &30 hrs/wk
00.2
0 4 8 12 16 20
Wks
Student 750 ng/m3 &12 hrs/wk
Mercury Body Burden
700
800Teacher 3000 ng/m3 &30 hrs/wk
200
300
400
500
600
ug Daily Exposure at RfC
30 hrs/wkStudent 3000 ng/m3 &12 hrs/wk
Teacher 750 ng/m3 &30 hrs/wk
0
100
0 4 8 12 16 20
Wks
Student 750 ng/m3 &12 hrs/wk
11/23/2009
11
Modeled Hg concentrations with ventilation (CFM / Gym Volume)
2500
3000
Modeled Hg concentrations with ventilation (CFM / Gym Volume)
2500
3000CFM / vol (closed)0.46% / min
Modeled Hg concentrations with ventilation (CFM / Gym Volume)
2500
3000
CFM / vol (closed)0.46% / min
RecommendedMax - Shortterm
Modeled Hg concentrations with ventilation (CFM / Gym Volume)
2500
3000
CFM / vol (closed)0.46% / minRecommendedMax - ShorttermRecommended
1000
1500
2000
2500
Hg (n
g/m
3)
CFM / vol (closed)0.46% / min
1000
1500
2000
2500
Hg (n
g/m
3)
RecommendedMax - Shortterm
RecommendedMax - Longterm
1000
1500
2000
2500
Hg (n
g/m
3)
Max Shortterm
RecommendedMax - Longterm
CFM / vol 3.11% /min
CFM / vol 3.70% /min1000
1500
2000
2500
Hg (n
g/m
3)
RecommendedMax - LongtermCFM / vol 3.11% /minCFM / vol 3.70% /minCFM / vol 2.25% /min
0
500
0 2 4 6 8 10 12
Time (hr)0
500
1000
1500
2000
2500
3000
3500
0
500
0 2 4 6 8 10 12
Time (hr)0
500
1000
1500
2000
2500
3000
3500
0
500
0.0 2.0 4.0 6.0 8.0 10.0 12.0
Time (hr)0
500
1000
1500
2000
2500
3000
3500
0
500
0.0 2.0 4.0 6.0 8.0 10.0 12.0
Time (hr)0
500
1000
1500
2000
2500
3000
3500
Mercury Exposure Concentration @ 2000 CFM(Annual average - 1500 ng/m3)
1500
2000
2500
3000
y Va
por (
ng/m
3)
0
500
1000
1-Jul-08
31-Jul-08
30-Aug-08
29-Sep-08
29-Oct-08
28-Nov-08
28-Dec-08
27-Jan-09
26-Feb-09
28-M ar-09
27-Apr-09
27-M ay-
09
26-Jun-09
26-Jul-09
25-Aug-09
24-Sep-09
Mer
cury
Ventilation needed to maintain at target (750 ng/m3)
12 000
14,000
tilat
ion
-
2,000
4,000
6,000
8,000
10,000
12,000
1-Jul-08
31-Jul-08
30-Aug-08
29-Sep-08
29-Oct-08
28-Nov-08
28-Dec-08
27-Jan-09
26-Feb-09
28-M ar-09
27-Apr-09
27-M ay-
09
26-Jun-09
26-Jul-09
25-Aug-09
24-Sep-09
Cubi
c Fe
et p
er M
inut
e (C
FM) V
ent
11/23/2009
12
= ventilateMitigation option
http://www.health.state.mn.us/divs/eh/hazardous/topics/mercury/hgvaporcalc.html
NeedsNeeds
How many floors? How many floors? Temporal variability?Temporal variability?What happens when covered?What happens when covered?
________________________________Disposal options?Disposal options?p pp pOther uses?Other uses?