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Welcome to the
Model Aquatic Health Code Network Webinar
Indoor Air Quality and Swimming FacilitiesFeatured Presenter: Ernest R. Blatchley III, Ph.D
Join the MAHC Network! Email MAHCnet@naccho.org and request to be added to the mailing list.
Please use your computer speakers to listen to today’s presentation.
Questions may be submitted via the chat box.
This webinar is being recorded.
We will begin at 1:30 PM Eastern.
Tuesday, January 22, 2018
Thank you for your interest and attendance!
MAHC NETWORKCMAHC UPDATES
January 22, 2019
Douglas Sackett, Executive Director
Council for the Model Aquatic Health Code
CMAHC UPDATES:
▪ CMAHC Ad Hoc Committee Update-▪ Indoor Aquatic Facility Ventilation Design and Air Quality
▪ Membership
Indoor Aquatic Facility Air Quality
❑ Issue
▪ Poor indoor air quality has increasingly been linked to health effects
▪ Increased reporting of health events
▪ Large indoor facilities have proliferated
▪ Bather exposure times longer in these facilities
▪ Does not appear that ventilation standards are adequate to keep up with aquatics needs
CMAHC UPDATESAd Hoc Committee
❑ Indoor Aquatic Facility Ventilation Design and Air Quality ▪ Chair: Ralph Kittler, Seresco
▪ Members:Michael Beach, CDCDouglas Sackett, CMAHCChip Blatchley, Purdue UniversityJason Schallock, Anderson PoolworksJeff Nodorft, Councilman-HunsakerStephen Springs, Brinkley Sargent Wiginton ArchitectsJames Harrison, GMB HVAC and pool water filtration designerHarry Milliken, retired from Desert-AireGary Lochner, InnoventSandy Kellogg, Fairfax County Park AuthorityDon Baker, Paddock Pools
CMAHC UPDATESAd Hoc Committee
❑ Indoor Aquatic Facility Ventilation Design and Air Quality
▪ Objectives and Outcomes ▪ Identify and assess the factors affecting air quality at indoor
aquatic facilities, including:
– Air handling/air distribution system design, effectiveness, and operation
– Water quality/water chemistry
– Pool water treatment operation and maintenance
– Pool types (flat water, agitated water, water features, hot water)
» Evaporation rate calculation.
– Bather load
– Spectator areas
CMAHC UPDATESAd Hoc Committee
❑ Indoor Aquatic Facility Ventilation Design and Air Quality
▪ Objectives and Outcomes (continued)• Review and evaluate current Model Aquatic Health Code (MAHC)
requirements to determine if identified factors affecting air quality are adequately addressed.
• Develop revisions to the MAHC design and operational standard/best practice recommendations and corresponding Annex content to address ventilation/air quality design and operational criteria, as appropriate
CMAHC UPDATESMembership
▪ Renew your membership for the 2018-2020 Conference Cycle or join for the 1st time! (memberships expired Nov. 2017)▪ https://cmahc.org/membership-signup-form.php
MAHCMore Information: Search on
“CDC MAHC” or visit the Healthy Swimming MAHC Website:
www.cdc.gov/mahc Email: mahc@cdc.gov
CMAHCMore Information: Search on “CMAHC”
or visit the CMAHC Website: www.cmahc.org
Email: info@cmahc.org
Contact Information
Doug SackettExecutive Director, CMAHC
E-mail: DouglasSackett@cmahc.orgPhone: 678-221-7218
Indoor Air Quality inSwimming Facilities
Ernest R. Blatchley III, Ph.D., P.E., BCEE, F. ASCE
Lee A. Rieth Professor in Environmental Engineering
Lyles School of Civil Engineering and Division of Environmental & Ecological Engineering
Purdue University
blatch@purdue.edu
Presented as a Webinar for the Council for the Model Aquatic Health Code
22 January 2019
11
Overview
• Background/motivation
• Why do we chlorinate pools?
• DBPs in pools and their precursors
• Health effects of DBP exposure in pools
• Effects of swimmers on indoor air quality (IAQ)
• Physics of DBP transfer from water to air
• Planned research• Scope of work• Methods• Pool selection• Modeling• Expected outcomes
• Relationship to other IAQ in other facility types
• Q&A
12
Swimming as Exercise, Recreation, Therapy
• Second most common form of exercise in the U.S.
• Benefits• Cardiovascular health
• Fitness
• Used as therapy for a wide range of medical conditions
13
Water Management Systems for Pools
• Physical separation for particles• Filter
• Membranes
• Disinfection/Oxidation• Chlorine is most common
• Alternatives• UV
• Ozone
• Monopersulfate
• Combinations
Image from: https://www.inyopools.com/Blog/how-a-swimming-pool-works/
14
Chlorination of Swimming Pools
Advantages
• Effective against bacteria, viruses
• Powerful oxidant
• Inexpensive, simple to use
Disadvantages
• Ineffective against protozoa, especially Cryptosporidium
• Disinfection Byproducts (DBPs)
E. coli O157:H7Image from:
https://www.researchgate.net/figure/E-Coli-
CDC_fig1_311753193
Human NorovirusImage from: Kniel (2014) “The makings of
a good human norovirus surrogate,” Current Opinion in Virology, 4, 85-90.
Cryptosporidium parvum OocystImage from:
https://esemag.com/archive/0103/crypto.html
From: Hlavsa et al. (2015) “Outbreaks of
Illness Associated with Recreational Water –
United States, 2011-2012, MMWR, 64, 24, 668-672.
15
DBPs in Pools
• > 100 DBPs identified
• Include volatile and non-volatile (polar and ionic) forms
• Volatile DBPs• Inorganic chloramines (NH2Cl, NHCl2,
NCl3)
• Organic chloramines (CH3NCl2)
• THMs (CHCl3, CHBrCl2, CHBr2Cl, CHBr3)
• Halogenated nitriles (CNCl, CNBr, CNCHCl2)
• Present in all chlorinated pools
From: Weaver et al. (2009) “Volatile disinfection by-product analysis from chlorinated indoor swimming pools,” Water Research, 43, 13, 3308-3318.16
• Only trace quantities of NH3 in pools
• Reduced-N in pools• Urine
• Sweat
• Urea
• Creatinine
• Uric acid
• Amino acids
Inorganic Chloramines in Pools:Where Do They Come From?
Uric Acid3.0 mmol/d
Urea343 mmol/d
Creatinine12.9 mmol/d
Arginine0.025 mmol/dGlycine
1.80 mmol/d
Free Amino Acids: 5.7 mmol/d
Histidine1.10 mmol/d
17
Sources of DBP Precursors in Pools• Urine
• 30-35 mL/Bather (Gunkel and Jessen, 1986)(0.6-0.7 g Urea/Swimmer)
• 60-78 mL/Bather (Erdinger et al., 1997)(1.3-1.7 g Urea/Swimmer)
• Sweat• Production is Highly Variable• Competitive Swimmers: 1 L/Person/Hour
(1.5 g Urea/Swimmer/hr)• Less for others
• Natural Moisturizing Factor (NMF) – Skin• Attract and Retain Water from Atmosphere• Amino Acids, Urea, Lactate, …• Easily Removed from Skin with Water
(0.2 g Urea/Swimmer)
Based on values reported by Institute of Sport and Recreation Management (ISRM, 2009)
Image from: https://jezebel.com/5914953/an-anonymous-interview-with-a-grown-man-who-pees-in-the-pool
18
Health Effects Associated with Chemical Exposure in Chlorinated Pools
Bernard et al. (2009) “Impact of Chlorinated Swimming Pool Attendance
on the Respiratory Health of Adolescents,” Pediatrics, 124, 4, 1110-1118.
“CONCLUSIONS. Our data suggest that infant swimming practice in chlorinated indoor swimming pools is associated with airways changes that, along with other factors, seem to predispose children to the development of asthma and recurrent bronchitis.”
19
Health Effects Associated with Chemical Exposure in Chlorinated Pools
Bougault et al. (2009) “The Respiratory Health of Swimmers,”
Sports Med., 39, 4, 295-312.
“Although swimming is generally beneficial to a person’s overall health, recent data suggest that it may also sometimes have detrimental effects on the respiratory system. Chemicals resulting from the interaction between chlorine and organic matter may be irritating to the respiratory tract and induce upper and lower respiratory symptoms, particularly in children, lifeguards and high-level swimmers. The prevalence of atopy, rhinitis, asthma and airway hyper-responsiveness is increased in elite swimmers compared with the general population.”
Fantuzzi et al. (2013) “Airborne trichloramine(NCl3) levels and self-reported healthsymptoms in indoor swimming pool workers: dose-response relationships,” Journal of Exposure Science and Environmental Epidemiology, 23, 88-93.
“In conclusion, this study shows that lifeguards and trainers experience ocular and respiratory irritative symptoms more frequently than employees not exposed. Irritative symptoms become significant starting from airborne NCl3 levels of 40.5 mg/m3, confirming that the WHO-recommended value can be considered protective in occupational exposure to airborne NCl3 in indoor swimming pools.”
20
Chiu et al. (2017), “Respiratory and Ocular Symptoms Among Employees of an Indoor Waterpark Resort — Ohio, 2016,”
MMWR, 66, 37, 986-989.
• July 2015: complaints of respiratory and ocular symptoms
• January 2016: site visit• Survey of employees
• Water, air quality measurements
• Chloramines in water*
• Endotoxin, microbial causes unlikely
• HVAC system problems
21
Health Effects Associated with Chemical Exposure in Chlorinated Pools
• Respiratory Problems• Research in US, Europe
• > 100 Articles Since 1976
• Asthma, Other Adverse Respiratory Endpoints• Children
• Elite Athletes
• Swimming Instructors and Lifeguards
• Swimming Often Prescribed for Asthmatics
• Bladder Cancer (Villanueva et al. [2007] American Journal of Epidemiology, 165, 148-156).• Linked to THM Exposure
• Swimming Enhanced Risk
• Eye Irritation 22
Effects of Swimmers on Gas-Phase NCl3
Date, Time
6/15 6/22 6/29 7/6 7/13 7/20 7/27 8/3
Bath
er L
oadin
g
0
20
40
60
80
100
120
140
160
Gas-p
hase N
Cl 3
Concentr
ation (
mg/m
3)
0.0
0.2
0.4
0.6
0.8
Bather Loading
Gas-Phase NCl3
WHO (2006) NCl3 Guideline
Bernard et al. (2006) NCl3 Guideline
23
Time
13:00:00 14:00:00 15:00:00 16:00:00 17:00:00
Bath
er N
um
ber
0
10
20
30
40
50
60
NC
l 3 C
oncentr
ation (
mg/m
3)
0.0
0.2
0.4
0.6
0.8
Total
NCl3 Concentration - Pool Deck
NCl3 Concentration - 1.6 m Above Deck
WHO (2006) NCl3 Guideline
Bernard et al. (2006) NCl3 Guideline
Effects of Swimmers on Gas-Phase NCl3
24
25
Re
lative
Hum
idity
(%)
35
40
45
50
55
60
65
[NC
l 3] (m
g/m
3)
0.0
0.2
0.4
0.6
0.8
1.0
Ba
the
r L
oa
d
0
10
20
30
40
50
60
70
NCl3Bather Load
[CO
2]
(pp
mv)
0
1000
2000
3000
4000
Date
11/2
7/17
11/2
8/17
11/2
9/17
11/3
0/17
12/1
/17
12/2
/17
12/3
/17
12/4
/17
[VO
C]
(pp
bv)
0
20
40
60
80
IAQ Monitoring Data
Gas-Liquid Transfer: Two-Film Model
Liquid Film
Gas Film
NCl3(aq)
NCl3(g)
lg
OH
L kHk
RTC
K
112 +=
Overall Resistance Liquid-Film Resistance
Gas-Film Resistance
Diffusion(liquid)
Diffusion (gas)
26
Gas-Liquid Transfer: Two-Film Model
Liquid FilmGas Film
lg
OH
L kHk
RTC
K
112 +=
Overall Resistance Liquid-Film Resistance27
Compound
Typical Liquid-Phase
Concentration(mg/L)
Henry’s Law Constant
(atm)
Equilibrium Gas-Phase
Concentration (mg/m3)
ReportedGas-Phase
Concentration (mg/m3)
HOCl 1.2 0.060 0.053 N.A
Cl2 0.000012 767 0.0067 N.A
NH2Cl 0.30 0.45 0.10 N.A
NHCl2 0.10 1.52 0.11 N.A
NCl3 0.070 435 23 0.1-0.7
CHCl3 0.080 185 11 0.009-0.058
CHBr2Cl 0.0040 57.3 0.17 0.002-0.003
CHBr3 0.0010 21.5 0.016 0.0008
CNCl 0.0030 108 0.24 N.A
CNCHCl2 0.00080 0.21 0.00013 N.A
CH3NCl2 0.020 154 2.3 0.016-0.07
Fro
m:W
eng,
S.C
.; W
eave
r, W
.A.;
Afi
fi, M
.Z.;
Bla
tch
ley,
T.N
.; C
ram
er, J
.; C
hen
, J.;
B
latc
hle
y II
I, E
.R.
(20
11
) “D
ynam
ics
of
Gas
-ph
ase
Tric
hlo
ram
ine
(NC
l 3)
in
Ch
lori
nat
ed
, In
do
or
Swim
min
g Po
ol F
acili
ties
,” I
nd
oo
r A
ir, 2
1, 5
, 39
1-3
99
.
28
Fraction of Total Gas-Transfer ResistanceIn Liquid-Phase: Two-Film Model
H (atm)
0.01 0.1 1 10 100 1000 10000
Liq
uid
Resis
tance/T
ota
l R
esis
tance
(K
L/
)
0.0001
0.001
0.01
0.1
1 = 0.05
Equal Resistance
HOCl
CNCHCl2
NH2Cl
NHCl2
CHBr3
CHBr2Cl
CNCl
CH3NCl2
CHCl3
NCl3
Cl2 Rn
29
Factors that Affect Air Quality in Indoor Pool Facilities
• Water chemistry
• Mixing in liquid phase (swimmers, spray features)
• Mixing in gas phase (HVAC system design, operation)
• Water treatment, management practices
• But ... quantitative understanding is lacking
30
Study Objectives
• Define relationships among design, operational parameters of swimming pools and IAQ• NCl3 as a sentinel compound
• Proxy measurements
• Define (quantitatively) mass transfer rates associated with mixing• Baseline conditions
• Swimmers
• Water features
• Develop recommendations for facility design and operation to improve IAQ
31
Project ScopePhase I (6 months)
• Collaboration with Michigan State University (College of Medicine)
• Water Chemistry
• Air Chemistry
• Pool Characteristics• Water treatment
• HVAC
• Bather Load
• Human Physiology
• Competition Pools• Before/during competitions
• Effects of heavy bather load
Phase II (12 months)
• Water Chemistry
• Air Chemistry
• Pool Characteristics• Water treatment
• HVAC
• Bather Load
• Expand Range of Pool Types• Therapy pools
• Splash parks
• Broad Geographic Distribution
• Pool Selection by 2-Stage Survey32
Measurements
Water Quality
• Urea (digestion, colorimetric)
• TOC
• pH
• Residual chlorine (DPD/KI)
• T
• Volatile DBPs (MIMS)
Air Quality
• IAQ Monitoring Device• NCl3, RH, CO2, VOCs
• NCl3 (air sparging)
• RH
• CO2
• VOCs
• Radon (Rn)
• Corrosion coupons33
Measurement of NCl3 in Air
Air
Flow
DPD/KI
solution
Air
Pump
A B
34
Membrane Introduction Mass Spectrometry
35
Solution
Outlet
Solution
Inlet
Outlet to
Mass SpectrometerInert Gas Inlet
Pervaporation
Membrane
Pool Characterization
• Bather Load (digital camera)
• Air Handling System (return air flow, location of supply/return vents, dehumidification, heating, cooling, air T)
• Water Management (recirculation rate, water volume, locations of drains/returns, methods of water treatment)
• Maintenance (filter backwash method/frequency, water replacement method/frequency, cleaning methods/frequency)
36
Photos and Data Provided by Jessica MaloneyWisconsin Department of Health Services
Madison, WI 37
38
39
Turning on more aeration, windows closed
Reducing aeration processes,
windows opened.
Weekend
40
41
2 MGD Groundwater
2 MGD Aerated Groundwater
O2 In
Rad
on
Ou
t
42
Process Model: Mass-Balance Approach
• Mass emission rates• Ambient circulation
• Swimmers
• Water features
• Compare model results with measurements
• Calibrated/verified model used as basis for development of recommendations for facility design, operation
43
Expected Outcomes
• Quantitative information about relationships of IAQ to:• Pool design
• Pool use
• Water treatment
• HVAC system
• Recommendations for pool design and operation
• Input from swimming community
44
Thank You!
Ernest R. Blatchley III, Ph.D., P.E., BCEE, F. ASCE
Lee A. Rieth Professor in Environmental Engineering
Lyles School of Civil Engineering and Division of Environmental & Ecological Engineering
Purdue University
blatch@purdue.edu
45
Abstract
In response to need expressed by the Council for the Model Aquatic Health Code (CMAHC), a study will be launched in January 2019 to collect data illustrating relationships between the operational features of indoor swimming pool facilities and indoor air quality (IAQ). The study will involve parallel measurements of water/air chemistry in indoor pools, along with measurements of human physiological responses to exposure to the indoor air environments at these pools. Join the CMAHC, NACCHO, CDC, and principal investigator Dr. Ernest Blatchley for a presentation of this novel research.
46
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