Produced by and for the Hot Science - Cool Talks Outreach Lecture Series of the Environmental...

Produced by and for the Hot Science - Cool Talks Outreach Lecture Series of the Environmental Science Institute. We request that the use of any of these materials include an acknowledgement of Dr. Richard Corsi and the Hot Science - Cool Talks Outreach Lecture Series of the Environmental Science Institute of the University of

Texas at Austin. We hope you find these materials educational and enjoyable.

by Dr. Richard CorsiHot Science - Cool Talks Volume 56

Is Your House Killing You?

Co-sponsored by the McDonald Observatory and Department of Astronomy Board of Visitors

Title SlideIs Your Home Killing You?Indoor Air Quality: A Time for Recognition

Richard L. Corsi, Ph.D., PEE.C.H. Bantel Professor for Professional Practice

Director – Program on Indoor Environmental Science & EngineeringDepartment of Civil, Architectural and Environmental Engineering

When did indoor air quality

problems begin?

http://kuroow.blox.pl/html

Situation Persists in Developing World

½ world’s population (> 3 B) relies on coal and biomass for domestic energy, and number is increasing!

• Used in simple stoves.

• Incomplete combustion.

• Often not ventilated.

• 2 – 2.8 million deaths/year

• 4% of global mortality

• 1 million childhood deaths/year

• Women: 2/3 w/ lung cancer are non-smokers!© Ron Giling Panos Pictures

UN ITDG Briefings

Developed World - Evolution of IAQ

affordablehousinginstitute.orgwww.cdc.gov

• Demand for homes (end of WW II)

Demand for Ease of Life

• Wall-to-wall carpet

• Cleaners

• Air fresheners

• Pesticides

• Personal care products

• Much more

Global Production: Synthetic Organic Chemicals

050

100150200250300350

1920 1940 1960 1980 2000

YearBill

ion

kg/y

ear

Air Conditioning

• Energy crisis of 1970s (buildings ≈ 70%)

• Energy crisis of 21st century (buildings ≈ 40%)

• Advantageous to keep the outdoors out. Why?

• How: Seal up home, re-circulate conditioned air

Infrogmation

Building Blocks

ventoutsideinside Q

ECC

ventilation (Qvent)

emissions (E)

outdoor pollution (Coutside)

control (η x Qcontrol)

vent

control

ventoutside

inside

QQ

QE

C

C

1

Qvent Qvent

E

Cinside

Coutside

Qcontrol

η x Qcontrol = CADR (clean air delivery rate)

Ion Generators

HEPA Filter

Ion Generator 3

Ion Generator 2Ion Generator 5

Ion Generator 4

Ion Generator 1

ProfessorJeffrey Siegel

Clean Air Delivery Rate (CADR)C

lean

Air

Del

iver

y R

ate

(m3 /

hr)

Test Aerosol: Incense

vent

control

ventoutside

inside

QQ

QE

C

C

1

Particle Diameter (µm)

It’s Not Only In the Air!

“If truckloads of dust with the same concentration of toxic chemicals as

is found in most carpets were deposited outside, these locations would

be considered hazardous waste dumps”

Ott & Roberts, “Everyday Exposure to Toxic Pollutants,” Scientific American, 1998

• 360 mid-western homes (1992 – 1993)

• Pesticides and Polyaromatic Hydrocarbons

(PAHs; soot and parking lot sealant)

• DDT (toxic pesticide) in 25% of homes (banned in 1972!)

• PAH levels in > 50% of homes ……………

How much time do you spend indoors?How much time do you spend indoors?

Americans = Indoor Creatures

• Indoors 89%• 18 hours indoors for every 1 outdoors

• 2/3 of time in home

• Transit 6%

• Outdoors 5%

Klepeis et al. 2001

How do risks from poor indoor air qualitycompare with other environmental risks?

USEPA Risk Rankings

1. (tie) Worker exposure to chemicals

1. (tie) Indoor radon

3. Pesticide residue on foods

4. (tie) Indoor air pollutants (non-radon)

4. (tie) Consumer exposure to chemicals

(includes cleaning fluids, etc.)

6. Hazardous/toxic air pollutants

7. Depletion of stratospheric ozone

8. Hazardous waste sites (inactive)

9. Drinking water (radon and THMs)

10. Application of pesticides16 others .. (including groundwater contamination at 21, criteria air pollutants at 22, etc.)

Risk of cancer/death - breathing indoor air as high as 0.5 to 1% (conventional risk assessment) Corsi, Environ. Manager (2000)

http://www.epa.gov/oppt/rsei/index.html

Indoor pollution sourcesLet’s discuss some sources

(those things that emit pollution indoors)

Lots of images

ventoutsideinside Q

ECC

A few examplesNow let’s examine just a few examples

(some might surprise you!)

Scented candles

Emission Factor (g/g)Scented 1200Unscented 20

Scented Candles

Average Concentrations of VOCs

00.050.1

0.150.2

0.250.3

0.350.4

0.450.5

Co

nce

ntr

atio

n (

g/m

3)

ScentedUnscented

Exposure to fine particulate matter (a heavily regulated outdoor air pollutant):

What is the outdoor source equivalent of burning a single candle in a home?

Every major industrial point source emitter, including all coal-fired power plants in the State of Texas!

p-DCB = 1,4-Dichlorobenzene

• Molecular structure of p-DCB

• Where does it come from?

Average Emission Rates: 5 Day Test

1

10

100

1000

10000

closet freshener mothcase moth crystal toilet deodorizer

E (m

g/h

r)

Chamber Fume Hood Garment Bag Closet

closet freshener moth case moth crystal toilet deodorizer

Model: Buildup of Emissions (Concentration)vs. Air Changes

Three product (super) user

Field Samples: Cancer Risk Estimates

CCR: cumulative CRFOR: formaldehydeDCB: p-dichlorobenzene

ACE: acetaldehydeCHL: chloroformBZ: benzene

STY: styreneMCL: methylene chlorideTCE: trichloroethylene

CT: carbon tetrachlorideEBZ: ethylbenzeneTET: tetrachloroethylene

153

14

Hun et al. 2008

Toxic Air Contaminants

• Large computer manufacturer

• Clients getting sick when new computers arrive

• What is emitted?

48 toxic chemicals identified

75% decay within a few days

Personal Computers

Smell of apples?Smell of Apples?

Apple says that “… an unusual odor may be detected when a product has been turned on and allowed to warm up to operating temperature. Typically, the odor is detected when the product is new… In most cases the odor will dissipate over a short period of time.“

Apple suggests that if the odor problem persists, that the machine be placed in a well-ventilated room and allowed to operate over an "extended" period of time (possibly 24-72 hours) or until the odor dissipates.

-- Applelinks Contributing Editor Charles W. Moore“Sorry, Steve, But The G4 Stinks, And So Does My PowerBook”

"perhaps today's olfactory status symbol is the smell of scorching plastic."

-- Salon.com's Janelle Brown

Vaccuum cleanersVacuum Cleaners

• Previous tests on several vacuum cleaners

• Particle re-suspension by wheels on carpet

• Particles through collection device (bag, etc.)

• Particle emissions from motor

• 48 tests in 12 apartments in Austin

• Recall previous study related to toxic pollutants in carpet

• Those with dust allergies/asthma should leave during and following vacuum events

Dishwashers & Washing Machines

Carlos Paes

• Detergents / bleaches with sodium hydrochloride (“chlorine”, classified as hazardous)

• Experiments show large amounts of chloroform

• Dishwashers GREAT as chemical strippers

Lkayama

Major Appliances: How good are they at putting toxic chemicals into the air?

0

10

20

30

40

50

60

70

80

90

100

Kitchen Sink Bathtub WashingMachine

Shower Dishwasher

Av

era

ge

Tra

ns

fer

Eff

icie

nc

y (

%)

AcetoneEthyl AcetateTolueneEthylbenzeneCyclohexane

0.00

0.10

0.20

0.30

0.40

0.50

% I

nta

ke

ingestion inhalation dermal

SCENARIO 1

57%29%

5%9%

0%

0% show er

laundry

dishw asher

toilets

cooking

w ash basins

Contributions to inhalation exposure

Exposure to Chloroform in Tap Water

50

40

30

20

10

00

Exposure to Chloroform w/ Reactions

0.00

0.20

0.40

0.60

0.80

% I

nta

ke

ingestion inhalation dermal

SCENARIO 2

80

60

40

20

00

Contributions to inhalation exposure

22%

16%59%

0%0%

3% shower

laundry

dishwasher

toilets

cooking

wash basins

Contributions to inhalation exposure

22%

16%59%

0%0%

3% shower

laundry

dishwasher

toilets

cooking

wash basins

Indoor OzoneIndoor Ozone

What are major sources of ozone indoors?

• Outdoor air

• Laser printers

• Photocopy machines

• Ion generating air purifiers

• Electrostatic precipitators

• Explicit ozone generators as air “purifiers”

Aris et al. 1993

Ion Generators

HEPA Filter

Ion Generator 3

Ion Generator 2Ion Generator 5

Ion Generator 4

Ion Generator 1

ProfessorJeffrey Siegel

Ion Generators: Ozone Emission Rates

Pers. data

Ion Generator

Ozo

ne

Em

issi

on

s (m

g/h

r)

Ozone in a Typical Residence

10 ppb increase in the previous week’s ambient ozone concentration was associated

with a 0.52% increase in daily mortality --(Bell et al. 2004)

Explicit Ozone Generators

Nursery Air Purifier

“Give your baby healthy air. Make baby’s nursery a healthy place, with our stat-of-the-art purifier and ionizer! This powerful little unit releases billions of negative ions that effectively remove allergens, bacteria, dust, and odors (all of which are positively charged). Think of invigorating mountain air… also rich with negative ions. Wonderful for respiratory systems that are still developing. Purifies up to 200 square feet, trapping particles as small as 100 microns. With a wipe-off, reusable filter.”

Is your home a chemical reactor?

Is your home a chemical reactor?

Ozone + Unsaturated Organic Compounds

O3 +R1

R4R2

R3

C CR1

R4R2

R3

C CO

OO

Many by-products are formed:• Irritating and even toxic gases (e.g., formaldehyde)• Particles

Sources of (C=C) – Numerous!

• Carpet (e.g., styrene)

• Cleaning products

• Polishes and waxes

• Air fresheners

• Personal care products (soaps, perfumes, etc.)

• Cooking oils

• Wood / plants

• Human skin oils (squalene)

O3 +R1

R4R2

R3

C CR1

R4R2

R3C C

OO

OO3 +R1

R4R2

R3

C CR1

R4R2

R3C C

OO

OO3 +R1

R4R2

R3

C CR1

R4R2

R3

C CR1

R4R2

R3C C

OO

O

Example: Solid Air Freshener

# P

artic

les

Time (min)

Particles released over time by size class

Sarwar et al. 2004

Is near head chemistry possible?

Perfumes and Colognes

• 25% of Americans use perfume or cologne daily

• 5% use perfume or cologne 3-5 × per day

• 3+ million “super users”

• Source composition:

• over 3,000 chemicals (terpenes, alcohols, etc.)

• loaded with C=C double bonds

• reactive – top notes, middle notes, base notes

• Odor thresholds: ≈ 100 – 1,000 × typical indoor

• typical indoor concentrations = < 1 to 10 ppb

Personal Reactive Clouds: Conceptual

O3

O3

O3

C=C

Product

Product

Product

Wisthaler et al. 2005

Product

Screening Experiments

O3 O3(meas)

VOC/ald

particles

T, RH, CO2

Screening Experiments

λ = 1-2 min-1

~ 70 ppb

28 L

0

1,000

2,000

3,000

4,000

Perf 1 Perf 2 Perf 3 HS 1 HS 2Co

nc

en

tra

tio

n in

cre

as

e (

#/c

m3 )

Experimental ResultsParticle increase with product vs. without product (corrected for background)

Statistically significant increase (α = 0.05)

perfumes hair sprays

What can you do?

• Become as educated as possible

• Educate as many others as possible

• Let your elected reps know of your concern

• Become a smart policymaker/engineer of your home

• The things you can do are too numerous for a slide

- avoid specific sources

- use selective ventilation

- use appropriate control devices (air purifiers)

Summary

• Indoor air quality is very important issue

– Greatest environmental health issue in U.S.!

• Affects everyone almost all of the time

• Great need for more public education

• Great need for more experts in field

• Great need for more research

– Miles behind other environmental issues

– US years/decades behind other countries

• University of Texas is a national leader in field

• And we have fun, too!

Questions

www.caee.utexas.edu/igert

IGERT: Indoor Environmental Science & Engineering

The University of Texas

IGERT: Indoor Environmental Science & Engineering

The University of Texas