RADON IN REAL ESTATE
TRANSACTIONS
2013
Overview





Radon Basics
Radon Entry
Radon Testing
Radon Mitigation
Radon Disclosure
Radon Basics
Radon

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

Radon is colorless, tasteless and odorless
ionizing gas
Radon comes from radioactive breakdown (decay) of
uranium in soil and rock.
Radon is a cancer-causing, radioactive gas that
can be found in all homes.
 Minnesota has especially high indoor radon levels
Leading cause of lung cancer for non-smokers
 Lung Cancer is the deadliest and most preventable
cancer
What Level of Radon is Considered
Safe?


There is no known safe level of radon
World Health Organization (WHO) recommends that all homes
be below:


2.7 pCi/L health based standard
Environmental Protection Agency (EPA) recommends that all
homes be below:
 2 pCi/L pseudo health based standard
 4 pCi/L based on mitigation technology (action level)
Where Can Radon Be Found?

Soil


Water



Major source
Groundwater
Surface waters
Air


Ambient
Indoor
Minnesota Radon Potential



Entire state is high or
moderate potential
Red: average > 4 pCi/L
Yellow: average 2-4
pCi/L
Health Effects Of Radon

Second leading cause of lung cancer in the United States
 Estimated to cause 21,000 deaths annually*
 MN
800-1,000
Second only to smoking
Leading cause of lung cancer for non-smokers


* EPA Assessment of Risks from Radon in Homes (June 2003, EPA -402-R-03 -0003)
Chances Of Developing Cancer Due
To Radon Depend On:



The levels of radon in the home
The amount of time spent in the home
Whether or not a person is, or ever was a smoker
Radon Entry
Radon Pathways
(page 4-5)
A.
B.
Cracks in concrete slabs.
Spaces behind brick veneer walls that rest on
uncapped hollow-block foundations.
F.
G.
H.
C.
Pores and cracks in concrete blocks.
D.
Floor-wall joints (cold joints).
J.
E.
Exposed soil, as in a sump or crawl space.
K.
I.
Weeping (drain) tile, if drained to an open sump.
Mortar joints.
Loose fitting pipe penetrations.
Open tops of block walls.
Building materials, such as brick, concrete, rock.
Well water (not commonly a major source in Minnesota homes).
Foundation Type


All homes can have radon
concerns
Slab-on-Grade and Basements


Crawl-Space


Entry through floor joints, cracks,
plumbing penetrations.
Entry from large soil area and drawn
into living space.
Mobile Homes

If well skirted, they act like crawl
spaces.
Air Pressure is Driving Force
Stack Effect:
As warm air
leaves the top of
the house, air
comes in the
bottom of the
house
Down Wind
Draft Effect:
Wind flowing
over the top of a
house creates
the same effect
as the stack
effect
Vacuum Effect:
Air mechanically
exhausted from
the house is
replaced from
other pathways
Water Aeration


The aeration of water can cause some radium to come out of
the water, which could cause an elevated radon level.
Usual conversion factor is 10,000 pCi/L in water turns into 1
pCi/L in air.
Radon Testing
Radon Testing Devices
Short-term tests measure radon levels
for 2 to 7 days, or use a continuous
monitor for a minimum of 48 hours.
Long-term tests determine the
average radon concentration for a
minimum of 90 days.
Charcoal



Use activate charcoal to absorbs the surrounding air. Lab
analyzes the charcoal for radiation content.
Cheap and Quick results. Accurate reflection of only the time or
season tested.
Does not estimate the annual radon level which is how radon
risk is calculated.
Continuous Radon Monitor


Uses electronic sensors to count the
number of disintegrations per minute.
Alpha flashes are averaged over entire
period.
Better indicator of radon level due to
hourly averages show the range or
radon levels.
Alpha Track


Uses a material to collect the damage created by the alpha
particles colliding with that testing material.
A year long test accurately estimates the radon risk.
Average Radon Levels
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EPA states any home 4.0 pCi/L or higher be fixed
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Not health based
Outdoor- 0.4 pCi/L*

May be higher in some areas of Minnesota

Indoor- 1.3 pCi/L*
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Minnesota:

2 in 5 homes are over 4.0
*estimated national averages
Where Should A Test Be ConductedReal Estate?
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On the lowest “livable level”

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NOT in kitchens or bathrooms
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May require interpretation
Ultimately comes down to buyer’s opinion
Relocation companies may decide to test the lowest level that could be
used by the buyer
high humidity
Away from drafts
Away from high heat



appliances
fireplaces
direct sunlight
When Should You Test?

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It is better to test between October and April (the heating season) because
homes are sealed up
You can test anytime during the year, but you are more likely to get the
maximum levels during the heating season
Long-term tests should be conducted during at least part of heating season.
What If Your Neighbor Has Tested And
Found Low Levels?
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Radon levels are dependent upon several factors
Your neighbor may find low levels but your home could
still have high levels of radon
Don’t depend upon your neighbor’s test
Every home should be tested
Testing Procedures: Real Estate
Transactions

3 types of real estate tests (short-term)
 Sequential
testing
 Simultaneous testing
 Continuous Radon Monitor (CRM) or Continuous
Working Level Monitor (CW)
 Professionally

conducted
See MDH Measurement Service Providers fact sheet
Sequential testing

One short-term test conducted
 According
to EPA protocols
 48 hour test
 Sent in to lab for analysis

An immediate follow-up test conducted
 According
to EPA protocols
 48 hour test
 Sent to lab for analysis

Average two tests to get radon level
Simultaneous testing

2 short-term tests placed side by side
 Four
inches apart
 According to EPA protocols
 48 hour minimum duration
 Sent in for lab analysis
Simultaneous & Sequential
Testing: Interpretation of Results

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If average is < 4.0 pCi/L (or what buyer requests)
then simply disclose and move on
If average is ≥ 4.0 pCi/L (or what buyer requests)
then mitigate
No requirement for both test to be the same
Some difference is expected due to variation of
radon levels
Report each result and the average of both tests.
Continuous Radon
Monitor Testing

Sophisticated electronic devices
 Must
integrate and record hourly or more frequently
 First 4 hours may be discarded, but remaining 44
hours can be used



Professional conducted
48 hour minimum
One single test
Continuous Radon Monitor
Testing

Must be able to print out to paper or computer



Helps detect abnormal radon swings
Built in motion detectors can determine if device
was moved
May record pressure, temperature and proximity
Help determine tampering
 Specialty tape on exterior doors and windows

Radon Mitigation
(page 15)
Can’t We Just Seal The Cracks?


Radon can enter
through very small
openings.
Without affecting
house pressures,
sealing is not a
stand-alone
technique.
Active Soil Depressurization


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Primary mitigation
method
A PVC pipe is routed
under the foundation of
the home.
Fan pulls air out from soil
Contact a NRPP or
NRSB certified radon
contractor
2
Types of Mitigation
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Sub-slab
Drain tile
Sump pit
Sub-membrane (crawl space)
2
Mitigation Process
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Walk-though and Designing the System
3
System Design

Designed and installed to:


Be a permanent and integral part of home
Avoid the creation of other health, safety or environmental
hazards.

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Backdrafting/spillage of combustion appliances
Blocking exits with pipe runs
Degrading fire rated assemblies
3
Mitigation Process
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Things to Consider:

Are they listed with MDH, if not why?

Are they certified, if not why?

Do they offer a guarantee to below action level, if not why?
3
Mitigation Process
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Diagnostics – to ensure a successful system
6
Mitigation Process
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Sealing Gaps and Cracks
7
Mitigation Process
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Seal the crawlspace
7
Mitigation Process
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Drill a hole and dig out a bucket sized hole
8
Mitigation Process
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Pipe Routing
8
Mitigation Process
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Run pipe up through the roof or up outside the home.
8
Mitigation Process
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Fan located in an unconditioned space
8
Mitigation Process
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Electrical Wiring (licensed electrician)
8
8
Mitigation Process
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Performance indicators.
Non-Working System
Working System
Documentation
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Upon completion of project, contractor will provide:
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Copies of contracts and warranties
Description of system and operating procedures
Description of proper operating procedures of any mechanical or electrical
systems installed, including manufacturer's operation and maintenance
instructions
A list of appropriate actions for clients to take if the system failure warning
device indicates system degradation or failure
The name, address, and phone number of the contractor
9
Post-mitigation Procedures
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After you mitigate, you should test your home to determine if the mitigation is
working (24 hours to 30 days after mitigation)
You should retest your home once every 2 years or so
If you do any remodeling, or if you start to occupy the basement of your
home, test again for radon
10
Radon Disclosures
Radon Awareness Act

Effective January 1, 2014

Before the seller signs a purchase agreement they must do the following:
(1) Disclosure of radon information:

have there been radon tests on the property

describe radon concentrations & provide reports

provide information on any mitigation system installed

provide a radon warning statement
(2) Provide the document “Radon in Real Estate Transaction”
Radon Warning Statement
“The Minnesota Department of Health strongly recommends that ALL homebuyers have
an indoor radon test performed prior to purchase or taking occupancy, and recommends
having the radon levels mitigated if elevated radon concentrations are found. Elevated
radon concentrations can easily be reduced by a qualified, certified, or licensed, if
applicable, radon mitigator.
Every buyer of any interest in residential real property is notified that the property may
present exposure to dangerous levels of indoor radon gas that may place the occupants
at risk of developing radon-induced lung cancer. Radon, a Class A human carcinogen, is
the leading cause of lung cancer in nonsmokers and the second leading cause overall.
The seller of any interest in residential real property is required to provide the buyer with
any information on radon test results of the dwelling."
Radon in Real Estate Transactions
Publication

The publication can be downloaded from:
www.health.mn.gov/radonsale
Contacts For More Information
MDH - Indoor Air Unit
651-201-4601 or 800-798-9050
PO Box 64975
St. Paul, MN 55164-0975
www.health.state.mn.us/Radon
U.S. Environmental Protection Agency
www.epa.gov/radon