an introduction to radon

An Introduction to Radon


A Public Works PresentationPrepared and offered by the

Information used in this presentation was taken from U.S. EPA

documents and publications


What is Radon?

• It is a radioactive gas • It is in the soil and the

air• It has no color• It has no odor


Why is Radon Bad? Radon has been classified as a Class A

carcinogen

Radon causes about 20,000 lung cancer

deaths per year

Radon is the second leading cause of lung cancer in the United

States


How Can Radon Hurt Me?

Radon can be present in the air in our homes. When we

breathe, Radon can enter our lungs and damage our DNA

causing cancer


How does radon get into my home?

•Radon comes from the uranium present in soil nearly everywhere in the U.S.

•The soil allows radon to move into a home through cracks in the concrete slab, basement, or crawlspace

•Air pressure differences between the basement or crawlspace and surrounding soil draws radon into a home


How do I know if there is radon in my home?

Use a test kit to determine the radon level in your home. These can be purchased at a

local hardware store.

First, check to see the zone in which your home is

located


What does testing consist of?

•Tests can be short-term, for 2 or 3 days, or long term, for 90 days.

•The test kit is placed in the lowest level of the home used by its inhabitants.

•After the required exposure time, the kit is sent in for analysis

•You receive test results within a few weeks


What Levels are Acceptable?

The EPA, the Surgeon General, the Centers for

Disease Control and other health organizations

recommend levels under 4.0 pCi/L


How can I reduce radon levels in my home?

•Install a sub-slab (or sub-membrane) depressurization system

•Use mechanical barriers

•Reduce stack effect

•Install air distribution systems so that soil air is not “mined”


1. Sub-slab or sub-membrane depressurization system

Consists of the following components:

•4-inch layer of clean, coarse gravel beneath the bottom concrete slab in a basement – allows soil gas to move freely beneath the home

•Polyethylene sheeting placed on top of the gravel layer – helps prevent soil gas from entering the home and keeps the concrete from entering the gravel layer when placed

•A 3- or 4-inch PVC or other gas-tight pipe running from the gravel layer through the home and roof – safely vents the soil gas above the house

•Sealing and caulking of all openings in the concrete foundation and floor – prevents soil gas from entering the home


2. Active sub-slab or sub-membrane depressurization system

Consists of the following components:

•Same system as the passive with the addition of an in-line fan – this is used to facilitate movement of soil gas through the pipe. Virtually all homes with an active system have radon levels below the 4 pCi/L level


Important tips:

•The vent pipe must not be routed through an outside wall in colder climates. Running the pipe through the warmer part of the house will help to encourage the natural draft upward of air. This also provides more room for the installation of a fan should that be necessary.

•Install the vent pipe in a vertical run with minimal bends and elbows.

•Install a screen on the end of the vent.


Important tips, cont.:

The vent pipe must be terminated:

•A minimum of 12 inches above the surface of the roof.

•A minimum of 10 feet away from any windows or other openings in the building.

•A minimum of 10 feet away from any windows or other openings in any adjacent buildings.

•A minimum of 10 feet away from the furnace flue.


Important tips for fans:

•Fans cannot be inside the living space of the home or in a crawlspace.

•Fans are usually installed in attics or garages if there is no living space above the garage.

•Fans require a 30-inch vertical run of pipe.

•Fans require an unswitched electrical junction box.


Find out more! Additional resources:

National Safety Council – coupons for test kits

www.nsc.org/EHC/indoor/coupon.htm

National Environmental Health Association

www.neha.org

U.S. EPA – many resources

www.epa.gov/radon/

an introduction to radon

Health & Medicine