CEMP-E
EI 15M001
1 November 1996
INDOOR RADON PREVENTION AND MITIGATION
1. PURPOSE AND SCOPE. This document establishes design criteria for all U.S. Army facilities to
reduce health risks due to indoor radon. The design standards established herein are applicable to all newly
constructed and substantially altered Army facilities both inside and outside the Continental United States.
2. APPLICABILITY. These instructions are applicable to all elements responsible for the design of military
construction.
3. REFERENCES.
GOVERNMENT PUBLICATIONS:
Department of the Army
TM 5-805-6
Joint Sealing for Buildings
CEGS-02221
Excavation, Filling and Backfilling for Buildings
CEGS-0790
Joint Sealing
U.S. Environmental Protection Agency (EPA)
EPA 402-R-93-078
Radon Mitigation Standards
EPA 520/1/-87-20
Radon Reference Manual
EPA 625/5-87/019
Radon Reduction Techniques for Detached Houses
NONGOVERNMENT PUBLICATIONS:
American Society for Testing and Materials (ASTM)
1916 Race Street
Philadelphia, PA 19103
E 1465
(1992) Guide for Radon Control Options for the Design and
Construction of New Low Rise Residential Buildings
4. PROPERTIES OF RADON. Radon is a naturally occurring, chemically inert and water soluble
radioactive gas that is undetectable by human senses. It is formed by the radioactive decay of thorium and
uranium. These source elements are found in low, but varying, concentrations in soils and rocks. Radon,
being a gas, escapes from the ground following paths of least resistance such as through small fissures,
gravel, sand, and other porous soils. Normal subsoil investigations do not locate these radon paths with
sufficient detail and accuracy to reliably predict points where radon emerges from the earth or probable
levels of concentration. Radon-220, derived from thorium, has a half-life of 55 seconds giving it limited time
to enter buildings before it decays to a nongaseous element. Radon-222, derived from uranium and having
a half-life of 3.8 days, is the primary source of indoor radon. Refer to EPA 520/1-87-20 for more detailed
information.
5. OTHER RISKS. Health risks associated with radon are from its decay products, not the radon gas.
Radon-222 decays in several steps to form non-gaseous radioactive isotopes with short half-lives. Four of
these successive decay products have half-lives less than 30 minutes. These isotopes are chemically
reactive and attach to building surfaces and airborne dust particles. Both attached and unattached decay
products can be inhaled and attach to lung tissue. Further radioactive decay of these isotopes releases
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