Jump to main content.


Model Report


Last Revision Date: 10/12/2011 View as PDF
General Information Back to Top
Model Abbreviated Name:

Model Extended Name:

Model Overview/Abstract:
The CARBDOSE program was again revised in 2001 because major changes had occurred in computer operating systems. DOS character based programs like CARBDOSE 4.0 were increasingly difficult to run under modern 32 bit operating systems. The CARBDOSE 5.0 program uses the revisions of 1999 reflecting major changes occurring in calculating radon health effects. EPA/NAS presently believes that the ingestion risk for radon in water is 4 times less than thought in 1993. The CARBDOSE program reports risks via inhalation and ingestion separately as risks of cancer per 10,000 population. CARBDOSE was written to provide a way for people, with or without a strong technical background in health physics, to make important radiation health calculations related to the removal of radon from water by granular activated carbon (GAC).

CARBDOSE version 5.0 is being released in conjunction with the establishment of a public water supply MCL and AMCL for radon. While the establishment of final PWS radon maximum contaminant levels has not yet been made, it seems advisable to go ahead with dissemination of public health risk information to facilitate the planning process. Health effect data in the program, including smoking history, are based on domestic point of entry volumes and are, with the exception of gamma data, independent of the removal method. CARBDOSE provides health effect information applicable to radon removal by domestic aeration units or the larger packed tower aeration systems favored for public water supplies.

CARBDOSE reports the following:

  • The amount of radon (Rn-222) removed per day

  • The buildup of radon on the filter

  • The effluent radon concentration and health effects, and the health effects associated with other radon concentrations

  • The minimum Rn removal efficiency needed to meet the EPA proposed Public Water Supply MCL

  • The probable gamma radiation dose at 1 meter from the tank wall and at other user specified distances

  • The radiation dose from an equivalent point source at any specified distance measured from the tank centerline

  • The distance at which the probable exposure dose from the GAC tank becomes less than the residential health guideline

  • The growth of lead-210 (Pb-210) on the filter for the number of years specified

  • The Pb-210 activity per gram of carbon

  • The time when the carbon exceeds the 2000 pCi/gram waste disposal category.

Model Technical Contact Information:
Stan Rydell, Ph.D.

U.S. EPA, Region 1
Telephone: (617)-918-1637

The model was developed and is maintained by Dr. Stan Rydell.

User Information Back to Top
Technical Requirements
Computer Hardware
Pentium II or higher and 300 MB ROM
Compatible Operating Systems
Windows 95, 98, NT, or later.

This software was developed for microcomputers of the IBM PC or PC clone types that use 32 bit Microsoft Window operating system and developed at video resolution of 800x600 with 256 colors

Other Software Required to Run the Model
Visual Basic
Download Information
The model is publicly available from the U.S. EPA, Region 1. Equations are available; but, source code is not available.

Using the Model
Basic Model Inputs
Screening model with moderate input requirements.
User Support
User's Guide Available?
Documentation can be downloaded from:

User Qualifications
User needs only moderate level of technical education and/or modeling experience.

Model Science Back to Top
Summary of Model Structure and Methods
The model simulates formation and fate/transport of daughter products of primary pollutants.

The model uses mixed U.S. / S.I. units and flexible (user-defined) units.

Governing equations are solved numerically.

Model Evaluation
Code verification was performed in-house by U.S. EPA Region 1.


Moderate model testing (evaluation) was performed by comparing results with commercial software: Grove Engineering's Microshield and Raddecay programs.


Model has been internally peer reviewed U.S. EPA Region 1, New England Radon Committee, New England Radiological Health Committee.


Model has been externally peer reviewed.


Other QA/QC activities include software Beta testing.

Local Navigation

Jump to main content.