The Canadian

Centre for Environmental Modelling and Chemistry

ChemCAN Model

Version 6.00 - September 2003

New in version 6.00!

Software Description

ChemCAN is a Level III model of 24 regions of Canada. It estimates average concentrations in air, fresh surface water, fish, sediments, soils, vegetation, and marine near-shore waters. It is intended to assist in human exposure assessment. Designed for use in Canada, a database of 24 regions of Canada is included. Other regions can be defined by the user and added to the database, however, areas should have a radius of at least 300 km. For investigations involving smaller areas, air dispersion will dominate and a plume model may be more appropriate.

Features of ChemCAN:
Provides a database of chemicals and chemical properties.
Permits temporary additions/changes of chemicals and their properties to a simulation.
Permits permanent additions, changes and deletions of chemicals and their properties to the database.
Provides a database of environments and environmental properties.
Permits temporary additions/changes of environments and their properties to a simulation.
Permits permanent additions, changes and deletions of environments and their properties to the database.
Provides context-sensitive Help.
Displays and prints the ChemCAN model calculations, as performed by the program.
Allows the printing of simulation tables and the summary diagram.
Allows the program results to be saved as a spreadsheet file.

This program was based on the following publications:

Webster, E., Mackay, D., Di Guardo, A., Kane, D., Woodfine, D. 2004. Regional Differences in Chemical Fate Model Outcome. Chemosphere. 55: 1361-1376.

Mackay, D., Paterson, S., Tam, D.D. 1991. Assessments of Chemical Fate in Canada: Continued Development of a Fugacity Model. A report prepared for Health and Welfare Canada.

The required input data are:
Chemical Properties:

  • chemical name
  • molar mass
  • reaction half-life estimates for 4 media
    Type 1 chemicals
  • data temperature
  • any two of
    log Kow
    log Koa
    - if the Kaw is used it may be entered as
    Henry's law constant, or
    water solubility and vapour pressure
  • temperature dependence coefficients for the partition coefficients
  • partitioning parameters for aerosols
    Type 2 and 3 chemicals
  • partition coefficients
    Environmental Properties:
  • dimensions of the environment
    - total surface area
    - % water cover by area
    - length of coastline for maritime regions
    - average air height
    - average water depth
    - average soil depth
    - average sediment depth
    - length of coastline
    - average coastal water depth
    - average coastal width
  • volume fractions for all subcompartments
  • densities for all subcompartments
  • temperature conditions (winter, summer or annual average)
  • residence times for air, water, and coastal water
  • organic carbon content (soil, sediment, suspended sediment only)
  • fish and vegetation lipid content (Type I chemicals only)
  • a fitted, solids-water partition coefficient to calculate the sorption attenuation factor
  • transport velocities
    - air side air-water mass transfer coefficient
    - water side air-water mass transfer coefficient
    - rain rate - aerosol deposition
    - soil air phase diffusion mass transfer coefficient
    - soil water phase diffusion mass transfer coefficient
    - soil air boundary layer mass transfer coefficient
    - sediment-water mass transfer coefficient
    - sediment deposition
    - sediment resuspension
    - soil water runoff
    - soil solids runoff
    - sediment burial
    - diffusion to higher altitudes
    - leaching from soil
  • rain and snow scavenging ratios


  • chemical input rates for each bulk medium or compartment
  • inflow concentrations in air and water

    Model Output:

  • partition coefficients (Type 1)
  • Z values
  • fugacity of each medium
  • intermedia transport rates and D values
  • reaction and advection D values and loss rates
  • residence times or persistences (overall, reaction, and advection)
  • concentrations and amounts for each medium
  • a summary diagram

    Minimum system requirements:
    Pentium-75MHz with 8 Mb of RAM running Windows 95. On some systems it may be necessary to adjust your screen resolution.

    The ChemCAN Model Version 4.95, released May 1996 and updated Nov 1997, continues to be available.

    For non-Windows users the BASIC, evaluative, Level I, II and III fugacity models are available.

    Please read the CHEMCAN SOFTWARE LICENSE before downloading the software. Use of the software constitutes your agreement to abide by the terms and conditions set out in the license agreement.

    Bug Report


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    Last updated June 10, 2013.