CalTOX is designed to run in Microsoft Excel®

CalTOX Model Structure

CalTOX is an innovative spreadsheet model that relates the concentration of a chemical in soil to the risk of an adverse health effect for a person living or working on or near the contaminated soil. CalTOX computes site-specific health-based soil clean-up concentrations given target risk levels or human health risks given soil concentrations at the site.

The CalTOX spreadsheet contains a multimedia transport and transformation model that uses equations based on conservation of mass and chemical equilibrium. This model predicts the time-dependent concentrations of a chemical in the seven environmental compartments of air, water, three soil layers, sediment, and plants at a site.

After partitioning the concentration of the chemical to these environmental compartments, CalTOX determines the chemical concentration in the exposure media of breathing zone air, drinking water, food, and soil that people inhale, ingest and contact dermally. CalTOX then uses the equations found in the U.S. Environmental Protection Agency Risk Assessment Guidance for Superfund (US EPA RAGS) to estimate exposure and risk.

CalTOX has the capability of conducting Monte Carlo simulations with a spreadsheet add-in program. Used in this way, CalTOX will present a range of risks or health-based soil target clean-up levels that reflect the uncertainty/variability of the estimates.

CalTOX Files and Documentation

Frequently Asked Scientific Questions

Troubleshoot CalTOX Problems