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Updated: Jul 7, 2026
05:37
An R-Based Landscape Validation of a Competing Risk Model
Published on: September 16, 2022
Cadmium-hazard mapping using a general linear regression model (Irr-Cad) for rapid risk assessment
Robert W Simmons1, Andrew D Noble, P Pongsakul
1International Water Management Institute (IWMI), South Asia Regional Office, c/o ICRISAT Patencheru, AP, India. r.simmons@cgiar.org
Environmental Geochemistry and Health
|March 4, 2008
Summary
A new model, Irr-Cad, accurately predicts soil cadmium contamination in rice fields, crucial for public health and food security. This method aids in assessing risks and informing policy decisions in affected regions.
Area of Science:
- Environmental Science
- Agricultural Science
- Toxicology
Background:
- Long-term consumption of cadmium (Cd)-contaminated rice is linked to human Cd disease.
- Accurate and rapid spatial Cd contamination assessment is vital for public health and livelihood security.
- Cd contamination is a potential hazard in rice cultivation areas, especially those with historical mining activities.
Purpose of the Study:
- To develop and validate a model (Irr-Cad) for predicting the spatial distribution of soil Cd in irrigated rice systems.
- To assess the practical applicability of the Irr-Cad model for Cd hazard assessment.
- To provide a basis for intervention options and policy decisions regarding Cd contamination in rice-growing regions.
Main Methods:
- Developed a General Linear Regression Model (Irr-Cad) using data from 2001-2004 in Mae Sot District, Thailand.
- Utilized Field Order in Irrigation Sequence (Field Order(IS)) and soil Cd measurements for model development.
- Validated the Irr-Cad model in 2004-2005 using secondary validation on randomly selected field groups.
Main Results:
- The Irr-Cad model explained 98% of the variance in mean Field Order total soil Cd.
- Preliminary and secondary validations showed significant correlations (R² = 0.92 and 0.89–0.97) between predicted and observed soil Cd values.
- Incorporating soil pH into the Irr-Cad model accounted for over 79% of the variation in bio-available soil Cd.
Conclusions:
- The Irr-Cad model offers a practical and accurate method for predicting spatial soil Cd distribution in irrigated rice systems.
- Minimal input requirements make Irr-Cad suitable for widespread application in Cd hazard assessment.
- The model can support policy decisions to protect public health, livelihoods, and food export security in Cd-affected regions.
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