University of California, Riverside

Environmental Sciences

Andrew C. Chang

Andrew C. Chang

Andrew Chang Photograph

Professor Emeritus

  • Department of Environmental Sciences
  • University of California, Riverside, CA 92521

Academic Degrees:

  • Ph.D., Purdue University, Lafayette, Indiana, 1971


  • Land application of organic wastes: Transformations of C, N, and P in soils, effects on physical properties of affected soils.
  • Trace elements: chemistry and bioavailability of trace metals in terrestrial and aquatic ecosystems, risk assessments and methodology of establish pollutant loading limits.
  • Water reuse: assessing long term sustainability of reclaimed wastewater application sites, soil enzyme activities of soils receiving reclaimed wastewater application, and human-health related chemical guidelines for reclaimed wastewater irrigation.
  • Environmental chemistry of phosphorus: 31P nuclear magnetic resonance examination of P chemical forms in soils and sediments, enzymatic hydrolysis of organic P in soils, and accumulation of P in agricultural soils of volcanic origin.

Representative Publications:

  • Bar-Yosef, B., A. C. Chang, and A. L. Page. 2005. Mass balance modeling of arsenic processes in cropland soils. Environ. Geochem. Health 27:177-184.
  • Koo, Bin-jun, A. C. Chang, D. E. Crowley, and A. L. Page. 2006. Characterization of organic acids recovered from rhizosphere of corn grown on biosolids treated media. Comm. Soil Sci Plant Anal. 37:871-887.
  • Chen, W. P., A.C. Chang, L. S. Wu, L. Li, S. Kwon, and A. L. Page. 2007. Probability distribution of cadmium partitioning coefficients of cropland soils. Soil Science. 172 (2): 132-140.
  • Chen, W. P., A.C. Chang, L. S. Wu, and A. L. Page. 2006. Modelling dynamic sorption of cadmium in cropland soils. Vadose Zone Journal. 5 (4): 1216-1221.


  • Technical Reports:
    • G. R. Bradford, A. C. Chang, A. L. Page, D. Bakhtar, J. A. Frampton, and H. Wright. 1996. Background Concentrations of Trace and Major Elements in California Soils. Kearney Foundation of Soil Science Special Report.

    • Pier Montovani, Takashi Asano, Andrew C. Chang, and Daniel A. Okun. 2001. Management Practices for Nonpotable Water Reuse.  Water Environment Research Foundation Project 97-1RM-76 (this report is available through Water Environment Foundation, Alexandria, Virginia, USA(

    • Chang, A. C., A. L. Page, and N. J. Krage 2004. Role of Fertilizer and Micronutrient Applications on Arsenic, Cadmium, and Lead Accumulation in California Cropland Soils. Final Report Submitted to California Department of Food and Agriculture, Sacramento, California. (available for download at

    • Chang, A. C., Weiping Chen, B. Bar-Yosef, A. L. Page, Seongju Kim. 2004. A Generalized Trace Element Mass Balance Model for Cropland Soils: Arsenic and Cadmium. Final Report Submitted to California Department of Food and Agricultura, Sacramernto, California. (available for download at

    • Khosravifard, M., A. Maan, S. Match, J. van Rein, A. C. Chang, and M. Petreas. 2005. Evaluation of Heavy Metals and Dioxin in inorganic chemical fertilizers and California Cropland Soils. (

    • Chang, A. C., W. P. Chen, and A. L. Page. 2007. Soil-solution Partitioning of Trace Elements in Cropland Soils of California: Estimating the Plant Uptake Factors of As, Cd, and Pb. Final Report submitted to California Department of Food and Agriculture. 150pp.

    • Bull, R. J., A. C. Chang, C. F. Cranor, R. C. Shank, and R. Trussell. 2004. Perchlorate in Drinking Water: A Science and Policy Review. Final Report, University of California, Irvine, Urban Water Research Institute, Scholars Committee on Perchlorate Review. May, 2004. 53pp. (

    • World Health Organization1. 2006. WHO guidelines for the safe use of wastewater, excreta and greywater. v. 1. Policy and regulatory aspects, v. 2. Wastewater use in agriculture, v. 3. Wastewater and excreta use in aquaculture - v. 4. Excreta and greywater use in agriculture. World Health Organization (ISBN 92-4-154686-7). 702pp. (

    • Chang, Andrew C., Thomas Harter, John Letey, Deanne Meyer, Roland D. Meyer, Marsha Campbell Mathews, Frank Mitloehner, Stu Pettygrove, and Ruihong Zhang (University of California, Division of Agriculture and Natural Resources, Committee of Experts on Dairy Manure Management) 2007. Groundwater Quality Protection: Managing Dairy Manure in the Central Valley of California. University of California, Division of Agriculture and Natural Resources publication 9004 (ISBN-13: 978-1-60107-447-8). 178pp.

  • Computer Models:
    1. STEM (Soil Trace Element Mass Balance Model)-single layer model
      • This model is useful to assess the risks associated with trace element in cropland soils with sensitivity and uncertainty analysis. The model frame is based on mass balance. The change in total metal content in the root zone is balanced with the input at the soil surface, the output caused by leaching from the root zone, and by uptake removal in harvested products. The uptake and leaching was dynamically related to trace element soil solution concentration which was governed by adsorption-desorption, precipitation-dissolution, and organic matter mineralization.
      • Help file: help_stem_singlelayer.pdf
      • Setup file: stem_singlelayer_setup.exe
    2. STEM-profile distribution model
      • This model conceptually approximates the mechanics and kinetics of a real field cropland system. The soil profile was discretized into number of uniform adjoining sections. The water flow was modeled by the Richard’s equation and the solute transport is simulated with the convective-dispersive equation. Dynamic plant growth and root water uptake was adopted.
      • Help file: help_stem_profiledistribution.pdf
      • Setup file: stem_profiledistribution_setup.exe

More Information

General Campus Information

University of California, Riverside
900 University Ave.
Riverside, CA 92521
Tel: (951) 827-1012

Department Information

Environmental Sciences
Geology 2460

Tel: (951) 827-5116
Fax: (951) 827-4652