University of California, Riverside

Environmental Sciences

Jay Gan

Gan Research
Professor of Environmental Chemistry
(951) 827-2712 (office)
(951) 827-3993 (fax)
210 Science Laboratories


Research areas:

  • Environmental chemistry and toxicology of classic and emerging contaminants, including PCBs, DDT, PBDEs, PAHs, current-use pesticides and pharmaceutical and personal care products (PPCPs)
  • Transformation, transport, bioavailability, plant uptake and risk mitigation of organic chemicals in the environment
  • Method development for trace contaminant analysis

Dr. Jay Gan is a Professor of Environmental Chemistry in the Department of Environmental Sciences at UC Riverside, where he also served as the Department Chair in 2007-2010. He is a fellow of the American Society of Agronomy (2006), a fellow of American Association for the Advancement of Science (2008), and a fellow of Soil Science Society of America (2010). Professor Gan is an Associate Editor of Environmental Pollution, and an Editorial Board member for J. Agricultural & Food Chemistry. He has also served as an Associate Editor for Journal of Environmental Quality (2001-2006) and Soil Science Society of America Journal (2012). He was the Chair of Environmental Quality Division (S11) of Soil Science Society of America (2009-11), and is the Chair of Agrochemicals Division of American Chemical Society (2014).

Professor Gan received his Ph.D. degree from Zhejiang University in China in 1988, followed by postdoctoral training at the UN-International Atomic Energy Agency’s Laboratories in Seibersdorf, Austria (1990-91), University of Minnesota (1991-93) and the USDA George E. Brown Salinity Laboratory (1993-95), where he was a project scientist till 2001. He joined the faculty rank at UCR in 2001. Professor Gan is the (co)author of over 230 peer-reviewed journal articles, 4 edited books, and about 30 book chapters. To date his publications have received 5600 citations (ISI Web of Knowledge), with an H-index of 42.

View Jay Gan’s complete CV in PDF format


Emerging contaminants in the environment:

Our ongoing research in this topic area includes 1) plant uptake and accumulation of pharmaceutical and personal care products (PPCPs) during treated wastewater irrigation or biosolids application, 2) transformation pathways of PPCPs in soil and metabolism in plant, and 3) abiotic and biotic processes of brominated flame retardants (BFRs) and bisphenols in the environment. Funding sources: USDA-NIFA, EPA

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Bioavailability of organic contaminants:

Organic compounds such as PCBs, PAHs, DDT, PBDEs and pyrethroid insecticides are strongly hydrophobic and they tend to sorb to solid particles and DOM. This phase partitioning behavior dictates that the bioavailability of these compounds in sediment, soil or surface water may not be directly related to their bulk chemical concentration. Our research in this area involves 1) development of bioavailability measurement methods such as solid phase microextraction (SPME), isotope dilution method (IDM), and Tenax extraction, 2) characterization of processes and factors regulating bioavailability, such as aging and black carbon types, and 3) application of bioavailability in improving risk assessment and evaluation of remediation efficiency. Funding sources: NIEHS, CDPR, PWG

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Pesticide runoff and mitigation in urban environments:

Pesticides are frequently used by home owners and professional applicators around homes to control structural pests (e.g., termites), ants, and other insects. Such uses have been associated with contamination and aquatic toxicity of urban surface streams. In collaboration with California Department of Pesticide Regulation, the State Water resources Control Board and the Pyrethroid Work Group (PWG), we have been carrying out research to 1) evaluate the sources of urban pesticide contamination, 2) understand the abiotic transformation and sorption processes of pesticides on impervious surfaces such as concrete, and 3) develop mitigation strategies and education/outreach materials for stakeholders. Funding sources: CDPR, SWRCB, PWG

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Chiral contaminants:

A high percentage of current-use pesticides and pharmaceuticals are asymmetrical molecules with chiral centers. These chiral chemicals consist of two or more stereoisomers. While enantiomers have identical physico-chemical properties, their interactions with biological macromolecules are often chiral selective, leading to enantiomer selectivity in biodegradation, ecotoxicity and human health effects. In collaboration with Prof. W.P. Liu at Zhejiang University, China, we have been conducting research to 1) develop analytical methods enabling separation of enantiomers using GC and HPLC, and 2) evaluate chiral selectivity during biodegradation, aquatic toxicity and human health effects. Funding sources: USDA

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  • ENSC 002: Introduction to Environmental Science (Lower Division, Undergraduate Level, 240-320 students)
  • ENSC 127: Fate and transport of contaminants in soil (Upper Division, Undergraduate Level)
  • ENTX 200: Fate and Transport of Chemicals (Graduate Level)

Graduate programs:

Gan Research


Edited books

  • Gan, J., P. Zhu, S.D. Aust, and A.T. Lemley. Pesticide Decontamination and Detoxification. American Chemical Society Symposium Series 863, American Chemical Society: Washington, DC, 2003.
  • Gan, J., F. Spurlock, P. Hendley, and D. Weston. Synthetic Pyrethroids: Occurrence and Effects in Aquatic Environments. American Chemical Society Symposium Series 991, American Chemical Society: Washington, DC, 2003.
  • Goh, K., B. Bret, T. Potter, and J. Gan. Pesticide Mitigation Strategies for Surface Water Quality. American Chemical Society Symposium Series 1075, American Chemical Society: Washington, DC, 2011.
  • Garrison, A.W., J. Gan, and W.P. Liu. Chiral Pesticides: Stereoselectivity and its Consequences. American Chemical Society Symposium Series 1085, American Chemical Society: Washington, D.C. 2012.

Recent journal publications

Emerging contaminants: Transformations and plant uptake

  • Lu, Z.J., and J. Gan. Analysis, toxicity, occurrence and biodegradation of nonylphenol isomers: A review. Environmental International(in press)
  • Lin, K.D., J. Gan, and W.P. Liu. Production of hydroxylated polybrominated diphenyl ethers (HO-PBDEs) from bromophenols by bromoperoxidase-catalyzed dimerization. Environmental Science & Technology(in press)
  • Wu, X.Q., J. Conkle, F. Ernst, and J. Gan. Treated Wastewater Irrigation: Uptake of Pharmaceutical and Personal Care Products by Common Vegetables under Field Conditions. Environmental Science & Technology(in press)
  • Dodgen, L., J. Li, X. Wu, Z. Lu, and J. Gan. 2014. Transformation and removal pathways of four PPCP/EDCs in soil. Environmental Pollution193: 29-36.
  • Li, J.Y., Q.F. Ye, and J. Gan. 2014. Degradation and transformation products of acetaminophen in soil. Water Research49: 44-52.
  • Lu, Z.J., and J. Gan. 2014. Isomer-specific oxidation of nonylphenol by potassium permanganate. Chemical Engineering Journal243: 43-50.
  • Lu, Z.J., and J. Gan. 2014. Isomer-specific biodegradation of nonylphenol in river sediments. Environmental Science & Technology48: 1008-1014.
  • Lin, K.D., C. Yan, and J. Gan. 2014. Production of hydroxylated polybrominated diphenyl ethers (OH-PBDEs) from bromophenols by manganese dioxide. Environmental Science & Technology48: 263-271.
  • Li, J.Y., J.B. Zhang, C. Li, W. Wang, H.Y. Wang, J. Gan, Q.F. Ye, X.Y. Xu, and Z. Li. 2013. Stereoisomeric isolation and stereoselective fate of insecticide Paichongding in flooded paddy soils. Environmental Science & Technology47: 12768-12774.
  • Wu, X.Q., F. Ernst, and J. Gan. 2013. Comparative uptake and translocation of pharmaceutical and personal care products (PPCPs) by common vegetables. Environmental International60: 15-22.
  • Dodgen, L., D. Parker, and J. Gan. 2013. Uptake and accumulation of four PPCP/EDCs in two leafy vegetables. Environmental Pollution182: 150-156.
  • Lu, Z.J., and J. Gan. 2013. Oxidation of nonylphenol and octylphenol by manganese dioxide: Kinetics and pathways. Environmental Pollution180: 214-220.
  • Li, J.Y., L. Dodgen, Q.F. Ye, and J. Gan. 2013. Degradation kinetics and metabolites of carbamazepine in soil. Environmental Science & Technology47: 3678-3684.
  • Wright, L., D.A. Devitt, M.H. Young, J. Gan, B.J. Vanderford, S.A. Snyder, M. McCullough, and L. Dodgen. 2012. Fate and transport of 13 pharmaceutical and personal care products in a controlled and irrigated turfgrass system. Agronomy Journal104: 1244-1254.
  • Wu, X.Q., J. Conkle, and J. Gan. 2012. Multi-residue determination of pharmaceutical and personal care products in vegetables. Journal of ChromatographyA.1254: 78-86.
  • Bondarenko, S., J. Gan, F. Ernst, R. Green, J. Baird, and M. McCullough. Leaching of pharmaceutical and personal care products (PPCPs) in turfgrass soils during recycled water irrigation. Journal of Environmental Quality41: 1268-1274.
  • Lu, Z.J., K.D. Lin, and J. Gan. 2011. Oxidation of bisphenol F (BPF) by manganese dioxide. Environmental Pollution159: 2546-2551
  • Liu, W.P., H.H. Zhang, B.P. Cao, K.D. Lin, and J. Gan. 2011. Oxidative removal of bisphenol A using zero valent aluminum-acid system. Water Research45: 1872-1878.
  • Lin, K.D., W.P. Liu, and J. Gan. 2009. Reaction of tetrabromobisphenol A (TBBPA) with manganese dioxide: Kinetics, products, and pathways. Environmental Science & Technology43: 4480-4486.
  • Lin, K.D., W.P. Liu, and J. Gan. 2009. Oxidative removal of bisphenol-A with manganese dioxide: Kinetics, products, and pathways. Environmental Science & Technology43: 3860-3864.

Bioavailability: Method development and applications

  • Jia, F., L.J. Bao, J. Crago, D. Schlenk, and J. Gan. 2014. Use of isotope dilution method (IDM) to predict bioavailability of organic pollutants in historically contaminated sediments. Environmental Science & Technology48: 7966-7973.
  • Jia, F., and J. Gan. 2014. Comparing black carbon types in sequestering polybrominated diphenyl ethers (PBDEs) in sediments. Environmental Pollution184: 131-137.
  • Cui, X.Y., and J. Gan. 2013. Solid-phase microextraction (SPME) with stable isotope calibration for measuring bioavailability of hydrophobic organic contaminants. Environmental Science & Technology47: 9833-9840.
  • Bao, L.J., JF. Jia, J. Crago, E.Y. Zeng, D. Schlenk, and J. Gan. 2013. Assessing bioavailability of DDT and metabolites in marine sediments using solid phase microextraction with performance reference compounds. Environmental Toxicology & Chemistry32: 1946-1953.
  • Cui, X.Y., and J. Gan. 2013. Comparing sorption behavior of pyrethroids between formulated and natural sediments. Environmental Toxicology & Chemistry32: 1033-1039.
  • Delgado-Moreno, L., and J. Gan. 2013. A stable isotope dilution method for measuring bioavailability of organic contaminants. Environmental Pollution176: 171-177.
  • Cui, X.Y., P. Mayer, and J. Gan. 2013. Methods to assess bioavailability of hydrophobic organic contaminants: Principles, operations, and limitations. Environmental Pollution172: 223-234.
  • Jia, F., X.Y. Cui, W. Wang, L. Delgado-Moreno, and J. Gan. 2012. Using disposable solid-phase microextraction (SPME) to determine the freely dissolved concentration of polybrominated diphenyl ethers (PBDEs) in sediments. Environmental Pollution167: 34-40.
  • Wang, W., L. Moreno, Q.F. Ye, and J. Gan. 2011. Improved measurements of partition coefficients for polybrominated diphenyl ethers (PBDEs). Environmental Science & Technology45: 1521-1527.
  • Cui, X.Y., W. Hunter, Y. Yang, Y.X. Chen, and J. Gan. 2010. Bioavailability of sorbed phenanthrene and permethrin in sediments to Chironomus tentans. Aquatic Toxicology98: 83–90
  • Bondarenko, S., and J. Gan. 2009. Simultaneous determination of free and total concentrations of hydrophobic compounds. Environmental Science & Technology43: 3772-3777.
  • Yang, Y., W. Hunter, S. Tao, and J. Gan. 2009. Microbial availability of different forms of phenanthrene in soils. Environmental Science & Technology43: 1852-1857.
  • Hunter, W., Y. Yang, F. Reichenberg, P. Mayer, and J. Gan. 2009. Measuring pyrethroids in sediment porewater using matrix-solid phase microextraction. Environmental Toxicology & Chemistry28: 36-43.

Pesticides: Fate, risks and mitigation

  • Riar, N., J. Crago, W.Y. Jiang, L.A. Maryoung, J. Gan, and D. Schlenk. 2013. Effects of salinity acclimation on the endocrine disruption and acute toxicity of bifenthrin in freshwater and euryhaline strains of Oncorhynchus mykiss. Environmental Toxicology & Chemistry32: 2779-2785.
  • Anderson, M., J. Conkle, P. Pacheco, and J. Gan. 2013. Delineation of organochlorine pesticide and PCB contamination in lake sediment by coupling hydroacoustic measurements with chemical analysis. Science of the Total Environment458-460: 117-124.
  • Luo, Y.Z., F. Spurlock, W.Y. Jiang, B.C. Jorgenson, T. Young, J. Gan, S. Gill, and K.S. Goh. 2013. Pesticide washoff from concrete surfaces: literature review and a new modeling approach. Water Research47: 3163-3172.
  • Jiang, W.Y., A. Soeprono, M. Rust, and J. Gan. 2013. Ant control efficacy of pyrethroids and fipronil on outdoor concrete surfaces. Pest Management ScienceDOI 10.1002/ps.3555
  • Wang, W., L. Delgado-Moreno, J. Conkle, M. Anderson, C. Amrhein, Q.F. Ye, and J. Gan. 2012. Characterization of sediment contamination patterns by hydrophobic pesticides to preserve ecosystem functions of drainage lakes. Journal of Soils and Sediments12:1407-1418.
  • Jiang, W.Y., and J. Gan. 2012. Importance of fine particles in pesticide runoff from concrete surfaces and its prediction. Environmental Science & Technology46: 6028-6034.
  • Gan, J., S. Bondarenko, L. Oki, D. Haver, and J.X. Li. 2012. Occurrence of fipronil and its biologically active derivatives in urban residential runoff. Environmental Science & Technology46: 1489-1495.
  • Jiang, W.Y., D. Haver, M. Rust, and J. Gan. 2012. Runoff of pyrethroid insecticides from concrete surfaces following simulated and natural rainfalls. Water Research46: 645-652.
  • Budd, R., A. O’Geen, K. Goh, S. Bondarenko, and J. Gan. 2011. Removal mechanisms and fate of insecticides in constructed wetlands. Chemosphere83: 1581-1587.
  • Jiang, W., J. Gan, and D. Haver. 2011. Sorption and desorption of pyrethroid insecticide permethrin on concrete. Environmental Science & Technology45: 602-607.
  • Delgado-Moreno, L., L. Wu, and J. Gan. 2010. Effect of dissolved organic carbon on sorption of pyrethroids to sediments. Environmental Science & Technology44: 8473-8478.
  • O’Geen, A.T., R. Budd, J. Gan, J.J. Maynard, S.J. Parikh, and R.A. Dahlgren. 2010. Mitigating non-point source pollution in agriculture with constructed and restored wetlands. Advances in Agronomy108: 1-76.
  • Jiang, W., K. Lin, D. Haver, S. Qin, F. Spurlock, and J. Gan. 2010. Wash-off potential of urban use insecticides on concrete surfaces. Environmental Toxicology and Chemistry29: 1203-1208.
  • Budd, R., A. O’Geen, K. Goh, S. Bondarenko, and J. Gan. 2009. Efficacy of constructed wetlands in pesticide removal from tailwaters in the Central Valley, California. Environmental Science & Technology43: 2925-2930.
  • Gan, J., Q. Wang, S.R. Yates, W.C. Koskinen and W.A. Jury. 2002. Dechlorination of chloroacetanilide herbicides by thiosulfate salts. Proceedings of National Academy of Sciences (USA)99: 5189-5194.

Chirality: Method development and toxicology

  • Sanganyado, E., Z. Lu, and J. Gan. Mechanistic insights on chaotropic interactions of liophilic ions with basic pharmaceuticals in polar ionic mode liquid chromatography J. Chromatography A(in press)
  • Lao, W.J., and J. Gan. 2012. Enantioselective degradation of warfarin in soils. Chirality24: 54-59
  • Delgado-Moreno, L., K.D. Lin, R. Veiga- Nascimento, and J. Gan. 2011. Occurrence and toxicity of three classes of insecticides in water and sediment in two Southern California Coastal watersheds. Journal of Agricultural and Food Chemistry59: 9448-9456.
  • Lao, W.J., and J. Gan. 2010. Temperature effects on a doubly tethered diproline chiral stationary phase: Hold-up volume, enantioselectivity and robustness. Journal of Separation Science33: 3052-3059.
  • Nillos, M.G., S. Chajkowski, J.R. Rimoldi, J. Gan, R. Lavado, and D. Schlenk. 2010. Stereoselective biotransformation of permethrin to estrogenic metabolites in fish. Chemical Research in Toxicology23: 1568-1575.
  • Lao, W.J., and J. Gan. Characterization of warfarin unusual peak profiles on oligoproline chiral high performance liquid chromatography columns. Journal of Chromatography A.1217: 6545-6554.
  • Nillos, M.G., J. Gan, and D. Schlenk. 2010. Chirality of organophophorus pesticides: Analysis and toxicity. Journal of Chromatography B878:1277-1284.
  • Nillos, M.G., S.J. Qin, C. Larive, D. Schlenk, and J. Gan. 2009. Epimerization of cypermethrin stereoisomers in alcohols. Journal of Agricultural & Food Chemistry57: 6938-6943.
  • Nillos, M., K. Lin, J. Gan, S. Bondarenko, and D. Schlenk. 2009. Enantioselectivity in fipronil aquatic toxicity and degradation. Environmental Toxicology & Chemistry28: 1825-1833.
  • Liu, W.P., J. Gan, D. Schlenk and W.A. Jury. 2005. Enantioselectivity in environmental safety of current chiral insecticides. Proceedings of National Academy of Sciences(USA) 103: 701-706.

Group Members

Former Ph.D. Students
Susie (Sujie) Qin (Ph.D., 2006)
Lecturer, Xi'an Jiaotong Liverpool University, Suzhou, China (
Robert Budd (Ph.D., 2009)
Scientist, California Department of Pesticide Regulation, Sacramento, CA (
Wesley Hunter (Ph.D., 2009)
Staff Fellow, Center for Veterinary Medicine, U.S. Food and Drug Administration, MD (
Mae Nillos (Ph.D., 2009)
Associate Professor, Department of Chemistry, University of the Philippines at Visayas, the Philippines (
Weiying (Tim) Jiang (Ph.D., 2012)
Environmental Scientist, California Department of Pesticide Regulation, Sacramento, CA (
Zhijiang Lu (Ph.D. 2014)
Postdoctoral Fellow, Massachusetts Institute of Technology, Boston, MA (
Fang (Echo) Jia (Ph.D. 2014)
Postdoctoral Scientist, Bayer Crop Science, Research Triangle Park, NC (
Laurel Dodgen (Ph.D., 2014)
Postdoctoral Fellow, University of Illinois at Urbana Champaign, IN (
Former Visiting Scientists, Postdocs and Students (2001-2014)
Weiping Liu
Professor and Dean, College of Natural and Environmental Resources, Zhejiang University, Hangzhou, China (
Qiquan Wang
Associate Professor, Department of Chemistry, Delaware State University (
Jianming Xu
Professor, College of Natural and Environmental Resources, Zhejiang University, Hangzhou, China (
Sangjin Lee
Scientific Affairs Officer, Northwest Pacific Action Plan, UNEP, Busan, Korea (
Svetlana Bondarenko
Analytical Chemist, Valent U.S.A. Corporation, Dublin, CA (
Monica Antilen
Departamento de Qca. Inorgnica, Facultad de Qumica, Pontificia Universidad Catlica de Chile, Chile (
Michele Arienzo
Associate Professor, University of Department of Earth and Environmental Sciences, University of Naples Federico II, Italy (
Kunde (Ken) Lin
Professor, Xiamen University, Xiamen, China (
Wayne (Wenjian) Lao
Chemist, Southern California Coastal Water Research Project (SCCWRP), Costa Mesa, CA (
Wendy Quayle
Research Scientist, CSIRO Land and Water, Griffith, Australia (
Weichun Yang
Scientist, Kemin Industries, Des Moines, IA (
Lizethly Caceres Jensen
Universidad Metropolitana de Ciencias de la Educación, Chile (
Yiping Xu
Research Scientist, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, China (
Yu (Frank) Yang
Assistant Professor, University of Nevada, Reno, NV (
Xinyi (Lizzy) Cui
Associate Researcher, Nanjing University, China (
Laura Delgado-Moreno
Estación Experimental del Zaidín, Spanish National Research Council (CSIC), Granada, Spain (
Wei (Vivienne) Wang
Associate Professor, Zhejiang University, Hangzhou, China (
Haizheng Wang
Associate Professor, Zhejiang University, Hangzhou, China (
Ruben Reif-Lopez
Jefe de Proyectos I+D - Departamento Innovación y tecnología, FCC Aqualia, Spain (
Juying (Irene) Li
Lecturer, Shengzhen University, China (
Jeremy Conkle
Assistant Professor, Department of Physical & Environmental Sciences, Texas A&M University, Corpus Christi, TX (
Kunming (Kim) Dong
Associate Professor, Yangzhou University, China (
Jinhua (Jean) Wang
Associate Professor, Shandong Agricultural University, China (
Guoqing Shen
Professor, Shanghai Jiaotong University, Shanghai, China (
Xiaoqin (Sherry) Wu
Postdoctoral Scientist, Lawrence Berkeley National Laboratories, Berkeley, CA (

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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