Joan E. McLean

Research Associate Professor
Utah Water Research Laboratory
Civil and Environmental Engineering

Electronic Mail:
Phone: +1 (435) 797-3199
FAX: +1 (435) 797-3663
Office: UWRL Room 315
U.S. Mail Address:
Utah State University
Utah Water Research Laboratory
College of Engineering
8200 Old Main Hill
Logan, Utah 84322-8200


  • M.S., Soil Chemistry, University of California, Davis, California, 1978
  • B.S., Chemistry, University of San Francisco, California, 1975

Research Interests

My research interests over the last 30 years has focused on the biogeochemistry of pollutants in soil/water environments, with emphasis on heavy metals and metalloids. Current research projects include:

  • Evaluating sources of hexavalent chromium in drinking water
  • Evaluating microbial reduction of iron containing minerals
  • Investigating microbial processes controlling arsenic release to groundwater
  • Investigating how nanoparticles of silver and the oxides of copper and zinc affect plant root-bacteria interactions 
  • Development of bacterial biosensors for determining bioavailable metals in soil and water
  • Fate and behavior of metals in soil and subsurface systems
  • Defining bioavailability of metals to soil organisms
  • Phytoremediation of metal-contaminated soils; metal-soil-plant interaction

Teaching Experience

  • Soil chemical processes in environmental engineering systems
  • Environmental quality analysis, natural attenuation of metals in soil ground water systems

Present Professional and Honorary Societies and Committees

  • American Society of Agronomy
  • American Chemical Society
  • Soil Science Society of America

Selected Publications

  • Dimkpa, C.O., J.E. McLean, D.W. Britt, A.J. Anderson (2015). Nano-CuO and interaction with nano-ZnO or soil bacterium provide evidence for the interference of nanoparticles in metal nutrition of plants. Ecotoxicology, 24: 119-129.
  • Dimkpa, C.O., T. Hansen, J. Stewart, J.E. McLean, D.W. Britt, A.J. Anderson (2015). ZnO nanoparticles and root colonization by a beneficial pseudomonad influences essential metal responses in bean (Phaseolus vulgaris). Nanotoxicology on line April 9 2014 doi: 10.3109/1743539.2014.900583.
  • Watson, J-L, T. Fang, C.O. Dimkpa, D.W. Britt, J.E. McLean, A. Jacobson, A.J. Anderson (2015). The phytotoxicity of ZnO nanoparticles on wheat varies with soil properties. Biometals doi 10.1007/s10534-014-9806-8. On-line published Oct 29 2914.
  • Martineau, N., J.E. McLean, C.O. Dimkpa, D.W.Britt, A.J. Anderson (2014). Components from wheat roots modify the bioactivity of ZnO and CuO nanoparticles in a soil bacterium. Environ. Poll., 187:65-72.
  • Mirza, B.S., S. Muruganandam, D.L. Sorensen, R.R. Dupont. J.E. McLean (2014). As(V) reduction in relation to iron (III) transformation and molecular characterization of the structural and functional microbial community in sediments of a basin-fill aquifer in Northern Utah. Appl. Environ. Microbiol,. 80(10):3198-3208. doi:10.1128/AEM.00240-14.
  • Dimkpa, C.O., D.E. Latta, J.E. McLean, D.W. Britt, M.I. Boyanov, A.J. Anderson (2013). Fate of CuO and ZnO nano- and microparticles in the plant environment. Environ. Sci. Technol. 47:4734-4742.
  • Dimkpa, C.O., J.E. McLean, D.W. Britt, A.J. Anderson (2013). Antifungal activity of ZnO nanoparticles and their interactive effect with a biocontrol bacterium on growth antagonism of the plant pathogen Fusarium graminearum, 26:913-924.
  • Dimkpa, C.O., J.E. McLean, N. Martineau, D.W. Britt, R. Haverkamp, A.J. Anderson (2013). Silver nanoparticles disrupt wheat (Triticum aestivum L.) growth in a sand matrix. Environ. Sci. & Technol. 47:1082-1090.
  • Fang, T., J.-L Watson, J. Goodman, C.O. Dimkpa, N. Martineau, S. Das, J.E. McLean, D.W. Britt and A.J. Anderson (2013). Does doping with aluminum alter the effects of ZnO nanoparticles on the metabolism of soil pseudomonads? Microbiol. Res. 168:91-98.
  • McLean, J.E., M.W. Pabst, C.D. Miller, C.O. Dimkpa. A.J. Anderson (2013). Effect of complexing ligands on the surface adsorption, internalization, and bioresponse of copper and cadmium in a soil bacterium, Pseudomonas putida. Chemosphere 91:374-382.
  • Calder, A.J., C.O. Dimkpa, J.E. McLean, D.W. Britt, W.P. Johnson and A.J. Anderson (2012). Soil components mitigate the antimicrobial effect of silver nanoparticles towards a beneficial soil bacterium, Pseudomonas chlororaphis O6. Sci. Total Environ. 429:215-222.
  • Dimkpa, C.O., J. Zeng, J.E. McLean, D.W. Britt, J.Zhan, and A.J. Anderson (2012). Production of indole-3-acetic acid via the indole-3-acetamide pathway in the plant-beneficial bacterium Pseudomonas chlororaphis O6 is inhibited by ZnO nanoparticles but enhanced by CuO nanoparticles. Appl. Environ. Microbiol., 78:1404-1410.
  • Dimkpa, C.O., J.E. McLean, D.E. Latta , E. Manangón, D.W. Britt, W.P. Johnson, M.I. Boyanov, A.J. Anderson (2012). CuO and ZnO nanoparticles: phytotoxicity, metal speciation and induction of oxidative stress in sand-grown wheat. J. Nanopart. Res. 14:1125-1140.
  • Dimkpa, C.O., J.E. McLean, D.W. Britt and A.J. Anderson (2012). CuO and ZnO nanoparticles differently affect the secretion of fluorescent siderophores in the beneficial root colonizer, Pseudomonas chlororaphis O6. Nanotoxicology, 6:635-642.
  • Dimkpa, C.O., J.E. McLean, D.W. Britt, A.J. Anderson (2012). Bioactivity and biomodification of Ag, ZnO, and CuO nanoparticles with relevance to plant performance in agriculture. Industrial Biotechnol. 8:344-357.
  • Dimkpa, C.O., J.E. McLean, D.W. Britt, W.P. Johnson, B. Arey, A.S. Lea and A.J. Anderson (2012). Nanospecific inhibition of pyoverdine siderophore production in Pseudomonas chlororaphis O6 by CuO nanoparticles. Chem. Res. Toxicol., 25:1066-1074.
  • McLean, J.E., L.S. McNeill, M. Edwards and J.L. Parks (2012). Hexavalent chromium review, part 1: health effects, regulations, and analysis. Journal AWWA, 104:E348-E357.
  • McNeill, L.S., J.E. McLean, M. Edwards and J.L. Parks (2012). Hexavalent chromium review, part 2: chemistry, occurrence and treatment. Journal AWWA, 104:E395-E405.