Contact Gary G. Leppard:

Phone & Address


Member of the Brockhouse Institute for Materials Research, McMaster University

Participant in the Faculty of Health Sciences Electron Microscopy Facility, McMaster University, Hamilton

Invited Member, American Nano Society

Member of Sigma Xi


Invited Partner in AFMNet, 2003-09, a national Network of Centres of Excellence, University of Guelph

RITE International Award 1993, Global Environment category (oceanic sinks for CO2), from the Japan Institute for Research on Innovative Technology for the Earth

Co-recipient of a Green Plan Award from the Tri-Council Eco-Research Program of Canada, for their 1993-96 project on the Hamilton Harbour ecosystem (McMaster University)

Director and Chief Organizer, NATO International Conference on "Trace Element Speciation in Surface Waters and Its Ecological Implications", Nervi (Italy), 1981

Education - Yale University, USA Ph.D. 1968; M.Phil. 1967; M.Sc. 1966: University of Saskatchewan M.A. 1964; B.A.(Hons) 1963; B.A.(Dist) 1962


Gary G. Leppard

Research Scientist - Urban Water Management Project (nanoparticles, biofilms, flocs)

CURRENT S&T / RESEARCH - To develop techniques for researching fundamental problems of the rehabilitation and conservation of water resources, and use them to obtain improved data collection for urban wet weather pollution and municipal wastewater studies

  • Contributing to technology development and application in support of Environment Canada priority needs to understand the activities of nanoparticles, colloids, biofilms and flocs in natural and engineered aquatic ecosystems
  • Creating new protocols for the determination of contaminant carriers by means of analytical electron microscopy and correlative spectromicroscopy techniques, including X-ray microscopy and nanotechnology protocols
  • Providing new information on the effectiveness of street sweeping as a pollution source control, with an emphasis on the PM10 fraction and its constituent nanoparticles
  • Providing new information on the fouling of membrane filters used for the decontamination of wastewaters
  • Providing new information on the structure, chemistry, activities and microbiology of riverine biofilms, with an emphasis on those individual components which are involved in the bioprocessing of antimicrobials released from personal care products


Consulting Fellow to international organizations such as the World Innovation Foundation and the International Union of Pure and Applied Chemistry

Member of research teams based at several synchrotron facilities in North America, including Canada's national CLS Synchrotron at Saskatoon, where I am also an advisor on environmental analyses which involve correlated electron and X-ray microscopy

Editorial activities, including co-editor of "Flocculation in Natural and Engineered Environmental Systems", Editorial Board Member of "Current Nanoscience" and "The Open Environmental and Biological Monitoring Journal", and past Editorial Board Member of the "Encyclopaedia of Analytical Science"


Liao, B.Q., Lin, H.J., Langevin, S.P., Gao, W.J. and Leppard, G.G. 2011. Effects of temperature and dissolved oxygen on sludge properties and their role in bioflocculation and settling. Water Res. 45: 509-520.

Makdissy, G., P.M. Huck, M.M. Reid, G.G. Leppard, J. Haberkamp, M. Jekel and S. Peldszus. 2010. Investigating the fouling layer of polyamide nanofiltration membranes treating two different natural waters: internal heterogeneity yet converging surface properties. J. Water Supply: Res. & Technol. - AQUA 59: 164-178.

Domingos, R.F., M.A. Baalousha, Y. Ju-Nam, M.M. Reid, N. Tufenkji, J.R. Lead, G.G. Leppard and K.J. Wilkinson. 2009. Characterizing manufactured nanoparticles in the environment: multimethod determination of particle sizes. Environ. Sci. Technol. 43: 7277-7284.

Leppard, G.G. 2008. Nanoparticles in the environment as revealed by transmission electron microscopy: detection, characterisation and activities. Current Nanoscience 4: 278-301.

Mavrocordatos, D., D. Perret and G.G. Leppard. 2007. Strategies and advances in the characterisation of environmental colloids by electron microscopy, p. 345-404. In K.J. Wilkinson and J.R. Lead (ed.).Environmental Colloids and Particles: Behaviour, Separation and Characterisation. Wiley, Chichester.

Dynes, J.J., J.R. Lawrence, D.R. Korber, G.D.W. Swerhone, G.G. Leppard and A.P. Hitchcock. 2006. Quantitative mapping of chlorhexidine in natural river biofilms. Sci. Total Environ. 369: 369-383.

Leppard, G.G., I.G. Droppo, M.M. West and S.N. Liss. 2003. Compartmentalization of metals within the diverse colloidal matrices comprising activated sludge microbial flocs. J. Environ. Qual. 32: 2100-2108.

Lawrence, J.R., G.D.W. Swerhone, G.G. Leppard, T. Araki, X. Zhang, M.M. West, A.P. Hitchcock. 2003. Scanning transmission X-ray, laser scanning, and transmission electron microscopy mapping of the exopolymeric matrix of microbial biofilms. Appl. Environ. Microbiol. 69: 5543-5554.

Liao, B.Q., D.G. Allen, G.G. Leppard, I.G. Droppo and S.N. Liss. 2002. Interparticle interactions affecting the stability of sludge flocs. J. Colloid Interface Sci. 249: 372-380.

Expertise Categories associated with this S&T Expert:

Pollution & Waste
          Chemistry - inorganic
          Pharmaceuticals and personal care products
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