Siciliano, Steven


Steven Siciliano

Soil Science
5E26 - 51 Campus Drive
Saskatoon, Saskatchewan, Canada
S7N 5A8

Phone: 306-966-4035



I explore how humans poison soil and how soil poisons humans. In Canada, soil cleanup guidelines protect the most sensitive organism at a site for a specific contaminant. For example, typically humans are very sensitive to polycyclic aromatic hydrocarbons (PAH) pollution, whereas soil nutrient cycling is sensitive for Total Petroleum Hydrocarbons (TPH) [REFs 96,92,76]. Thus, at a site contaminated with PAHs and TPH, the site would have to be cleaned up to protect humans and nutrient cycling if both receptors are present. As a result, improving policy and technologies in Canada requires that we investigate how humans and all other ecosystem components interact with, and are affected by polluted soils. Incidental ingestion of soil by humans is the primary exposure pathway by which polluted soils poison humans. And among soil biogeochemical cycles, the nitrogen cycle is proving to be the most sensitive to pollutants. Thus, I focus on incidental soil ingestion and the soil nitrogen cycle to understand how human activities impact ecosystems and how these ecosystems impact human health.

Academic Degrees

Ph.D. Toxicology (Saskatchewan)

B.Sc. Biochemistry (Concordia)

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Dr. Steven Siciliano Studies soil in the Arctic

Current Teaching

Lecture courses:

Graduate courses:

  • TOX 820: Advanced Environmental Fate Modelling (if demand warrants)
  • TOX 821: Human Health Risk Assessment (every year co-taught with Mark Richardson)
  • EVSC 821: Contaminated Site Remediation  (every second year)

Graduate Students

Current and Recent Research Projects

The laboratory has two divisions: toxicology and ecology.


  • Modelling and assessing the transfer of pollutants from soil to children.
  • Development of new soil toxicity test methods and approaches for Antarctic and the Arctic.
  • Assessment of cardiovascular effects of metals and polycyclic aromatic hydrocarbons.
  • The fate of mercury in soil: how do soil ecosystems purge mercury from their systems?
  • Industrial barrens and metals: how do ecological and toxicological stressors impact the nitrogen cycle.


  • Unravelling the mechanisms of greenhouse gas production in Arctic desert ecosystems.
  • Exploring how liquid water at sub-zero temperatures influences the expression of degradation genes.
  • The Arctic nitrogen cycle in Polar deserts.

With Eric Lamb

  • Smooth brome invasion in the tall grass prairie: root competition and the nitrogen cycle.
  • Root competition in the polar deserts: the role of diapirs in ecosystem sustainability.
  • Global drivers of microbial composition in the Arctic and Antarctic: nano to global scale synthesis.
  • Landscapes of the four kingdoms: roots, bacteria, archae, and fungi competition in the prairie pothole region.


SD Siciliano, AS Palmer, T Winsley, EG Lamb, A Bissett, MV Brown, J van Dorst, J Ji, BC Ferrari, P Grogan, H Chu, I Snape.  Accepted June 2014. Soil fertility is associated with fungal and bacterial richness whereas pH is associated with community composition in polar soil microbial communities. Soil Biology and Biochemistry

Peters, RE, M Wickstrom, SD Siciliano.   Accepted June 2014. The absolute bioavailability of polycyclic aromatic hydrocarbons from different dose media after single and sub-chronic exposure in juvenile swine.  Human and Ecological Risk Assessment.

Pannu, R. SD Siciliano, NJ O'Driscoll.  Accepted 2014.  Quantifying the effects of soil temperature, moisture and sterilization on elemental mercury formation in boreal soils.  Environmental Pollution. I was co-supervisor of R. Pannu and this manuscripts summarizes his PhD work.

Winsley T, I Snape, J McKinlay, J Stark, J van Dorst, M Ji, B Ferrari, SD Siciliano.  Accepted 2014. The Ecological Controls on the Prevalence of Candidate Division TM7 in Polar Regions. Frontiers in Terrestrial Microbiology.

van Dorst, J, SD Siciliano, T Winlsey, IS Snape, and B Ferrari. Accepted 2014. Bacterial targets as potential indicators of diesel fuel toxicity in subantarctic soils.   Applied & Environmental Microbiology. I designed the data interpretation and link to soil risk assessment for this diesel impacted soil.

Lamb, EG, KL Mengersen, KJ Stewart, U Attanayake, SD Siciliano. Accepted 2014. Spatially-explicit structural equation modelling.  Ecology.

Stewart, KJ, P Grogan, SD Siciliano. Accepted December 2013. Topography as a Key Factor Driving Atmospheric Nitrogen Exchanges in Arctic Terrestrial Ecosystems. SB&B.

Kuperman, RG, SD Siciliano, J Römbke, K Oorts. Accepted November 2013. Deriving Site-Specific Soil Clean-up Values for Metals and Metalloids: Rationale for Including Protection of Soil Microbial Processes. Integrated Environmental Assessment and Management.  This is a risk assessment workshop report providing the rationale for including soil processes in clean up values.

Brummell, ME, RE Farrell, SP Hardy, SD Siciliano. 2014. Greenhouse gas production and consumption in High Arctic deserts. SB&B.68:158-165

Bruckeridge, KM, S Banerjee, SD Siciliano, P Grogan. 2013. The seasonal pattern of soil microbial community structure in mesic low arctic tundra. SB&B. 65:338-347.  The PFLA and QPCR was completed in my laboratory. 

Bradham, KD, BD Laird, PE Rasmussen, RA Schoof, SM Serda, SD Siciliano, MF Hughes. 2014. Assessing the bioavailability and risk from metal contaminated soils and dusts.  Human and Ecological Risk Assessment. 20:272-286.  This is a summary report of a special session at the Society of Toxicology meeting to which I was an invited speaker.

Bissett A, MV Brown, SD Siciliano, PH Thrall. Microbial community responses to anthropogenically induced environmental change: towards a systems approach.  Ecology Letters.  16:128-139. I contributed the section discussing how pollutants impact the nitrogen cycle.

Koch I, KJ Reimer, MI Bakker, NT Basta, MR Cave, S Denys, M Dodd, BA Hale, R Irwin, YW Lowney, MM Moore, V Paquin, PE Rasmussen, T Repaso-Subang, GL Stephenson, SD Siciliano, J Wragg, GJ Zagury. 2013. Variability of Bioaccessibility Results Using Seventeen Different Methods on a Standard Reference Material, NIST 2710. The Journal of Environmental Health Science Part A. 48:641-655. My lab participated in this round robin of different in vitro digestors. 

Laird BD, KJ James, TR Van de Wiele, M Dodd, SW Casteel, M Wickstrom, SD Siciliano. 2013. An Investigation of the effect of gastrointestinal microbial activity on oral arsenic bioavailability.  The Journal of Environmental Health Science Part A. 48:612-619.

Stewart, KJ, ME Brummell, DS Coxson, SD Siciliano.  2013. How is nitrogen fixation in the High Arctic linked to greenhouse gas emissions?  Plant and Soil. 362:214-229.

Henry GHR, KA Haper, W Chen, JR Deslippe, RF Grant, PM Lafleur, E Levesque, SD Siciliano, SW Simard. 2012.  Effects of observed and experimental climate change on terrestrial ecosystems in -northern Canada: results from the Canadian IPY program.  Climate Change. 115:207-234. I was responsible for the soil ecology section describing resistance to climate change. 

James KJ, RE Farrell, SD Siciliano.  2012. Comparison of human exposure pathways in an urban brownfield: reduced risk from paving roads.  ET&C. 31:2423-2430.

Banerjee S, SD Siciliano.  2012. What factors drive potential ammonia oxidation in Canadian arctic ecosystems: Does spatial scale matter? Applied and Environmental Microbiology 78:346 -353.

Owojori OJ, J Healey, J PrinczSD Siciliano.  2011. Can avoidance behaviour of the mite Oppia nitens be used as a rapid toxicity test for soils contaminated with metals or organic chemicals.  ET&C. DOI: 10.1002/etc.658.

Harvey-Schafer ANI Snape, SD Siciliano.  2012. Changes in liquid water alter nutrient bioavailability and gas diffusion in frozen Antarctic soils contaminated with petroleum hydrocarbons.  ET&C.  DOI: 10.1002/etc.745.

Harvey-Schafer ANI Snape, SD Siciliano.  2012. Validating potential toxicity assays to assess petroleum hydrocarbon toxicity in polar soil.  ET&C.  DOI: 10.1002/etc.744

Princz JI, M Moody, C Fraser, L van der Vliet, H Lemieux, R Scroggins, SD Siciliano. Accepted 09/2011.   Development and evaluation of ten new toxicity tests to assess the impact of hydrocarbons and salts on boreal forest soils.  ET&C.

Banerjee S, B Si, SD Siciliano. 2011. Evidence of high microbial abundance and spatial dependency in three arctic soil ecosystems.  Soil Science of America Journal 75:2227-2232.

Stewart KJ, I Snape, SD Siciliano.  2011. Physical, Chemical and Microbial Soil Properties of Frost Boils at Browning Peninsula, Antarctica.  Polar Biology. DOI: 

Ma WK, RE Farrell, SD Siciliano.  2011.  Differences in microbial community composition are correlated to changes in nitrous oxide emissions from ephemeral wetland soils. Frontiers in Terrestrial Microbiology.  2:1-11.

James K, R Peters, B Laird, WK Mai, M Wickstrom, G Stephenson, SD Siciliano.  2011.  Human exposure assessment: a case study of 8 PAH contaminated soils using in vitro digesters and the juvenile swine model.  ES&T. 45:4586-93.

Lamb EG, S Han, BD Lanoil, GHR Henry, ME Brummell, S Banerjee, SD Siciliano. 2011.  A High Arctic soil ecosystem resists long-term environmental manipulations.  Global Change Biology. 17:3187-3194. 

Laird BD, JD Peak, SD Siciliano.  2011. The bioaccessibility of metal cations in soil is linearly related to its water exchange rate constant.  ES&T. 45:4139-44.

Stewart KJ, EG Lamb, DS Coxson, SD Siciliano.  2011.  Bryophyte-cyanobacterial associations as a key factor in N2-fixation across the Canadian Arctic.  Plant and Soil. 344:335-346.

Stewart KJ, D. Coxson, SD Siciliano.  2011. Small-scale spatial patterns in N2-fixation and nutrient availability in an arctic hummock-hollow ecosystem. SB&B.  43:133-40.  *In this project, I was only responsible for the molecular ecology.  KJS worked in my laboratory for several months on this project analyzing the results but the field work was designed by KJS and DC.

Banerjee S, A Bedard-Haughn, B Si, SD Siciliano.  2011.  Soil spatial dependence in three Arctic ecosystems. Soil Science Society of America Journal.  75:591-94.