Roxanne demuysère

MScA candidate
(Chemical Engineering Department - cole Polytechnique de Montral)
roxanne-2.demuysere@polymtl.ca

Expertise :

• Terrestrial ecotoxicity
  
• Soil microbiology
  
• Life cycle impact assessment

Start: September 2008
Director: Louise Deschênes
Co-director: Réjean Samson

Research project:

Development of an Ecotoxicological Enzyme-Based Indicator to Evaluate a Complex Contamination Influence on Soil Health

Project summary:

In Life Cycle Impact Assesment (LCIA), the terrestrial ecotoxicity data come generally from ecotoxicological tests based on worms and plants. However, these tests are insufficient to evaluate how a soil health is really affected by toxic substances. Soils are complex matrices with many microbial activities. Microbial communities are present in almost all types of soils and have a considerable contribution in soil stability by producing various enzymes, involved in the main biogeochemical cycles (carbon, nitrogen, sulfur and phosphorus). Microorganisms are therefore an interesting way to evaluate soil health, but by operating in communities and by interracting with many species, their vital functions cannot be measured easily. However, the role of enzymes represents one of the most important microbial activities in a soil and correlates with soil stability functions. Enzymatic activity monitoring appears to be a promising way of studying the health condition of a soil.

A sensitive method called the Relative Soil Stability Index (RSSI) was elaborated to evaluate the impact of a pollutant on soil health based on the soil enzymatic stability (Béacert, 2004). It has already shown its sensitivity on low contamination level of simple organic and inorganic pollutants (Bécaert et al, 2006; Dussault et al, 2008). But when confronted with high contamination levels, this tool does not perform well because of a significant inhibition in enzymatic activities. The main objective of this project is also to develop an ecotoxicological tool in order to evaluate the health of a contaminated soil with a pollutant mixture.

This project particularly applies to contaminant mixtures with polycyclic aromatic hydrocarbons (PAHs). The interest of studying PAH mixtures is that they are highly toxic and persistent compounds in the environment.

Publications/presentations:

Demuysère, R., Jean, L., Bécaert, V., Samson, R. et Deschênes, L. (2009). Enzyme-Based Indicator to Evaluate a Complex Contamination Influence on Soil Health. Conférence présentée au 19th annual meeting SETAC Europe, Göteborg, Suède, 31 mai-4 juin 2009.

Career path:

M.Sc.A., Chemical Engineering
École Polytechnique de Montréal, in progress

Degree in Chemical Engineering
Institut National des Sciences Appliquées (INSA), Toulouse, France, 2008