Higher tier risk assessment of chemicals: from the population to the landscape level

From ERAC Edu

Time:	11.- 12.1.2011, 9:00 AM - 5:00 PM
Place:	University of Eastern Finland, Joensuu Campus, Natura Building, Yliopistokatu 7, classroom N202
Credits:	1.0
Language:	English
Organizers:	Organized jointly by the Finnish Graduate School in Environmental Science and Technology (EnSTe) and Environmental Risk Assessment Centre (ERAC)
Lecturers:	Paul J. van den Brink and Nika Galic, Wageningen University, The Netherlands

General course information and topics

This course will focus on experimental and modelling approaches for the tiered ecological risk assessment of chemicals. The first tier consists of well-described rules, which are supposed to yield a worst-case risk assessment. When chemicals fail at the first tier, a higher tier risk assessment can be performed which consists of less well-described procedures and is thus more flexible to address potential concerns. At the higher tiers a range of experimental tools and simulation models can be used to assess the risks more realistically. These tools can range from additional single species tests in the laboratory, man-made experimental ecosystems (microcosms or mesocosms) to mechanistic effect models.

Microcosms and mesocosm are made up of parts of natural ecosystems. They are established in a container (for instance an aquarium or a concrete tank) and are left to develop into a system that is complex enough to serve as a model for a natural ecosystem in terms of structure and function. The use of microcosms or mesocosms provides a bridge between the laboratory and the field. They permit the use of a controlled, replicated experimental system on the one hand, whilst providing realism in terms of ecological processes and exposure to the chemical on the other.

The focus of the ecological risk assessment of chemicals, has shifted from the individual to the population level and therefore from species sensitivity to toxicants alone also to their life-history traits. In addition, population recovery potential has started to gain a significant role in determining risks to the system. It is widely acknowledged that some life-history traits, such as short generation times, high fecundity and good dispersal abilities, enhance population recovery, mainly through recolonization processes. Spatial structures that surround disturbed systems also play a significant role in population recovery, e.g. availability and accessibility of undisturbed patches that provide organisms for recolonization, presence of refugia, but also bigger structures that might act as barriers or corridors for repopulation.

A modelling approach can integrate life-history traits, landscape characteristics and chemical exposure regimes for an ecologically realistic and relevant estimation of recovery times supporting the risk assessment. During the course, we present some results and developments of MASTEP, an individual-based, spatially explicit metapopulation model. From interactions among individuals and their environment, population-level responses emerge. The main purpose of this model is to quantify and predict the spatial and temporal recovery of arthropod populations after chemical induced mortality.

The course will be two days, the first day will deal with experimental approaches in higher tier risk assessment while the second day will focus on modelling approaches.

Course fee

Free of charge for all participants.

Registration by December 28, 2010

Registration form

Further information: enste@uef.fi