Biomarkers Program Leader Prof Ary Hoffmann FAA, Laureate Fellow
Contact Details: Hoffmann Laboratory, The University of Melbourne, Bio 21 Institute, Parkville, Vic 3052
My group develops methods for the early and unambiguous detection and monitoring of environmental stress. We focus on pollution stress as well as climatic stresses arising from climate change. We use insects and other invertebrates. Our group combines pure research with applied efforts aimed at solving environmental and pest problems at a very practical level. Our CAPIM program will innovative ways of using genes, proteins and insects to monitor pollution and other stresses, and we are more broadly developing new markers to assess the ability of organisms to cope with stressful conditions, and new applied monitoring techniques within a landscape context.
We work closely with Melbourne Water in developing new methods for aquatic pollution detection. This has included the application of a microcosm method for testing the impact of sediment pollution in environmental degradation, a new in situ method for assessing pollutants within the context of local indigenous fauna, and new DNA based methods for identifying chironomids. These techniques have been used in projects with other industry bodies including water management agencies, local councils and the wine industry. We are funded through Melbourne Water, the Commonwealth Environmental Research Fund (CERF), ARC Linkage with partners including DSE, and agricultural funders such as GRDC. We have developed an industry consultant group (CESAR Consultants) and interact with government though participation in science advisory groups.
Biomarker Program Objectives:
- To develop biomarkers in macroinvertebrates from estuarine and freshwater environments exposed to pollutants (including pesticides, metals and veterinary medicines)
- To produce a matrix of biomarker responses for Australian species following exposure to contaminants.
- To integrate macroinvertebrate biomarkers into biomonitoring programs.
What are Biomarkers?
Definition: Biological variations in the tissue or body fluids or at the level of whole organism that provide evidence of exposure to chemical pollutants, and may also indicate a toxic effect. Biomarkers can be biochemical, molecular, physiological, behavioural and whole organism changes. Biomarkers have potential application in assessing impacts on, or monitoring the condition of, living organisms, because they can provide evidence of exposure to chemicals (both individual compounds and mixtures of compounds), exposure to other stresses (such as salinity and change in temperature) and/or an early warning of ecological impacts. CAPIM will initially focus on biochemical biomarkers, specifically proteins and gene expression.
The advantages of Biomarkers
Changes in biological responses of an organism following exposure to chemicals demonstrate that the chemical has been taken up by the organism and is having an effect on the biological functioning of that organism. Carrying out chemical analyses alone only demonstrates that chemicals are present in the organism but they may not be having an effect. Some chemicals are quickly metabolised and eliminated from the body, so measuring the concentration of the chemical may not accurately illustrate the extent to which exposure has occurred whereas the biomarker response may be elevated for a longer time period and measuring the response may be more reliable in demonstrating exposure has occurred.
Measure of the effects of single and mixtures of chemicals
Biomarkers respond to chemicals present in the organism and so whether there is only one chemical or a number of different chemicals biomarkers provide a measure of chemical exposure. Biomarkers may also be able to demonstrate whether combinations of chemicals are more or less toxic than exposure to the single chemical.
Mechanisms of toxicity/mode of action of a chemical
Some biomarkers can demonstrate the mechanism of toxicity, for example the novel approaches such as looking at changes at the genome or protein level. We will be able to determine the target sites in the body for the chemicals, for example some chemicals may target genes or proteins that are responsible for maintaining energy or adverse effects on the nervous system. This will help in predicting adverse effects of chemicals with the same mode of action.
Predictive tool that could trigger further study of a site
Biomarkers have the potential to demonstrate that a site is in an unfavourable condition, for example there may be an increase in enzyme activity in organisms which is only elevated when there are chemicals present and there is no increase in activity in organisms at the reference site. They can be used as a rapid, cost-effective screening tool to demonstrate this at a number of sites. Following this, more detailed, focussed monitoring would then be carried out, which may include chemical-specific biomarker measurements, chemical analysis and community-level analysis, to determine what the stress is and what is causing the stress. This would help inform decision makers regarding the course of remedial action to be followed.
Show the effectiveness of remedial action
Once a site has been earmarked as being impacted and remedial action agreed and implemented, subsequent integrated biomonitoring studies (which should include biomarker measurements, chemical analyses and community level responses) would be carried out at that site over time. If remedial action was being effective the monitoring tools would show the site returning to a more healthy condition. Conversely the biomonitoring schemes could also demonstrate that the site was still impacted and that the remedial action was not effective. The Biomarker Program is closely integrated with the Freshwater, Estuarine and EDC Research Groups in the CAPIM centre.