An important milestone in 20th century environmental science was the publication of several reports from the United Kingdom in the 1990’s showing reproductive abnormalities in fish living downstream of sewage effluent outfalls. These observations triggered a significant international research effort targeted at endocrine-disrupting chemicals (EDCs), pharmaceuticals and personal care products (PPCPs) in sewage treatment plants (STPs) and effluent-receiving environments.
The major concern associated with EDCs and PPCPs in freshwater systems is the very low dose required to elicit adverse effects in exposed species (parts-per-trillion or lower).
The evidence base for EDCs and PPCPs in the Australian environment is limited compared to North America, Europe and Asia. Differences in population characteristics, sewage treatment methods, climate and hydrology make extrapolation from Northern Hemisphere data problematic. This multi-disciplinary study is targeted at Australia’s largest inland STP, located in Canberra, and the Molonglo/Murrumbidgee effluent-receiving environment. Using a range of chemical, immunological, in vitro and ecotoxicological techniques, the following topics were investigated:
- Application of hydrochemical sewage tracers to quantify seasonal effluent mixing and dilution in the Molonglo/Murrumbidgee Rivers
- Behaviour of certain EDCs and PPCPs during sewage treatment, and loads in the effluent-receiving environment in high- and low-flow conditions
- Whole-sediment toxicity in freshwater invertebrates
- Biomarkers of estrogenic effects in wild fish in effluent-impacted areas
- Screening-level risk assessments of ‘contaminants of concern’.
This seminar will discuss research highlights related to significant seasonal changes in EDC/PPCP loads and behaviour during sewage treatment, changes in the ‘zone of impact’ in the receiving environment, priority micropollutants requiring further investigation, and other sources of potential anthropogenic contamination.
Dr Roberts is a senior policy officer in the Department of Agriculture and Water Resources, working in an area that deals with policy and regulation of agricultural chemicals and veterinary medicines. She specialises in providing scientific advice to inform policies that have tangible impacts on agricultural productivity, particularly the relationship between international chemical regulation and Australian trade.