Assessing Community Health Risks: Proactive Vs Reactive Sampling

Problem statement: A considerable number of native birds died in the West Australian coastal town of Esperance and surroundings during late 2006 and early 2007, which raised community concerns about environmental contamination. Forensic investigations of dead birds suggested that lead may have been the causative agent. At the time, lead and nickel, as well as iron ore and other materials, were being exported through the Port of Esperance (port). Government agencies undertook a targeted environmental sampling programme to identify the exposure sources and the extent of contamination. Results of ambient air monitoring, blood lead level investigations and analysis of metals in rainwater tanks suggested widespread contamination of the Esperance town site with lead and nickel. The Department of Environment and Conservation (DEC) retained Golder Associates Pty Ltd., (Golder) to undertake a human health and ecological risk assessment (risk assessment) using the information collected through the investigation of lead and nickel contamination in Esperance. The quantity and quality of exposure data are an important contributor to the uncertainty associated with the outcomes of a risk assessment. Conclusion: As the data were collected essentially as part of the emergency response to the events in Esperance, there was some uncertainty about the suitability and completeness of the data for risk assessment. The urgent nature of the emergency response meant that sampling was opportunistic and not necessarily sufficient or suitable for risk assessment from a methodical and scientific perspective. This study demonstrated the need for collecting ‘meaningful and reliable’ data for assessing risks from environmental contamination.