In 2006, we commissioned the independent Lead Pathways Study.
It is the most comprehensive study of its kind in Australia, investigating the natural and industrial pathways of lead and other heavy metals into the Mount Isa community and assessing the potential risks to human and environmental health.
The health and wellbeing of our people and community is paramount and studies like this are helping us identify further opportunities to improve our environmental performance.
About the Lead Pathways Study
The independent and comprehensive study was conducted by The University of Queensland's Centre for Mined Land Rehabilitation (CMLR) in collaboration with the National Research Centre for Environmental Toxicology (Entox).
It consists of three parts: Land, Water and Air.
The Land Report
The Lead Pathways Study Land Report was released in 2009, showing the risk to human health from historical mine sediment was low.
The Land report resulted in a number of key environmental initiatives, including the Leichhardt River Remediation Project (LRRP).
To date we've invested over $2.7 million in relocating around 160,000 tonnes of soil containing historical mine sediment material from the Leichhardt River, onto our mine site.
Between 2008 and 2011 we conducted an annual post-wet season sampling program, which confirmed the success of the Leichhardt River Remediation Project. We continue to closely monitor sediment quality to ensure we meet our environmental regulatory regime.
The Water Report
The Water Report was released on 27 September 2012 and concluded that the risk to human health from heavy metals and other metalloids in the Leichhardt River Catchment, including Lake Moondarra, was low.
CSIRO's Land and Water Environmental Biogeochemistry Research Program Chief Research Scientist, Dr Graeme Batley, peer reviewed the report to verify its scientific validity and outcomes based on facts evident in the data.
The purpose of the Water Report was twofold:
- Investigate potential sources and pathways of lead and other heavy metals and metalloids in water from a number of tributaries leading into the Leichardt River Catchment - particularly at and below Mount Isa City and the mine lease.
- Assess the risk to human, pastoral and ecological health from lead and other heavy metals and metalloids in water.
The study area covered water and sediment samples at sites upstream of Mount Isa City to Rifle Creek dam, Mount Isa City and downstream to Lake Moondarra.
The Water Report considered multiple potential contaminant sources, including our mining operations, urban activities and wastewater discharges, natural mineralisation and historical mine sediment.
The Air Report
The Air Report was released on 9 February 2017, concluding many years of research and analysis into the pathways and potential health impacts of lead in the Mount Isa community.
In 2006, Mount Isa Mines commissioned The University of Queensland (UQ) to undertake a series of studies to better understand the impacts of industrial and naturally occurring lead in the environment.
The Air Report builds on the findings of the land and water studies and concluded that the potential exposure risk of children from inhalation was limited and mostly related to ingestion via hand to mouth activity.
The study reinforced the importance of Mount Isa residents taking active steps to minimise their exposure to lead and participate in regular blood lead level testing, particularly young children.
Led by Associate Professor Barry Noller and Dr Jack Ng, the Air Report covered the period 2006 to 2013 and included a health risk assessment that focused on children under five years of age.
Read more about the Air Report.