Sustainability website / Case Studies 2006 / Xstrata zinc / Australia: Xstrata Zinc's community health initiatives to manage lead at Mount Isa

Australia: Xstrata Zinc's community health initiatives to manage lead at Mount Isa

Mining in the Mount Isa region

Lead, copper and zinc mining operations have been active in the Mount Isa region in north Queensland, Australia since 1923. Xstrata assumed control of Mount Isa Mines in 2003. Prior to 1990, historic practices, such as uncontrolled releases of storm water from mining areas, donations of mine-site fill material for use in the community and a leak from the process water dam caused some areas of lead contamination in Mount Isa.

Remediation of contaminated land

In the early 1990s, Mount Isa Mines, the Queensland Government CHEM unit and Mount Isa City Council (MICC) co-operated in a joint campaign to remediate community areas with lead contamination. Remediated areas were returned to a state suitable for public use and handed over to the MICC. While these historic practices have long since been discontinued, the town of Mount Isa lies within a highly mineralised area, with outcrops of lead-based minerals and naturally occurring lead in local soils, and is in close proximity to lead mining and smelting operations. Community lead exposure therefore remains a potential risk.

Voluntary free blood testing

Mount Isa Mines has provided a voluntary free blood lead testing service for Mount Isa residents for a number of years, funded by Xstrata. Confidential blood lead test results can be discussed with a general practitioner, who provides advice on how to minimise lead exposure.

Children's blood levels

In response to concerns raised in the media about whether children's blood lead levels were being monitored closely enough, the Queensland state health organisation (Queensland Health) commenced a targeted campaign in September 2006, supported by Xstrata, to test the blood lead levels of 400 Mount Isa children aged one to four. This age group is considered most at risk from prolonged exposure to high blood lead levels. By the end of March 2007, 251 children had been tested. No children tested with blood lead levels requiring clinical intervention (in excess of 25µg/dl), and 23 children tested had blood lead levels within Queensland Health's 'marginally elevated' level (above 10µg/dl).

Blood lead awareness

Xstrata continues to work closely with MICC, the Environmental Protection Agency (EPA) and Queensland Health to review potential community lead exposure risks and to provide information through a comprehensive blood lead awareness and education campaign. We are also trialling an alternative finger prick method of taking blood lead samples, which, if effective, may encourage more parents to take up regular testing of their children in the future.

Buffer zone

A greenbelt buffer zone of woodland has been established between Mount Isa Mines operations and the community. The greenbelt continues to be developed with an ongoing annual budget of A$500,000 for rehabilitation.

Air monitoring

Levels of respirable lead, cadmium and arsenic in the air are monitored by five high-volume samplers scattered throughout the community. Average lead levels are below 0.5 micrograms per cubic metre (µg/m³) and consistently well below the EPA limit of 1.5µg/m³. The results of monitoring programmes are reported to the EPA.

Independent study

Mount Isa Mines has also commissioned an independent land, air and water emissions study. This 'Whole of Emissions Study' will assess the major sources of non-natural forms of lead in the Mount Isa community and potential risks. The study will be conducted by recognised toxicologist Associate Professor Barry Noller, through the Centre for Mined Land Rehabilitation at the Sustainable Minerals Institute, University of Queensland.

The study will be completed in a consultative process with regulators and the MICC. We will work with these groups to address the study's recommendations. Initial results are expected in mid-2007 and an executive summary of the final results and recommendations will subsequently be released to regulators, the community and media.