Asbestos is a group of naturally occurring fibrous minerals that were once widely used in construction. It is still present in bonded materials such as cement sheeting, pipes and insulation.
When these materials deteriorate or are illegally dumped, asbestos can end up in soil and mulch.
Recycled products such as soil blends, crushed concrete and landscaping mulch may contain asbestos if they include unscreened demolition waste or construction debris.
Contamination often occurs when materials are reused without proper inspection or when asbestos-containing materials (ACM) are mixed into mulch, topsoil or road base during processing.
When asbestos is found in soil, it is usually because of:
- poor or incomplete asbestos removal or demolition work
- deterioration of a building or structure on site
- past or recent illegal dumping
- waste burial on site
- previous use of contaminated fill or topsoil.
Health risks
Asbestos in soil can be a health risk to workers if the fibres become airborne and are breathed in. The likelihood of exposure depends on:
- how much asbestos is present and how widely it is spread
- its condition, whether it is non-friable (bonded) or friable (crumbles easily under hand pressure)
- how much the soil or material is disturbed
- systems of work and control measures used to prevent the release and inhalation of asbestos fibres.
Contamination risk
Asbestos contamination in soil, mulch, and recycled materials can cause serious health problems and environmental harm. When disturbed, asbestos fibres can become airborne and may cause life‑threatening diseases such as mesothelioma, asbestosis, lung cancer and other long-term lung and breathing conditions.
In 2024, asbestos was found in landscaping mulch used in public parks, schools and homes across New South Wales, Victoria and the Australian Capital Territory. This puts gardeners, children and other community members at risk. In Western Australia, contamination from past demolition work and poor waste handling still affects many sites across the state.
Identifying and managing contaminated soil or mulch
If you notice fibrous minerals, unusual debris, or if you know the site has a history of demolition or waste disposal, asbestos contamination may be present. If you suspect contamination has occurred:
- stop work immediately
- avoid disturbing the soil or mulch
- isolate or cordon off the area
- contact a licensed asbestos assessor to conduct testing and a professional risk assessment.
Find more information about how to handle, remove, transport and dispose of asbestos safely.
Resources and guidance
- Asbestos in mulch, Asbestos and Silica Safety Eradication Agency (ASSEA)
- Asbestos in mulch, University of Western Australia
- Asbestos – contamination of soil, Department of Health
- Asbestos - contaminated sites, Department of Health
- Asbestos in soil, WorkSafe, Department of Local Government, Industry Regulation and Safety
- Contamination free mulch, Department of Health
- Guidelines for the assessment, remediation and management of asbestos contaminated sites, Department of Health
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