Cadmium is a naturally occurring heavy metal found in trace amounts in rock and soil. In agriculture and urban areas, cadmium levels can rise due to phosphate fertilisers, industrial emissions, sewage sludge application, and waste disposal practices. While small amounts occur naturally, excessive cadmium can contaminate soils, entering the food chain and posing health risks.
Cadmium and Its Risks
High cadmium levels in soil are concerning because:
- Human health risks: Cadmium accumulates in plants and can be transferred into food crops such as cereals, leafy greens, potatoes, and tobacco. Long-term dietary exposure has been linked to kidney damage, bone demineralisation, and cancer.
- Environmental impacts: Elevated cadmium affects soil microorganisms and can reduce soil fertility.
- Agricultural productivity: Excess cadmium uptake by crops can restrict export opportunities, as international food safety standards have strict cadmium limits.
Australian Standards and Guidelines
In Victoria and across Australia, cadmium management is guided by the National Environment Protection (Assessment of Site Contamination) Measure (NEPM, 2013, amended 2020) and Food Standards Australia New Zealand (FSANZ) maximum levels in food. For soil:
- Guideline limits vary depending on land use (residential, agricultural, or industrial).
- The Australian and New Zealand Environment and Conservation Council (ANZECC) also provides trigger values for soil and water to protect ecosystems.
- Cadmium contamination is closely monitored in agriculture, particularly in vegetable-growing regions of Victoria, to ensure compliance with both domestic and export food safety requirements.
Sources of Cadmium in Melbourne Soils
In Melbourne and regional Victoria, cadmium contamination is most commonly linked to:
- Historic use of phosphate fertilisers (which contain cadmium as an impurity).
- Industrial activities near urban centres.
- Application of biosolids or manures to farmland.
- Stormwater runoff carrying pollutants into soils.
Why Testing for Cadmium is Essential
Soil testing helps identify whether cadmium levels are within safe limits. This is particularly important for:
- Farmers and growers supplying food to local and export markets.
- Developers and builders working on sites with a history of industrial use.
- Home gardeners growing vegetables in urban soils that may be contaminated.
Testing provides confidence that soils meet Australian guidelines and that food crops are safe for consumption.
Managing Cadmium in Soil
If testing identifies elevated cadmium levels, management strategies may include:
- Applying lime to raise soil pH, reducing cadmium uptake by plants.
- Choosing low-cadmium phosphate fertilisers.
- Selecting crop varieties that absorb less cadmium.
- Avoiding overuse of biosolids or manures with trace metals.
Book Heavy Metals Testing Today
At Test Needs, we provide accurate heavy metals analysis, including cadmium testing, starting from just $79. Ensure your soil meets Australian safety standards and protect your crops, customers, and environment.
- Phone: 03 9115 8105
- Email: info@testneeds.com.au
