What's in your soil, Victoria?
Trace elements are substances that naturally occur in our environment in small quantities. They are elements on the periodic table and include metals (e.g., lead) and metalloids (e.g., arsenic).
Some elements are beneficial to human and plant health at trace levels. Trace elements including copper, manganese, and zinc are essential for plant function. Deficiency will occur if concentrations are too low, and toxicity if concentrations are too high. Other trace elements, including lead and arsenic can be harmful to human health, even at low levels.
Previous research (Taylor et al. 2021) has shown that lead (Pb) is the most common trace element of concern in Australian garden soil. While modern paint and petrol no longer contain high levels of lead, the impact of their historical use remains a concern in some gardens today.
Houses built before 1970, are within 10 km of the Central Business District, near industrial processing facilities, or contain peeling paint are more likely to have elevated lead in their garden soil.
GardenSafe screens your garden soil for 8 trace elements. These were selected because they may be present in garden soil at concentrations that could impact human or environmental health, or they can influence how plants grow. A summary of each trace element assessed, and their common sources are provided below.
|Trace element||Abbreviation||Common sources|
|Arsenic||As||Wood preservatives (CCA treated timber), pesticides, wallpaper|
|Cadmium||Cd||Rechargeable batteries, photovoltaics, paint, ceramics, metal plating|
|Chromium||Cr||Wood preservatives (CCA treated timber), metal plating, some paints, pesticides, leather tanning and textiles|
|Copper||Cu||Electrical wiring, plumbing, roofing material, brake pads, wood preservatives (CCA treated timber), pesticides, coins|
|Manganese||Mn||Steel production, vehicle exhaust, gasoline additive, pesticides|
|Nickel||Ni||Rechargeable batteries, metal plating, jewellery, coins, brass fixtures|
|Lead||Pb||Old paint, leaded gasoline, ceramics, batteries, ammunition, solder, plumbing, pesticides, mining and industrial processing, hobbies (including fishing and shooting)|
|Zinc||Zn||Steel production and galvanisation, tyres, vehicle exhaust, mining and industrial processing, coins|
After sending us your soil samples, the concentration of trace elements in your soil will be measured using X-ray fluorescence spectrometry. A short report outlining the results from your garden will be emailed to you. This is paired with guidance on how to interpret your results using Australian guideline values and strategies to improve soil health and reduce your exposure to trace elements.
Your soil will also be screened for a suite of garden soil quality indicators.
Complete the GardenSafe registration to submit your samples.
Note: Only a qualified medical professional can advise how a contaminant could impact an individual’s health. Please see your doctor if you have any health concerns about soil contamination from trace elements.
The 360 Dust Analysis program is a global research initiative to collect and analyse data on contaminants of concern that may be harmful to human health in homes and gardens.
Environment Protection Authority, VIC, Australia.
Macquarie University, NSW, Australia.
Northumbria University, Newcastle, United Kingdom.
IUPUI, Indianapolis, United States.