Dieldrin and DDT soil contamination

Dieldrin is part of a group of chemicals called organochlorines. These chemicals were once used to control insects.

Organochlorines were used to protect:

• crops
• livestock
• buildings
• homes.

Most uses of these chemicals were stopped by the 1990s.

Scientists found that these chemicals can stay in the soil for decades, breaking down slowly. Livestock and some produce can absorb the chemicals from contaminated soil.

Chemical residues in food

International standards are set for the maximum allowable level of acceptable chemical residues in produce. Residues above these levels can affect access to Australian and overseas markets.

Farmers must manage contaminated land to reduce this risk.

Risks to livestock

Cattle and other livestock can swallow contaminated soil while grazing. This includes:

• free-range pigs
• poultry
• large flightless farmed birds.

Dieldrin and DDT can accumulate in an animal’s body fat.

The chemicals can also be present in:

• eggs from free-range poultry
• milk from lactating animals.

The chemicals do not affect the health or productivity of livestock. However, farmers must manage affected animals carefully. This helps prevent unacceptable residues from entering the food chain.

Test soil for contamination

Past use of dieldrin and DDT caused unacceptable residues in some exported beef. This led to trade restrictions in the late 1980s.

The Victorian Government has tested properties to identify contaminated land. It also works with the livestock industry to manage residues in beef.

If your property is contaminated, we can help you understand your management options.

A soil test can confirm whether organochlorine chemicals are present.

Before taking soil samples:

• speak with an agricultural consultant or a testing laboratory
• ask how and where to collect samples
• make sure the laboratory can test for organochlorine chemicals.

Arrange suitable tests before you commit to buying the land.

Manage contaminated land

Agriculture Victoria has notified property owners who know their property is contaminated. Farmers have been informed of the risks with grazing livestock on contaminated land.

The Victorian Government created property management plans for livestock owners. The plans help those who want to keep farming livestock. The Livestock Production Assurance (LPA) program now audit these plans.

A property management plan can help you:

• manage how livestock use contaminated areas
• reduce the risk of livestock absorbing residues
• meet industry and government requirements
• reduce the risk of contaminated produce entering the food chain.

Farmers who use a property management plan are less likely to have chemical residues. The plan applies to both their livestock and crops.

Residue monitoring

The livestock industry works with Australian governments to monitor chemical residues.

The National Residue Survey includes testing for organochlorine residues in livestock. Authorities may randomly test livestock from properties with known contamination.

Supermarkets may also require horticultural growers to monitor chemical residues.

Agriculture Victoria and the Australian Government conduct other residue monitoring programs.

Farmer responsibilities

You must make sure you do not sell contaminated produce.

Authorities may act if a farmer does not manage known residue risks.

Farmers raising livestock or growing crops under a property management plan are unlikely to experience any issues with soil residues being detected in their produce.

Check if land is contaminated before buying

A Section 32 (S32) statement gives buyers information about a property.

The person selling the land must give the buyer relevant documents. This includes:

• notices
• reports
• property management plans
• orders about livestock disease
• orders about chemical contamination.

Agriculture Victoria can search for information about known land use restrictions. We can only give this information to:

• the landowner
• another person who has the landowner’s permission.

To get this information, call Agriculture Victoria at 136 186.

Test land before buying

A property might be contaminated. This can happen even if the Section 32 statement has no land use restrictions.

Testing is the only way to confirm whether the land is contaminated.

Arrange suitable soil testing before you commit to buying the property.

Understanding past soil test results

Past soil test results may not show whether the whole farm is contaminated.

Residue levels can vary:

• within a paddock
• between paddocks
• between farms.

Organochlorine chemicals break down slowly.

Residue levels may decrease over time. However, the chemicals can still be detected decades after their use.

Reassure customers about produce safety

Monitoring of chemical residues shows a high level of compliance with Australian standards.

Many farmers take part in quality assurance programs. They may also regularly test their produce for chemical residues.

Testing can help reassure farmers and customers that produce is not contaminated.

Consider soil testing if you believe organochlorine chemicals were used on your property. Test results may help reassure you and your customers.