Groundwater contamination by EDC at Botany

Last updated: 01 August 2003

What is EDC?

1,2-Dichloroethane, also called ethylene dichloride (EDC), is a manufactured chemical that is not found naturally in the environment. It is a clear liquid and has a pleasant smell and sweet taste.

The most common use of EDC is in the production of vinyl chloride, which is used to make a variety of plastic and vinyl products including:

• polyvinyl chloride (PVC) pipes
• furniture and automobile upholstery
• wall coverings
• house wares
• automobile parts.

What is the situation at Botany?

On 16 July 2003, Botany Bay Council sampled Botany Golf Course's bore water supply and found elevated levels of EDC. The Environmental Protection Authority (EPA) has tested other bores in the area. All shallow bores, which are the type found at homes, have found no detectable levels of EDC.

What happens to EDC when it is pumped up from ground water?

EDC is highly volatile and most will evaporate into the air within a few hours.Any that remains will travel down through the soil and re-enter the ground water system.

How might I be exposed to EDC?

Exposure to EDC occurs through breathing air or drinking water that contains EDC. EDC can also be absorbed through the skin, but at the concentrations discovered in the Botany Golf Course bore water supply, any effects from skin contact are likely to be minimal.

How can EDC affect my health?

At the levels detected at Botany it is unlikely that there will be any health effects.

Exposure to undiluted EDC has been known to cause:

• mental confusion
• dizziness
• sleepiness
• nausea
• vomiting
• gastrointestinal disturbances.

Nervous system disorders, liver and kidney diseases, and lung effects have been reported in humans ingesting or inhaling extremely large amounts of EDC.

How likely is EDC to cause cancer?

Some factory workers exposed to high levels of EDC over many years have had a high rate of cancer. It hasn't been determined if the cancer was due to EDC or other chemicals used in the factories. For the exposure levels likely to be found in Botany, any association between EDC and cancer has not been observed.

How can EDC affect children?

Animal studies suggest that EDC does not produce birth defects.

Children are not thought to be affected any differently than adults by EDC.

Does it bioaccumulate?

EDC does not bioaccumulate in fish or other sea animals. The physical and chemical properties of this compound indicated that bioaccumulation is not likely to occur.

Are there any recommended guidelines for EDC exposure?

There are Australian drinking water guidelines that specify the maximum acceptable level for EDC.

What is the general population exposure?

When it has been measured, general levels of EDC are found to be low. It is thought the main exposure route is via breathing.

Until further advice is provided we continue to recommend the following precautionary measures:

• bore water should not be used for any purpose
• homegrown produce should be washed before use.