New research by scientists from Monash University and the CSIRO has raised concern over the use of rainwater tanks.
Threats of water shortages and a genuine desire to do their bit to conserve resources has meant many Australians have installed tanks in their yards to collect rainwater.
However this latest research implies the tanks could in fact present a health issue because the researchers have found that many are often contaminated with high levels of lead and other heavy metals such as aluminium and iron.
The joint project conducted in a Melbourne suburban area has revealed a third of the Melbourne suburban rainwater tanks studied have lead levels which exceed the Australian drinking water guidelines - one household's tank contained lead concentrations that exceeded safe drinking levels by 35 times.
Senior researcher Dr Grace Mitchell from Monash University, says traces of other heavy metals such as cadmium were also found but the main concern is to isolate the source of the lead.
Dr. Mitchell says the source could be environmental or atmospheric and associated with the dust that blows around an urban area.
Dr. Mitchell suggests the lead could come from lead flashing on roofs or pipes that haven't been properly coated, or industrial processes which may be emitting lead - until relatively recently lead was also present in petrol.
According to Dr. Mitchell the lead will not have an effect if people do not drink the water; if the water is drunk the main concern then is the developmental delays associated with lead in children.