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Monday 14 April 2008

RAPID ROUNDUP: Lead contamination - Rainwater tanks and Mt Isa mining - Experts comment

Lead contamination has again hit the public consciousness thanks to two separate reports of lead contamination. First, media reports have linked mining in Mt Isa to high lead levels in children.

Secondly, separate media reports on water quality in rainwater tanks have highlighted lead levels well beyond acceptable levels for drinking water.

The AusSMC has rounded up toxicologists to comment on these two stories.

Feel free to use these comments in your stories. If you would like to speak to one of these or other experts, please don’t hesitate to contact us on (08) 8207 7415 or by email.

On lead in rainwater tanks...

Dr Heather Chapman is program leader for the Sustainable Water Sources program in the CRC Water Quality and Treatment and Associate Professor at the National Research Centre for Environmental Toxicology in Brisbane.

“Now that we have identified that lead and other metals are an issue in rainwater tanks, what we need to know is how we manage rainwater collection systems so that they are fit for purpose. If you are drinking the water it is a completely different story to if the water is just being used on your lawn. If there is no maintenance and intervention to improve the water quality from rainwater tanks then it should not be drunk.”

“There have also been some cases of excess lead in tanks in Western Australia and the Northern Territory, these tend to be from industrial sources of lead. Melbourne is a larger city and it may be that Melbourne has a more significant problem. “

Professor Brian Gulson is a Professorial Fellow at the Graduate School of the Environment at Macquarie University in Sydney. He is a geochemist and toxicologist who has contributed to lead documents by the US Environmental Protection Agency, to the International Agency on Research in Cancer and US National Toxicology program. He is on the NHMRC steering committee for lead, and head of the Technical Advisory Board of the LEAD Group.

"Rainwater is certainly one way that industrial environmental contaminants like lead can be ingested and in areas with water of lower pH the lead can be more easily dissolved from such locations as
roof flashing. Lead contamination in rainwater tanks was one of the main concerns in Esperance as many residents preferred to drink rainwater rather than tap water. Water filter systems can be helpful in removing lead from water, so if people are concerned about lead in rainwater they may wish to consider a filtration system rather than discarding their tanks."

On lead contamination in Mt Isa...

Professor Brian Gulson is a Professorial Fellow at the Graduate School of the Environment at Macquarie University in Sydney. He is a geochemist and toxicologist who has contributed to lead documents by the US Environmental Protection Agency, to the International Agency on Research in Cancer and US National Toxicology program. He is on the NHMRC steering committee for lead, and head of the Technical Advisory Board of the LEAD Group.

"I would not want to down play the concern about lead levels at Mount Isa, as 10% of children with high lead levels in their blood is still worrying, but it should also be put in context. Mt Isa has been
operating since the 1920s and compared with some of the other areas of lead contamination such as Broken Hill, Boolaroo and Port Pirie, we might have expected to see higher numbers of children with
unacceptable lead levels. In these three communities, the initial screening of lead blood levels conducted in the 1980s and 1990s showed more than 80% of children had lead levels in their blood above
acceptable levels. This could be down to the type of ore that is present in Mount Isa, the bioavailability of the emissions being lower than in some of these other places where lead contamination has been a significant issue, or emission controls from the mining and smelting operations.

The major difference between Mt Isa and the other three communities is in the mining and smelting of copper ores which may contain some other toxic metals besides lead and cadmium. The mine and smelter at Mount Isa have been running for many years so one might expect some level of contamination as the mine started before many of the environmental regulations were put in place in the 1970s.

Outside of mining/smelting based contaminations, now that lead has been removed from petrol, a lot of the remaining lead contamination of children in Australia can be traced back to lead paints."

Other background information

External links:

Try www.tenby10.com.au on lead exposure to children in Port Pirie, South Australia