Environmental scientists are worried that a rush to renovate old homes after the Queensland floods may have exposed hundreds of people to harmful amounts of lead.

Research from the US has shown that what were once considered small and safe exposures to lead can damage the brains of young children, shaving off IQ points and changing behaviour in some cases.

There have already been cases of lead poisoning in children after parents sanded paint from old flood-damaged homes without taking precautions.

“The effects are insidious,” said Professor Mark Taylor, an environmental scientist at Macquarie University.

“Often, the children don’t present with any clinical signs, and problems may not really arise until maybe children start entering school and they’re struggling in school, for example, with their reading and writing abilities.”

Homes with old paint in good condition or buried under layers of other paint are not considered a big risk.

The risk comes when old paint weathers or is damaged by water, and is then scraped or sanded, and there are children around who might eat the paint chips, crawl on the floor and lick their fingers, or inhale the dust.

“You probably will start seeing [high levels of lead in blood lead] now if you started to measure children’s blood,” says Dr Bruce Lanphear, a professor of environmental health at the Simon Fraser University in Vancouver.

New research coming out of the US is showing that low levels of exposure can cause brain damage in children, but there is a debate about how significant that research is to Australia.

Toxicologist and emeritus professor Michael Moore, who is on Australia’s National Health and Medical Research Council’s lead working group, says the effects seen in big, population-wide studies cannot be applied to individuals, and the magnitude of the problems associated with lead in paint is probably less than people imagine.

“The fact is that over the last 30 plus years there’s been a concerted program of de-leading of a whole range of things in our general living environment,” he said.

However, in the US, a committee of the Centres for Disease Control has already recommended halving the blood-lead intervention level from 10 micrograms per decilitre to five. The World Health Organisation is considering doing the same.

Government to blame?

After the floods last year, Cathy Mason and Michael Valance renovated their Ipswich house and discovered both of their boys had lead poisoning.

One recorded a level 22 micrograms per decilitre – more than twice the current limit – and the other recorded a level of 15 micrograms.

“When we found out, I was actually a bit angry at the Government for not warning us,” said Cathy Mason.

“When it flooded, everyone in the media pushed about, ‘Be careful of the mud’ because the water is diseased, ‘Be careful of the asbestos’ because we all know about that. But nothing was said about lead.”

Queensland Health would not talk to Radio National’s Background Briefing program, but released a statement saying the information on lead was readily available.

“Queensland Health’s post-flood focus was on the issue of asbestos debris and contaminated water problems as these were the issues of key public health concern,” the statement said.

“Information for the public in relation to dealing with lead in paint during home renovation and restoration work was already available and accessible to renovators and contractors.”

Ipswich painter Nigel Gorman, who now runs a lead paint advisory service, says he has seen unsafe practice in action.

“I’ve been driving past watching people grinding off their houses … that was the scariest part. And not just home owners, but painters.”

Standards review

Last October, a panel of scientists on the US National Toxicology Program said there was “sufficient evidence” that lead levels even under five micrograms per decilitre could harm children and adults.

The Australian National Health and Medical Research Council’s Lead Working Group is now considering the evidence, and whether to halve its blood-lead standard.

Environmental scientist Professor Mark Taylor says if Australia’s spread of lead exposure was similar to the US, there would be at least 100,000 Australian children already over that lower level.

The parents of just about all of them remain unaware of the risks.

“As a whole will we have failed. The public health community has failed and physicians have failed to warn families of these problems,” said Professor Bruce Lanphear, one of the scientists on the US National Toxicology Program panel.

– Listen to “Lead Poisoning: A Silent Epidemic” on Background Briefing, ABC Radio National, Sunday 6th May at 8.00am.