12 June 2014 — Childhood blood lead levels have fallen sharply in developed countries in recent decades but not in Australia, and according to a report from Macquarie University, the National Health and Medical Research Council has for two years stalled on making a decision to reverse Australia’s woeful legacy.
But while one of the most significant causes of exposure is living near a lead smelter, inner urban areas, such as Sydney’s Inner West, also have major “legacy lead” contamination, and there is serious concern with the rise in verge gardening and high levels of lead found in plants such as lettuce, parsley and leek.
The Environment International report, Australia’s leading public health body delays action on the revision of the public health goal for blood lead exposures, by Professor Mark Taylor, Professor Chris Winder and Professor Bruce Lanphear, argues for lower blood lead levels of no more than five micrograms per decalitre, with a national goal for all children under five years of age to have a blood lead level of below one microgram per decalitre by 2020.
The current national goal is 10 micrograms per litre but in some areas levels of 30 micrograms per litre have been found.
Studies show that impacts of lead exposure in early childhood include: lower IQ and academic achievement; socio-behavioural problems such as ADHD, learning difficulties, oppositional/conduct disorders and delinquency. Disabling mental health issues caused by lead exposure often persist into adolescence and adulthood.
“There is now an overwhelming body of evidence showing that Australia’s lead level for children is too high,” Professor Taylor told The Fifth Estate. “We’re asking why would it take Australia’s leading public health body, the NHRMC, so long – from 2012 to 2014 – to undertake what appears to be a review of reviews. Are they anticipating that they might conclude something different from other global experts?”
The report shows how childhood blood lead levels have fallen sharply across the world’s developed countries in recent decades, as a result of work by the World Health Organization and Food and Agricultural Organization of the United Nations.
However, Australian policy responses have stalled, despite “the incontrovertible evidence that adverse neurocognitive and behavioural effects occur at levels well below the current national goal of 10 micrograms per litre”, the paper reports.
Urgent changes are required to both state and national policy approaches, to bring them into line with contemporary international standards, Professor Taylor said.
“All of the regulatory ducks [on lead] need to be in a row.
“This delayed response is happening when blood lead levels are actually rising by some measures in two of Australia’s three primary lead mining and smelting cities: Port Pirie, South Australia and Broken Hill, New South Wales.”
The third hot spot for lead levels is Mt Isa, where Professor Taylor said there has been no significant testing regime, even though it is known lead is being emitted and deposited, and the effects of lead exposure are being seen in local children.
“In Broken Hill, the levels have been rising, with 21 per cent of kids over the recommended limit (10 micrograms of lead per decalitre of blood). In Port Pirie, 22.5 per cent of kids are over the [safe] level,” Professor Taylor said, explaining that in Port Pirie and Broken Hill, there has been systematic testing of children annually between birth and age five.
Port Pirie kids are being knowingly put at risk
The Port Pirie issues have been known for more than two decades. Julian Cribb said in his book Poisoned Planet that a study published in the New England Journal of Medicine in 1992 found that 492 children living around the Port Pirie smelter had lead levels of up to 30 micrograms per decalitre of blood, with those children experiencing a four to five per cent loss of intelligence. He says:
“In the first 10 years of the 21st century, more than 3000 children were poisoned in the Australian town of Port Pirie, with the full knowledge of governments, health officials, regulators, industry and the community itself. The poisoning had actually been going on for more than 120 years, ever since the first lead smelter was built in the small, regional South Australian industrial centre; the first warning had been sounded in a government inquiry as far back as 1925, with reiterations being made on numerous occasions, particularly in the 1980s and ’90s.”
In a 2001 study, Professor Taylor and his team sampled dust from children’s play equipment in the town, finding average lead levels 173 times higher than nearby Port Augusta where there is no smelter. The team also took samples from children’s hands after they had spent time playing outside, and found that 20 minutes use of play equipment resulted in an average daily dose of more than 40 times the recognised safety limit.
- See our review of Poisoned Planet
Delays as polluters hold out the hat
The Adelaide Advertiser reports that a current proposal to upgrade the smelter at a cost of $350 million is yet to be financed, with the Belgian-Swiss owner Nyrstar offering to contribute $80 million, and requesting assistance from the South Australian government and federal government for underwriting of a financing package comprising third party investments and forward sales of metals produced by the plant.
The report says it is expected the upgrade would result in 50 per cent lower lead emissions, a smaller carbon footprint for the plant, and increased profitability. However, the concerns raised by these reports suggest that 50 per cent lower emissions may not be sufficient.
Lead’s legacy spreads across the urban landscape
Professor Taylor said there also remains the issue of lead in the air, the soil and the food supply, both in areas where airborne lead emissions have been deposited through time, and more broadly across Australia’s urban landscape.
One of the challenges is the lack of broad-based population data on lead and other chemicals. Professor Taylor said that the US undertakes a national nutrition audit of child health, which includes the testing of blood samples for a range of toxins and contaminants.
In Australia, the information is far more scattered. Professor Taylor said a study by Brain Gulson in 1995 was the last comprehensive testing that looked at lead levels across Australia’s urban population.
Gulson found that in 1575 children, the average lead level was 5.1 micrograms per decalitre, but 7.3 per cent of children had a level above 10 micrograms/decalitre – the level at which neurocognitive and behavioural effects become apparent – and 1.7 per cent exceeded 15 micrograms.
If these numbers were extrapolated across the Australian population, it would add up to around 100,000 children with blood lead levels higher than the “safe” threshold, he said.
In areas where there is not a lead smelter to account for levels, the sources of lead contamination includes lead paint in older houses, dust and the legacy of airborne lead from vehicle emissions that has been deposited in the soil through time.
“The old lead paint is still impacting older houses which are being subject to renovation,” Professor Taylor said, explaining that while the Painters and Decorators Association had mitigation protocols, do-it-yourself renovators and sites where proper protocols were not followed in the past both posed an ongoing source of risk.
“There is quite a lot of information about lead exposure [from paint], but people forget,” he said. “It is kind of off the radar. We went to Ipswich to look at a house [where there had been a case of lead poisoning] and it was just after the floods, and there were all these people sanding and drilling with no protective masks.”
Not so healthy home-grown produce
Legacy lead issues in older areas is not only a problem for children playing in dirt but also for home vegetable growers, as lead accumulates in plants and is then ingested.
A 2006 study of vegetables sampled from the Sydney Basin area found 32 per cent contained lead levels that exceeded the allowable limits for vegetables, with lettuce, parsley and leek the worst offenders.
Professor Taylor and a team from the Environmental Science Department at Macquarie University have developed a Facebook project, VegeSafe, that aims to educate urban green thumbs about the risks of lead and a range of other contaminants. The project also provides access to simple soil testing, and gives advice about what it is safe to plant, where and how. It is also one of the most comprehensive study of Australian vegetable gardens ever undertaken.
The testing has revealed a disturbing picture of the lead legacy, with 20 per cent of 750 soil samples from private residences and community gardens across Sydney exceeding the Australian lead guideline for domestic gardens of 300 mg/kg, with a maximum value above 4000 mg/kg. ??Nearly a third of the private Sydney residences had one or more samples exceeding the Australian guideline, with the highest metal concentrations being found in the Inner West and inner city suburbs of Sydney.
“The problem [of legacy lead] has not gone away, the issue still remains, and it is about knowing [the risks],” Professor Taylor said.
VegeSafe’s quick guide to lead contamination hot spots
The VegeSafe website says that certain Sydney gardens are more likely to be lead contaminated than others. The hot spots are properties exposed to:?• A pre-1997 painted residential building or pre-2010 painted industrial building, where paint has deteriorated or been dry-scraped, heat-gunned or dry-sanded and allowed to contaminate the yard?• Older inner city homes or those near main busy roads – pre-2002 leaded petrol vehicle emissions emitted air-borne lead particulates that accumulate in dust, soil and ceilings?• Lead flashing or lead acid batteries, manufacturing or recycling plants, or a waste dump/landfill