Children's Health

Vulnerability of Children
International Research
Australian Testing
Variability in Tests
References

Vulnerability of Children

The findings that heavy metals can be dislodged from CCA-treated timber has raised concerns about the health impacts of this on children. This is because children are especially vulnerable due to:

• their hand-to-mouth behaviour which can transfer the heavy metals into their bodies both during and after play (CPSC, 2003a),
• their close contact with treated timber structures when playing in backyard cubby houses and crawling and sitting on decks,
• their faster metabolic rate (Belluck et al, 2003).

There is a lack of direct health studies to determine how arsenic affects children so extrapolations have to be made from studies on adults or rats. Currently, risk assessment is undertaken to determine the lethal dose for 50 percent of rats (LD50), and this is then extrapolated to an 80 kilogram male adult, and further extrapolations have to be made for a child. As Jo Immig of the APVMA’s Community Consultative Committee remarked, ‘children are the most vulnerable in our society, and health standards needs to be calculated to protect them’ (Pers. Comm, 22/11/04).

Belluck et al (2003) warn that infants and children may be more susceptible than adults to arsenic exposure, with ingestion of soil as the main pathway for arsenic intake. Another means of exposure is through children handling treated timber play equipment and then putting their arsenic-coated hands in their mouths. Children living near industrial and hazardous waste sites may also be at risk through dust inhalation. The health symptoms experienced by children exposed to high levels of arsenic have been found to be similar to adults, and including respiratory, cardiovascular, dermal and neurological effects.

International Research

A number of overseas studies have been undertaken to find out the amount of arsenic, chromium and copper that can be dislodged and ingested from contact with CCA-treated timber. The amounts of arsenic dislodged from CCA-treated timber varies from study to study. The table below displays some of this information for ease of comparison.

The Consumer Product Safety Commission also conducted peer-reviewed scientific studies of exposure to arsenic via playground equipment. Their scientists found that ‘exposure to arsenic from CCA-treated playgrounds could be a significant source of arsenic’ for children (CPSC, 2003a). They estimated that children between 2 and 6 years old who play regularly on CCA-treated playground equipment have a significantly increased lung or bladder cancer risk over their lifetimes (CPSC 2003b: 1).

Australian testing

In Australia, children are likely to spend more time outdoors playing on treated timber equipment than in many northern industrialised nations because of the warmer more temperate climate. However, Australian authorities have been remiss in not carrying out any soil or wipe test in children’s playgrounds. The only known published residue testing carried out in Australia since CCA-treated timber was put on the market was a limited wipe test on playground equipment in the City of Maroondah, Victoria. The tests were commissioned by the Croydon Conservation Society and undertaken by the State Chemistry Laboratory, in June 2003. Noting that the maximum safe amounts of arsenic in Australia for a 12kg child is 3.4 µ/day, the results showed a range of 21 µg to 710 µg from a single wipe, compared to a background control of less than 0.1 µg (See Table 2.3 below). These amounts available to children from contact with the CCA-treated timber far exceed the maximum amount of arsenic allowed in a glass of drinking water (Loveridge, 2004b).

Results from wipe-testing of playground equipment in City of Maroondah

Source: Loveridge, 2004