The Australian Building Codes Board own Final Regulatory Impact Study sets out the risk to children as follows:

“Children are particularly vulnerable to the neurotoxic effects of lead and even low levels of exposure can cause serious and, in some cases, irreversible neurological damage. The potential for adverse effects of lead exposure is greater for children than for adults because the intake of lead per unit of body weight is higher, lead absorption in the gastrointestinal tract is higher, the blood-brain barrier is not yet fully developed and neurological effects occur at lower levels than in adults.”