A Queensland Health study shows 11.3 per cent of Mount Isa children have elevated blood lead levels, putting them at risk of behavioural and intellectual impairments.
400 children aged one to four have blood lead levels greater than 10 micrograms per decilitre.
Dr Linda Selvey says one child had 31.5 micrograms per decilitre more than three times the World Health Organisation's recommended safe level.
Indigenous children are also four times more likely than non-indigenous children to show high levels of lead in their blood.
Dr Selvey says it is very important to ensure that lead levels in children are as low as possible.
She says as soon as the elevated lead results became known Queensland Health began actively case managing the children and assisting their families to bring those levels down to below 10.
Dr Selvey says tests show there is no evidence that any particular part of Mount Isa has higher lead levels than others.