A toxicologist's urging parents not to panic - but suggests children exposed to contaminated coloured sand should be regularly monitored

Last month, asbestos was detected in several sand products used at early childhood centres and schools.

Canterbury University toxicologist Professor Ian Shaw says exposed children could face an increased risk of health issues when they're older.

He says that risk's largely dose-dependent - but it's worth having annual medical check-ups.

Shaw says that's just to ensure they're not developing the early signs of the lung cancer this type of asbestos is most likely to cause.