It's still not clear exactly what caused dozens of children to fall ill at a Wairarapa school

Ten children from Carterton's South End School were taken to hospital yesterday, with nausea and other effects after noticing a sulphuric smell.

They were all discharged last night.

Up to a hundred more were treated for their symptoms on the school grounds.

Fire and Emergency says the idea something was dropped from a plane is still unsubstantiated, and the source of the problem remains a mystery.

Wairarapa District Health Board advised parents to give their children a good scrub in the shower.

It says anyone concerned about symptoms should call Healthline.