'Incredibly disheartening': Airborne asbestos found in children's play sand

Airborne asbestos has been found in New Zealand testing on children's play sand, in results researchers say they did not want to see.

It has been found in several samples that were painstakingly tested earlier this year in the first research of its kind.

"Unfortunately, we found that asbestos fibres could be detected," AUT Associate Professor Terri-Ann Berry said.

Her team's findings have spurred the Ministry of Health to reconvene its Technical Advisory Group to quickly assess the results.

MBIE is also now working to update its advice to the Commerce and Consumer Affairs Minister, as well as contacting businesses that sold the children's sand.

Both ministries say they understand the new results may be worrying for parents and caregivers.

RNZ met with Berry and her research team in March as they carried out the research in suburban Auckland.

In results being made public on Thursday, the small team has made what could be big findings.

"We really hoped that our suspicion that those fibres could get in the air would be wrong and we would be able to come back and say 'hey, there were no fibres, it's great, everybody take a sigh of relief'," Berry told RNZ ahead of the public release.

"And it just unfortunately didn't work out that way and we did find the fibres," she said.

"It was incredibly disheartening to be honest, but at least we know now."

Since first inviting RNZ to report on the research, Berry has been ever-conscious of the anxiety felt by children, parents and others who have handled the play sand.

"There's an awful lot of panic and worry and concern and that really worries me," she said.

"Look, there's no safe level of exposure to asbestos - on the positive side, being exposed does not mean that you're necessarily going to develop an asbestos-related illness.

"It doesn't quite work like that, but of course, finding no fibres is a much nicer place to be," Berry said.

She said she understood the results will be confronting for many parents.

"We've gone from something that was just a potential to something that's now realised in that we know those fibres can get into the air from play."

Two labs in two countries the samples were sent to have found the same thing, that tremolite and chrysotile asbestos fibres were in the air during mock play activities.

They used a licensed asbestos removalist working in a sealed chamber in head-to-toe protective gear to simulate children's play activities.

It included writing and drawing in the sand, driving toys through it, scooping it up and tipping it out and making sand castles.

Several air pu